Board logo

Picking a front suspension (USDM)
turbo time - 30/5/04 at 12:38 AM

I need to pick a front suspension (uprights/ discs, manual steering rack) for my middy. Needs to be a from a car thats relatively common/ cheap in the american market, and preferably something that is front wheel steering (The steering rack and tie rods are located in front of the wheel's center rather than behind it.) I would likely just buy the car and take what I need from it, then sell the rest to get my money back. Anybody have some reccomendations? I should mention that my drivetrain/ wiring harness donor car is a 1990 Turbo FWD DSM (eclipse/ talon/ laser) and is about 66 inches wide overall. So the front ought to be relatively close....although I suppose I could always shorten/ lengthen the tie rods if that were really an issue.

Also, as of now, I also have three sets of bike coilovers to choose from, I'm also looking for input on which to use: 2001 Yamaha R6, 2002 Suzuki GSX-R, and 2002 Honda F4i. I personally like the F4i since the resovoir is remote and has a flexible line running from it so that the shock body itself is more compact, and offers more mounting possibilities, but I'm not sure which will actually preform the best. I could also go with one set for the front and another set on the rear. Thoughts on this....

Thanks,
Kent

[Edited on 30/5/04 by turbo time]


Alan B - 31/5/04 at 12:25 AM

Kent, I wish I could help, as I'm interested in the answer too......

Even considering doing my own uprights for the next iteration of my own project.

Using the front of a car at the rear does leave a new front choice as an open issue....


kb58 - 31/5/04 at 12:52 AM

I'll ask the obvious, why not use 1990 Turbo FWD DSM uprights? Front vs. rear steer issues are easily solved by moving the uprights to the opposite side...

[Edited on 31/5/04 by kb58]


Spottty - 31/5/04 at 03:04 AM

I think kb58 has a good point. It would keep the same parts for brakes all around when its time to change them. It would also keep the same bolt pattern and offset for the rims. If you get into custom offsets they start to get really expensive.

My buddy works at a tuning shop and some guy ordered rims for his scratch built lambo replica and the custom offset made the rims about $1000/rim!!!

The only thing I can think of is a S10 truck. But I think they are pretty bulky.


TheGecko - 31/5/04 at 05:29 AM

Just to be difficult, I'll both agree and diasagree with kb58

I think using another set of the same uprights has a lot to recommend it. You have the same stud pattern and offset without any extra work; you have identical brakes front and rear , removing that variable from any brake bias calculations; any work you do to make strut to wishbone adaptors is usable at either end.

Downsides: you need to make adpators frum strut to wishbone; you need to convert driven hubs to un-driven (not too hard - check the front end of an MR2).

The disagreement? Swapping the hubs left-to-right might solve the front-steer/rear-steer issue but potentially introduces some Ackerman angle problems and still means finding an appropriate rack. I originally designed my chassis with the intent of using Corolla FWD hubs in the front with a rear steer rack. Now that I'm using front steer nothing much changes except that I've got more clearance at the back of the front suspension box. I was never going to put my feet in amongst the front wheels - the human ankle is NOT a crumple zone!

My approach? I'm using FWD Corolla running gear in the back of my middy. At the front I'm using Holden Gemini (Chevette in the US). These are wishbone, front steer, and same 4x100 PCD as Corolla although different offset (+20 vs +38). I've picked up a set of wheels in RWD (+20) offset which will fit the front uprights perfectly. The resulting extra 36mm of track at the back won't hurt things.

Hope this gives some food for thought.

Dominic


giel - 31/5/04 at 02:19 PM

"Swapping the hubs left-to-right might solve the front-steer/rear-steer issue but potentially introduces some Ackerman angle problems"

Swapping left-to-right will give Ackerman problems for sure, because the outside tire will turn more than the inside. You will have to modify the track arms (pointing them outward) to prevent excessive tire scrub in turns.


derf - 31/5/04 at 02:53 PM

s10/blazer/sonoma/jimmy running gear is good for what you are looking for. I have a set, that I bought for 250 from the junkyard. All they really need are a new set of pads (which should be a mandatory job anyway). Yes the front uprights are slightly bulky, but from looking at them it shouldnt be to much of a task to "remove some weight", and not lower the strength of the uprights. Just dont go too crazy. They are way over engineered for being light duty truck parts.


derf - 31/5/04 at 02:54 PM

I meant $250 with a rear axle.


turbo time - 2/6/04 at 01:41 AM

Hey, Thanks for the replies everyone. This gives me some important info to go junkyarding with. I suppose I'm off to the yard tomorrow to have a look at some S10 components. I'll also keep an eye out for any other promising donor cars.

Hmm...if only the Starion/ conquest came with a non-power steering rack (It's that horrible recirculating ball system too), then I could keep mitsubishi OEM parts all around the car, oh well.

-Kent


violentblue - 2/6/04 at 02:57 AM

SAAB uses a double wishbone suspension with front wheel drive, and get this, E-Brake is to the front wheels.

but the brakes you have avaliable might be somewhat lackluster


derf - 2/6/04 at 12:03 PM

Keep in mind that it took me 3 weeks of calling every junk yard within 200 miles of my house before I got a price I could stand, and the parts were in a decent shape. I got a few prices that were better, but not all were in good shape. The cheapest quote I got was for the front spindles, no brake hardware, and a bent rear, cost $50. And I spent alot of time running around inspecting parts too.