lose low end with new exhaust

**LT1 > LS1** · 08-16-2008, 08:21 AM

I made a thread on another forum about my car, and I said on the bottom, that I was gonna chop the cat out, and put in a 3" stright pipe.

a bunch of idiots on there said my 2.5" factory y-pipe was too big, and with a 3" I will not gain much power, and lose a ton of low end. they also said my fuel economy and torque is gonna go in the toilet!

so, who has gone from a stock to a 3" y-pipe in their car? a lot of guys right? all I have ever heard is good things about the swap......

**LT1 > LS1** · 08-16-2008, 08:23 AM

oops, can a mod please move this to "external engine"

I clicked the wrong sub-forum

**nhraformula** · 08-16-2008, 09:08 AM

Originally Posted by nitrorustler41

I made a thread on another forum about my car, and I said on the bottom, that I was gonna chop the cat out, and put in a 3" stright pipe.

a bunch of idiots on there said my 2.5" factory y-pipe was too big, and with a 3" I will not gain much power, and lose a ton of low end. they also said my fuel economy and torque is gonna go in the toilet!

so, who has gone from a stock to a 3" y-pipe in their car? a lot of guys right? all I have ever heard is good things about the swap......

if you have the stock manifolds(exhaust) still on the car, you wont gain more than 5 rwhp by swapping out y pipe. the stock manifolds are were the exhaust restriction is.

**Blackout99** · 08-16-2008, 03:35 PM

uhh i have LT's wit a 3 inch y pipe, slp catback n shits fine i also have a cam n my new exhaust set up definelty made my car faster, with the LT's ull lose a lil low end but gain on the top end

**raysz28** · 08-16-2008, 07:10 PM

So, would it be ok if i did the cam without/before doing LTs and exhaust?
i'm really looking forward to doing the cam. wont the stock manafolds/exhaust hold up to 400hp flow?
i know this will add some back pressure to the system, but wont it increase my torque because of that?

**nhraformula** · 08-16-2008, 09:33 PM

Originally Posted by raysz28

So, would it be ok if i did the cam without/before doing LTs and exhaust?
i'm really looking forward to doing the cam. wont the stock manafolds/exhaust hold up to 400hp flow?
i know this will add some back pressure to the system, but wont it increase my torque because of that?

you will be lucky to pick up half of the cams gain with stock manifolds.

just adding headers to a stock ls1 will add up to 30 rwhp with a tune, that right there is telling you how choked the ls1 is

**fxgs** · 08-17-2008, 05:28 AM

Originally Posted by raysz28

i know this will add some back pressure to the system, but wont it increase my torque because of that?

http://www.ls1.com/forums/showthread.php?t=81972

**9t8z28** · 08-19-2008, 06:10 PM

Originally Posted by Blackout99

uhh i have LT's wit a 3 inch y pipe, slp catback n shits fine i also have a cam n my new exhaust set up definelty made my car faster, with the LT's ull lose a lil low end but gain on the top end

I don't know where this myth comes from but I can only guess.

When you add LTH's, you do not loose power on the bottom end. You think you loose it because you gain so much on the top end. Its all in your head.

**BlackSS1** · 08-20-2008, 06:22 PM

Originally Posted by nitrorustler41

I made a thread on another forum about my car, and I said on the bottom, that I was gonna chop the cat out, and put in a 3" stright pipe.

a bunch of idiots on there said my 2.5" factory y-pipe was too big, and with a 3" I will not gain much power, and lose a ton of low end. they also said my fuel economy and torque is gonna go in the toilet!

so, who has gone from a stock to a 3" y-pipe in their car? a lot of guys right? all I have ever heard is good things about the swap......

Those other forum guys are just wrong. I gained more torque than HP with LTs and 3" Y. You will gain HP, torque, and even MPG with headers and larger exhaust pipes. Less restriction = more efficiency/power.

**raysz28** · 08-20-2008, 08:06 PM

So, i think the third and forth gen camaros have the same rear end setup right?
if that is true can i get a third gen cat back setup to fit my forth gen?

**LT1 > LS1** · 08-21-2008, 06:34 AM

right. I dont know 100% if it will line up with your y-pipe properly though.

the exhaust on thrid gens is located more to the passenger side skirt. the 4th gen's is located closer to the center. you are better off gettin a 4th gen one

**JwMonE99** · 08-22-2008, 06:55 PM

2.5 inch is good enough till 450RWHP

**camarojunky74** · 08-23-2008, 01:52 PM

a 3" cat back is just right for your setup, going 3" inch duals however would be overkill, maybe the guys misunderstood you or didnt understand the setup or schematic of a late model f body's system, i would recommend getting a magnaflow cat back, unlike many others that become to loud once you start modding the car, the magnaflow works just right. keeps the rasp and the loud idle down, and then at wot it screams. the tips are nice to look at as well.

**Hi-Po** · 08-25-2008, 01:10 PM

Originally Posted by 9t8z28

. Its all in your head.

This is exactly what I was going to write when I saw the thread. In your head, thats it.

Your mind will play tricks on you when it comes to 5-10 HP in certain rpm ranges!!!