LocostUSA.com

Enough lurking already.... I'm ready to start a build thread.

I've been wanting to build a tube car for a while, in fact ever since I saw my first Ar-i-el At-om.

I've got some history building vehicles, just nothing built for the road. I have built several VW powered rails from zero as well as a few vehicles for offroad competitions. I will dig up some pics later and post up for reference. I know my way around a welder, tube roller, tube bender, notcher etc.

The donor car I have picked up for this build is a 1998 Pontiac Grand Prix GTP. Runs a 3.8 Liter Supercharged V6 mated to a 4T65E-HD Automatic Trans. This will of course be rear-engine,

Now I have done a ton of research here but there is a lot of conflicting opinions about a few setups etc. My first question posed to you guys is what to keep from the donor car. I want to go ahead and pull everything I need now and get rid of the car body so I have more room to work.

So far I'm thinking I need to hang onto the following from the car:
Engine
Transmission
Full wiring harness
Full engine cradle (to copy)
Existing front a-arms (to use as jig to build tubular from)
Front knuckles with brakes
All 4 wheels (if for nothing else, rollers)
Radiator
Gauge panel (possible reuse)
Steering column with ignition/starter switch
Fuel Tank and Pump/Sender

What am I not thinking of? Any input?

Now my next set of questions....
What is the most common and easiest to use/source set of knuckles to build my front suspension and steering from?
Do I go with a non-power steering? If so, what is the best rack to source? If i should do power steering, what is the best rack to source?

I know these are noob questions, but it doesn't hurt to rehash a little bit of knowledge here and there.

Here is the car as it sat at the yard, and then a shot of it in my shop finally, ready for tear down...

1/ Awesome choice, good luck, will subscribe to this thread on a regular basis!

2/ Whichever has the same PCD (wheel stud pattern) and relative ease of fitment, Chev S10 maybe? - certainly experienced people on this forum with those.

3/ You decide, going to cruise around town a lot or autocross events then I would use the power steering, high speed race tracks maybe don't need. One things for sure, power steering is the easiest way to get quick steering (as in 2 turns lock to lock).

Fuel tank and pump are very important to keep.

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The biggest thing in motocross.

Add wiper system to your list, and possibly the seats and seat belts, depending on how wide of a frame you plan on building. Dave W

Thanks for the input cheapracer... I figured it was a fun choice for motor. Not the most common for this kind of build, that's why I like it.

Looks like my lug pattern is 5x115. Here is a list of other cars that have a 5x115 pattern.... which is best to use for front knuckles you think?
Cadillac
1987-1993 Allante
2003-2007 CTS V6
1994-1999 DeVille
1994-1999 DeVille Concourse
2000-2005 DeVille DHS
2000-2005 DeVille DTS
2006-2009 DTS
1986-2002 Eldorado
1992-2002 Eldorado ETC
1985-1992 Fleetwood
1986-1991 Seville
1992-2004 Seville SLS
1992-2004 Seville STS
2005-2010 STS
Pontiac
1988-2009 Grand Prix
1988-2005 Bonneville
2001-2005 Aztek
1997-2009 Montana
Buick
1988-2004 Regal
1990-2005 Century
1991-2005 Park Avenue
1986-2005 LeSabre
1986-1999 Riviera
Chevrolet
2000-2009 Impala
1995-2007 Monte Carlo
1990-2001 Lumina
2005-2008 Equinox

I guess I can see how great the knuckles are on the car I have and will be using for the rears, and possible source another set of those for the front. Same bearings all around may be nice.

On the power steering, I'm torn. All the rails I have built I have used either a non-power Wright or Saeco rack without issue. But i plan to take this to cruise ins and romp around town in it. I never had issue with my rails being unable to steer, as the front ends were very light. What is the consensus here on power vs non-power steering? Seems like a lot of plumbing to run lines all the way to the front end.

Ah, never even thought of that. LOL. I plan to make my own tank, but it sure would make it easy if i used the stock pump and float, etc... fuel gauge may even work, eh. I will update my list at the top... thanks egoman!

I plan to use some race buckets and 5 points in it, so the bulky huge barcalounger type seats this thing has will be trashed for sure. But that would be good for a lower budget build for sure.

Check out my build and you will see that with a fuel cell if you do it right you can use all the stock fuel pump system.

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The biggest thing in motocross.

Have you checked out www.midlana.com? With a bit of a stretch, that drivetrain might fit.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Its a great power plant. Oh,and you can move things around if you want.

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American 7 5.0 T5
Lotus 15 ish?
914/H6

I was a bit brain dead reading your post and didn't realise it was a middy in which case really great choice of not just engine, but the entire wheel to wheel driveline.

Have a serious consideration for what I have done previously based on how simple it would be for you ..

viewtopic.php?f=39&t=12756

Thanks Cheap racer... I have a chassis idea in mind, used rolled tubes, but has a squared off front. I know i've seen one around on here somewhere similar to what I want to do... I will have to dig into my bookmarks and find it.

The miata community routinely "de-powers" the power steering racks in NA models even on street cars, usually looking at ~2000lb machines with engines at the front and ~50/50 distribution. With a middy around 1500lbs (or maybe less) you should have no steering issues with a manual rack. I'm in the planning stages of a middy build as well and plan to use a de-powered miata rack (mainly because I already have 2).

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im CAD hat's passt

They take a power steering rack and depower it? I had no idea you could do that... will it still operate without fluid flow? I know most cars that lose a PS pump are hard as hell to steer...

Hard to steer because you are trying to now push fluid though a no working pump when you are turning the wheel. Remove the PS lines and it steers with ease. I am also going with a depowered Mini Cooper rack on my build. Time will tell if it's manageable, but the car is a middy also and quite light so should be fine.