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how much HP?

jimmers

Well-known member
Joined
Mar 27, 2005
Messages
302
Location
Canada
Corvette
1990 Red Coupe 6 speed
Well my mufflers finally went south so its time for a new exhaust setup. At the shop the guy suggested removing my cats and precats, putting true dual exhuast with 2 1/4"pipe and some flo pro mufflers. He said that i will be able to feel the performance difference in my seat with this setup. How much horsepower do you think id gain?
 
I did the same thing on my ride. The Borlas with gutted cats helps you out nicely. I'm estimating 25-30 HP gain.
 
How are you fellow Canadians going to pass emissions. Any of you guys going to the Vette show at the Beach ???
 
fredk said:
How are you fellow Canadians going to pass emissions. Any of you guys going to the Vette show at the Beach ???

I live in Winnipeg Manitoba and there arent any emission laws here.
 
jimmers said:
I live in Winnipeg Manitoba and there arent any emission laws here.

Headers, Y pipe, and muffler eliminators are good for about 70 HP. The TPIS ones are really easy to install and come with the Y pipe.

:w
 
Hrtbeat1 said:
Headers, Y pipe, and muffler eliminators are good for about 70 HP. The TPIS ones are really easy to install and come with the Y pipe.

:w

WOW! Seriously? I have been curious where I'm at for hp. I have a similar set up as stated above but have magnaflows. I wonder where that puts me? :cool
You're making me want to dyno the car!!!!!
 
87blackroxi said:
WOW! Seriously? I have been curious where I'm at for hp. I have a similar set up as stated above but have magnaflows. I wonder where that puts me? :cool
You're making me want to dyno the car!!!!!

Those numbers are guesstimates from some reputable sources ... Mad-Mic

With the mufflers probabally 20-30 HP less.

:w
 
Hrtbeat1 said:
Those numbers are guesstimates from some reputable sources ... Mad-Mic

With the mufflers probabally 20-30 HP less.

:w

Still not bad!
 
Hrtbeat1 said:
Headers, Y pipe, and muffler eliminators are good for about 70 HP. The TPIS ones are really easy to install and come with the Y pipe.

:w

Im planning on getting some TPIS headers this winter. What's the difference between long and short tube headers? I really wanted to do the muffler eliminators but couldnt. I did take my mufflers off like a few suggested and it sounded great. Really loud but great!
 
jimmers said:
Im planning on getting some TPIS headers this winter. What's the difference between long and short tube headers? I really wanted to do the muffler eliminators but couldnt. I did take my mufflers off like a few suggested and it sounded great. Really loud but great!

Short tube headers are more like exhaust manifolds than real headers. The long tubes definitely flow better so they give you more power.

The problem with the stock exhaust system on an L98 is that each muffler only flows through one outlet.
 
Edmond said:
Short tube headers are more like exhaust manifolds than real headers. The long tubes definitely flow better so they give you more power.

The problem with the stock exhaust system on an L98 is that each muffler only flows through one outlet.

That's why we put those true duals on right? ;)
 
87blackroxi said:
That's why we put those true duals on right? ;)

Like Lenny Leonard would say, "You know it!!!":L:L:L Plus, the stock ones are so quiet.
 
Thanks for the replies everyone. Im really looking forward to when i get some headers. Should be real fun!
 
Hrtbeat1 said:
Those numbers are guesstimates from some reputable sources ... Mad-Mic

With the mufflers probabally 20-30 HP less.

:w

:w you are correct! but that was with some supporting mods, K&N open air box, MAF descreened, TB Bypassed, 160* T-Stat, Accel Super Coil, 12* degree advance timing, TPiS Long Tube Headers, !Air, !EGR, dumps off rear Y pipe.

the car dynoed hot on water temp at over 220 degrees and blew the egr feed into #8 cylinder. just by the water temp being HOT i left a good 20+ rwhp and 20+ rwtq on the table and probably another 10-20 each from the EGR blowing and having absolutley no backpressure on # 8 cylinder. at around 3600 rpm you can see a sharp down spike on the dyno sheet from the EGR letting loose. i am positive if the car was cooled down to atleast 160 water temp or lower and the EGR didn't let loose she would of pulled in the 270 rwhp range and about 370+ rwtq range. AF was a cool 12.9:1 ratio :D

DSC00586-1.jpg


DSC00585-1.jpg


other mods that went on after this dyno run was crank pulley +10 rwhp, air elim pulley +10 rwhp, cut back plugs gapped at .047 indexed +10rwhp, and a bit more timing :D

here is a vid of what my car sounds like now with the muffler chambered elims from MAD i bought.

http://www.corvettekillstories.com/photogallery/albums/Mad-Mic/Racing/Sweet_Sin.wmv

hope this answers your questions as to whats being held up by the stock exhaust.
 
Does TPiS make a "true dual" setup for an 89 vert. I mean no Y pipe, but two Random Tech cats, back to some good mufflers, like Borlas, or Corsas. I like the sound of Flowmasters, but hate those skinny 2 & 1/2" tailpipes. Someone on here mentioned getting Flowmasters w/single center outlet, then welding on ZR1 tips, but can't remember who it was. Sure looked good though. Anyone wanna kick in here about the elimination of the two y pipes, since essentially that's what we seem to be stuck with? All replies appreciated. TIA

Rich K
 
thirdtimevetteowner said:
Does TPiS make a "true dual" setup for an 89 vert. I mean no Y pipe, but two Random Tech cats, back to some good mufflers, like Borlas, or Corsas. I like the sound of Flowmasters, but hate those skinny 2 & 1/2" tailpipes. Someone on here mentioned getting Flowmasters w/single center outlet, then welding on ZR1 tips, but can't remember who it was. Sure looked good though. Anyone wanna kick in here about the elimination of the two y pipes, since essentially that's what we seem to be stuck with? All replies appreciated. TIA

Rich K

best bet is have a local shop do it for you. hardest things is finding someone that will do it because of regulations.

i got a guy in baltimore that is doing mine. off the headers i'm going with electric cut-outs, then bullet cats, X pipe straight back to old Y area with an H pipe to mufflers. :D
 
Thanks Mic,
So, it will be duals all the way back w/the setup you described, right? Isn't there a certain place where the H pipe should be installed? I've seen it mentioned about painting the pipes, and then where it burns off, is the spot, usually in the vivinity of the cats. If that's correct, won't your H pipe be back too far? Or aren't you worried about resonance, like me? Thanks for your help, as always.

Rich K
 
thirdtimevetteowner said:
Thanks Mic,
So, it will be duals all the way back w/the setup you described, right? Isn't there a certain place where the H pipe should be installed? I've seen it mentioned about painting the pipes, and then where it burns off, is the spot, usually in the vivinity of the cats. If that's correct, won't your H pipe be back too far? Or aren't you worried about resonance, like me? Thanks for your help, as always.

Rich K

the X pipe will be up front where the 2 bends come together to travel down the tunnel and approximatly 16" of the rear split is where the H goes.
 

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