adam c

iTrader: (2)

Not a joke. A bigger stiffer front sway bar worked very well for me for many years in CSP.

RotaryAXer

iTrader: (4)

I guess I have a few questions then.

What spring rates were you using front and rear?

What if anything did you do about poor rear geometry? (watts link/trailing arm bindage)

In CSP (if you have the desire and or money) I think there are better ways to get a well balanced car than adding a large front bar. In all reality if you are changing springs and other stuff anyways the cost really is pretty even. If you are keeping stock springs and rear suspension geometry then I suppose a large front bar would be an ok compromise to counteract the binding/infinite roll rate in the rear.

adam c

iTrader: (2)

Lots of good questions

I sold that car about 4 years ago, after racing it for about 10 years, so my memory about each detail may not be perfect.

The car was a 79 base model. The front sway bar was a "big stiff one" Front springs were around 400 lbs, with modified homemade coilovers and the car was very low. I had very little suspension travel. I had camber plates set at about 3* negative. The rear end had stock springs that had been significantly cut down to lower the rear. In fact, they were so short that I could jack up the rear of the car, and remove them easily with no tools. The rear sway bar was a stock bar from an 82 GSL. I had a limited slip rear end. The rest of the rear was stock, including the drum brakes. And of course, my cheapo fender flares to allow the 225/50/15 tires. As you can see, there wasn't much money available to modify this car.

It had twin weber 36's, dual fuel pumps, a header, and a custom exhaust. No cats. It was very competitive. I won many local season championships, and was in the middle of the pack at Pro Solo events.

I had to sell it to get the FD. I sold it to a local kid who didn't take care of it. I was very sad to find out that it had been abandoned somewhere with no engine, and towed to a junk yard. Stupid kid

slowautoxr

iTrader: (6)

The front bar in my black/white RX-7 is a Koni which is supposedly the biggest one you could get. Like adamc my front springs are 400# but my rear springs are probably a bit stiffer. The stock rear springs were 80# so unless you cut 'em in half (which would bring them up to 160#) you'd be a bit softer. Unlike adamc my black/white RX7 responded well to being raised from the very low condition it was in. My new autox car though is very very low. I'm going to have to raise it a bit though to clear my 205/50-15's.

31rx7

Jack up the steering wheel and drive an RX7 under it. Sorry, couldn't resist.

Seriously, there was some info I saw on a mini-pickup site some time ago. Most mini PU's share similar characteristics so start there. Sorry I can't remember the name of the site.

I recall racing in 1987 against an SCCA "sport truck" with my IT car, and the truck (a Toyota) was damn fast. Not so much in a straight line, but it was great in the corners. Might be a another source for research.

RotaryAXer

iTrader: (4)

Jim Susko has great info on this. The front roll center ends up below the ground if you go too low. (the reason for his turn in spacers I think) It will also move side to side drastically if you are too low. The only way to really know where you are at is to either buy a suspesion modelling program or to make your own.

I have created a mathmatical model of the suspension that has helped determine spring rates, anti-roll bars and ride height. Basically I can adjust all he ***** on the computer and figure out what my weight transfer is. Getting the correct balance front to rear is the key to getting a well handling, pedictable car.

I have found a happy medium on ride height so that I can stick my 205/50-15s on without rubbing. It is also pretty good when going to the 13s as far as weight transfer is concerned.

wrxracer55

iTrader: (3)

anyone know how you could leagally run a 13b in a 12a car? is it possible to do the swap, and what would be involved? can you run a 2nd gen engine (the rules say same model car in same class, and n/a 2gs are in csp last i checked)? i have heard that youhave to mod the mounts to install a 13b in a 12a, and as far as i kow that is illegal, just wanted to double check.

slowautoxr

iTrader: (6)

You have to run a 84-85 GSL-SE motor. You cannot legally run a 2nd gen motor. I'm not sure of all the details but you would have to swap the K-member in there as well. You can update and backdate for models on the same line. To make the 2nd gen motor work, you would have to change at least the front cover and engines have to be swapped as a complete unit.

wrxracer55

iTrader: (3)

thats what i thought, think i'll try to stick with the 12a for weight purposes, plus its whats in there.

wrxracer55

iTrader: (3)

i was looking on the g force website, and was wondering if the tri link can be run with the stock watts linkage? i know the panhard setup is said to be better, but was wondering if this would be allright to do (i might go to the panhard eventually, just want to work in small steps). removal of the upper links would really help with the binding issues, just curious how this might work.

RotaryAXer

iTrader: (4)

I don't think that Jim Susko would suggest that you do that. He designed both of them to work together. I don't think you would be that much better off with just one or the other. Either live with it the way it is until you have the cash for both or do both now.

There are some ways to help the situation temporarily.

slowautoxr

iTrader: (6)

Carl at PB and J racing has a neat little how to on a rear end tweak that'll help you - sorry don't have a link but you should be able to do a search to get it. Basically you can do all the front end work and run the rear springs you mentioned and you'll have a good handling car. Mine was good enough for my small pond but I was beat by 2.5 seconds per day when I went to a CenDiv Divisional.

wrxracer55

iTrader: (3)

yeah, i saw his bushing mods on the site. i plan on doing that and running that way til i can afford to do the tri link and panhard. looks like the car will be built in steps due to costs. in a few years it will be pretty nice though. i can't wait.

slowautoxr

iTrader: (6)

I made changes in steps as well. I have a GC panhard I was going to try next on my black/white RX-7. The panhard rod and tri-link were pretty serious changes to my otherwise STREET prepared car - with emphasis on STREET. I'm glad this other car came along.

wrxracer55

iTrader: (3)

gothca, this car is gonna be mostly for racing, maybe a little saturday driving (and driving to the races until i can afford a trailer), but thats is it. i have a daily driver, so comfort is not a big concern to me.

wrxracer55

iTrader: (3)

ok, i've looked a little more into the rims/tires and would like a few opinions. i'm gonna go with the diamond 13x8s, but wasn't sure what backspace to get, 4" or 4.5." i have heard of people using both. also, i am stuck between 225 and 235 45/13 tires, i know the 235s will rev a lottle slower, but might help on faster courses, any opinions? lastly, i have heard that hoosiers are lighter, i was gonna go with kumhos, but should i go with the hoosiers to keep weight down? thanks

RotaryAXer

iTrader: (4)

You may need a 1/4" spacer if you get 4.5" backspacing. I got the 4" backspace and have no issues. They do stick out pretty far though. Keep in mind I have a GSL-SE. I am not sure if the others are different.

Hoosiers are historically lighter then most other brands in the same size. If you have the cash you should get Hoosiers at least once. I really can't decide what my tire will be this coming season. I don't think there will really be a significant difference in speeds from the 235 or 225 in a 45 series tire. It will more than likely come down to money rather than weight or actual diameter.

wrxracer55

iTrader: (3)

ok, thanks. i think i'll stick with the 4" backspace. i'll lok into the tire prices, and see what looks best pricewise. i'll probably go with the 225s for the quicker acceleration

slowautoxr

iTrader: (6)

The 13x9 Duralights on my new car measured at a 4" backspace as well. Oh, non -SE suspension.

wrxracer55

iTrader: (3)

well, i looked on the tirerack site, and the hoosiers (A3S04) are available in the 225, not 235, and they are 157 a tire, the kumhos(ecsta v700, shaved) are available in the 235, not the 225, and were 128 a tire. anyone know what the weight difference between the 2 is? what to do, what to do.

slowautoxr

iTrader: (6)

Not sure about the weight difference but they're both radials so I would guess that they'd be similar in weight. If you look at the section width of the you'll see that Ecsta V700 (9.2" on a 8" rim) and the A3S04 (8.8" on a 7" rim) are very similar and the tire diameters are similar as well with the Hoosier being just a bit shorter (20.7" vs 21.1"). I've driven the Ecsta V700's (on a G Stock Neon) and found that they get too hot and then become greasy (at least for a two driver car). The Hoosiers are faster but more expensive. If you got the money...... get the Hoosiers. I've also been on V710 (on C Stock Miata) and like them. They're available in a 215/50-13......

wrxracer55

iTrader: (3)

ok, thanks for the info. looks like i might go the hoosier route, especially if its worth the extra money.

wrxracer55

iTrader: (3)

i had another thought. i got a holly manifold for a pretty good choice, and was thinking of going with the holley fuel injection setup (throttle body style). anybody run this setup, or see a car running this setup. i have seen them used on ebay for decent prices, and fuel injection will offer much better tunability than the carb. any opinions?

slowautoxr

iTrader: (6)

After autoxing a Neon and a Miata I had completely forgotten about the fuel issues with my RX-7. As my RX-7 got faster throughout the year - the limitations of my carb setup (or maybe my lack of know how) fuel issues have become a concern. Hopefully my new car - although not fuel injected - will not have problems. Fuel injection would be nice.

wrxracer55

iTrader: (3)

i decided against the fuel injection swap for now, the kit is like $1200, and i can put the money elsewhere. gonna go with the sterling carb/ported stock manifold setup