most boost with stock 3.8?

hyperformance

Registered User
how much boost is possible with a stock super coupe? 11-12 is stock... i'm interested in buying an S/C, but i wanna know how much power I can expect with a custom chip and the smallest pulley possible for a stock blower and now run into blower incapacition.......is 18lbs possible? i'm not concerned with reliablity of the 3.8, i know head gaskets are awful with these engines...... so please tell me what the max boost is with a stock blower?
 
Basically you have forget about performance with the stock M90 when you reach over 10Psi of boost. Without increasing the blowers ability to flow you will just end up sucking up more horsepower from the motor than what the blower can provide. If you want to run that high of boost send in your blower and have it ported and modified by MP so that you can acheive the level of boost you want.
 
well, i'm offically not interested in the idea now hehe... thanks for the info....

i own a new '03 cobra, and i can pull 20lbs out of it (with custom machined pulley)......with only a complete exhaust, custom air intake tubing, and chip, i put 492 rwhp....(i'm tryin like heck for 500!!!)

so upgrading the s/c, if it requires blower work, i'm not interested... thanks...
 
hyperformance said:
well, i'm offically not interested in the idea now hehe... thanks for the info....

i own a new '03 cobra, and i can pull 20lbs out of it (with custom machined pulley)......with only a complete exhaust, custom air intake tubing, and chip, i put 492 rwhp....(i'm tryin like heck for 500!!!)

so upgrading the s/c, if it requires blower work, i'm not interested... thanks...


After spending close to $30K I can see where having to mod the car would be a issue. :)
 
money isn't an issue.... but i have this 'sleeper mentality'.... i like the most performance at the most stock appearing possiblity..... i have a 92 lx coupe mustang that runs 12.90's and its STOCK appearing.. (gt-40p heads with minor mods, explorer intake with mustang plate, 24lbs inj, 70mm mass air and 65mm throttle body, 333 cubes... 4.04 bore & 3.25 stroker... sounds stock, idles stock... runs high 12's haha)... i just like the idea of stock appearing and little work.....


wezar said:
After spending close to $30K I can see where having to mod the car would be a issue. :)
 
Sorry but you aren't making much sense. I don't claim to be an 03 Cobra guru, but last I checked they don't make 500rwhp or 20psi with a stock blower. Give me a break already. :rolleyes:

You've done as much work to your 92 LX as I have to my XR7 and it runs mid 12's so pppbbbffftttt!
 
It AIN'T all boost pressure!!!!!!

Doesn't the Cobra use an Eaton M112? The SC uses an Eaton M90, which is smaller. The Eaton blowers are very inefficient. That inefficiency tranlates into a LOT of heat in the output air charge. The most important consideration after the output of the eaton blower, is HEAT. Forget boost pressure. After the blower, the only way to change the number of oxygen molecules per cubic cm, is with an (effiecient) intercooler. If you can get more O2 molecules per cubic cm, you will make more hp/TQ, than you will by simply raising the boost level.

Hi Boost = Hi Heat = Low Density Air charge = lower performance

Hi Boost = Hi Heat = Low Density Air charge + Intercooler = Hi density Air Charge = MUCH Higher Performance.

Forget boost level & start thinking about removing HEAT!!!!!!!!!!!!!!

68COUGAR
 
My freinds 03 cobra is getting 515 rwhp and 494 rwtq with only 14psi with a stock ported blower and a 2.75 pulley and a MAc prochamber


Before those mods with a stock blower @ 10psi he was making 452 rwhp and 463 rwtq.

Regardless you can have a stock looking SC with 350 rwhp or so..Stock looking blower..Stock exhaust manifolds..Stock placement IC...Stock IC tubes ect ect.....Just ask Bill McNeal.....Then again..EVerything he has is for sale!! haha
 
Ok, but the 20 PSI thing has got me rollin'. :D At 20 psi he should be making a lot more than 492rwhp. But then again with the ole' Eaton sweating out 20psi I'm sure ACT's are at about- what 200deg? :D Bet that thing lasts a long time running like that.
 
XR7 Dave said:
Sorry but you aren't making much sense. I don't claim to be an 03 Cobra guru, but last I checked they don't make 500rwhp or 20psi with a stock blower. Give me a break already. :rolleyes:

You've done as much work to your 92 LX as I have to my XR7 and it runs mid 12's so pppbbbffftttt!

Well, last time I checked, people who don't know much about '03 Cobras shouldn't be telling people what kind of horsepower they create.... There's an article in the November '03 issue of MMFF, if you'll read it, you'll see that a stock blower is easily capable of 18lbs... and everyone knows that if the tolerances are right, more boost is possible....
 
Ya well blah blah blah. I don't go on Mustang boards and tell people their cars suck, why don't you take your own advice and don't come over here and tell us what is a waste of time or not. Sure you can get even more than 18psi from an Eaton. Guys here have gotten over 21psi. But of course anyone who knows anything about Eatons know that anything over about 18psi is a total waste of effort. But hey what do I know? :/

Oh, and SC's definately suck from a performance standpoint. Don't waste your time. :rolleyes:
 
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Yep,

Here is one thing though that people dont realize, a 89-95 SC is way older in technology and engineering than a 03 cobra, of course your gonna get more boost out of it dumb-***. People dont realize about the difference in years. All they just do is just talk and talk and talk more ****.

Its like going to a MUSCLE CAR forum and saying that my 98 Z28 will beat your 69 SS, of course it is.

I would prefer having a v6 run a 10 second quarter mile than a v8. Makes you feel cool.
 
XR7 Dave said:
Ya well blah blah blah. I don't go on Mustang boards and tell people their cars suck, why don't you take your own advice and don't come over here and tell us what is a waste of time or not. Sure you can get even more than 18psi from an Eaton. Guys here have gotten over 21psi. But of course anyone who knows anything about Eatons know that anything over about 18psi is a total waste of effort. But hey what do I know? :/

Oh, and SC's definately suck from a performance standpoint. Don't waste your time. :rolleyes:

What makes you guys so hostile? All I said was that I wasn't interested in the t-bird from a performance standpoint. I love t-birds, cougars, and LOTS of other stuff.... I don't come to ANYONES 'group' and tell them that their car sucks... if you can find where I said that at, I will gladly apologize and kiss ***... until then, take this for what it means... I have a 20psi mustang that makes about 10-15 (25lbs of torque @ 3000rpm) more rwhp than at 18psi.... so apparently its not a waste of time... I respect each and every one of you, except for people who run their mouths about crap they don't understand. I wasn't comparing the cobra and the SC t-bird... there is NO comparison between, I never even compared my cobra with a t-bird at all, you're talkin about 6 cylinder pushrod engine vs. a DOHC v-8?? I was just making a point that, I'm interested in something the SC can't provide me nor anyone else, cheap and easy hp. Sure my car was 27,000 used.. but its a heck of a car... and everyone knows it....

I understand about technological advances, and the difference a few years of R&D can make.... but i ALSO understand that some people will never grow up.... with little comments like 'my car is faster than your car...' haha... I don't try to have a faster car than everyone else, it just happened that way... deal with it...

I also noticed you changed your mind about boost on the cobra? First you were saying 20lbs wasn't possible haha, now you're saying 21 is? Hmmm...
 
What I took exception to was your attitude. Getting performance from one of these cars takes a little different path that simply cranking up the boost which is exactly what you asked in the first place. You make it sound like as if anything more than a pulley change is too much work for you, then you turn around and say that blown headgaskets are no big deal. This made no sense to me.

Then you went on to say that your 92 is an example of simple HP yet it has been stroked, has ported heads, and a number of other "stealth" parts and bolt ons to make it fast. I dont' understand how this is simpler and better than what might be needed to make an SC fast. :confused:

I took exception to the fact that you dismissed the SC after giving it 5minutes of thought and yet proceded to carry on about your other cars which we, being SC nuts, could care less about. I have no problem being corrected when I am wrong and I dont' take it personal, but your superiority attitude just rubbed me the wrong way.

i'm not concerned with reliablity of the 3.8
Why not? Do you have some secret we don't know about? Most of us are at least moderately concerned about reliability.
i know head gaskets are awful with these engines
Correction, you think the headgaskets on these engines are awful. The truth is that the OE gaskets all fail due to a design flaw of the original gaskets themselves. Once replaced they do not have any more problems than any other aluminum head/iron block motor with 4 bolts/cylinder (read most Fords).
i'm offically not interested in the idea now
Ok, bye!
i own a new '03 cobra, and i can pull 20lbs out of it (with custom machined pulley)......with only a complete exhaust, custom air intake tubing, and chip, i put 492 rwhp
But not before you try to point out that other cars are much superior.
i have a 92 lx coupe mustang that runs 12.90's and its STOCK appearing.. (gt-40p heads with minor mods, explorer intake with mustang plate, 24lbs inj, 70mm mass air and 65mm throttle body, 333 cubes... 4.04 bore & 3.25 stroker... sounds stock, idles stock... runs high 12's haha)
Once wasn't enough, you had to do it twice. If we wanted Mustangs we would have bought them instead. We all know (or at least have some idea what the perforance capabilities of other cars are. We choose to modify SC's. No one forced us into it and yes we could afford other cars if we wanted.
money isn't an issue
You've lost me here. If money is no issue then what is the problem with purchasing a ported blower or having one ported? That won't destroy your "sleeper effect".
Maybe if you spent less time reminding us of how your Cobra performs (remember, they have NOTHING in common with SC's) and talked to us about SC performance we could find some common ground. You did not seem to pay any attention to Damon's statement:
Regardless you can have a stock looking SC with 350 rwhp or so..Stock looking blower..Stock exhaust manifolds..Stock placement IC...Stock IC tubes ect ect
and instead continued to argue with about your Cobra. Speaking of which, shouldn't a Cobra with an efficient blower at 20psi be making around 600rwhp instead of 500? Seems I've seen articles in MM&FF which suggest that 600rwhp is the norm. :confused:

Not hostile, just a little defensive towards your condescending attitude. If I misread all that stuff then I apologize. Let's keep the discussion here centered on SC's, ok? :)
 
For the very last time, if you dont' know what you're talking about, don't talk about it..... I dont' claim to know much about SC's... but you keep bringin up my 20psi cobra... Well for your information, for the FINAL time.... page 144 of the May 04 issue of MMFF..... "The M112 supercharger from the factor is maxed out at around 500hp at the rear tires"

The next point I'm goin to make is that pressure doesn't make power. You seem to be under the age old belief that boost = power, and thats funny! Page 146 of the same issue..... "In this trim (14psi stock blower w/ pulley)... 462.9 hp at the rear tires...." ------> "With the SAME 14psi of boost (w/ procharger)... the cobra spun the dyno at 580hp at the rear tires"

So if you'll show me where the 600hp cobras are... Lemme know, I need to figure out what kinda sparkplugs they found to increase the power soooooo much haha.....

But thanks for tryin to point out where I tore down someone's car with negative comments... And thanks for showing me how bad my attitude is toward all the users in this forum...and most of all, thanks for the warm welcome to the site... I'll spread the word haha...

*notice* I'm not talkin about SC's, because i dont' claim to know anything about them haha.... With every message you send about your knowledge of Cobra's, you change your story completely.... You went from 20psi not possible... to 21 psi POSSIBLE.... from 500rwhp not possible... to 600rwhp POSSIBLE.... Lemme guess, you're vote is for John Kerry this year? or wait...I'll ask ya tomorrow, you'll have changed your mind by then ;-)
 
Guys Guys Guys WHHHOOOOO take it is....

This whole is more boost really more boost debt. GEEEZ SC ____ .Is what the whole SCCOA is about. The eaton M-90 which is almost enough to make a complete difference. Now, just from my experience it is all about how air flows through the motor.

Stock Eaton M-90 from Manuel flows 11psi at the most.

Stock Eaton M-90 from AOD flows 14psi at the most. This is the blower I was using when I blew the last motor to hell!!!!!!!!!!!!!. Now why does this M-90 flow more is it modified or what. Is there a difference between the AOD and Manuel.

Anyway with catalytic converters 11psi M-90 falls on its face at high RPM tolerance. Fells like so much more power is getting snuffed out. Is this a EEC problem. Take off catalytics revs real good and high still fades at 11psi feels like it could take even more without backpressure.

In my opinion these motors were detuned so they would last a while. They could take way more abuse then a stock set up could throw at the block.

It is my opinion that the M-112 is overkill.. Should be used on a viper. Still a quality unit works real great . Hey M-90 was the first in this era. Intake temp is what really matters. COOL !
 
i have a stock 90 sc and before i pulled the motor it was running on 5 cylinders and would bury the boost guage and everything was stock including the air silencer. "scooby" was a witness to how my car ran. i think i had a fluke because it had 181k on it but it would destroy my silver 90 sc that had 88k on it, and was running on 5 cylinders at that time too.
 
hyperformance said:
For the very last time, if you dont' know what you're talking about, don't talk about it..... I dont' claim to know much about SC's... but you keep bringin up my 20psi cobra... Well for your information, for the FINAL time.... page 144 of the May 04 issue of MMFF..... "The M112 supercharger from the factor is maxed out at around 500hp at the rear tires"

The next point I'm goin to make is that pressure doesn't make power. You seem to be under the age old belief that boost = power, and thats funny! Page 146 of the same issue..... "In this trim (14psi stock blower w/ pulley)... 462.9 hp at the rear tires...." ------> "With the SAME 14psi of boost (w/ procharger)... the cobra spun the dyno at 580hp at the rear tires"

So if you'll show me where the 600hp cobras are... Lemme know, I need to figure out what kinda sparkplugs they found to increase the power soooooo much haha.....

But thanks for tryin to point out where I tore down someone's car with negative comments... And thanks for showing me how bad my attitude is toward all the users in this forum...and most of all, thanks for the warm welcome to the site... I'll spread the word haha...

*notice* I'm not talkin about SC's, because i dont' claim to know anything about them haha.... With every message you send about your knowledge of Cobra's, you change your story completely.... You went from 20psi not possible... to 21 psi POSSIBLE.... from 500rwhp not possible... to 600rwhp POSSIBLE.... Lemme guess, you're vote is for John Kerry this year? or wait...I'll ask ya tomorrow, you'll have changed your mind by then ;-)

There you go talking about your Cobra again. :/

I said 21psi is possible with an M90 on a 3.8
Guys here have gotten over 21psi.
not a Cobra, please pay attention if you can. I don't know anything about Cobras other than that which I happen to read in National Enquirer - er - I mean Muscle Mustang. I appreciate your correcting me when I said something wrong. Thank-you for your information.

I made the off comment that in the case of 20psi resulting in only 500rwhp when I have read that Cobras "with a more efficient blower" (quoting myself here) make 100rwhp more than that makes me think that forcing the Eaton to generate 20psi is kind of a waste of time. Other than that I have nothing to add about Cobras.

I'm sure you won't respond to this post because it went from mildly inflamatory to down right argumentative, but nonetheless I have to point out that this comment of yours
The next point I'm goin to make is that pressure doesn't make power. You seem to be under the age old belief that boost = power, and thats funny!
after I stated this
Getting performance from one of these cars takes a little different path that simply cranking up the boost
in response to your first question
much power I can expect with a custom chip and the smallest pulley possible for a stock blower
and when someone else suggested that more boost wasn't the answer for performance with this car you simply stated
i'm offically not interested in the idea now
after which point in time you proceed to throw out Mustang numbers of which I have no interest whatsoever.

If on the other hand you had shown any interest whatsoever in the SC information that has been offered by other members (never mind me because you obviously don't care for me or my opinions) perhaps some other people who are not as argumentative as me would have offered some great ideas on how to get power out of these cars. Instead you blow them off and try to argue with me about your Cobra which I already stated before that I have no interest in whatsoever. :/
 
To be fair and impartial here is my take:

I have turbocharged a lot of different engines in my short 34 years.

I have found that PSI does not equal horsepower.

To prove this follow along with me.

I had a 5.0L 305 Chevrolet engine with 8.7:1 cr, 1.94 valved 58cc Dart SR torquer heads with nothing other than a gasket matching done, Summit Vortec truck shorty tube headers, factory 5.7L roller cam, Victor Jr drilled for 36 lb injectors, a 90* adaptor for a 70mm Mustang TB, a modified HEI and a Megasquirt computer and finally a Modified GN turbo.

The little Chevy engine made 391 horsepower 385 ft lbs and 24 PSI. (flywheel)

I took the Turbo, injectors, computer, throttle body and adapter and put them on my gasket matched GT40P headed 8.8:1 306 Ford with a factory GT cam, Flowtech shortys dimpled for the P heads, and a Victor Jr and guess what I came up with?

Henry made 401 horsepower and 377 ft lbs and did it at 19 PSI. (flywheel)

WHY?

As an air pump the Ford engine offered less restriction to the incoming charge building less reversion and in turn less pressure. When I cranked the boost up to the same 24 PSI we had passed the thermal efficiency of the 306. while we made 428 horsepower and 393 ft lbs they were peaks and the rest of the numbers suffered greatly.

PSI and boost pressure sound great but they need to be used in relative terms.
example:
Racer A - "My car flows X cfm through the system and I run XX PSI and make XXX horsepower with that boost."
Racer X - "My car also flows X cfm, but I only run Y psi to get to XXX horsepower, I think your intercooler sucks or something! Let's compare them to see the difference."

Now that that is said, I would like to know the target peak boost that can be made, and suggestions on how to get there, for the following combo:

-Stock million mile 1990 SC bottom end with fresh rings and bearings.
-Heads and lower intake gasket matched, Heads flange matched to 1998 Mustang shortys.
-1990 Blower case to be ported (need good reference as everyone their opinions!)
-Water injection pre blower switched on above 9 psi
-Larger TB (need reccomendations)
-Megasquirt-N-EDIS computer, 8x8 table, no mass air to get in the way.
-2.5" Mandrel bent exhaust, NO CATS, total exhaust length 52" per side with Dr. Gas x pipe and side pipes with Dynomax 2.5" race Bullets.
-Mandrel bent aluminized IC piping, Intercooling has cool air ducting as well as an Icewater sleeve on IC to manifold pipe near IC.
-50-125 shot Nitrous oxide shot in to the IC to manifold pipe for drag racing and/or smacking ricer bitches around.

I don't need a lot to complete phase 1 of this build, as I have most parts but I do like to know everything I need to know when going into these unexplored (for me) territories.

Oh yeah remember this ain't no stock heavy bodied MN12, this is a 1550 lb Datsun SPL1600 Roadster!

Click on pic for close up
 
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Quasi Mofo said:
I would like to know the target peak boost that can be made, and suggestions on how to get there, for the following combo:

-Stock million mile 1990 SC bottom end with fresh rings and bearings.
-Heads and lower intake gasket matched, Heads flange matched to 1998 Mustang shortys.
-1990 Blower case to be ported (need good reference as everyone their opinions!)
-Water injection pre blower switched on above 9 psi
-Larger TB (need reccomendations)
-Megasquirt-N-EDIS computer, 8x8 table, no mass air to get in the way.
-2.5" Mandrel bent exhaust, NO CATS, total exhaust length 52" per side with Dr. Gas x pipe and side pipes with Dynomax 2.5" race Bullets.
-Mandrel bent aluminized IC piping, Intercooling has cool air ducting as well as an Icewater sleeve on IC to manifold pipe near IC.
-50-125 shot Nitrous oxide shot in to the IC to manifold pipe for drag racing and/or smacking ricer bitches around.

I don't need a lot to complete phase 1 of this build, as I have most parts but I do like to know everything I need to know when going into these unexplored (for me) territories.

Oh yeah remember this ain't no stock heavy bodied MN12, remember this is a 1550 lb Datsun SPL1600 Roadster!

Wow that sounds like a trip waiting to happen.

Couple questions for you though. First off I know nothing about the engine management system you intend to use. Does it allow other than 90 degree firing? You will need 60 degree firing sequence and not all systems will do that. And is there a particular reason for using the Eaton on that motor? You would be much advantaged if you looked into using a junk yard twin turbo setup if you have room.

The reason I suggest that is the M90 will no allow you to make a ton of HP but it will give you gobs of torque. In a light car that will work against you in many circumstances.

But to answer your questions, you can port the blower to reduce outlet temps and there is a small amount you can do to the inlet to improve flow. Keep in mind though, that a stock M90 only flows about 550cfm before efficiency starts to really drop off. We have found that about 16psi is a reasonable amount of boost to run through that blower with a decent IC.

If that doesnt' flow enough air for you (if boost starts to drop off at higher rpm) then you can look at getting the blower modified for an aftermarket inlet (Magnum Powers) and then flow will reach as much as 750cfm and again, boost will be limited by your ability to cool the charge.

With a turbo setup you will be able to run 20psi on pump gas and will make at least 100hp more than otherwise. Count on 300rwhp as a max with the M90 as a baseline.

I'd limit the N2O to no more than 75hp for reliability reasons. I also recommend injecting the N20 after the ACT sensor (on the stock SC that means in the return adapter to the intake manifold.

Oh, and do a good job porting the heads, your motor will thank you. ;)
 
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