2MCHPWR

hi guys - i bought a c5 recently with DRM coilovers.
I'd like to see your combo if you run these.

swaybars - T1's
wheels- CCW's 18x10.5 front, 11.5 rear
tires - toyo r888's, 295/30 front, 315/30 rear.
alignment - getting it done next week. -2.5 front, -1.5 rear approx are my goals.
corner weights - getting it done next week.
ride height - measured to top of fender lip? I'm asking because my toyo's stick out slightly so I want to make sure the height it high enough to prevent any contact.

type of racing - will be doing HPDE's and maybe autocross. street driving too
miles on your coilovers - unknown, bought car used.
spring rates - stock AFAIK, 450 front, 600 rear. have you changed these?
any other suspension mods to compliment them? DRM 4 point chassis bar.

any suggestions/recommendations?
thanks!

kmagvette

I am putting DRM coil overs on my 02Z right now. I have a very similar set up, except Phadt Comp Bars, and 18x12, 18x11 CCWs. Same rubber. Camber goals are a bit more conservative, (-2.0 F, -1.0 R) but I have poly bushings.

Rear springs are 575, Front 425...at least that is what mine are.

Very interested to see what others are doing.

snitz

Give Randy a buzz at DRM. Great guy, will give you "spot on" advice.

haikun

Have DRM's coil over, using Pfadt street swaybars and also their camber kit (allows me to change front camber from 1.2 on street to 2.5 on track). Also using DRM's duct system for cooling the front brakes (helped taking temp on brakes down).

2MCHPWR

Do you use a backing plate also?

0Randy@DRM

Can't type so well right now something about 4.5 miles down river, and sleeping on a rock. I'm going to be up at the shop on Memorial day to about 4 ish. Tuesday-Friday 8am-8pm

Randy
763-477-9272

PA Z06

Congrats scott, any pics. You didnt sell the rx7 did you

0Randy@DRM

Ok, Today my hands are working much better (spelling I still can't do)

Keeping the front end off the fenders due to them sticking out is not the "right" setup. But it's going to have to work until you can get them sucked in. Measuring off the fender lip is the worst place in the world. It's pretty easy to make a mistake in where you are measuring. Cars right off the factory floor are off. The vast amount of tires and wheels will not make this a good place to measure. You should be measuring off the frame rail. There isn't a perfect answer for the ride height question. We suggest setting up the preload on the spring first and get it close. Then after that making fine adjustments.

This will get you pretty damn close.


Here is a video of just a few cars that we set up here. Your car's should be pretty close to this.


Give me a call anytime.

Randy
763-477-9272
www.dougrippie.com

2MCHPWR

here's my alignment and corner balancing:

http://209.177.55.37/c5align.htm

and some pics on the trailer:

0Randy@DRM

That is looking very good!!!

Randy

2MCHPWR

thanks randy - should i be considered with the rear drivers side sticking out slightly?
any chance the fender can come in contact with it?

0Randy@DRM

There is always a chance of something like that happening. But under normal track driving that should be just fine. Why is that wheel hanging out more then the other? I think you told me, but I forgot. Funny thing is, I had a different customer that only wanted one 3/8 spacer because he had two different wheel offsets.

Randy

2MCHPWR

not sure. I would like to know as well I see a few others have similar issue. Don't know cause though.

0Randy@DRM

Have you measured the wheels itself???

Randy

kmagvette

I just got back from the track after setting up the coil-overs as suggested, actually went to 3.2" on the fronts. Due to camber plates, my fronts stick out a bit even if I go to 295's and 2.6* neg camber. Well, the front fenders are still hitting the tires. I guess I will try going up 10 threads and see what happens then.

The car felt very solid on the track (The Glen) except going up the esses. I used to be able to hold full throttle from the entrance to 2 all the way to the bus stop. There is a bump where the car is just taking a set into turn 3 and with the stiffer suspension it is a real eye opener even at 10-15 mph slower than before on stock springs and shocks.

Perhaps I just need to get used to the stiffer car, but I felt that I would be slideways next to the Blue Bushes if I pushed any harder.

Alignment is -2.6* Front, -1.8 Rear. 1/16 Toe In Rear, 0 Front. 6* caster.

0Randy@DRM

You may want to start thinking about increasing front spring rate. Having the control arms out and wheels hanging out of the fenders is a big lever. That big lever takes the lower end of our prefered spring rate and makes it softer yet. Talk to Woods he runs up there a lot, maybe you guys can meet up and this is the first time I have heard anything about the bump. Can you drive a different line to miss the bump??? Double check your travel on the shock. A simple zip tie will tell the story there.


Randy

kmagvette

The big tire/lever theory make sense. I should qualify "the bump" as something that is felt rather than a confirmed physical attribute of the track.

As you transition from turn 2 to 3 you are also cresting a hill. The car typically takes it's set in the turn as you approach the concrete inlay in the track. It is at this point where the "bump" is felt. Substantial care is taken to be very smooth with all inputs to control weight transfer and minimize impulse loads to the suspension.

My student had a stock 2003 Z06 and I could feel the same "bump" in his car, but the effect was muted by his softer setup and slower speed.

Due to a tire ordering screw-up, I was running 305 R888's on all 4 corners. When I set the ride height, leaving the 3.2" of thread exposed on the fronts, I had to substantially back off the rears to get to 3/8" rake measured at the bolt centers on the lower control arms. Perhaps the car, when unweighted and cresting the hill combined with lighter preload on the rear springs is causing the initial spring rate to be very low at the beginning of the turn verses the point where the car sets into the turn. My motivation for this comment is that I was able to easily turn the rear adjusters, by hand, by rotating the spring in desired direction of adjustment. With the suspension relaxed, the springs still had enough load on them that they were retained top and bottom. Perhaps raising the car closer to stock height, with the required additional preload on the springs, would mitigate my turn 3 issue.

Excepting this one turn, I am very happy with the shocks.

2MCHPWR

randy - I'm gonna give you a call today. I just measured the threads and the shop only has 2.5 inches even though I showed them your picture. What are possible issues of keeping it so low besides scraping on every incline?

0Randy@DRM

Good talking with you, get that thing back out there!!!

Randy