jim_tucker

ok so im new to w bodys but have been playing with lsx engines for a couple of years. i have 06 impala ss and at this point all i have done is intake and tint. over the next month or two i plan to put headers, downpipe (w/ cat) because the county i live in its illegal to mod your car in anyway... it sucks haha and a magnaflow exhuast and a tune from someone i dont think any of you have used here but is big with silverado ss and trailblazer ss, blackbear performace.

my question is around where will i stand with fwhp? and what kind of 1/4 mile times can i expect? also will rockers really make that much of a difference on these cars? im just nervous about breaking into the engine and breaking my extended warranty.

thanks for all the input - jimmy

94ss06gxp

iTrader: (5)

first off welcome, next with the doug thorley headers you DO NOT need a down pipe so just a weld in highflow cat will do just fine, next is the magnaflow catback is pretty pricey about $700 ish is what i have seen them at, and a tune is awesome for sure, with all of that i would look at a LS6 intake manifold but that might be too much with that waranty. so i would budget around 1500 for all of that. BUT exhaust wise i would buy the mufflers you want and have a shop make a system for you, should be much cheaper, also i would recommend a exhaust cutout. anything else i missed im sure someone will also chime in. 1/4 mile times will vary depending on track conditions, elevation etc. i ran a 13.98 with over half a tank of gas bone stock/w exhaust cutout, on street tires, my elevation is really really low. ive seen anywhere from 13.7-14.3 in stock form, with these mods you will be mid 13's.

Red06SS

If you are 100% sold on the magnaflow system, this seems to be the cheapest place around. Setup for my 06 monte was 616 shipped.
http://www.performancepeddler.com/

AlabamaGuy

iTrader: (5)

I would rather pay for a shop to build me a 3" system. That's just me though.

Nick_Nasty's_GXP

iTrader: (4)

Reducing heat in your engine bay will also reduce your 1/4 mile times. Wrap your intake tubing and crossover pipe and you should be set for that.

2005gxp

i am slowly making my own 3" exhaust, bought a piece of 3" pipe and 2 90* bends so far, and i have a pipe expander so life is easy, i would suggest that you could get he 3" system made alot cheaper

tmichelena

I just put the Magnaflow kit on Saturday. Awesome. It is, however, only a 2.5 inch and is not a 3. Not sure of the pros/cons to that. On the flip side, the tubing is mandrel bent. So, that allows for increased flow.

Thanks,
Tom

06ImpalaSS

Are you guys saying you have a 3" system all the way to the mufflers or to the y pipe??

AlabamaGuy

iTrader: (5)

Most do 3" into 2.5" at the Y. I have 3" dumped under the rear bumper. No tips.

monte_with_a_LS4

iTrader: (4)

i still havnt seen pics of this AG! lol

DavidGXP

iTrader: (14)

A custom 3" exhaust will make an even bigger difference with headers, due to the 3" collector. This set up will build a broad torque curve. If your planing on keeping your stock exhaust manifolds then going 3" is pointless. The rear outlet of your stock exhaust manifold outlet is only 2 1/2". The 3" down pipe only makes a little bit more power. Not from it being 3 inches but from it not being as restrictive as the stocker. I would also recommend going custom. Get headers first and then finish up your exhaust with a High flow cat with a cut out, or go 3" into the split, exiting into dual 2 1/2"
To answer your question about power gains with just a exhaust and intake ( tune) You should be looking at 260 ish at the wheels with a 102mph in the 1/4.

AlabamaGuy

iTrader: (5)

When the new springs come in I'll take some pics of the lowered ride and get some of the underbelly.

jim_tucker

thanks for the help guys i think im going to do rockers and put the headers off until later because mods that cant be seen are better than ones that can when it comes to warranties. i have a exhaust shop that made side pipes for my silverado ss a few months back and ill call them up about putting something together for the new car. also anyone here spraying? i know chevys love nitrous and i was wondering how it was working for you all.

monte_with_a_LS4

iTrader: (4)

alright sounds good. im getting aligned on saturday so then i will beable to put my black wheels back on and it will be time for pics also. shell be lookin good again.