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XR7 Dave
12-22-2006, 11:27 PM
After initiating this test it quickly became apparent that I needed to establish some testing standards and parameters to prevent skewing results and getting innaccurate results so that is why I had to re-do the test. The results have changed.

I realized in the first test that each port wasn't flowing the same in each manifold and I became concerned about exit angles for each tube and possible turbulence in the collectors. This led me to do two things.

1) I added a pipe extension to all collectors. The longtube Kooks already have an 8.5" x 3" collector on them so I extended that slightly to a total of 14" and I used that length on all tests. The other headers all have 2.25" oulets so I used a 2.5" extension on those and the manifolds (and 96 Bird header) all have < 2" outlets so I attached a 2.25" extension on them. I then tested the Kooks longtubes with a 2.5" reducer and tried the 95 Mustang header with both 2.25 and 2.5" pipes. In each case the flow difference at full lift was just .5cfm. Now is also the time to point out that in EVERY case adding the 14" extension improved flow!

2) I tested each pipe in each manifold. I blocked off the remaining 2 pipes when testing each one and the results are noted below. Some manifolds/headers definitely have better balance than others.

The results include flow at all points from .100-.450" lift on a totally stock cylinder head and are compared to a straight diffuser for a baseline. All tests were conducted consecutively on the same day for the sake of consistency. I also included the % variation between all ports and the gain or loss relative to the straight diffuser. This first test was embarked on specifically to show what flow advantage there might or might not be for each manifold/header on a stock engine.

I hope you find these results helpful. I will be performing tests on ported stock manifolds also but that will have to wait as I do not have the porting done at this point. I will update the test when I have that data.

I will also be doing another test on a fully ported set of heads at lifts up to .600" to give a better perspective of what potential these manifolds/headers have.

XR7 Dave
12-22-2006, 11:43 PM
Official results are attached.

Scott Long
12-23-2006, 12:02 AM
Nice work Dave.

I see our stock manifolds flow slightly more than the 96 style, but look at how unbalanced they are. The 95 one seems to be a good choice. What was different about the 95 manifold?

I see the longtubes flow the most, that was expected. The mid lengths and mac's are very close in average and are pretty equal for each primary.

Going from stock un ported early style manifolds to a set of Kooks longtubes would gain an average of 13.5 cfm per cylinder, but at $700 is it worth it, and does 13.5 cfm make any power increase?

Looking forward to seeing what the ported SC manifolds can do as it is the common theory they are good to around 300 rwhp maybe more.

XR7 Dave
12-23-2006, 12:10 AM
I was pleased and surprised to see that the longtubes were the best flowing of the bunch and actually improved over a straight diffuser. To me that was impressive. The Kooks longtube has a nice evenly configured collector which I feel is a significant factor in the good results. The Kooks that I have contain an 02 sensor in one primary lead and it was this tube that had the lower flow #'s compared to the rest. I did not test it with the 02 out (it's not coming out either) so I can't verify that but that's what it looked like to me.

The mid length Kooks also performed well and I was impressed with the consistency port to port. It may not result in a performance enhancement on an otherwise stock SC but it seems like a good part nonetheless.

The MAC shows what happens when you try to stuff a header where a header doesn't fit. The longer tube had more bends and suffered due partly to it's poor entry angle into the collector. The middle tube was a little better because it dumps at a better angle into the cramped collector and #3 lead the charge because it is extremely short and also dumps straight out the collector. In this case you can clearly see how a very short and direct tube can outflow a better designed but longer tube. The MAC concerns me because of the variation between ports although it is clearly better than a stock manifold.

The 95 Mustang header did better with an extension on it but clearly it doesn't keep up with the rest. Why? Because the tubes are jammed up at the collector. They just don't have enough cross sectional area at the point where they join the collector. It's like 3 little venturies there. It should be noted that it is very consistent though which has value compared to the MAC, Bird Header, and the 89 stock manifold.

The 96 Bird header in this test was ported lightly so the results are most likely somewhat better than a stock untouched header would have been. I expect that this one will look much worse once we get some real flow going through the head but for now the results are not THAT bad. For a stock motor it may be a decent improvement over a stock 89 manifold due to it's improved consistency.

The 89 manifold surprised me. I always wondered why Ford changed the manifold in 94 and now I know. The center port is severely handicapped to the point of possibly causing a real issue. With over 17&#37; difference between it and the front port it is very unbalanced. If you look closely at the design you will see that the center port must make 2 almost 90 degree turns before exiting into the rest of the exhaust. Obviously this is a bad condition.

The 95 SC manifold rocks. I can't believe this thing. It looks ugly enough but obviously someone at Ford was burning the midnight oil to get this one right. Performance was on par with the headers and consistency was better than the MAC shortie. Who would have guessed?

So, in this test the results are as follows.....

#1 - Kooks Longtubes
#2 - MAC Shortie
#3 - Kooks Mid Length
#4 - 95 SC Manifold (unported)
#5 - 89 SC Manifold (unported)
#6 - 96 Tbird Header (ported)
#7 - 95 Mustang Header

More to come.....

:)

Scott Long
12-23-2006, 12:17 AM
I'm willing to bet a ported 95 manifold would outflow the Kooks mid length and the MAC at stock lift levels. With more lift, I'm not so sure as of right now.

Are you going to test the ported manifolds on the stock and modified head with both stock and higher lift?

cdchicago
12-23-2006, 04:02 AM
Thanks Dave,

Very cool of you to

a. do the testing

b.share the results

I'm also impressed with your attn to detail

joenintiesc
12-23-2006, 03:01 PM
Thanks for going through all the trouble of testing and sharing the results! :) Looking forward to seeing how a set of ported stockers stack up...

the-big-e
12-23-2006, 03:31 PM
Me too......

I have a set of stock 89 manifolds that I just got finished porting and are ready for installation.....

It looks like I might have to go find a set of 95s and port them.....:rolleyes:

XR7 Dave
12-23-2006, 06:40 PM
I couldn't help myself and started on phase II before spending any time porting any manifolds. For one thing I need to get the loaner headers back to their owners and second I have to complete some other work before I start porting exhaust manifolds. Some of you know what I'm talking about. ;) I'll do the manifolds later but you are not going to BELIEVE what I saw when moving up to a better flowing head and higher lift. :eek:

XR7 Dave
12-23-2006, 07:09 PM
What, 65 views and only three people have any comments about the test results?

Maybe I'll just send out an email with the final results. :rolleyes:

XR7 Dave
12-23-2006, 07:44 PM
I see our stock manifolds flow slightly more than the 96 style, but look at how unbalanced they are. The 95 one seems to be a good choice. What was different about the 95 manifold?
The center port on the 89 manifold on the passenger side in particular has some very poor exit angles and then the front port has no restriction at all and badly outflows it's neighbor. The 95 manifold adds some direction to the middle port and smooths the transition into the collector as well as changes the outlet angle of the collector. Then the 95 manifold also crimps the front port slightly. Whether this is done to limit front port flow or if it is done to minimize backflow between the two I can't say but it seems to work.


I see the longtubes flow the most, that was expected. The mid lengths and mac's are very close in average and are pretty equal for each primary.
I did not expect the longtubes to outflow the rest. I thought that the longer tubes would form a restriction of sorts but I was clearly wrong. The length of the tubes does not seem to have any bearing on flow. The key is collector design. On the MAC headers one tube has an awkward approach angle to the collector and that port is significantly down in flow compared to the other two. Where it not for that issue the MAC would outperform the Kooks mid length. I don't see how you can fix that issue so if you use those you'll just have to accept that.

Going from stock un ported early style manifolds to a set of Kooks longtubes would gain an average of 13.5 cfm per cylinder, but at $700 is it worth it, and does 13.5 cfm make any power increase?Therein lies the basis for all the claims of stock manifolds making as much power as headers. You have to look closely at the individual port flow numbers to see what is happening. With a stock manifold some ports are flowing darn near as much as a header where as other ports are lagging far behind. The average may be close, but each cylinder does not look at averages. So you have some cylinders pulling well and other cylinders having issues. Could this lead to detonation in some cylinders more than others? Many questions, not many answers.


Looking forward to seeing what the ported SC manifolds can do as it is the common theory they are good to around 300 rwhp maybe more.Ported manifolds have supported over 400rwhp, not 300rwhp. Was it efficient? I don't think so. But the truth remains that Jim Oneil made 390rwhp through stock unported manifolds, Bill McNeil made 380rwhp through ported manifolds, I made 425rwhp with ported manifolds.... And the list goes on. How much power would longtube headers provided over those manifolds? The answer is inconclusive.

One thing is very clear. The use of Mustang headers is a big mistake if you want to make power. Anyone who has them on their car might as well start making other plans. :cool:

Thunderbolt
12-23-2006, 07:58 PM
Hey Dave,
Thanks for doing this test. I always wonder what would work the best and for the money, especially the cost of the kooks headers. Looks like I'm going to have to bite the bullet and buy those over price headers.

David

(p.s If you decide to email the results, I be interested)

Mike8675309
12-23-2006, 08:18 PM
...
Some of you know what I'm talking about. ;)
...
What, 65 views and only three people have any comments about the test results?


Just trying not to distract you too much is all.;)

Let's start with some reality checks. Perhaps avg hp found on cars with each exhaust manifold. I.e. do we see a block occuring. Or if we work back from exhaust flow, to hit that cfm of exhaust flow, how much fuel and air is combusted in the chamber for a standard 3.8liter bore and stroke? Then is this what we are even capable of creating with our current intake capabilities? Say we have a 8.5:1 compression ratio with 12.5psi of boost at 4000rpm. Could we figure a needed flow from that input?

That the long tubes are proving better is very interesting. As we try to make our engines reliable at higher HP levels, cylinder balancing will be important. I.e. are we pushing that much fuel just because one cylinder is leaning out? Or is one cylinder on the ragged edge but it's not showing up in the wide band o2 sensor at the tailpipe?

So I guess I need to become familiar with we need going out for what we put in to be able to better place things on the priority list.

Paul93SC
12-23-2006, 09:04 PM
What, 65 views and only three people have any comments about the test results?Nice WORD doc there Dave... your hidden macro opened up my Mastercard account and sent $40 to "Super Coupes Unlimited" :eek:













Just kidding... :D

-----------------

Obviously, next to true headers, OE manifolds appear to be the next best choice. I look forward to seeing the results after porting :)

With regard to the middle runner, and knowing what we know now, perhaps a little extra porting to that one would help (I know there's not much material to work with, but every little bit could help).

Ddubb
12-23-2006, 09:09 PM
The center port on the 89 manifold on the passenger side in particular has some very poor exit angles and then the front port has no restriction at all and badly outflows it's neighbor. The 95 manifold adds some direction to the middle port and smooths the transition into the collector as well as changes the outlet angle of the collector. Then the 95 manifold also crimps the front port slightly. Whether this is done to limit front port flow or if it is done to minimize backflow between the two I can't say but it seems to work.

This brings another thought to my mind. The last two 3.8's with Blown head gaskets Ive seen were between the passanger side last two cylinders, and Ive heard of others blown in the same place. Im wondering if it might have anything to do with the exhaust manifold.

- Dan

XR7 Dave
12-23-2006, 09:40 PM
Let's start with some reality checks. Perhaps avg hp found on cars with each exhaust manifold. I.e. do we see a block occuring. Or if we work back from exhaust flow, to hit that cfm of exhaust flow, how much fuel and air is combusted in the chamber for a standard 3.8liter bore and stroke? Then is this what we are even capable of creating with our current intake capabilities? Say we have a 8.5:1 compression ratio with 12.5psi of boost at 4000rpm. Could we figure a needed flow from that input? From what I've seen it's not so much a matter of flow volume as it is efficient design. The fact that the 96 bird header flowed as much as it did points out that cross section area isn't the biggest factor. Velocity is probably a more important consideration and things that kill velocity will kill flow.


That the long tubes are proving better is very interesting. As we try to make our engines reliable at higher HP levels, cylinder balancing will be important. I.e. are we pushing that much fuel just because one cylinder is leaning out? Or is one cylinder on the ragged edge but it's not showing up in the wide band o2 sensor at the tailpipe?

I think this is an important consideration. The harder you run the motor, the more important consistency from cylinder to cylinder will become. If you believe that pulse tuning is important for a supercharged engine then longtubes are the answer. If you don't believe that then the next most important thing is a smooth collector and pipes that have similar flow capability. A header like what Wynn was working on might be just the answer for some people. I think the mid length Kooks also represent an excellent header choice.

I won't be flow testing the ported manifolds that were on the XR7 when it made over 400rwhp because - well - they are still on it. So I need to do another set. I spent quite a bit of time on those and I won't be spending that kind of time on an 89 manifold because I know that there is no way to balance out the extreme problem that exists there. You just can't get to the place where the problem is. I do have some 95 manifolds here that will be getting the extreme treatment though and we will see what that brings.

The only thing I'll be doing to the 89 manifold is a collector port and a minor cleanup around the port entry. I'm guessing that it will improve flow but I doubt it will do much if anything for the flow imbalance. I don't see any point in increasing flow if you can't cure the imbalance.

XR7 Dave
12-23-2006, 09:44 PM
Nice WORD doc there Dave... your hidden macro opened up my Mastercard account and sent $40 to "Super Coupes Unlimited" :eek:


Damn. I always mess up some mundane detail like a decimal place or something. It was supposed to take $400. :(


You wait until you see the results of all these parts on a head that flows good numbers. On a professionally ported cylinder head the choice of manifolds/headers can mean a big difference!

Dan, I don't know if there is a correlation or not. Could be a lot of these things adding up though.

V6Sprout
12-24-2006, 12:21 AM
nice work Dave, I was very interested to see how the Mustang headers did, great info, can't wait for ported numbers.

David Neibert
12-24-2006, 12:32 AM
What, 65 views and only three people have any comments about the test results?

Maybe I'll just send out an email with the final results. :rolleyes:

Dave,

I was waiting to see the rest of the results before opening my yap. But since you asked.......I'm not really concerned with what they flow on stockish heads. I want to see what they do with a set of Steig or similar heads and at higher lift.

So far the results are about what I expected, except for the late model factory manifolds....Is that what Bill McNeil had on his car ?

David

V6Sprout
12-24-2006, 12:33 AM
BTW, here is a pic of a Mustang header with the collector cut off, you can see how they are pinched into a triangular shape. At least they are all fairly evenly pinched which may be why they are fairly consistant. I dunno

http://www.mustangmods.com/ims/u/425/7543/119920.jpg

XR7 Dave
12-24-2006, 01:13 PM
Here you go.

Scott Long
12-24-2006, 01:40 PM
Whoa and the stock 95 Manifolds sure don't dissapoint!!!

Interested in seeing the ported 95's when you get a chance.

Ira R.
12-24-2006, 02:55 PM
The 95 ported manifolds, is that with 2.25 downtubes? Wonder what the numbers would look like with the SCP 2.5 inch'ers??

Ira

XR7 Dave
12-24-2006, 03:10 PM
The 95 ported manifolds, is that with 2.25 downtubes? Wonder what the numbers would look like with the SCP 2.5 inch'ers??

Ira
Yes, 2.25" downtubes. 2.5" downtubes will not show an increase in this kind of testing. In fact a larger tube can show a decrease but that is not relevant here because this test is gauging only the efficiency of individual tubes, not the exhaust as a whole. The down tube was only used to direct air and prevent backwash into the manifolds.

XR7 Dave
12-24-2006, 03:14 PM
I would like to take this opportunity to thank those who sent in their manifolds/headers for testing. They did so on their own time and money for the benefit of all of the rest of us. Thanks again!

96 Tbird manifold - Michael Marks
MAC Shorty header - Michael Marks
Kooks mid length header - Dale Clark
95 Mustang header - Payton

These will be on their way back to you on Tuesday.

Thanks everyone!

Ddubb
12-24-2006, 03:23 PM
Wow its nice to see how much more a set of ported heads actually flow compared to stock heads.

Do 95 heads flow the same as earlier heads ??

By looking at the test results, it looks like a set of Ported 94 manifolds probably wouldnt be necessary on my un-ported heads since they are pretty efficient in stock form on stock setup.

- Dan

XR7 Dave
12-24-2006, 03:27 PM
Wow its nice to see how much more a set of ported heads actually flow compared to stock heads.


Those aren't just any ported heads though. Those are the best flowing ported heads you will find anywhere. Most ported heads flow about 150-160cfm.

Flex
12-24-2006, 03:40 PM
I look at this results and can't believe that the cast manifolds with all those bumps and tiny little collector will outflow a tube manifold.

I own cast manifolds, a Tbird tube header and a Mustang tube header and and the Mustang header by far has the largest collector. I can't believe that the substantially smaller Tbird header with the crunched collector will outflow it.

As is obvious by sprouts pic, the merge point sucks. I ground down the huge merge welds with a dremel prior to coating and the collector opening is also small at ~2". This too was enlarged and would improve flow.

Can these results be indicative of how an engine would act under boost as well? Dyno testes with all these items would be a true test of benefit of each. Too many variables left just checking individual tubes for flow.

XR7 Dave
12-24-2006, 04:06 PM
Can these results be indicative of how an engine would act under boost as well? Dyno testes with all these items would be a true test of benefit of each. Too many variables left just checking individual tubes for flow.

These results are just one test and this isn't the definitive answer to what works and what doesn't.

The way that Ford chose to smash all three tubes into one 2.5" collector simply doesn't leave enough room there for enough cross sectional area for 3 tubes. It's just not there. Without quite a bit of welding (which is going to cause extreme distortion) you just can't get the proper cross section.

Clearly Ford realized that the 95 header is a bad design because they changed it on the trucks, Tbirds, and 99+ mustangs. They basically went back to a tubular version of the old cast iron manifolds.

While many people like to think that the larger 2.5" collector is better than stock they fail to realize that 2.5" is too big for the size of the tubes dumping into it anyway. 2 3/8" has been calculated to be the ideal collector for 1 5/8 tubing (on a real header). Since the Mustang header is 1 1/2" tubing, it remains that the collector is way too big.

Consider exhaust velocity. The exhaust port is larger than the tube. So the exhaust has to speed up to enter the tube. Then it has to speed up even more to get past the triangle/venturi, and then it immediately slows WAY down when it hits the collector. Now if you have less than 2.5" exhaust piping, it must speed back up to get into the rest of the exhaust system. All this shuffling of velocities is murder on flow. Just say no. This is not a good setup.

A simple manifold at least gets gradually bigger as it approaches the exhaust system so that when you reach the pipes you've been gradually slowing exhaust velocity, not increasing and then dropping it as the Mustang header does.

XR7 Dave
12-24-2006, 04:09 PM
It would be time and cost prohibitive to perform dyno tests on all the different configurations. I did run Kooks longtubes and highly ported stock manifolds on the same car at over 400rwhp. Track times before and after where the same but I did not get to the dyno for testing.

I will perhaps test a set of highly ported 95 manifolds against some longtube headers in the future. First I have to get the new motor running so don't hold your breath. :cool:

David Neibert
12-24-2006, 06:29 PM
Nice....the mid length headers did a little better than I expected and the longtubes did a little worse.

Dave...I've been thinking about reworking the collector on my mid length headers to eliminate the ball and socket arrangment and use a V-band connection instead. Is there something I should also be doing with the collector length to get more flow ?

David

XR7 Dave
12-24-2006, 07:22 PM
Nice....the mid length headers did a little better than I expected and the longtubes did a little worse.

Dave...I've been thinking about reworking the collector on my mid length headers to eliminate the ball and socket arrangment and use a V-band connection instead. Is there something I should also be doing with the collector length to get more flow ?

David

I would cut the bulb shape of the kooks where it has decreased to 3", attach a 3" ring to that, and then get a pair of 3"-2.5" header reducers and weld the other ring of the V-band clamp to that. That would create a smooth transition from the collector to the pipes. I don't believe there is a need for any real collector since there is no pulse tuning on those headers. You are only after a smooth flow transition into the exhaust.

In the kind of flow test that I did, all that was being determined was what headers/manifolds had a problem. It did not declare a winner and the flow differences that I measured between the mid lengths and longtubes are insignificant. I think both Kooks headers did excellent. As I stated above the one Kooks longtube primary had an O2 sensor in it that seemed to be slightly impeding flow. Otherwise I would say that the only flow difference between the two Kooks headers were in the collector design.

Damon's beef with this test, at least as far as I can determine, is that he thinks collector design or flow capacity is more important than primary tube flow capacity. I have been trying to suggest that a poor primary design cannot be negated by a better collector design, and in fact when talking about a branch manifold style design there really is no common collector and so the terminology doesn't even really apply. I feel my explanation goes a long way towards demonstrating why a branch manifold can perform as well as a tuned header in most cases (on an SC).

Diehard
12-25-2006, 01:32 AM
Those aren't just any ported heads though. Those are the best flowing ported heads you will find anywhere. Most ported heads flow about 150-160cfm.

DD, can you please tell us what type of ported heads you were using?:eek: What do you find the "BEST FLOWING PORTED HEADS"?:rolleyes: :o
thank you

Flex
12-25-2006, 03:44 AM
Dave,

Has anyone tried to mod the 95 to open the tubes up? It would not be that difficult, just minor welding if there is room around the block which I believe there is. I will do so on the set for my 91 before I get them coated and post some pics.

Toms-SC
12-25-2006, 09:50 PM
Wheres the Dave suggests part?

Flex
12-25-2006, 11:33 PM
Tom,
That would be determined by your budget and your needs. I think this test needs to be taken to a dyno level to be definitive. As of right now, the results are just individual tube flow rates and theory. I have seen too many parts not live up to predictions in real world dyno tests to make a call.

A major variable is boost. Normally aspirated engines do not react the same as boosted motors and not all SC's have the same amount of boost. We have alll seen how the 3.8 suffers from not enough exhaust by blowing hg's. Applying tube to collector calculations across the board may or may not prove right.

By way of logical reasoning, the Kooks should be king. The long tubes should kick asss for torque as demonstrated in similiar tests on small and big blocks. Torque is what launches a car of the line and takes a car to well past half track so major increases in torques should result in quicker et's.

Toms-SC
12-26-2006, 08:25 PM
Tom,
That would be determined by your budget and your needs.

Going to have to disagree with you there. I was under the impression before this testing that the 94/95 Mustang headers were good. WRONG! And thats a budget mod. :)

Flex
12-27-2006, 04:07 AM
We used a coated set of those headers on my brother's 92 and the car picked up huge power. According to the results posted, that should not only be impossible, we should have actually suffered a loss in performance.

As that was clearly not the case, logically we cannot state that the Mustang headers are not good. I actually own a set of the 96 Tbird headers as well and compared them to the Mustang header. The driver's side is actually uglier and way smaller in design than the scrunched Mustang's. The driver's side has all three tubes side by side and rectangular in shape. The passenger side is the same shape as the Mustang except much smaller yet outflows its larger brother?? Stating that this particular design is the flaw is thus illogical.

The tubes inside these manifolds are welded together and rather ugly. One of ours had the seam welded to nearly 3/8" thick. I ground down all the welds prior to coating and feathered the tubes into each other.

Performance prior to the swap does not even compare and the car detonated heavily with all the other add ons. Along with the major performance gain, the engine no longer detonated afterwards.

Flex
12-27-2006, 04:10 AM
I do have a question with regards to the tests. The headers all have individual tubes up to the collector while the cast manifolds all share one tube that they branch of. How were the "primaries" separated?

90coug
12-27-2006, 12:23 PM
Thanks Dave for posting your results, this will be useful to all of us.

Tickler
12-28-2006, 04:57 PM
Early manifolds look horribly unbalanced, and despite the flow results I still believe the mustang headers are the best for the budget minded.

Just a thought.

ratfink
12-28-2006, 09:35 PM
Thanks Dave you are a true HOTRODDER!

Toms-SC
12-29-2006, 12:18 PM
Performance prior to the swap does not even compare and the car detonated heavily with all the other add ons. Along with the major performance gain, the engine no longer detonated afterwards.

If it's detonating it means it needs a tune or maintenance. Did you happen to change the 02 sensors while you swapped the headers?

After seeing these results I will be ditching my Mustang headers. What would have been interesting is if Dave actually did the 'modification' to make them fit the drivers side. I.E. Weld an extension on and pound the ~~~~ out of the collector to make it clear the steering column. Then test the flow. :)


Early manifolds look horribly unbalanced, and despite the flow results I still believe the mustang headers are the best for the budget minded.

Just a thought.

The results are right there in front of your eyes. The real budget mod is just to port your stock manifolds.

Flex
12-29-2006, 02:24 PM
No the car had a complete tune with fresh plugs , wires, filters etc. The exhaust was just too restrictive with a &#37;10 pulley, underdrives, MP top hat, chip, rockers etc. The factory exhaust is too restrictive for a stock motor much less one with every bolt on. O2's were new. Detonation disappeared because the engine was finally ably to breathe with the headers and flowmaster setup.

This test means nothing yet. These are just individual tube flow rates. Does not address the needs of a working engine. At 2000 rpm, each manifold/header will have 6000 exhaust pulses flowing through it so the tubes and collectors are all going to and have to work together. That is a lot different than just measuring through one tube at a time.

Measuring airflow on a tube by tube basis does not tell you how these pieces will react on an operating motor. The results are too vague and conflict traditional exhaust theories. Boosted engines usually react better to larger exhaust. Generally why turbo diesels and even turbo 4 cylinders have huge exhaust relative to NA motors.

The only way to acurately assess the value of each piece is on a dyno sorry. Anything else is just theory.

Second, unlike the ported manifolds, no attempt was made to "port" the Mustang headers. I have personally gone through 3 sets and they definitely benefit from a little cleanup.

My question on how the "primaries" of the cast manifolds were separated has not been answered. Unlike the Mustang and Tbird tube manifolds and the Kooks, the cast manifolds share a common single "primary that the individual ports branch from. How were "individual" ports isolated so that airflow only came throught the collector end to the one port? If they were not, then you would have air flowing in from the other two as well as the collector.

David Neibert
12-29-2006, 03:11 PM
No the car had a complete tune with fresh plugs , wires, filters etc. The exhaust was just too restrictive with a %10 pulley, underdrives, MP top hat, chip, rockers etc. The factory exhaust is too restrictive for a stock motor much less one with every bolt on. O2's were new. Detonation disappeared because the engine was finally ably to breathe with the headers and flowmaster setup.


Weird....I once had a high flow cat that was about 70% clogged (one side of the motor only). Lost about 50 rwhp and the exhaust note sounded real goofy, but no detonation.

David

lilredstang
12-29-2006, 03:51 PM
I would have liked to have seen the mustang header ported at the collector. I have had several sets of these and the weld where all 3 pipes come together has been an absolute mess on all of them.

LOL And I have to thank you Dave. The exhaust was the one part of my setup that I was satisfied with. (stock mustang shorty headers, PYPES H-pipe and magnaflow catback) Now I am thinking "hey you know I do have an h-pipe and and a set of MAC mustang long tubes just rusting in the corner of the garage.";) I was wondering the other day if anyone has ever tried to use the mustang longtube form MAC on an SC?

Flex
12-29-2006, 06:21 PM
David,

This previous owner of my brother's car had removed the cats and replaced them with the spiral core units. Not bad in design but only 1.75" inlet/outlet.
The system was all almost new. It was just replaced prior to the owner dying of cancer. So he did not drive it a lot with the system. It was just too damn small and restrictive with the replacement pipes same as stock.

Everything else was done except for exhaust and you could not accelerate hard with knock. I yanked relay to retard a couple of degrees with little change. Even with 5 litres of Xylene added it still detonated.

After the swap, it not only stopped detonating but I did a 30 ft two wheel burnout which the car could not do before. If the results posted by Dave are absolute, then the car should have lost power as the Manifolds on it outflow the Mustang Headers.

Flex
12-29-2006, 06:22 PM
lilred,

I don't believe you would be able to use the MAC's without major surgery. The chasis of the two cars are too different.

lilredstang
12-29-2006, 07:42 PM
lilred,

I don't believe you would be able to use the MAC's without major surgery. The chasis of the two cars are too different.

Well... the passanger side may not be too bad. "major surgery" may be an understatement for the drivers side.

I am watching this close because if the long tube numbers seem to be well worth it with the SC headers the I may have the same luck switching from the stock mustang shorties to the rusty long tube MACs. I am looking for more torque cuz being able to smoke the tires throught half of 3rd gear just isn't enough.:D

XR7Kurt
12-29-2006, 08:45 PM
This test means nothing yet. These are just individual tube flow rates. Does not address the needs of a working engine. At 2000 rpm, each manifold/header will have 6000 exhaust pulses flowing through it so the tubes and collectors are all going to and have to work together. That is a lot different than just measuring through one tube at a time.

Measuring airflow on a tube by tube basis does not tell you how these pieces will react on an operating motor. The results are too vague and conflict traditional exhaust theories.
What are the variables that traditional exhaust theories work with? I would imagine individual tube flow rates are in there somewhere, at least for initial design maybe. What I get out of what you're saying is basically you need to just try each exhuast configuration on a particular engine, on a dyno?
This is all very interesting, it's great that you guys share all your knowlege.

Kurt

David Neibert
12-30-2006, 11:34 AM
David,

This previous owner of my brother's car had removed the cats and replaced them with the spiral core units. Not bad in design but only 1.75" inlet/outlet.
The system was all almost new. It was just replaced prior to the owner dying of cancer. So he did not drive it a lot with the system. It was just too damn small and restrictive with the replacement pipes same as stock.

Everything else was done except for exhaust and you could not accelerate hard with knock. I yanked relay to retard a couple of degrees with little change. Even with 5 litres of Xylene added it still detonated.

After the swap, it not only stopped detonating but I did a 30 ft two wheel burnout which the car could not do before. If the results posted by Dave are absolute, then the car should have lost power as the Manifolds on it outflow the Mustang Headers.

Were these spiral core units you mention also removed when installing the headers ?

David

Paul93SC
12-30-2006, 01:01 PM
I would have liked to have seen the mustang header ported at the collector. I have had several sets of these and the weld where all 3 pipes come together has been an absolute mess on all of them.Looking at the various pictures illustrating these header collectors, why couldn't you add welds on the inside of the three primaries further away (not the inside of the header; on the outside, but where the tubes merge into the collector) and then hog out the area on the inside where all the primaries are pinched? Instead of this -= you would have this -< . Am I making any sense here?

I too would like to see flow results for ported Mustang headers and ported OE manifolds. Perhaps Dave will find some time in the future to do this, but I appreciate all he has done for us thus far :)

-----------------

As far as these tests are concerned, they are static-flow tests only. We all knew that going in. Of course they don't tell the whole story and aren't the definitive answer to anything... however, they DO indicate one aspect of flow resistance, and flow resistance is the cause of backpressure.

Backpressure is no good period and you want to reduce this as much as possible. The popular theory that you need a certain amount of backpressure to keep the low RPM torque up is wrong. What you need to do is keep the exhaust gas velocity up at low RPMs, and in order to do that you need smaller manifolds. Backpressure is an unwanted symptom of smaller manifolds: It's a design trade-off we all have to live with.

Pipe diameters, bends and shapes, mufflers, cats, and resonators all contribute to flow resistance. Anytime pipe diameters suddenly change causes turbulence and thus resistance to flow. The OE Mustang headers are poorly designed in this aspect. BTW, guys who bolt on 2.5" downtubes to stock OE manifolds aren't doing themselves any favours either.

Vince_Hayduk
01-01-2007, 05:42 PM
Sorry if this is a dumb question :confused:

Are the 94/95 tbird manifolds the same or was it 95 only? If it's 95 only, did all 3.8 tbirds get them or only the SC's?

Thanks and happy new year!

Vince

XR7 Dave
01-01-2007, 05:59 PM
Sorry if this is a dumb question :confused:

Are the 94/95 tbird manifolds the same or was it 95 only? If it's 95 only, did all 3.8 tbirds get them or only the SC's?

Thanks and happy new year!

Vince

94/95's are the same. I can't answer about the N/A motors but that is a good question.

95pearlbird
01-01-2007, 08:33 PM
Nice Job, Dave! That was a lot of work. Thanks for sharing all of your results with all of us. You have confirmed two things about exhaust systems.

#1 Being the smooth flow of transitions and chamber areas being critical to the overall "pulse" flow of the exhaust. Often times a small tube gradually opening up will perform better overall than just a large diameter all the way down. This is because the flow itself is creating its own sort of vacumn effect back to the port, while keeping the exit velocity high at the port, improving the bottom end. This "cylinder scavenging" effect of the exhaust is well proven on single-cylinder, and multi-cylinder motorcycle exhaust designs.
I worked a long time on these designs. Two stroke vs. four-stroke designs differ because of the speed of the exhaust gas pulse, and the timing of it back to the port for the best scavenging effect. You've proven that when you have a combination of large/small chamber areas, it is disruptive to the pulse flow on a four-stroke engine. A simple large tube system is great for top end, but it kills the lower end torque due to the loss of velocity.Headers work best on an engine when the tubes are as close to equal length as possible, and that normally is not the case with a cast manifold, which often creates unequal cylinder scavenging, as you have shown.

#2- Is why a collector makes more power on a header. As the exhaust expands into this larger area, it creates a negative pressure, a vacumn, actually helping to "pull" the exhaust flow thru the tubes, all the way back to the exhaust valve. The diameter and length of the collector is critical to generating the maximum possible negative pressure, or "vacumn". Without a collector, a header won't make as much lower-end torque, even though it may improve top end. Long tubes with a collector will always boost torque over a shorty set.

Here is a tip for further improving the efficency of the collector. However, it applies only to an un-corked sytem being used on a track, and not to a streetable, muffled system.

It will tune a header for more flow at top-end RPM.You will find it best for a track-use only exhaust. The equal length header with a collector provides for better flow rates and increased torque. To gain a little extra at the upper RPM ranges(4-6000), you bolt to the collector flange what is known as a reverse-cone megaphone can. You can design the volume to perform best at a certain RPM range.

(Say you have a target of 5500-6000 RPM).
Picture the pressure wave of the exhaust gas flowing down the tube and into the collector, where the action of it expanding creates a slight vacumn, creating the scavenging effect, back to the ex. valve. As it leaves the collector, instead of simply dumping out(as with an un-corked sytem) it then enters the taper of the megaphone, which creates further expansion, and more vacumn. At the same time the gas velocity is slightly slowing.This action happens at sub-sonic speed, each time the exhaust valve of a cylinder opens, and the gas escapes, it creates a pulse. Then at the end of the tube, is where the reverse cone comes in. It need not be too long, with a sharper taper than the main cone. What this does is create a gas "pulse" back the other way, timed by the length and diameter of the can, to arrive back at the valve at the precise time, shutting down the scavenging effect to create a "pressure wall". The effect on the cylinder is that as the ex. valve opens, the pulse is escaping and expanding, creating vacumn, sucking the burned gas out of the cylinder as fast as possible. When the reverse pulse-wave shuts down that effect, even though the ex. valve is still open(as it is closing) it prevents the fresh intake charge from flowing out, thereby "charging" the cylinder more completely, increasing the efficiency of the fresh charge, resulting in more power overall. A reverse-cone megaphone on the end of a collector simply tunes the system for maximum effect at a certain desired RPM, increasing the efficiency of both the collector and the system overall. You can increase that effect with a megaphone, and increase it even more with a reverse-cone megaphone. A long slow taper works better as RPM goes up, a short fat cone works better at a lower RPM.

It really is nothing more than a type of "exhaust supercharger" to increase the gas flow. There are complex mathematical formulas, using the known speed of gas velocity, combined with the variables of tubing diameter, volume, and RPM, to arrive at the desired length and taper of each of the two cones to properly tune the exhaust pulse. Often some expirementation is necessary to find the best combination for a wide RPM and torque range overall, but it does add a little bit of tuning flexibility. Perhaps those formulas are on the internet, or in a local library, under exhaust gas theory. It was many years ago when I last visited that math nightmare.
An example of this in use, is on the space shuttle engines. They have no reverse cones because there is no reverse pulse, and no valves, it's all just a solid-fuel one-way burn, but the effect of increasing the flow, as well as directing it at the same time, is evident.
The effect of this, say on a 400 HP engine, may add 5-10 HP on the top end, it's not a huge gain, but a slight one. But it's free, and when you are at the track, every little bit you can get helps, especially if it adds on at the top end. This is more likely to add to your trap speed more than to your ET.
But if you have time to expirement, you will see a top-end boost on the dyno, over an un-corked set-up.
Unfortunately, a result of this design is also that it is really loud, and the more you muffle it, the less it works. So for most of us, this won't help us out on the street. But if you have a track-only car, you will see some gains.

Sorry if this became a little long, but hope that you found it interesting.
There is a lot more to a good exhaust than just plugging together tubing.
Components and sizes have to work together.

Thanks again for your hard work, Dave!

I found yet another reason why I prefer the 94/95 SC's, though I do have both an early and a late-model SC. I knew that extra 20 HP was from many things, not just the intake side alone. Your research points that out!

MrBlvd
01-04-2007, 11:12 AM
lilred,

I don't believe you would be able to use the MAC's without major surgery. The chasis of the two cars are too different.

This has been done on at least two occassions with some decent pictures and documentation. From my experience, the driver side takes far more work than the passenger. In fact, on 94/95 (which I have) I believe you could put the passenger side on as is ... on earlier cars, you need to make a modification for the starter ... I did this mod but don't believe I really needed the space.

I going to be redoing the drivers side as my hack job is leaking. Instead of turning the #3 tube under the stearing coluumn, I'm going to take it accross the top and then turn it down ... this should make for a much smoother turn

It is my opinion the mac v6 long tubes offer some advantages as the primaries are 1 5/8 and the collectors are 2.5 vs. 1 3/4 and 3

MrBlvd

Grims95SC
01-04-2007, 02:40 PM
Excelent thread! Thanks for the work Dave. Good to see that the 95 ported manifolds are pretty good, I didn't want to have to spend a lot of $ on headers.

Tickler
01-06-2007, 06:55 AM
Wasint the reason Ford switched back to cast manifolds in 96 cost related? im no expert but welded stainless costs way more than machined cast iron.

sooooo, if I put my manifolds back on will I need 4 34# & 2 30# injectors or vice versa?

427Cammer
01-18-2007, 07:03 PM
Regarding collector length -- we used to optimize the collector length on our old Pontiac SD motors by spraying them with a paint that will burn off as the collectors got hot -- wherever along the collector that the paint stopped burning, was where we sawed it off and welded on the collector flange -- typically, left to right collector lengths varied, and depended upon header type, cam profile, head flow capabilities, etc.

I still have a set of the old Pontiac long tube/long collector headers hanging in my barn -- they are no longer made or available new -- will likely have a couple of new sets made for existing old SD inventory, once their tri-tube headers rust out.


Cammer

A-man930
03-20-2009, 09:23 PM
Anyone tried extrude honing? Its not the cheapest procedure out there, but it seems like the only way to completely port a casting...

Anyways, so has anyone decided if the 94/95 N/A 3.8 manifolds are the same as the SCs??

qc89SC
05-19-2009, 08:24 PM
thats really impresive to see those test result thanks a lot!

but now im a bit disoriented i have "goofy" ported my 89 manifold and now i dont really know if the best bang would be 95 ported SC or the mustang MAC shorty??? do someone can help me with this??? i want to find it quick i wait for this to finish my setup

Mike8675309
11-27-2011, 06:22 PM
Added jpg of the test results for those without Word.

XxSlowpokexX
11-27-2011, 06:33 PM
Where i sthat smiley face for I will keep my mouth shut for now?

renello79
10-15-2012, 11:35 PM
Would 94/95 n/a v6 manifolds be the same? Or are these sc specific?

Ddubb
10-16-2012, 12:09 AM
Would 94/95 n/a v6 manifolds be the same? Or are these sc specific?

They are the same part number. For the Thunderbirds that is.


- Dan

renello79
10-16-2012, 12:19 AM
Thank you that will make it much easier to find a set.

90sc35thann
10-16-2012, 05:51 AM
I am looking this over and have a question. This is a great thread btw! Do the MAC short tubes for the 94-97 mustang fit in our cars with no modification or some modification. If some modification, what is involved?

Toms-SC
10-16-2012, 11:56 AM
I am looking this over and have a question. This is a great thread btw! Do the MAC short tubes for the 94-97 mustang fit in our cars with no modification or some modification. If some modification, what is involved?

This was brought up some time ago. Some folks have attempted to make them fit but it required a substantial amount of work on the drivers side.

Flex
10-16-2012, 12:31 PM
Not sure if the Macs are any different in design. Factory Mustang and JBs fit but come really close to the steering shaft.

Easiest way to make them work is to cut the pipes at the flange from 1 o'clock to 11 o'clock and then collapsing the gap and rewelding. I took a small wedge out like this on the stainless JBA's in my n/a car and then welded them back together. This tilts the header closer to the block and away from the steering shaft.

ricardoa1
10-16-2012, 05:28 PM
I am looking this over and have a question. This is a great thread btw! Do the MAC short tubes for the 94-97 mustang fit in our cars with no modification or some modification. If some modification, what is involved?

You can grab my set with downtubes. If you are interested. $100 if you are in the boston area you can grab them.

Miguel5671
02-06-2013, 05:46 AM
Nice ! Great write up

shoalcracker
07-23-2014, 05:58 PM
Les

See post 62

Paul

http://www.sccoa.com/forums/showthread.php?84828-Manfold-Header-testing-complete/page5&highlight=exhaust

trckfndr
05-26-2016, 01:16 PM
What, 65 views and only three people have any comments about the test results?

Maybe I'll just send out an email with the final results. :rolleyes:

Well this just goes to show some of us pay attention to you both here and on FB. I'm going to email you as I've got an issue and a question. Paul B.