97 M3/4/5 running in STU

[Fair!]

Re: 97 M3/4/5 running in STU

Oops! No proofreading skills.

Sorry, I quoted an earlier post...

The spring rates are 450F/500R. These are the crappy Dunlops. Loosened the bar already. What spring rates does everyone recommend?

Thanks,

Well if the car is a dual purpose street/autocross car then stiffer rates than that on Konis will probably ride like a dump truck and/or need to be revalved and will ride even worse.

When we sell AST monotube coilover kits for these cars our softest spring rate recommendation is the GT spring kit at 450/550, the GTS is 500/650, and GTR is 600/750. GTS and GTR are what we recommend for people that compete in autocross or track events (GTS outsells the other 2 spring sets by a big margin). My wife Amy drives to work everyday with the GTR springs (which won her 2 Championships) and it rides great, but these ain't twin tube Konis....


Left: on Yokohamas. Right: On Dunlops

Dunlops should have a better feel than RE01Rs, but they are still no Yokohama. The AD07 feels like a race tire - instant response, great transitional feel, etc. Driving the EVO X back to back at the Houston Tour practice on Dunlops and then Yokohamas was pretty interesting. The Dunlop is a damn good tire for the money. The Yokohama was just in another league. Can't wait to try the AD08!

[97M3]

Re: 97 M3/4/5 running in STU

Without changing spring rates what else could be done? Ride height?

She was corner balanced which helped a little but wasn't that far off. 12lbs.

[97M3]

Re: 97 M3/4/5 running in STU

Okay, tried a set of 600lb in the rear and the car rotated better and corner exit was flatter with no push. I left the 450s on the front though. Objections?

[Fair!]

Re: 97 M3/4/5 running in STU

Okay, tried a set of 600lb in the rear and the car rotated better and corner exit was flatter with no push. I left the 450s on the front though. Objections?

Still pretty soft up front but the front-to-rear spring rate balance sounds a lot better... that should rotate better, for sure.

[97M3]

Re: 97 M3/4/5 running in STU

Olivia.jpg

Loosened up the front bar and ran the 600lb rear springs. Very neutral, good turn in. Olivia took 2nd in our AAA classes with myself and another driver.

[97M3]

Re: 97 M3/4/5 running in STU

Put the 255s on the Koseis. Running S/A 450/600 lb springs set rebound to 1/2 turn off full stiff in front, full stiff rear. Pushed badly entering corners. Slight throttle oversteer exiting. Push never got any better even after we started loosing up the rebound on the front. Car is heavy: 3416 lbs with me and 1/2 tank of fuel.

Bought 550 lb springs for the front. Ride height seems a little low for the back. Want to set the height at 5 1/4 front 6 rear measuring from the side skirt between the tires.

Any observations would be helpful. Am running the divisionals with SCCA next weekend.

[Fair!]

Re: 97 M3/4/5 running in STU

Put the 255s on the Koseis. Running S/A 450/600 lb springs set rebound to 1/2 turn off full stiff in front, full stiff rear. Pushed badly entering corners. Slight throttle oversteer exiting. Push never got any better even after we started loosing up the rebound on the front. Car is heavy: 3416 lbs with me and 1/2 tank of fuel.

Bought 550 lb springs for the front. Ride height seems a little low for the back. Want to set the height at 5 1/4 front 6 rear measuring from the side skirt between the tires.

Any observations would be helpful. Am running the divisionals with SCCA next weekend.

Measure ride height from center of wheel to bottom of fender lip... this is easier to compare among all E36s...

[97M3]

Re: 97 M3/4/5 running in STU

Okay, the front is 12 3/4. The rear is 11 3/4.

[Fair!]

Re: 97 M3/4/5 running in STU

Okay, the front is 12 3/4. The rear is 11 3/4.

That sounds about right. You could possibly lower the front by another 1/4 to 1/2".... ask your shock maker.

Have you tweaked the swaybars yet? That could solve some of your push.

[97M3]

Re: 97 M3/4/5 running in STU

The UUC bars are set full soft front and rear right now. Installing the 550lb springs tomorrow then check for push.

[John in Houston]

Re: 97 M3/4/5 running in STU

What SA dampers are you running?

If Koni, and 'off-da-shelf', you are probably at the limit of them spring rate wise. Going up in spring rates is going to a) create a craptacular ride on the street and b) not create consistent handling characteristics.

[97M3]

Re: 97 M3/4/5 running in STU

Pete from TC Kline said that 550s for the front was the stiffest spring I could use without suffering. That will be 550/600 on the S/A adjustable setup.

[97M3]

Re: 97 M3/4/5 running in STU

Well, Terry was right. The S/A setup we installed never got it done so we traded up for a set of D/A and stiffer 550lb/650lb springs. The UUC 30mm/24mm bars are set to soft up front and medium for the rear.

Car feels very stable, good turn in and launched out of turns without drama. Still playing with compression and rebound but had some good baseline settings to start out with.

Let me just say that the first year with Olivia was very disappointing. Trying to run an underprepared car in this region was eyeopening. Especially since the Z3 was so competitive in both SCCA and BMWCCA.

Lesson learned...

[Fair!]

Re: 97 M3/4/5 running in STU

Something to contemplate:





Chris Mayfield's E36 M3 has been very fast ever since he added 18x10s and 285/30/18 Yokohama AD08s. He was 3rd in a fast field of 19 at the Vail Valley Tour. AST 4200s and the other usual stuff.

[97M3]

Re: 97 M3/4/5 running in STU

I want one year learning to drive Olivia without any significant changes. From the first slush event last October until now we haven't driven the same setup. I do like the 255s though.