Exhaust size vs horsepower

[wickedtsi]

Does anybody know how much horsepower a 3" exhaust pipe from engine back will support ? I am running a Talon TSI with a TO4 630hp turbo. I am building my own system and I just want to make sure it's the right size. The largest I see being sold is 3". However I see John Shepard running a 3 1/2" pipe and runs 9s in the 1/4, not sure of his horsepower though. Also what sizes are you guys running for header primary tubes?

 

[nickrule99]

Does anybody know how much horsepower a 3" exhaust pipe from engine back will support ? I am running a Talon TSI with a TO4 630hp turbo. I am building my own system and I just want to make sure it's the right size. The largest I see being sold is 3". However I see John Shepard running a 3 1/2" pipe and runs 9s in the 1/4, not sure of his horsepower though. Also what sizes are you guys running for header primary tubes?

Shepard is running around 1000hp. You'll be fine with a 3".

 

[kraka]

Why not an Exhaust cut-off? You can just have the piping exit straight out through the front bumper...Otherwise though, I am not sure about at what amount of HP DSMer's ditch the 3". Now that I think about it, I remember the a'pexi gt spec cat-back having like 3.75" piping or somewhere around that; I just don't know many DSM's running it...

------Just a Q tho...Are you actually running 630hp right now??? If so, what are the specs on that car?? I presume it is a street car because if it is race then there is no need for full piping all though way back...If it is street then...DAMN!! The only reason I bring this up is b/c if your car is no where near 600horses, then switching to a full turbo-back that is 3"+ is not neccessary...nor really a good idea at all

 

[yugotdonkey]

I am running a Talon TSI with a TO4 630hp turbo.

You might want to update your mod list.

Apexi SAFC, K&N filter Ported and polished '95 exhaust mainfold, 2.5" exhaust from downpipe back w/ test pipe, MBC, gauges including EGT, bost, air/fuel ratio, oil press, and Pocketlogger, oil cooler

 

[92awddsm]

Does anybody know how much horsepower a 3" exhaust pipe from engine back will support ? I am running a Talon TSI with a TO4 630hp turbo. I am building my own system and I just want to make sure it's the right size. The largest I see being sold is 3". However I see John Shepard running a 3 1/2" pipe and runs 9s in the 1/4, not sure of his horsepower though. Also what sizes are you guys running for header primary tubes?

Sounds like an scm-61. 3" will be fine with it.

 

[TSIfreek]

3" will be more than enough. 3'' is what I would go with for that turbo.
How dont you think its enough

 

[NDgsx]

Make 600hp with a 3" exhaust. Put a 3.5 or 4 on, then post. You guys replying don't make 600hp, haven't made 600hp, and aren't going to make 600hp. If you don't have first hand experience don't post.
If you do setup the car properly and make the much power a 3" is a restriction.

 

[wickedtsi]

Yugodonkey-- I do need to update my mod list. I am still in the process of building the car. My goals are to get 600hp at the wheels, street driver. I am working on the tuning aspect to get everyting to work together. It is not easy and I feel that my exhaust is the major problem at this point. My old setup is Buschur 2.5" with a ported '95 manifold. I had recently fabricated a custom header with 2" primary runners and I belive that it is too big b/c I can't make any horsepower and the I have major boost creep. Turbo kicks in at about 1200 RPM but dosen't much power all the way up to 25 psi. I think the problem is that I am losing my velocity when it reaches the manifold and major de-tunes the setup. For now I plan to run my '95 manifold and upgrade the pipes back. BTW my fuel mixtures are correct. I'm just taking it one step at a time eventually I will get there.

 

[wickedtsi]

Mod list is now updated

 

[wickedtsi]

Make 600hp with a 3" exhaust. Put a 3.5 or 4 on, then post. You guys replying don't make 600hp, haven't made 600hp, and aren't going to make 600hp. If you don't have first hand experience don't post.
If you do setup the car properly and make the much power a 3" is a restriction.

Do you run with a flex section? Is your car loud with 3.5" exhaust?

 

[NDgsx]

I haven't run my car with the new setup. My experience comes from supras.
I will be running a flex section, even with poly mounts the motor still torques quite a bit.

 

[wickedtsi]

Looks like 3.5" is what I will go with. John Shepard can get 1000 hp with 3.5". I will be only a fraction of that, however I think it will be the best size to go with given my setup. Thanks guys for all your help.

 

[95blackGsTurbo]

Whats the deal with the Supra's haveing a 3.75in exhaust systems out then?

 

[16g-95gsx]

Why not just go with a 3" and like others said either drop/dump the exhaust with a cutout at the track? I dont see a 3.5" downpipe happening from my own personal experience with my true 3" HRC downpipe, however a 3.5" catback and testpipe could easily be done, but I just see a cutout as gaining you that much more, and if you're going with a 3.5" exhaust I see it as being a custom job anyway. The bigger the better, that definately reigns true, but if you truly are aiming for a street car then a cutout, especially electronically controlled, seems to me to be the best answer for street comfort.

 

[GPTourer]

Now that I think about it, I remember the a'pexi gt spec cat-back having like 3.75" piping or somewhere around that; I just don't know many DSM's running it...

The GT-spec can be up to 3.75" depending on the application. For DSMs they are the same size as the comparable N-1's for 2G's, and a little difference between the T's and X's.

You guys replying don't make 600hp, haven't made 600hp, and aren't going to make 600hp. If you don't have first hand experience don't post.

One night I dreamt I had 600hp, and I'm almost positive I had a 3.5" system. The car ran great, but the only problem was - I had Beyonce riding shotgun and it was going to take waaay more then three and half inches to impress her.

 

[swordfish]

Whats the deal with the Supra's haveing a 3.75in exhaust systems out then?

The supra guys are running 4 and 5 inch systems now. I've been running a 3.5 setup for about a year or so now and it rocks. Still pretty quiet, and picked up power on the dyno. Since we have a dyno, my car gets before and after tests for just about every part that I add.

Here is some piping differences. 3.5 inch from my system on the left, then 4, then 5 and finally the all mighty T25.

Here is a pic of my 3.5 setup that's kind of a RE Amemiya Dolfin knock off. It uses a magnaflow 3.5 oval stainless race muffler and a dynomax bullet muffler as a resonator.

jeff

 

[Eclipsei95cl]

Does anybody know how much horsepower a 3" exhaust pipe from engine back will support ? I am running a Talon TSI with a TO4 630hp turbo. I am building my own system and I just want to make sure it's the right size. The largest I see being sold is 3". However I see John Shepard running a 3 1/2" pipe and runs 9s in the 1/4, not sure of his horsepower though. Also what sizes are you guys running for header primary tubes?

What kinda T04 is it?

 

[Morphius]

Here is a pic of my 3.5 setup that's kind of a RE Amemiya Dolfin knock off. It uses a magnaflow 3.5 oval stainless race muffler and a dynomax bullet muffler as a resonator.

jeff

Would the system be too loud using just the bullet muffler? That's what I picked up for a muffler to use on my diesel project. It packages best given the bends and routing needed on the GST with the large 3 1/2" tubing. I don't think four will even begin to fit.

How did you get the routing done? Get it bent? Welded sections? or did you purchase 90's/45's/30's from a shop and build it? I haven't found a shop yet that can bend this. However, I did find a diesel shop that's got tubing sections with bends. It just so expensive though.

 

[swordfish]

With just the bullet alone it's going to be fairly loud. Well, it's just going to be loud. It should still sound mean though.

On the routing, I bought a 180 degree 3.5 inch Ubend and we already had the 3.5 inch straight tubing here at the shop. Then I just broke out the welder and band saw and went to work. The GSX makes the routing easy because the only bend in the entire system is just at the rear diff. The muffler comes out at an angle and uses another section of the 3.5 Ubend for my dolfin style turn down.

Here is a picture of my old 3.5 inch setup where you can see the bends really well. Four inch would really be a tight fit on a GST but is definately doable on a GSX and I could probably get it to work on a GST with a little creativity. The honda guys are doing 4 inch setups on the high horsepower street hatchies and they have almost no room for piping that big.

jeff

 

[16g-95gsx]

Very nice, I've always thought people who ever said 3" was "overkill" were idiots. How far into the system is it 3.5"? Just curious if it stops at the catback or did you go all the way to the flex? The flex for my HRC 3" eliminator DP seems to be pretty close, not sure how much closer a 3.5" would be.

 

[92redman]

Would the system be too loud using just the bullet muffler? That's what I picked up for a muffler to use on my diesel project. It packages best given the bends and routing needed on the GST with the large 3 1/2" tubing. I don't think four will even begin to fit.

You shouldn't have a problem with it being too loud on a diesel. I have heard several Rams with 4" and larger turbo backs with out muffler or resonator and they just aren't that loud(and this is 5.9l Cummins by the way) compared to a similar exhaust on a gasoline engine. You may find that you don't even need the bullet.

 

[swordfish]

Very nice, I've always thought people who ever said 3" was "overkill" were idiots. How far into the system is it 3.5"? Just curious if it stops at the catback or did you go all the way to the flex? The flex for my HRC 3" eliminator DP seems to be pretty close, not sure how much closer a 3.5" would be.

All the way up to the oil pan. The only part that is still 3 inch is the 02 housing and down to the oil pan. The only reason that it's not 3.5 is to clear the oil filter. From the oilpan back, including the flex is 3.5.

jeff

 

[wickedtsi]

What kinda T04 is it?

It's a Tripple Threat Motorsports Full TO4 Monster supports 630 hp. It has custom housings A/R 63 and a trim of 50

 

[98TsiAWD]

RNR sells a 3.5" turboback system. I was gonna buy it back when I was building my car but funds were coming short at teh time so I took my 3" RNR off my other car.

I thinking about picking up a 3.5" bullet muffler and having a local shop do a 3.5" system from my downpipe back.

 

[wickedtsi]

All the way up to the oil pan. The only part that is still 3 inch is the 02 housing and down to the oil pan. The only reason that it's not 3.5 is to clear the oil filter. From the oilpan back, including the flex is 3.5.

jeff

I made a custom O2 outlet that I will weld a 3.5" pipe to. I also am running a external WG to atmosphere. To get around the oil filter being in the way I relocated it to the pasengers side fender, and am using a filter size for a 350 Chevy. The only thing I am going to have problems is #1 finding a 3.5" flex section, #2 ground clearance from the flex.