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Anyone doing IRS ever use Saab 900 front uprights?
erbieb02 - 2/8/05 at 01:25 PM

Hello

I am in the design phase of my project and need to decide on some uprights for my four wheel independent suspension before I can move further.

I have taken measurements of some older Saab 900 (back before they went to a MacPherson front setup) and think that they would serve well. The steering knuckle could also be used to provide some passive rear steer.

If not Saab parts then I will probably use the uprights from a Mazda MX-5. Anybody have access to a miata/MX-5's uprights for measurements?

Any ideas?
Eric B

jestre - 2/8/05 at 01:31 PM

I don't have the MX-5/Miata parts. but quite a few people are using them.

britishtrident - 2/8/05 at 02:36 PM

The old SAAB 99/90/900 suspension was based on old Triumph experience --- Triumph did a lot of sub-contract design for SAAB in the 1960s.

However I am not sure how good an idea it is to adapt a front suspension for the rear, a few people have done and ended up cursing the descision, the MX5 is a better rear end donor.

[Edited on 2/8/05 by britishtrident]

erbieb02 - 2/8/05 at 04:05 PM

Hello

Jestre, I see that you went with the Maxda RX-7 motor for your build. At least is how I interpret your having a stripped RX-7 in your garage. What did you use for your uprights?

BritishTrident, anywhere to look to see these horror stories, I'm just curious about what does commonly go wrong. I can see strengh issues due to the neceisisty for using a tie rod to keep the wheel straight. What else have you found.

jestre - 2/8/05 at 04:56 PM

i'm going to modify the Mcpherson struts that exist on the 1st gen rx7.

info is here:
http://locost7.info/files/suspension/McPhersonStrutMod.zip

britishtrident - 2/8/05 at 06:23 PM

quote:
Originally posted by erbieb02
Hello

Jestre, I see that you went with the Maxda RX-7 motor for your build. At least is how I interpret your having a stripped RX-7 in your garage. What did you use for your uprights?

BritishTrident, anywhere to look to see these horror stories, I'm just curious about what does commonly go wrong. I can see strengh issues due to the neceisisty for using a tie rod to keep the wheel straight. What else have you found.


Mainly been the expected bump steer issues usually because of difficulty providing an anchorage for the track rod in the right postion.

erbieb02 - 2/8/05 at 07:43 PM

Jestre, not to shabby. Certianly an option that I will keep avaliable.

Bump Steer, ah-ha, forgot about that. Would have seen it in the design phase but better to remember now. With the Formula SAE cars I helped build we did use an upright with a tie-rod to keep the wheel straight ahead, but it was on plane with the bottom A-arm so did not induce any bump steer.

Passive rear stear is out though, oh well. Ever hear of anyone doing four wheel steering on a Locost?