IIRC, the comps are monotube as well, whereas the I-III's aren't. If you're going to track your car, I'd probably suck it up and get the comps. They're still relatively inexpensive.

 

does anyone know how much these sets are?

 

http://www.pettitracing.com/rx7/index.htm

 

Feedback as promised.

If your going to Track your FD the Stage III's will do everything you thought good coilovers should do. The car will do exactly what you tell it. Tail Brake, chop throttle oversteer, power on oversteer, any slip angle you want with confidence. Run exactly what Cam advises and you'll be golden.

Best example I can give is hitting the transition into Turn 1 at TWS at 110 with my foot on the floor then braking over a few bumps in the track down to around 70 and the car being absolutely rock solid. For those not familiar with TWS the transition is where you come off the banked front straight of an oval into the flat infield section. Youtube has some good videos if you look.

Final thoughts: If your on the fence about these just buy them.

 

Great feedback! Are you on R-comp tires? What other suspension mods?

Thanks!

 

I'm running Sumitomo HTRZ's with a Tanabe front bar and stock '93 rear. The Sumi's are pretty good for street tires but R comps would pull a HUGE chunk of time off my laps.

 

I was on the fence between Trak Pro Stage 2 and Howard Coleman's recommended Koni Yellow + Eibach (or another spring) set-up. Koni set-up looked attractive as it's set it and forget it but then I decied to go with Trak Pro Stage 2 cause it's specially designed for FD RX7 and doesn't have cons like other coilovers like noisy pillowballs etc.

 

Howard??? Do you have any more updates for the spring rates and pro and cons for the twintube(Stg III) vs mono(comp)???

 

just returned from my first brief outing... i am currently running the Comps w 12/10 springs. i am favorably impressed albeit after only a few miles.

i am going out, now, to put some miles on them on the back roads and will get back later today. new engine, 6 speed trans, new CPR design turbo manifold, turbo (GT4094r) exhaust, etc etc, so 'alot to shake down.

hc

 

did about 30 miles thurs...

i hadn't had a chance to check the shock settings (thurs) and found them to be on full soft. there are 24 clicks. for friday i elected to do 6 clicks in the front and 2 in the rear from full soft. the reset definitely change things. measurably more firm.

i purposely found some bumpy country road as well as some smooth twisties.

i am happy to report that at no time did i get the hammer/jarlike reaction over the bumps. this is no doubt because of the rubber upper mounts.

at the 6/2 setting w the 12/10 springs (Comps) i am at the end of quite acceptable firmness. ( and if you spend alot of time on crappy old roads like some of the NE cities i would encourage you to dial the springs back a bit) any more and it is track only for me. the Comp comes w 15/12. when i received the Stage 3 and Comps i elected initially to swap in the stage 3 springs to the Comps. if you drive on the street, and want the Comps, IMO, i would get a set of the 12/10 or 10/8s. run them on the street and perhaps the 15/12s if you run race rubber on the track.

that said, i very much like the setup.

not harsh, but firm. and LINEAR.

race suspensions should be all about LINEAR. Linear is easier to control. Linear is why the RX8has longer A arms.

the car feels very planted.

i am going to do a run at 12 clicks from full soft front and 6 rear and will report in.

my next move will be to swap the Comps for the stage 3.

howard

 

Howard, I'm just wondering if you've run them same setting front and rear. I believe you're running softer rear to increase rear traction but would it not be more neutral factory like feel if you run them same f & r, plus the spring rate in the rear is a touch softer. I'm asking cause I have Stage 2 on order and was planning to run 4/4 or 6/6 from full soft for everday driving.

 

if you read the first post in my suspension thread you will learn what you need to know. i suggest 6/2 for you. further i will bet you love the springs in your Stage 2.

howard

 

Howard,

Now that you mention you are running 12k/10k on the comp. I am curious to know whether if the comp can accept those spring rate without the need to re-valve. I heard that most damper can accept +/- 2k without the need to revalve. Would that explain why you are running the dampening in the lower limit 6/2?

Another question is that are the F and R springs the same dimension? So that for people who can afford one set of coilover(unlike mr baller howard with comps and stg3) could just buy the 10k and use the 12k provided with the front. Please keep the feedback coming.

 

any TrakPro coil over can work w any of the available spring packages due to the wide adj of the interior valving.

you could easily run 8/6 or 10/8 with the Comps if you wished. i had a long talk w Cam last night and he pretty much agreed that the 15/12 springset was for track.

i will be very interested to swap in the Stage 3 setup.

back to your questions:

while i cannot speak for all coil over manufacturers, i can tell you that Tein and Trak Pros due to their valving width can handle alot more than 2 K...

F & R are same free height and width so they can be interchanged.

why set shocks diff front and rear?

first off. note Mazda spring rate for the FD is 263 pounds front and 195 rear. (that's about 4.6K fr and 3.4K rear.) according to my shock dyno i had for a number of years the shocks were differentiated similarly.

how come, given close to 50/50 weight distribution?

you really need to read post one in my sticky suspension thread but... the FD is a front engine rear drive car. in order to go fast in that type of chassis the rear needs help to hook up. the rear wheels drive the car. they need more adhesion V the front. softer bias V the front delivers this adhesion.

remember:

stiffer springs decrease roll but do NOT decrease lateral weight transfer. stiffer springs decrease feedback to you as to where the chassis is w re to breaking loose. the FD has a racecar suspension that delivers negative camber gain to the all important outside wheels so a little roll (3 degrees or less) is fine as to laptimes. stiffer springs mean the tire spends less time in contact w the road surface and more time in the air.

air doesn't have a really great coefficient of friction...

hc

 

after 2 days chasing an electrical problem my car is finally ready for prime time. way behind schedule but given the way it ran yesterday the time was well invested.

i have two items re the TrakPros to share from yesterday.

i traversed a set of 4 railroad tracks. i admit i was gritting my teeth and gripping the wheel w a bit more energy. what a surprise! there was no hammering whatsoever. the rubber upper mounts are superb at soaking up blows.

i am beginning to realise i do not like the 12/10 springs. it isn't that they are overly harsh over the bumps. they aren't. i do not like the frequency of oscillations. too fast, too stiff kneed, too bound up. maybe, maybe, it is just that i am used to one spring speed and am now dealing w a different speed. i am sure they will work great ontrack.

but my deal is dual purpose. i want it all. i want to enjoy driving my FD on the street and blow off 90% of the cars on an occasional track day w non R rated tires. 12/10 is too much rate for that business plan. i am going to try 10/8 and
8/6.

BTW, changing springs, once you have done it before is an hour and a half simple fairly non-dirty job. so if you are an aspiring track star and you also enjoy your FD on the street a second set of springs would not be a big deal.

do not confuse bigger spring rate numbers w bigger hp. the FD geometry was purposely designed to exploit body roll not, like strut suspensions, suffer from it. body roll does not transfer all important lateral weight. body roll gives you the driver communication as to where the edge is as to max traction. the less roll the less warning you have and therefore the more careful you have to be as to driving at the limit. some body roll is good.

of course if you are running ultra sticky R tires ontrack you may develop too much roll and need the spring rate to dial it back a bit so your tires don't touch the fenderwells. (actually body roll is better addressed w swaybars...)

i am going to put a bunch of miles on my current (Comp w 12/10) setup and then switch to the Stage 3 w 12/10.

 

Awesome-sauce! I like when you post...

 

Howard, I can't wait to hear how the Stage III's compare to the comps. Hopefully you can get some time logged with them before fun midwest snow.

 

I'm sold. I'm giving the Comps a try. No track days in sight, so it will be some time before I do any testing.

 

Well I haven't had a lot of track time since my last post, but I have been driving the car on the street when time allows and the destination is going to take me down some of my favorite local roads. Actually I tend to make excuses now to take the car and my favorite roads seem to all be on the way to where ever I am going.

The car drives so well now with the comps that I can't imagine not driving it all the time. I'm sure you could get a little smoother ride from the stage III's, but I built this thing to be a race car. And it drives wonderfully for a race car. The fact that I get to drive it on the street and I don't have to change a bunch of things (actually I don't even change to the street spark plugs anymore)makes this the most enjoyable vehicle I've ever owned. It handles great, looks great, turns heads and is fast as hell. I find that I don't really even drive it fast unless I'm on a set of twisties, because I know it's faster than most of the cars around me and can out handle nearly all of them.

I'm not the professional that Howard is, and I respect what he says as golden, but for my level of road course driving ability, the comps let me play with my full race car on the street with complete comfort. And I haven't been passed by many when it comes to corner handling on track.

 

Sounds like Stage 3s and 8/6 is the way to go for the street

 

The only difference between stage 2 and 3 is the springs rates. If your gonna change springs to 8/6, you would get the same result by going with stage 2s. Only difference is you have spent $50.00 less.


Howard, does Pettit sell the 8/6 springs? I didn't see them on the site.

 

"does Pettit sell the 8/6 springs?"

Pettit is in the position to sell any rate springs if they wish.

Cam and i differ a bit on rates but we have decided it is partially because he runs 40 aspect tires which provide some softening. i run 35 fr and 30 rear...

if you are on the street you will like the 8/6 or 10/8 and they will work fine on any of the options.

howard

 

^ That's nice to know that a slightly thicker tire will play a role. I'll await your results as I too will be running 35 fronts and 30 rears.

 

If you want softer ride you can also look into tire load ratings and speed ratings.

 

any updates?