wheelman Posted November 13, 2006 Share Posted November 13, 2006 In a thread discussing the merits of a clutch type LSD vs a Quaiffe or Torsion LSD a reference was made to setting up the susension of a Z as West Coast style and East Coast style. The difference in performance was referred to as west coast being fast into a corner, slight over steer, and slower out where the east coast setup was slower into the corner, slight understeer, and fast out. Unfortunately the actual differences in setup were not described, at last not that I remember, the actual topic of the thread was not suspension setup but LSD types. So my request is, would one of the suspension gurus please describe the two setups and the theory behind them. I'm looking for things such as spring rates (ratios front to back), sway bar configurations, camber, castor, ride height, etc.. Thanks Wheelman Quote Link to comment Share on other sites More sharing options...
johnc Posted November 13, 2006 Share Posted November 13, 2006 I'm more familiar with the West Coast setup. Here's what I know about both. East Coast More roll stiffness in front, softer rear. Slight bias towards understeer. East coast tracks tend to be faster and have a smoother track surface. Spring rates: 300 to 375 front - 250 to 325 rear. "Typical" is 350 front and 275 rear. ARBs: 25mm front and 15mm (or none) rear. Alignment: Not sure, probably simialr to West Coast. West Coast Roll stiffnes more balanced front to rear. Softer overall compared to the East Coast setup. Slight bias towards oversteer. West coast tracks tend to be slower and have a bumpier track surface. Spring rates: 275 to 325 front - 300 to 350 rear. "Typical" is 300 front and 325 rear. ARBs: 25mm or 27mm front and 19mm or 21mm rear. Alignment: Front camber -3 to -3.25 (depends on tire width) Rear -2.25 to -3 (depends on tire width and horsepower) Front caster: +5 to +7 Front toe: 3/16" out to 0 Rear toe: 0 to 1/8" in Ride height: 5" to 5.5" front and 5" to 6" rear. A recent experiment by Bryan Lampe running his ITS car at a VARA event showed a 1 second per lap time improvment at the Willow Springs Big Track (fast track) using the East Coast setup. A similar experiment at Buttonwwillow (slower, more technical track) showed that the West Coast setup was faster. What that tells me is that suspension setup/tuning is track dependent (Duh!) Quote Link to comment Share on other sites More sharing options...
wheelman Posted November 14, 2006 Author Share Posted November 14, 2006 Thanks John, I was hoping you'd be one of the guys to respond to my question. I'm a bit surprised at the spring rates though, most times you see springs discussed on here the 200-250 range is what most guys use. Wheelman Quote Link to comment Share on other sites More sharing options...
katman Posted November 14, 2006 Share Posted November 14, 2006 "East Coast" alignment: -3.0 to -3.5 camber front -1.5 to -2.0 camber rear 1/16 to 1/8 toe out front Zero to a smidge toe in rear Ride heights at bottom of flat on rockers: 5-1/4 front and rear with driver. With the ShockTek's we were up to 400 #/in front, 350 #/in rear on the springs, and a hollow custom front bar equivalent to about a 15/16 solid with no rear bar. Clutch type LSD. Slow in fast out, is always the quick way around, east coast or west, unless of course the track is dominated by a plethora of ingress oriented turns like turn 6 at Road Atlanta, but its rare to have more than one of them per circuit. John's right- it's track dependent, although a lot of the tracks in the southeast we could run the same "east coast" setup with minor camber and bar adjustments. But Road A and Mid Ohio- totally different setup. I also have a theory that front roll center is a big player in spring rates required. I've had several different Z's on the same track and it seems the closer to streetable ride height you're at the more likely you'll need closer to west coast spring bias versus east coast. And I'm also of the strong opinion that softer is "faster sooner" for a dual purpose car and driver. In other words, if you don't track but a few times a year you'll be faster in a soft car sooner than you'll be fast in a stiff car. You are inquiring for what goals? Quote Link to comment Share on other sites More sharing options...
wheelman Posted November 14, 2006 Author Share Posted November 14, 2006 I'm going to be converting from Tokico springs to coilovers for use in Auto-X and was wondering what the difference was between the 2 setups. Currently my car rides too low and I can't adjust caster or camber (no plates) so I figured I'd gather as much info as possible before deciding which coilover/camber plate setup to buy. I like the strut setup John sells but would like to get a kit to convert my struts rather than buy the whole package. Haven't asked John about it yet so maybe he'll jump in and tell us if he is willing to sell just those parts and for how much. I also run fairly large ARBs front and rear (bought the pair MSA sells) which consequently makes the tail a bit happy. Before I blame it on the bars I have to say the tires I'm running are pretty hard so breaking them loose with the throttle is very easy and the car is a bit nose heavy. I plan on switching to Kumho tires next season and have ordered a Power Brute LSD. I want to combine these changes with coilovers to get the ride height back up and camber plates to add a bit of adjustability. Switching to coilovers means I can choose the spring rates I want which is what really prompted the question. The car will be driven some on the street, mostly to Auto-X events, so I don't want rattle the teeth springs if I can avoid it and my struts are stock Tokico blues which I'm sure can't handle very stiff springs. I'm thinking the west coast setup will work better for me as Auto-X courses tend to be very tight and I don't see myself attending HPDE events any time soon (to far to travel). Any thoughts or suggestions? Wheelman Quote Link to comment Share on other sites More sharing options...
katman Posted November 14, 2006 Share Posted November 14, 2006 Hoosier 225/50-14 Autocross tires. Since you're usually in a parking lot, and the car has to be streetable, I'm a big fan of "normal" spring rates, like 115F/145R and matching Koni or Bilstein struts. I'm also not a big fan of really big bars; I like to stop at 7/8 front and 3/4 rear. By far the two biggest things that reduce time in an autoX is driver and tires. A low profile tire will lower you for the autox and you'll still be able to drive around town at a decent ride height with your street tires. In the case of a 225/50-14 it will lower you almost an inch without screwing up your roll centers. Reasonable springs, good shocks, poly bushings, a good seat and belts, real tires, and a killer stereo. Call me old, but that's my recipe for a good autox/street car. The Betamotorsports setup would be the cats meow, and revalvable to your specific app when you're ready for national competition. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 14, 2006 Share Posted November 14, 2006 How far do you want to go with this? Only you know the answer, and going with a setup like katman describes leaves A LOT of room for improvement. It might be a FUN dual purpose car, but if you're wanting to get serious I'd forget about poly bushings and reasonable springs, and most definitely the stereo. If you just want to putz around and have a good time, then go for it. My biggest mistake was underbuilding my car the first time around, so now I have redone every piece in the suspension at least once, some things are on their 3rd or 4th go around. Figure out what you want to do and then do it all the way. If you want streetable build it really streetable. If you want it race ready build a full on race car. Compromise cars might do everything decently, but they won't do anything exceptionally in my experience. Quote Link to comment Share on other sites More sharing options...
wheelman Posted November 14, 2006 Author Share Posted November 14, 2006 Katman, I've already got a set of ROHS 16X8 rims and plan to run 225/45-16 size tires. I'm running 205/45-16 Yokohama Avid H4s now. I'm going with the Kumhos for a couple seasons so I can remain in the novice class. Hoosiers force me into E-Mod where I'll have to run because of the engine swap. I've already done the poly bushings upgrade and the sway bars are close to the sizes you stated, 1" front and 7/8" rear I believe. Jon, I don't plan on going "all out" with this car. I'm just getting started in Auto-X and just want to have some fun while I learn to drive better. The main reasons for going coilovers is to get the ride height back up and get rid of the progressive springs I have on the front of the car (Tokicos). When I start thinking about making changes my competitive nature comes out and I want some adjustability for when I am forced into E-Mod. It may very well happen this coming season, if I win 1 event as a novice I'm booted out of that class. I'm just exploring ideas and considering what to do so I really appreciate the input from you guys. Wheelman 1 Quote Link to comment Share on other sites More sharing options...
katman Posted November 14, 2006 Share Posted November 14, 2006 Ah, to have enough money for a street car and a race car..... 1 Quote Link to comment Share on other sites More sharing options...
heavy85 Posted November 15, 2006 Share Posted November 15, 2006 If you are going into E-mod anyway because of the engine just go full slicks. That's where I'll be next year with the LS1 from FP this year. You can buy used with basically full tread (take-offs from the nationals with one heat cycle) for about $70-75 a piece and mine could probably last two seasons if I push it. In the end you will be faster and save $$. I'm running Hoosiers 9.5x22.5(going from memory)x15 running on 15x10 rims in the R35 compound. R35 worked well in the spring and summer but really sucked this fall because they wouldn't build any heat. Cameron 1 Quote Link to comment Share on other sites More sharing options...
tube80z Posted November 15, 2006 Share Posted November 15, 2006 If you decide to go the slicks route make sure you jump straight to radial slicks. Currently the hot setup is the GY FA radials, which we've found to work much better than the Hoosiers. I'm sure Hoosier will respond with a radial as there seems to be a lot of people talking about them after nationals this last year. And if you run where it is cold you will probably be faster with a good DOT radial (Kumho, Hoosier, or possibly Hankook). Their tread compounds generally work about ten degrees less than any of the slicks. cary 1 Quote Link to comment Share on other sites More sharing options...
heavy85 Posted November 15, 2006 Share Posted November 15, 2006 If you decide to go the slicks route make sure you jump straight to radial slicks. Currently the hot setup is the GY FA radials, which we've found to work much better than the Hoosiers. That's new as just last year this time discussions centered around Hoosier bias plies. Glad for the heads up but I just quickly internet searched and teh GY FA's are $300 a piece which is nearly double the Hooisers. Even if you can finds some used one's that's a lot. And if you run where it is cold you will probably be faster with a good DOT radial (Kumho, Hoosier, or possibly Hankook). Yeah I found that out the hard way. With ambient temps mid 50's I lost at least 2 seconds a lap (~50 sec lap times) to where I had been relative to the DOT cars in the summer. Went from within 1 sec of FTD (to a SS Z06 who ALWAYS gets FTDI) or even FTD once to about 3 seconds back. Sorry to threadjack the WC/EC question but should be useful to the discussions none the less. Cameron Quote Link to comment Share on other sites More sharing options...
tube80z Posted November 16, 2006 Share Posted November 16, 2006 That's new as just last year this time discussions centered around Hoosier bias plies. Glad for the heads up but I just quickly internet searched and teh GY FA's are $300 a piece which is nearly double the Hooisers. Even if you can finds some used one's that's a lot. We've got a number of the used tires in Portland for a lot less than that, more like $200 a set at times. John Berget has these as well as a few other people if you don't want to make the drive to PIR. FWIW, I'm told Hoosier radials will have a similar price tag new. Cary Quote Link to comment Share on other sites More sharing options...
wheelman Posted November 17, 2006 Author Share Posted November 17, 2006 If I go straight to slicks I can't run in Novice class. When I do move to E-Mod I plan to run slicks, I just don't want to make that move yet. If I win an event as a Novice I will be forced to run E-Mod so I may have to do that sooner than I plan. When the time comes I'll have to figure out a way to get the car and the extra tires to the track. Getting the wife out of bed to drive the pickup with the tires will be a bit of a fight. I guess I'll have to get a trailer or dolly so I can tow the car. Thanks for the suggestion to look at used tires as well. I tend to always think I have to buy new so this will help me save a little money for other mods. Wheelman Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 17, 2006 Share Posted November 17, 2006 I was able to carry 4 250mm wide slicks in my Z. One rides shotgun, one in the spare tire well, one shoved all the way to the passenger side of the hatch, and one all the way on the driver side. The hatch would just barely close, and there was enough room in front of the strut tower bar for a small tool box and a helmet. Jack fit underneath the top layer of tires. It's tight, but you can do it... Quote Link to comment Share on other sites More sharing options...
Clifton Posted November 17, 2006 Share Posted November 17, 2006 I'm in the same boat with the engine swap. You can run XP too though. Here the cars in that class are a little more streetable and not as fast as emod. Realisticly you'll never be competetive in Emod with 1500lb slick shod, purpose built cars, even XP, especially if you want to keep it street friendly. IMO you'll be happier just running for fun and not thinking about how fast you are in that class as you are out classed with the engine swap. Quote Link to comment Share on other sites More sharing options...
wheelman Posted November 17, 2006 Author Share Posted November 17, 2006 Fortunately for me the local club combines all modified and prepared classes into one and uses PAX to make things a little more equal. I still get hammered with the PAX though so you're right Clifton I'll probably never really be competitive. I try to tell myself it's for fun and not to worry about whether I win or how I place but you know how well that works. That good old competitive spirit rears it's head and I start thinking "OK, I need to do this and that to the car and I'll be able to beat that guy." "Resistance is Futile" Anyway I am going to convert to coilovers so I might as well do it right and set the car up in a way that works best for me, thats what prompted the original question. I'm thinking the "West Coast" setup is better for Auto-X and fits my driving style a little better as well so I'll choose spring rates accordingly and retain the relatively large ARBs I already have, possibly adding adjustable end links to the rear bar. I will run Kumho Ecsta MXs next season and switch to slicks when I starting running E-Mod. Wheelman Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted November 18, 2006 Share Posted November 18, 2006 For those Oregon people, what would you consider PIR as? Would the east coast or west coast setup work better? Quote Link to comment Share on other sites More sharing options...
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