Alignment specs?

aroot1

SCCoA Member
Just rebuilt/replaced just about EVERYTHING in the suspension of my '90 XR7. I used a set of used Eibach springs sourced from a member here. I did not measure ride height before, with the broken pigtail stock springs :rolleyes: I also changed to 18's with 245/45 s at all 4 corners (slightly shorter than stock 225/60-16's). I made sure to tighten everything with weight on the suspension, but it still sits like a 4X4. Does Eibach make a stock ride replacement spring for SC/cougars?

I have the factory manual with stock alignment specs. Is there anything that needs to be to a different spec on a lowered car? My priority's are 1 tire life/wear, 2 performance, 3 road noise, in that order.

Thanks

Adam
 
The springs will settle in a bit, not sure if it will be enough of what you're looking for though. Also bear in mind that the shorter sidewall profile and larger wheel diameter creates the illusion that the tire to fender gap is larger than before with the stock wheels.

Also, I'd recommend against those aggressive alignment specs. In my experience they will just eat the insides of your tires for no good reason. First tried those settings when I put 17s on the car with Eibachs, killed tires quickly. Ended up dialing things back very close to stock settings and it worked just fine. The MN12 suspension design has enough camber gain with the SLA front and IRS that you don't need a bunch of static negative camber. I did some track days with mine as well, and it didn't wear the outsides of the tires from not having enough camber.


cheers
Ed
 
As far as recommended specs go, this is what I would suggest:

Front:
Camber: Negative 0.8-1.3 You can go further, but you'll start wearing the insides of the tires. I typically prefer mine at ~ -0.8-1.0.
Caster: Positive 5.0-6.0
Toe: Positive .05-.15 On a autocross car, you can go slightly negative, but you'll give up stability at speed. I keep mine at ~ +0.1.
Cross Camber: As close to zero as possible.
Cross Caster: 0 to -0.3 Going negative helps on crowned roads, but will cause a slight drift to the left otherwise.
Total Toe: Positive 0.1-0.3 Once again, this is for a car you'll be driving on the street. If it's an autocross car, a little negative toe will help on turn in.

Rear:
Camber: Negative 0.5-1.0 Same as the front, you can go further, but you'll start wearing the insides of the tires. Also keep in mind that as the rear squats, the camber will tend to go further negative. I like mine set at ~ -0.5.
Toe: Zero to +0.15 I'd lean toward +0.1 on both sides with Delrin LCA bushings and toward zero with the stock LCA bushings, as they'll allow an increase in toe when under power.
Cross Camber: Same as front. Keep it close to zero.
Total Toe: 0-0.3


These settings have worked well for me as an all-purpose alignment (drag racing, corner carving, and highway cruising) on this chassis without any real adverse effects on tire wear. If the intended use was autocross-type events only, drag racing only, etc., I'd set things a bit differently. These are just my recommendations.
 
Well it's off to alignment shop 2 morrow. Guess I should have mentioned this, but just didn't think about how it may affect those answers. I installed a full set of DLF's rear knuckle bushings in MK VIII lower control arms which eliminate the tow links. Does that change the rear specs any?

DOH! Sorry Rod, just reread your answer, and you were already on top of it.
 
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