Don't know why I checked in today for the first time in a long time but this thread really brings back some memories. I tried every rate combo from 400# Front all the way to #750 rear with AST DA shocks that could handle it. By the end of my time in the Z, I was sitting on #550F with H&R sway on soft/#700 rear using stock RSB. The rear of the car really was better when the spring/shock/RSB tuning de-emphasized the rear trailing arm tendencies to dislike fast transitions.
Now in E92 M3 ZCP -- Absolute beast
I called up TC a few weeks ago and ordered the 300F/700R combo, and will be installing this weekend. TC gave me a hard time about ordering such a large disparity in spring rates, but had no comment on the motion ratios, wheel rates, or ride frequencies. I know the guy has been around a lot, but not sure if he was on the same page here. I did get a few interesting things out of him though:
- he told me that back in the day they ran 400F on Hoosiers, finding that to be the fastest setup. Yeah, RE71R's are the cheater tire, but they're no Hoosiers. So if I can't generate the same grip levels, why would I need that much spring? One more data point to confirm my 300F choice.
- he told me stock springs were something like 160F/350R. Double each of those numbers and what do you get? About 300F/700R, preserving the stock wheel rate split front/rear. Then square up the tires and remove the rear bar, and you dial out the stock understeer without taking away grip from either end. At least that's my hypothesis.
I'll be spending the coming weekend in the garage. Here's my current plan:
Rear suspension
- Poly bushings
- 700#
- Remove bar
Front suspension
- Condor UHMW FCABs
- 300#
- Stock bar
- Adjustable end links
Rake
- 0.5 inches
Alignment
- camber: ~-2* rear, ~-3* front
- toe: in a little rear, out a little front
- caster: ~stock
Also picked up a set of scales for a corner balance.
Hoping to have time to do a valve adjustment and fix my leaking CPV valve too.
Good to hear from you Clark. I'll be at the CCSCC Test and Tune on the 8th to start sorting this all out. Where do people hang out these days now that CICEnet is dead?
I know you thought that these cars had a lot of potential in STR back in the day, and if I'm not mistaken that was before the S54 cars were part of the class. It's still going to take me a while to get to full prep, but I see the potential here too. The biggest hurdle for the S54 is headers since the cats need to stay within 6". But if that can be figured out...fully prepped with headers-back exhaust, CSL airbox (can't believe that that's class legal!), tune, 25lb. seats, battery...all of a sudden we're talking -250lb. and +50hp.
I won't be at the CCSCC event as I just had knee surgery today. The advanced TNT is a great event for dialing in your car. You've have plenty of time to pull the car and make adjustments. There has been no replacement for CICENET as far as I know. I honestly think Robin has a good shot if he ever went to an event to trophy in STR but it will be really tough, especially now that the ND has been developed but it's a sharp knife in a gun fight. I would not waste the time on modifying the header to move the CAT as power in the S54 won't be its achilles heal. The Bimmerworld 3.5" single exhaust would be a consideration back from the CAT. The airbox is legal and supposedly really produces results. Weight reduction is key as tire to weight ratio is what dictates more than hp. The seats are a huge reduction but there is a proposal to change that which just came out increasing it to 35 lbs a side. Battery saves a ton.
Now in E92 M3 ZCP -- Absolute beast
2001 Z3 3.0 Coupe--Sterling Gray/Sunroof Delete/5MT
Fasteners needed more heat and PB Blaster than I had anticipated, and the shock bodies were so bad that I had to cut the old lock rings and lower spring seats off, but I got most of this completed this weekend. Haven't aligned or corner balanced yet, but took it around the block to settle the springs into place. Tough to report anything yet because it was 35 degrees on tires that still had mold release...but initial results are promising.
IMG_1996.jpgIMG_2007.jpgIMG_2016.jpgIMG_2019.jpg
The only thing better than greasy summer tires and cold pavement is greasy summer tires, cold pavement, and supercharger.
Corner balanced this weekend. Here's the results with 5/8 tank gas, 170 lb. driver, floor mats and tools removed:
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So Matt did not have the best conditions to start for his first SCCA event o the new setup. We will see how his setup works on a better day. Maybe he will let me take a run or two. Either way, high 30's and wet was not the day for RE-71's. I was 2.5s faster then the best RE-71 shod s2000 and even 1s ahead on the 2nd place on what I would have expected was the preferred Continental "rain tire". The Bridgestone S-04's were working well for me and resulted a good result overall as well.
My best run was 2nd fastest RAW time for the event (69 cars were brave or stupid enough to come out).
Last edited by SunzOut; 04-18-2018 at 10:02 PM.
Sweeeet!!! Love the enthusiasm!
Good stuff man!
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