Steve.H I have Koni ? too(UPDATE!!!)

racerx

racerx

Autoxer
Steve I too have a question about Koni shock’s.
First let me tell you about my car I have an 82 stock engine stock trans no bumpers if I had guess it weighs 2000/2100 pounds tires yokohoma A048 (SRF) 185/60-13 on all 4 CD91 wheels air pressure 40psi hot on all 4
Koni’s front and rear
Custom height adjustable coil over
450# front
350# Rear
No sway bars front or rear
Now for camber and tow
I had the front at 2.25 camber tow 1/8 total out- rear camber stock at 2.25 tow 1/8 total tow in. the rebound on the shocks are set at ½ on all 4 now at the last Autox with this setup the car has a lot of oversteer.
Every thing else benign equal if I change the front tow to 1/8 total in camber 2.5 put the front shocks to full hard and leave the back alone I’m I handed in the right direction?
Is there anything I can do different to help reduce the oversteer?
Should I do something different with air pressure?
I’m going to an autox this weekend and willing to try any suggestions you have.

Thanks
 
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One thing comes to mind...

....those pressures sound *really* high for A048s.

I've running the same SRF takeoffs as you except that I'm running the rears (205s) too. Haven't had 'em on the track though, so no direct experience-- I'm running mine at ~30 psi on the street.

However, I have run tons of miles in Elises on tracks and there the A048s like tons less pressure than you're running.

Again, no direct experience with auto-x on A048s but if it was my car I'd drop the tire pressures at least 10 pounds and start over from there. IIRC, the Elise likes 23/26 cold and it weighs just under 2k on my scales. I'd start at 26/28 and play around from there.

Surely Steve will have some better input but thought this might help. Worth every penny you paid for it. ;-)

Hope you'll post your findings. Would be interesting to know how you solve this.

///Mike
 
Some answers

First, Mike is exactly right. You are too high on air pressures. Below 30 on the 048s for sure.

I would prefer to know how the car is after loweing the air pressure but.... I am pretty sure that your oversteer is coming from the front toe out and the lack of front spring rate. You need more front spring and set the front toe at 1/8 total toe in.

X1/9s really don't like front toe out at all. It makes the car loose in transitions. And they need a lot of front roll stiffness. Overall, you are a little too soft with 450F/350R and the car could easily be rolling onto the bump stops and compounding the problem. I would recommend putting the 450s on the rear and getting a set of 550 for the front. Or possibly 600s. Assuming you don't drive the car on the street that much.

If you can't do that by this weekend, at least toe the front in and dial the front struts full stiff. That will help some.
 
I will

Set the front tow 1/8 total in and front shock to full hard.
I was thinking of changing to 550# front 450# rear anyway so as soon as I get the beget I will get the 550# and put them on the front .I do street drive a lot so 600# will be to much for me.
As for air pressures when I ran 32 psi it would go right on to ware the red straw is pointing ( take a look at pic ) isn’t that to far? At 40psi you can see how far it would go with the white still showing just above the line that the straw is pointing at.
The line the straw is pointing at is suppose look like the double line just below it but as a singl line it got ruined from racing on it at 32 psi so is that ok to be that far on the tire side wall?

Agene thanks for all your help

bill023.jpg
 
That's OK

The O48s should roll to the edge of the tread cap but not beyond. At least part of the rearson for that much roll is the excessive body roll from the low spring rates.
 
Toe-in

Question-- when technical manual gives a spec for front toe-in, is that a TOTAL amount or a per-corner amount?
 
Bob Shutan said:
Question-- when technical manual gives a spec for front toe-in, is that a TOTAL amount or a per-corner amount?
Click to expand...

I am not sure. I would have to see the document. Its been a long time since I read the alignment specs in the factory service manual.

Basically, I don't care what the factory spec is. I know what works and use those settings.
 
it's

the technical manual specs are toltal not pre side .

Bob if your still not shure thats the answer why don't you call Autosprint .

Steve correct me if I’m wrong when you said “I don't care what the factory spec is. I know what works and use those settings.”

That’s for racing not for a car that’s for street only .for a street only car go with what the technical manual gives as spec.
 
racerx said:
Steve correct me if I’m wrong when you said “I don't care what the factory spec is. I know what works and use those settings.”

That’s for racing not for a car that’s for street only .for a street only car go with what the technical manual gives as spec.
Click to expand...

Nope. I align my '74 street car to my "street" specifications. Which probably arn't too far off the factory spec. I am not objecting to the factory specs because I don't know what they are. I know mine work great on my car and every other X I have done.
 
Street specs?

Which street specs are you using? I've got conflicting numbers from my sources. Are you quoting a factory manual or one of the aftermarket repair manuals?
 
well

The new settings helped ( front 1/8 total in front shocks full hard ) but my over steer didn’t really reduce until I put the rear tire presser to 40 psi . I want to reduce it some more so when I get some money into the race budget I will get 550 # springs for the front and put the 450# in back.
For now will it help to put the rear shocks to full soft ?
 
Steve Hoelscher said:
...
X1/9s really don't like front toe out at all. It makes the car loose in transitions. ...
Click to expand...

Is this generally true with all mid engine cars? I have a 2005 MR2 with the TRD suspension kit that feels loose in the transitions. Currently I have zero front and rear toe set.
 
spiggs said:
Is this generally true with all mid engine cars? I have a 2005 MR2 with the TRD suspension kit that feels loose in the transitions. Currently I have zero front and rear toe set.
Click to expand...

Yep. Every one I have played with had this characteristic.

Incidentally, I love the MR-S. Very nice car. If only it wasn't SO ugly.
 
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