How much am I leaving on the table?

[ShadowFromHell]

Hey guys I have a 86 NY with a 88 T1 motor on 87 T2 electronics, 86 T3 turbo, SRT4 FMIC, 15psi other wise stock. Ive never done anything with the exhaust other then remove the cat. Im just wondering how much power I am leaving on the table by keeping the stock exhaust. Originally, the exhaust was left stock to keep it a sleeper. But with the FMIC its not much of a sleeper anymore. How much power would I gain with a 2.5 or 3" side exit system? Ive also been wanting to bump the boost to 20ish psi, how much would I be giving up then by keeping the stock exhaust?

[turbovanman²]

Alot. Put it this way, stuff your mouth full of rags and go for a run, :p

[ShadowFromHell]

I understand that... Im just wondering how much Im trading at attempt to keep the sleeper cops dont look at me status. lol

[turbovanman²]

I understand that... Im just wondering how much Im trading at attempt to keep the sleeper cops dont look at me status. lol

I repeat, stuff your mouth full of rags and go for a run, :p

[supercrackerbox]

It's not hard to hide a bigger exhaust system. Find an exhaust tip off of an '84-'88 Turbo Z or Shelby Z Daytona. Open up the end of the tip where it is mated to the muffler. That end will fit over a 3" pipe. Tack weld it on there, and then hang the muffler up high in the stock location with the tip just barely out far enough to protect the rear bumper. Looks totally factory; I've never had anyone even question the exhaust on my Charger.

Side exit on the other hand is obnoxious as hell, and just begging for cops to hassle you.

[contraption22]

Besides simply raising boost, an exhaust upgrade is the easiest and most cost effective way to get power out of a turbo car.

[Rrider]

Sounds like what you want is a full exhuast all the way to the bumper, maybe with a 3" super turbo or something a little quieter than a straight through. I'm running a cheapy 3" glasspack and I was surprised how quiet it sounds. I was thinking about one of the "S" path super turbo type jobs, but I'm glad I went with a straighter thru one. I guess a lot of the noise gets held up in the turbine housing on these cars.

[turbovanman²]

3" is too big, if he want's a bit more, just go 2.5".

[Tbird232ci]

Doing a 2.5" will be easier considering do go with a full 3", youd either need to run a downpipe that goes 2.5" to 3", or swap to a 2.5" swingvalve.

[ShadowFromHell]

So no one has any sort of number? After all these years no one has done a back to back on stock to open exhaust?

[contraption22]

No, not really. The numbers will vary. The more other modifications you have, the more a free-flowing exhaust will benefit you, but it will be a dramatic improvement, even on the mildest of turbo engines.

[turbovanman²]

So no one has any sort of number? After all these years no one has done a back to back on stock to open exhaust?

Read some tuner mags when they do back to back, very noticeable gains, not sure why your fighting this.

Again, stuff your mouth full of rags and go for a run, then remove them and go for a run, that's exactly what we are dealing with here, :p

[ShadowFromHell]

Im not disagreeing or fighting that there is power to be gained at all TVM. I posted this looking for a number, either dyno or track or something like that. But, since its one of the first mods normally done, it doesn't surprise me that info like that really doesn't exist. I read somewhere once that there was "30hp" to be unlocked, but that seems VERY high to me. Ive never seen any butt dyno gains that come close to that. Im thinking 10hp at the most.

[dwh4784]

Way more than 10hp. 30hp could even be low. Your car sounds like a perfect candidate for a back to back comparison. Most people wouldn't have spent the time to run 15psi and a front mount IC before doing an exhaust, so it's on you to test it out!

A ported exhaust manifold also helps, not sure if you would be doing that at the same time.

[turbovanman²]

Im not disagreeing or fighting that there is power to be gained at all TVM. I posted this looking for a number, either dyno or track or something like that. But, since its one of the first mods normally done, it doesn't surprise me that info like that really doesn't exist. I read somewhere once that there was "30hp" to be unlocked, but that seems VERY high to me. Ive never seen any butt dyno gains that come close to that. Im thinking 10hp at the most.

10 whp is very low, that's like a 2 psi increase in boost.

30 whp+ is easily attained with exhaust and boost modifications.

Any dyno's in your area? If so, dyno your car then drop the exhaust, that will give you a pretty good idea of what a good exhaust will do.

[ShadowFromHell]

100+hp is easily attained with "boost modifications" hahhaa. I do luckily have a local dyno. I may for now rig up a cheap and easy side exit because I want to track the car this year. But if I do that, eventually Id like to go back to a full exhaust with a cutout. If I end up doing that a back to back will be pretty easy.

The front mount was done because the T2 rad/IC I was running sprouted a leak. I was tired of fighting heat and wanted a full size radiator and a FMIC. The FMIC helped alot, the car pulls quite well. But since it took me 3 months to get the modification done (winter) I didn't get to do a back to back. Im trying to get a race setup with a stock SRT that is local to give me a idea what it runs. But every time I bring it up I get a excuse!

[Vigo]

This is not what you're looking for but i dyno'd a stock 2.5 with a FMIC at 16psi through an exhaust that was part 2.25" and part 2". The exhaust choked the motor so much it moved the power peak down to 3700 rpm. That is NOT GOOD.

[GLHNSLHT2]

sure it was the exhaust and not the lifters collapsing?

[ShadowFromHell]

Mine is pulling hard until it shifts but I have no tach.

[wallace]

Not sure about the HP but there will be a dramatic increase in the torque and when it comes on. I would say an easy 50 ft/lb from stock to 3" at the boost level you are running.

[bgbmxer]

I remeber Chris at tu saying that going from a regular swingvalve to a 3 inch was a 20 horse gain. And that's only one exhaust component.

[GLHNSLHT2]

the dyno test they did was from a 2.5" to a 3" and picked up 5 peak hp. but the area under the curve was 40ft-lbs of torque and 40ish hp.

[bgbmxer]

the dyno test they did was from a 2.5" to a 3" and picked up 5 peak hp. but the area under the curve was 40ft-lbs of torque and 40ish hp.

Wow that's even better than I thought. Hence the reason I bought a 3" swing valve when it came out. Even tho I'm running a kind of tiny turbo I'm gonna make sure the turbo is the only real restriction in the system.

[GLHNSLHT2]

What I'd like to see is a TU vs. ATP vs. Shadow SV test. That'd be really interesting to see. I like the ATP and Shadow's the best, not sure which one would win and by how much over the TU Piece. I like my TU piece but that's because ATP and Shadow's weren't available when I bought mine.

[bgbmxer]

What I'd like to see is a TU vs. ATP vs. Shadow SV test. That'd be really interesting to see. I like the ATP and Shadow's the best, not sure which one would win and by how much over the TU Piece. I like my TU piece but that's because ATP and Shadow's weren't available when I bought mine.

I haven't seen this one you speak of. But I do remember the ATP one. Looked at using it when I put the mitsu turbo on my old diesel rabbit.

[GLHNSLHT2]

Shadow welds a nice 3" mandrel bend onto a stock SV housing.

[bgbmxer]

Shadow welds a nice 3" mandrel bend onto a stock SV housing.

What's the wastegate setup? External.

[GLHNSLHT2]

http://www.turbo-mopar.com/forums/showthread.php?55142-3-quot-mandrel-S-V&highlight=

All 3 are internally gated.

[bgbmxer]

http://www.turbo-mopar.com/forums/showthread.php?55142-3-quot-mandrel-S-V&highlight=

All 3 are internally gated.

Looks cool but I already have a TU piece.

[GLHNSLHT2]

oh yes if you already have the TU piece I wouldn't bother changing it. I'd just like to see a back to back dyno comparison between all 3 pieces.

[bgbmxer]

oh yes if you already have the TU piece I wouldn't bother changing it. I'd just like to see a back to back dyno comparison between all 3 pieces.

Yea. if your goin for even more flow you would go with a tubular header and And external anyways all custom.

[Vigo]

the dyno test they did was from a 2.5" to a 3" and picked up 5 peak hp. but the area under the curve was 40ft-lbs of torque and 40ish hp.

Honestly, unless we know the boost number at those points 'under the curve' i think it's pretty meaningless. For example, if your car normally starts making boost at 2500 and you put on a big exhaust and it starts making boost at 2000, you can say you gained 40 hp/tq at 2300 rpm but it all came from the boost, not making more power per psi.

[GLHNSLHT2]

Honestly, unless we know the boost number at those points 'under the curve' i think it's pretty meaningless. For example, if your car normally starts making boost at 2500 and you put on a big exhaust and it starts making boost at 2000, you can say you gained 40 hp/tq at 2300 rpm but it all came from the boost, not making more power per psi.

Not meaningless at all. You're exactly right in where the power comes from. What the power gain under the curve is showing is how much better the TU flows than a stock 2.5" SV. So the boost spools that much quicker and you get more power under the curve than before.

[Vigo]

Sure, but increasing the boost is different from making more power at the same boost level. As long as people know the difference they can do what they want, but for example if you already had a 3" exhaust and bought a 3" swingvalve looking for a big 1/4 mile gain you wouldnt get it because all the gain would be at a lower rpm than you could actually use on the track and all you'd see is that ~5hp peak increase.

[GLHNSLHT2]

no one is disputing that at a 1/4 mile track you wouldn't see much. It'd be around town and on a road course where you'd see more of that quick spool potential.