bfurches

iTrader: (12)

Putting together a LS4 Grand Prix and figured this would be the best place for the build thread to land.

Even though I primarily build RWD stuff, I have always had a thing for the W-Body cars. Actually, my daily driver is a 2008 Dark Slate Metallic GXP, and I have a 2005 Supercharged Monte SS for my wife.




A little over a month ago, I came across a decent deal on a 2005 Black Cherry Metallic GXP that needed a transmission. Overall the car was pretty clean, it had an aftermarket hood and a few little goodies.





I have been basically undecided since I bought the car as far as what I wanted to do with it. I have a few good friends that work with me regularly that really want to get their feet wet with racing, so we came up with the idea that we are going to turn the car into a street/strip project. I am going to handle all the major fab work late nights and Sundays while my two friends help out with all the tedious prep work throughout the week.

There are a few standing w-body records that are fairly impressive in the 3800 world. Quite a few really fast cars came from Ed Morad, Bob Cook, Zoomer and etc with the same chassis. Were going to see what we can do to be competitive and set the bar. At the very least we will have a lot of fun trying!
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Here are a few pics from the past weekend. Nothing major; we started stripping out he interior to perform a few chassis mods and pull a bunch of weight out of the car. It will still have an OEM interior appearance, but a lot of things are getting tossed.




I will keep a detailed list of what we remove and the weight for any of you in the future looking to do something similar.

blkchevyz

good luck on the build

91parkave

iTrader: (4)

Good to see a old 3800 head I've been around d since 06 so all those names are very familiar.

I would say I'd start with 97-03 body and run that since all the ls4 subframe **** will bolt right up. But I suppose the 04 and up can be lightweight

rottonj

iTrader: (4)

Good luck. You are close to me, I'm in Enfield. Update this post as often as you can. Thanks

bfurches

iTrader: (12)

Thanks guys,

I think I can get this one where I would like it to be weight was. Curb with the LS4 isn't too bad to begin with fortunately.

Oh no kidding? Are you friends with Bonneville Bill? haha. He seems to know just about anybody even remotely w-body related.

Feel free to stop by the shop anytime.

rottonj

iTrader: (4)

Actually yes I am, he stopped by to take a look at my daughters blown motor in her GTP. He just bought a new Audi, he seems to be giving these cars a rest, for now anyway. Let me know what you pull from that car. I don't really need anything but you never know. Thanks

05GXPjake

Holy weight reduction, Batman!!!

In all seriousness, I look forward to where this thread will go

higsy

I think the first thing you should do to lose weight in that car is to get rid of that hood. Lol. The color is a perfect match for my car if your ever thinkin of getting rid of it. Haha

GXP25

iTrader: (3)

higsy doesn't know what he's talking about.

Send it my way instead.

bfurches

iTrader: (12)

You guys are funny! I usually am not a fan of body/ aero mods, but I really like the hood. Kinda makes the car look like a baby G8 haha.
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On a side note...we figured something interesting out this evening. The TBSS 90mm Truck Intake fits flipped with a little bit of work. More on that to come, but here is a teaser

spawne32

iTrader: (2)

well of course it fits flipped, all of them do lol even the fast manifolds, its when you flip them around the other way that you have problems lol

91parkave

iTrader: (4)

Good luck clearing the power steering and fuse box. I've modded the suction on my pump to clear the back end on mine. Clears the hood fine though. You should defiantly poet it out though. This truck intakes flow a shot ton. But have distrubition issues with airflow.

dezldave961

Check out "jamhoney" from ClubGP (can't believe I remembered his name). He did a big weight reduction breakdown on his 2004 GTP Comp G about 10 years ago, and got it to low 11's with a full compliment of ZZP upgrades to his 3800 S/C. The car not only had good HP, but was track-prepped like crazy to maximize ET potential.

11.23 @ 120.8 1.68_jamhoney_|XPZcam|zS3Hds|2.55|S3IC|Wizair|85MA F|95oct|Slicks|<#s|togXHdrs|65inj|zzpPCM|50ft
(<#s = weight reduction... 50ft = elevation at track)

Here's a quote from a 3800Pro post, since his ancient website seems to not exist anymore:
http://www.3800pro.com/forum/weight-...tion-list.html

ramairetransam

iTrader: (18)

all right , i used to be big into the 3800 world . I had a 04 dale jr that was cam , headers, s3 ic, fuel rail , injectors , 2.7 pulley . I ended up running a few 13.0 at 107 . It was my daily .

My wife drives an 05 impala ss . 3" catless downpipe, wizair, tune .

Im looking forward to this build .

bfurches

iTrader: (12)

I guess I should have been more specific. I was more impressed with the fact I could shut the hood over the fact that is bolts up in the traditional orientation haha.

We have made really good power on some of our turbo builds with the TBSS manifolds. I don't believe they are as bad as the earlier manifolds internally. Plus, boost is the great equalizer...somewhat negates any distribution issues.

Thank you very much for the information. I will be sure to sit down and take a look later today.

Thanks!
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In regards to the intake manifold selection:

Some things that are dead giveaways right off the bat....power steering pump and fuse box are direct interference as mentioned above. Also, alternator bracket interferes with the modified rear fuel rail.

-Fuse box is not a big deal, I have no problem extending the harness and relocating it which I planned on doing anyways to clean up the engine bay.
-Power steering most likely will be installed where the AC Compressor is now. We can live without the AC for a more strip oriented, limited use combination, however I really want to retain the power steering with any decent sized front sticky.
-I am going to pull the alternator bracket off and machine a lower profile aluminum piece. Absolutely no reason to have that massive cast piece hanging off the side of the motor taking up space.

The biggest reason for taking on this portion of the job is packaging as well as creating a more fluid line of travel for the airflow. The largest draw back to the turbo kits offered for the LS4 is the way everything is packaged in the drivers side nose area. You are fighting exhaust crossovers, inlet pipes, charge pipes and throttle body. These engine bays have enough problems with heat soak. The last thing you want to do is induce more by stuffing the crossover directly below the throttle body/ charge pipe in addition to trying to snake a downpipe out the back.

In my opinion, the effort it takes to make the intake work is far worth the benefits of having a more dynamic flow path and should really help with reducing inlet temps at the throttle body.

91parkave

iTrader: (4)

This will literally be just like fbody 3800 intake swap when guys go turbo

bfurches

iTrader: (12)

Exactly! In my opinion, its what these cars really need if you plan on running big boost.

Hell, I would have loved to run an Edelbrock Pro-Flo intake...but it's just not worth it with the additional weight and the heatsoak.

Hell, on the Caprice the Holley Modular Mid Rise was 40 lbs!

91parkave

iTrader: (4)

I really want to verify if we can or can't use the 4t80 trans. The only limiting factor is the block hitting the trans due to its sheer size difference. But again this has not been verified. Just passed from turbocharged400sbc (james) not sure if your familiar with him.

spawne32

iTrader: (2)

doubt it, even with a visual comparison you can see where it would hit in several locations.

91parkave

iTrader: (4)

People said the same about the 3800 until they tried. I don't doubt it probably would be a no go. But it'd be good to have it verified you know