Suspension tuning - dampers, spring rates, etc.

[coolhandluke]

@Xian - I want to pick your brain on my EG project:

Goals:
-Switch to 0 toe alignment for longer tire life
-Fun street/track car that drive to/from track

Driving preference:
-Neutral with hint of oversteer

Tires:
-Rcomp (NT01) and street (Extreme Performance Summer category)

Suspension:
-Eibach R2's, rates are TBD. Leaning towards 450lb F/400lb R
-FSB: Stock / TBD
-RSB: Eibach adjustable w/ spherical endlinks
-UCA's: Adjustable

Bushings:
-Rubber with exception of Kingpin Front lower compliance and RSB endlinks.

[Xian]

Yup, I don't see anything wonky with that as a setup. Rates are a little low but should be fine with enough bumpstop rate and as long as the car's not slammed on ride height. If it was me, I'd be tempted to run a little more front spring and a little more rear bar but it shouldn't be a big deal either way.

I assume the shock choice is because you've got them on hand already? If you're buying another set, I'd also at least consider calling Whitener. I have yet to hear a bad thing about his shock package.

I guess some stuff to keep in mind is that you can run a little toe in at the rear of the car feels looser than you want (generally). You can add more rear camber if it's too loose at mid-corner.

FWIW and all that but if this is just a fun street/track car, I'd consider skipping the NT01's and try out the Maxxis VR1. It's a little harder than the pointy end 200TW stuff but it lasts WAY longer and is much more heat tolerant. They've got 205-225-245 in 15" sizes so you can choose to run a square or stagger setup. I've been running them as street tires for the last couple months and have been pleased with them in the dry, rain, at autox, and on track. Seems like another great "do everything" tire that should last reasonably well.

[coolhandluke]

Quick response, thank you sir!

I'm open on rates and FSB. This is a switch for me based on recent reading from you and others. I have historically ran higher rear rates, I currently have 650lb F/750lb R in my 98. My 97 was an exception, I ran 450lb F / 400lb R, but with a larger 26mm RSB. It was a DD for ~6 months on chitty roads so it was a compromise that worked fairly well. I can step up the rates, but I was aiming to solidify the sways first and then select rates to compliment. The Eibach RSB is 3-way adjustable, which allows room for adjustment.

[Xian]

Quick response, thank you sir!

I'm open on rates and FSB. This is a switch for me based on recent reading from you and others. I have historically ran higher rear rates, I currently have 650lb F/750lb R in my 98. My 97 was an exception, I ran 450lb F / 400lb R, but with a larger 26mm RSB. It was a DD for ~6 months on chitty roads so it was a compromise that worked fairly well. I can step up the rates, but I was aiming to solidify the sways first and then select rates to compliment. The Eibach RSB is 3-way adjustable, which allows room for adjustment.

Always happy to help out dude! If it were my car, this is where I'd start:

550 front, 400 rear
Stock front bar (possibly an ITR bar if you've got a clutch diff)
At least the Eibach rear bar. Maybe bigger. What's the sizing on the Eibach one?
Front camber around 3-3.25*
Rear camber around 1.75-2*
Front tires as big as you can fit... 225-245 preferably. 205's in the rear unless you're running square and then I'd try for 225's.
Tiny bit of toe out up front (let it fall on the toe out side of zero toe). Tiny bit of toe in at the rear (same thing with it being on the toe in side of zero).

Don't be afraid to use tire pressure and alignment to impact balance. In my autox car, I made some spring and bar changes that tightened the car up... bumped rear pressure to 45psi to compensate.

[coolhandluke]

As always, thank you for the feedback. I plan to start with 15x7 wheels but that may change later on. The Eibach DC2/EG adjustable rear sway bar is 25mm. The rates are:
1.) Setting 1: 418lbs/in
2.) Setting 2: 533lbs/in
3.) Setting 3: 630lbs/in

The EG Si's OEM front sway bar is 21mm.

Good points on tire pressures. I always dial in tire pressures first at the track, then make setup changes. I can go with a hair of toe out.

[aw614]

Do you know if Whitener makes the shocks to support the eyelet lcas or does it require a change over to the standard fork lcas?

[Xian]

As always, thank you for the feedback. I plan to start with 15x7 wheels but that may change later on. The Eibach DC2/EG adjustable rear sway bar is 25mm. The rates are:
1.) Setting 1: 418lbs/in
2.) Setting 2: 533lbs/in
3.) Setting 3: 630lbs/in

The EG Si's OEM front sway bar is 21mm.

Good points on tire pressures. I always dial in tire pressures first at the track, then make setup changes. I can go with a hair of toe out.

With 15x7's you may be best off with a 205... can do a 225 but the street tires will take some extra pressure and/or camber. Is this a B-swapped EG? Clutch diff or gear diff?

25mm solid bar should be ok but I still wonder whether you may want some more rear bar once you drive it.

[Xian]

Do you know if Whitener makes the shocks to support the eyelet lcas or does it require a change over to the standard fork lcas?

Pretty sure he does either/both. The eyelet one may actually be easier with the parts that he's using.

[coolhandluke]

Do you know if Whitener makes the shocks to support the eyelet lcas or does it require a change over to the standard fork lcas?

Pretty sure he does either/both. The eyelet one may actually be easier with the parts that he's using.

Is this the correct site?
http://www.whitener-racing.com/

[Xian]

Do you know if Whitener makes the shocks to support the eyelet lcas or does it require a change over to the standard fork lcas?

Pretty sure he does either/both. The eyelet one may actually be easier with the parts that he's using.

Is this the correct site?
http://www.whitener-racing.com/

Believe so, yup. I've heard that he's pretty busy with the business so response times may be a little slow... be patient.