New LS1 Owners - Newbie Tech - 2 Cutouts on the Y-Pipe

Guys-

My friend insists that dual cutouts on the Y-Pipe is better then a single one on his '99 WS6. I think he's just wasting money on a second one. Who's right?

if you dont have enough pressure pushing out (ie enough HP) its pointless to have two. some of my friends have two with there qtp headers and y pipe but they are pushing over 500 hp so for them it might be necassery but for a slightly modded car you might loose hp from no back pressure.

if you dont have enough pressure pushing out (ie enough HP) its pointless to have two. some of my friends have two with there qtp headers and y pipe but they are pushing over 500 hp so for them it might be necassery but for a slightly modded car you might loose hp from no back pressure.

that's what I was thinking, I had imagined that there would be very little difference in flow numbers when comparing one to two cutouts, and I wouldn't want to waste the extra $100 or so from the QTPs.

We believe that one cutout is all you need. Street Pro ran a dyno test on a 2003 stock C5 Vett using only 1 cutout on an otherwise duel system. We showed NO drop in HP by installing the 1 diverter of 3" size and then showed a gain of 24 HP by opening the cutout. The shop doing the work said there was nothing to gain by using 2 cutouts. The car was stock except for having the LS1 edit done. If you want to see the installation, go to www.streetpro.us click on "Products" then click on the small corvette photo next to "C5 Street / Strip Diverter". You can see more applications, including a duel set up on a 700 HP pickup, on the "Customer Photos" page.

yea i think it would be a waste to get two.. b/c i was askin the same thing b4.. and im only pushin stock HP on my t/a so they said just get a cutout and put it in the (i) pipe ..so i guess thats what im gonna do

any suggestions on what brand or types?

A cutout on the I-pipe won't do much. Get it on your stock Y before the cat. Go with Q-Tec if you're going electric, Flowtech if you're going manual.

so get two? ..im not pushin enought hp for all that am i? stock 2000 ws6 t/a

so get two? ..im not pushin enought hp for all that am i? stock 2000 ws6 t/a

No, get one before the cat on the Y-pipe

from what i understand the stock cats are right after the stock headers. so there is no where to put a cutout before the cat. then the stock y pipe isnt round... the i pipe is the only place to put a cutout on a stock exhaust. isnt this correct? oh, im speeking of ls1's by the way. i guess the lt1's are different?

from what i understand the stock cats are right after the stock headers. so there is no where to put a cutout before the cat. then the stock y pipe isnt round... the i pipe is the only place to put a cutout on a stock exhaust. isnt this correct? oh, im speeking of ls1's by the way. i guess the lt1's are different?

Not sure, I've never put a cutout on a stock y-pipe but I'm almost positive that there is a place for it.

yes ls1 and lt1 are very different when it comes to y pipes. the only way to get two cutouts on the y pipe is to order one like QTP or custom fab one. basically stock ls1 the best thing to do is put it on the ipipe. if you think you can fit cutouts on the stock ypipe show me a picture when you are done.

That's where my cut-out is. almost directly under the passenger side door on i-pipe before the muffler. And with the cut-out i noticed a difference in power. My best time is in sig and only mods on the car are lid and cut-out

Jon, on the LT1 you could put a cutout prior the cat, however on the LS1's the stock cats are almost directly after the manifolds (actually one of them is almost mounted vertically) so the only choice is in the I-pipe prior to the axle. That's where mine is. Also, the QTEC is an electric valve that attaches to a flowtech cutout. Barry at QTP told me that that is the actual cutout they send you with their electric flapper motor. When I get my FLP's. I will get another QTEC and put both of them in the interchangeable straight pipes where the cats would be on the FLP y-pipe. I think it'll be a little loud :D . Miracle Ear anyone?

I think it'll be a little loud :D . Miracle Ear anyone?

WHAT??!??! LOL serously. i cant wait to get mine. but since i have the borla, im going to stick it where the cutout is back there by the muff.

mike do u drive extremly well?

b/c a 13.11 seems pretty good..i have a 00' ws6 m6 stock..and i dont wanna spend to much i was thinkin about a lid and cutout like u have.. nice job on the time tho..

on the 1 cutout or 2 question...

1 is plenty for most.
2 is for people that are making big hp (FI,n2o,strokers)

but being over kill and being bad are 2 differant things... 2 IS over kill in most setup however you will not LOSE hp because of no backpressure...
(who the hell came up with that???)
the more you open up your exhast the further up the rpms you tq curve moves.
the power loss that some people have "felt" is not a power loss at all .. it is a power move...
your tq curve now starts higher in the rpm band and that is why at lower rpms it feels slugish. but it makes MORE power higher up... and most often will get down the 1/4 faster too...
the only time you truely loose power is when you move your curve into an rpm band that your motor can not spin up to....

http://www.stang.cc/tmcaalbums/album09/exhaustfinishedypipe.jpg

tha is a great looking set up :)