Manfold/Header testing complete.

Whoa and the stock 95 Manifolds sure don't dissapoint!!!

Interested in seeing the ported 95's when you get a chance.
 
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
 
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.
 
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!
 
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
 
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.
 
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.
 
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.
 
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:
 
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
 
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).
 
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: :eek:
thank you
 
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.
 
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.
 
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. :)
 
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.
 
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?
 
Headers

Thanks Dave for posting your results, this will be useful to all of us.
 
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