RotorMotor

iTrader: (5)

its not particularly sloppy, but then again im not sure what its "really" supposed to feel like anyway... maybe i should hold of on the bushings.... they're expensive, but im afraid that jim will never get around to making them again.... there are so many other places that 600bucks can go... im torn!

ZeroBanger

If you get a clunk when you hit the brake its your lower control arm lower rubber bushing. If you get screetching like a rocking chair kinda squeel its the metal bushings in the upper control arms.

I used to get mad wheel hop. I have not been to the track in several months, I had 3 changes to the car since then I when I went back last week I had no wheel hop at all. I mean literally of the 80 timeslips I have at home these last 4 were the only ones that I did not get wheel hop. The 3 changes were:

Brand new passenger side upper control arm. The bushins were bad it was cheaper to replace the whole thing. Brand new bushing in the lower passenger side control arm. (all bushings are good now) and lastly I got a brand new transmission from Mazda.

one of those things curedd it for me. I use 21 PSI in my tires.

BTW, what rpm do you launch at? thanks.

RotorMotor

iTrader: (5)

in this car i have a clunk when the car comes to a complete rest (compressing the rear suspension). i have tryed a few rpm's but kinda gave up when i saw my best time being 14.5 sec. also, as far as shifting i have been shifing up at around 7.5K RPM.

DaiOni

My car is 'clunk-free' when in motion. However, when the car has been sitting for a few days or so (ie: not driven) - it often 'clunks' when it begins to move (ie: first second of motion). Anyone know if this is indicitive of a similar problem?

RotorMotor

iTrader: (5)

ive had that before too... never got to the bottom of it.

also i was thinking about doing some rolling starts with the car (using a gtech) to try and get some meaningful mesure of performance... i could start the 1/4 mile test while going like 5mph... wouldnt that just mean the trap speed would be 5mph more... the quarter mile time would be slightly better as there is already traction, but other than that it should be able to figure out how far i traveled as it just integrates acceleration over time (i think thats right? its been a while). anyway, a quarter mile time from a 5mph roll would be useless (except for me to compare it to my other 1/4 5mph roll times) unless someone else has a gtech and would be intersted in doing a test like that to compare to. the good thing about testing using this method (although hard to get a good standard of comparison) is that you have relativly little stress on your drivetrain so you dont risk much testing your car. i dont know about you but i just want a measute relative to other FD's because how many times in everyday life do you drag someone.... people usually race from a roll... the FD usually does well from a roll cause you can get your revs up easily and turbos have sort of an exponential power band vs a linear NA powerband. i love racing from a roll cause the FD usually does well ive found if you can get into full boost quickly

jspecracer7

ah yes....wheel hop.

Some of you need to think about what type of SUSPENSION you have. Stiffer springs = bad for launch.

K2rd toe links/trailing arms
diff/tranny brace
cusco diff
HKS hiper-D drag
OS twin
7000 rpm launches on Nitto 555r's with NO wheel hop.

Best cure for wheel hop? Launch HIGHER.

SkywarpR

The last time I went to the track, I didn't get any wheel hop at all. I am running stock R1 suspension, and 245/45 16 SO3's. I launched at about 4500 rpm, and I had about 15lbs in my tires.

I ran a 13.8@100mph when it was 94 degrees out! My mods for that run were:
ACT clutch
K&N drop in
M2 radiator

At the track tire pressure really seems to make the difference for me. I must say, I still haven't figured out at what rpm I should launch yet though.

On the street with 35lbs in my tires the wheels hop all the time. I think I need to try a lighter launch. Any suggestions?

rotary

get softer tires it will help alot. softer tires will give you more traction and less hop.

rotary

sorry

ZeroBanger

yea but launching higher can break your diff when you have drag radials, ask me how I know, please.

jspecracer7

Because you had the stock POS torsen diff. Forgot to mention I have a 4.777 final in the pumpkin.

ZeroBanger

The pumpkin grenaded. It split completely in half.

jspecracer7

What type of suspension? I'm guessing you didn't have a diff brace either.

Damn, forgot about the solid diff mounts too.

RotorMotor

iTrader: (5)

ok so to elliminate the wheel hop i tryed doing a 1/4 mile from a rolling 20mph using the gtech. i got a ~15.8sec 1/4 and the gtech said the trap was 91MPH so adding 20MPH to that i finished the 1/4 @111 MPH. this info is kinda useless however unless someone else were to try the same thing

ZeroBanger

was completely stock suspension. Was the first run after I got my midpipe (had a cat before). I tried doing a dry burnout launching at 6000 RPM.

TobiasRX

U can eliminate wheelhop by getting coilovers. But dont get coilovers unless u want to, cause they're not cheap.

SkywarpR

I find it hard to believe that getting stiffer suspension will solve all of my wheelhop woes.

Beast From The East

No offense, but coil-overs will not eliminate wheel hop. I've got very good coil-overs, but the springs are 450s which don't squat as well as softer springs. This is because I also road race the car, but actually hurts things from a drag racing perspective.

Wheel hop on our cars is caused by the multi-link independent suspension system, as previously mentioned. Eliminating the energy absorbsion points on it helps, as does lower pressure stickier tires, but coil-overs on their own will not eliminate the hop generated by high rpm clutch drop launches.

Beast

jspecracer7

This is a FALSE statement. SOFT springs help launch. 99% of all coil overs are manufactured for circuit/road racing/auto cross...basically they're made STIFF. STIFF=wheel hop The only coilovers I have seen that are soft are the HKS Hiper-D Drag suspension.