A co-worker has a 2008 Impala SS and due to construction in the area he has to take a long route home which just happens to be the same way I go home. As we were leaving work yesterday I followed him and knowing we would get a chance to line them up just for the hell of it.

We pulled up to a line with me behind him, right lane was occupied but no one in front of us (who puts a stoplight on an interstate? honestly?)

The light turned green and he took off pretty slow (he told me today he just didn't want to deal with wheelspin) and I sat behind him in first waiting for him to hit it. He went WOT at about 20mph and as soon as he moved I hammered it... hit 2nd and couldn't pull on him at all... since the other lane was open and clear I moved over and shifted to 3rd... after hitting 3rd I started pulling like crazy and ran right past him shutting down after running through 3rd with him a couple lengths back.

He expected it and when I came into today he told me he thought I was just sitting behind him to be an *** and then finally just passed him. LOL When I told him I honestly couldn't gain on him through 1st and 2nd he didn't know what to think. I must say the LS4 moves out like crazy..I was very impressed. After looking at some track runs of stock LS4 cars they seem to be running high 8s in the 1/8th at about 80mph but ending the 1/4mile around 100mph... looking back at my last track outing and I guess it makes sense but still frustrating as I was hoping to pull the entire time.

Ah well.. at least I got in a friendly run so I know how well an LS4 runs.

 

Nice run...but I think if you two lined them up and then took off, then you would get more of the pull that you expected, even if its not much. He did get a tiny jump.

Those LS4's are cool cars...maybe they will be back in the near future.

 

I was thinking those impala's were slow, I used to always see a riced out one in billings, riced out as in aftermarket hood and racing stripes and smoked lights chrome autozone looking wheels, and a few other things, loud exhaust... anyway I always figured his car was slow.. which it was, i've seen him hit the gas but I guess it isnt as bad as I thought it was.

 

I think it was combination of things that helped him hold you off for a few seconds. One, the fact that it was from a roll, two, he got the hit, and three, he was most likely smack dead in the middle of his sweet spot. Sounds like those Impalas are geared pretty aggresively down low, but with a high ratio up top for cruising. Still, I'm pretty surprised he was able to hold you off like that. Good run s8er.

 

http://www.youtube.com/watch?v=rEe8p...eature=related

A hit from about 20 would be right in (or just below) the sweet spot of first it looks like.

 

That explains a lot!... btw the video displays this pretty well but the massive pull I had apparently occurred just after I went to my 3rd gear and he (coincidently) hit his 3rd gear... you can see the acceleration in the video fall into the toilet.

With reports like this popping up....
http://www.ls1tech.com/forums/14778544-post10.html
2008 Grand Prix GXP - 13.88 @ 100.43 MPH -Magnaflow Exhaust

It's clear that GM was on to something but screwed it up (again) with a horrible trans/gear combo. A 5speed auto or just a more agressive 3rd gear and they would probably be hammering mid 13s and higher traps with no issue.

 

Dang, those things must be a surprise in the light to light crowd with that low gearing. On the other hand it must be a disappointment to them when it falls flat up higher.

 

I want to know if their aftermarket for the ls4 in that car is as big as the 3800 series engines...I don't think there is a selection like the other lsx cars just because there aren't that many ls4's.

For a 30 grand car though, the Impala SS has a plain interior.

 

As far as the LS4 itself goes... LS4 shares many many parts with LSx so modding the engine isn't a huge deal.... in individual applications some things are pretty limited.

2007 Grand Prix GXP, Modded CAI Intake, 85mm MAF, LS6 Intake Manifold, 42# LS3 Injectors, New Era G8GT High-Lift DOD Cam (Modded Timing Gear, "Lots" of Advance), PAC 1218 Springs, Trickflow 7.45" Pushrods, Doug Thorley Headers (w/Custom Crossover Pipe), 3" Exhaust to 3" Cutout, TEP Transmission (Hardened Input Shaft, 3.29s), HP Tuned by Me.

2006 Fully loaded GXP.
Custom cam 218/222@.050" 113L/S .595/.601 lift, DOD delete, Ported LS6 intake, Conceptual polymer catch can, 243 Milled heads=10.25:1 with back cut valves, PAC springs, Hi-Tech 7.450" molly pushrods. DT headers into 3" Magnaflow exhaust,CAI intake. Lew tuned engine and HP tuned transmission with a TransGo shift kit. 12.71@109.95 1.913 60ft

http://www.ls1tech.com/forums/ls4-pe...t-cam-ls4.html

One look at this and I would say FORGET IT and just leave it stock.

 

I like that GXP....but FWD is tough to launch. That OP is local, though..kinda cool, might run into them at some point (doubt it but eh).