C5natie

iTrader: (1)

Keep my 1 3/4 headers or upgrade to 1 7/8?

Ok guys. Ive read a few threads on the matter but I wanted to see more specific results specifically dealing with a supercharged motor. Please let me know what you recommend and why. Also I'd love to hear any personal experiences. Wondering since I can sell my headers and get a good deal on some LG 1 7/8s. Thanks.


Motor and mods:
Vortech v2 si trim 8psi 610/570 to the wheels, 6500 redline
LS3, forged 10.1:1cr
LS3 heads, stock with ported exhaust
TSP cam 231/236 114lsa
LS3 intake stock
TSP 1 3/4 headers with 3in x pipe
4L65E w/Circle D 3200 triple disc converter and 3.42 gears

Silver408z

iTrader: (1)

I don't know if I would change from 1 3/4 to 1 7/8 at your power levels. You setup is capable of way more power than 8 psi and your power levels. There are c6/ls3 cars making over 800 on stock ls3's with a cam being the only internal mod. If you decide to start upping the boost and going for more power, then change headers. Otherwise I would keep it where you are.

C5natie

iTrader: (1)

Thanks for the advice. I've decided to keep my headers for now and go with a bigger intercooler and a 3.4 pulley which I already have. This should give a few extra ponies.

35th SS

iTrader: (2)

IMO your inhaling plenty air from the ls3 heads but exhaling and choking with those 1 3/4 headers.do a search youll find out in FI section.

Burken01

iTrader: (88)

I called LG about their 1 3/4 vs 1 7/8


Basically 1 7/8 are more optimized in a FI setup and will make more peak hp vs 1 3/4

But 1 3/4 will make a little more torque, he told me its a trade off..

More torque for street vs more peak for highway speeds

I honestly think its really minimal between the 2 idk

C5natie

iTrader: (1)

I thought about bigger headers because with my Circle D triple disc converter locked up, I get a little more torque down to the ground (570ftlbs). So I figured if I lost a little I'm still good with the hp I gain up top. What it came down to was the the 1 7/8 header system is about $1500 while the intercooler is $1000. The intercooler I have now is small so I will probably see more gains with the bigger cooler and the added boost from the pulley then from headers. I hadn't done the smaller pulley yet because my small intercooler was already just barely getting by. I'll see what I gain from this and the headers will stay on my next mod list.

01Z0H6

iTrader: (63)

This..... I too was considering selling my LG 1 3/4 Super Pro's for the 1 7/8's for my Stroker... bobby at LG told me the exact same thing. To me, the bottle neck is in the collector being 2 1/2 in..... The AR 1 7/8 have a 3in collector. Which is a viable option. I opted to go with the DMH 3in Electric cut outs... Problem solved....

Blackpanther99

iTrader: (8)

Go 1 7/8s

dr_whigham

iTrader: (49)

I'd go 1 7/8" beyond a doubt.

Oh wait, I did. And I haven't even done heads, cam, intake or anything yet... Numbers in sig. That's just the headers, Corsa, and a blackwing.

gamdrunk

I am debating which lg to get for my 2003 c5 with airaid Cai billyboat catback and Diablo tuner its already loud from b&b cat I am new to all this just want to make good choice . will be doing tb and intake plugs and wires thanks

Burken01

iTrader: (88)

It's subjective..

Rule of thumb is 1 3/4 for stock cube engines making less than 600hp

FI/stroker/big cubes 1 7/8 LT's

Basically 1 7/8 sacrifices some low end torque for more upper HP... In theory, it's been disproven in some combos though and has actually gained power everywhere in the power band..

Every build/car reacts different..

gamdrunk

How loud are they

dr_whigham

iTrader: (49)

Not loud at all really. Coupled with the Corsa it only "roars" at WOT. Other than that it just sounds like a catback car, but more refined (like Corsa sounds)

This is no cats as well