Ok, I know it's not something that I should be doing but it was a straight road that went on for a couple miles and plowed fields on both sides so I could see if any animals were going to hop out in front of me.

After a blast to 150mph I had brake vibration for a few miles afterwards, now they are back to normal and have been for ~30 miles. I checked the lugnuts and they were all torqued. what could cause this temporary vibration?

 

Did you feel it in the pedal or was it more that you felt it in the but (not trying to be funny at all) If you felt it in the but, could be a drive line issue-I'd check the prop-shaft and then on to your axle bearings and everything inbetween.

If it was in the pedal, maybe you felt your fluid boil? <-- an absolut guess

 

How hard did you hit the brakes from 150 to 30?

RXDad

 

Thats the thing, I didn't hit the brakes hard at all. I just gave it a little pressure and let off till I coasted to ~100 then I hit them again to slow to 60.

 

The vibration was in the pedal

 

I think the problem is that stock brakes weren't designed to slow you down from 150. Maybe half that, and thats all.

 

Really? I never thought about that.

*takes note for next time he needs to slow down real fast from 100-120*

 

I haven't had this problem from 120 braking harder. I did get brake fade then though.
Brakes are stock -se with braided lines.

 

Slight rotor warp that fixed itself after cooling?

 

Even if you dont push hard,at 150mph the rotors are gonna heat up really quick.Sounds like just plain too much speed.Theres just a LOT going on at 150moh.The dynamics of braking at those speeds will thow a lot of things into chaos.Considering the light gauge of the frontend components,wheel bearing play,slight existing rotor warpage,road conditions,and frontend alignment....at 150MPH our tinny little 20 year old cars are gonna flex and shake at under that kind of braking(among other things).Thats why racecars have seam welding,chassis braceing,big tires and susp./brake upgrades.

 

I had my car to 137mph the other day to slow down I just let off the gas as my rear brakes were already bad and my frint were warped and had very little pad left. Oh yeah are friggen crazy man 150mph in a first gen that is insane and I thought I was crazy.

 

Heh,heh....
150...137....your just as dead if somn' goes wrong.
Thats why I laugh when people ask me how many tickets I have or how fast my car goes.I drive like a grandma on the streets most of the time,except maybe 1st gear from the light!

 

same thing happened here at 145. I tried resurfacing the rotors, new bearings , grease the zerqs, new alinment, ended up being I threw one of those balanceing weights with the double sided tape on it. the stock rotors do warp a little with heat then go back when they cool. your tires are rated for that speed right? the flex in the car should not be a issue unless you are cornering or you have some serous rust. I donot think thats the case with your car. look at your wheel bal weights.

 

Maybe its the warp speed motor, Captain.

Slow down!

 

I'm surprised you didn't end up in 1956.. Guess the Flux Capacitor was offline for that test huh..

 

i agree with steve.
only us turbo snobs can get there usually.

first gens dont typically go 150mph
most cant and shouldnt.

 

rotor warpage, dont worry

 

I am just saying I would not try to do much over 140mph when I let off at 137mph my car was still pulling but it was shaking and rattling not to mention I had the factory 13 inch wheels on it, the tires have like 108 mph speed rating on them lol. Oh Steve I can't beleive you might only let your car lose through 1st I guess your in it more for looks than anything else lol. Oh and I know crash wise 137mph is just as bad as 150mph.

 

I didn't plan on going that fast but it was feeling happy in 4th and 5th felt good also and... you know how it goes. Before you know it you've been in the throttle a little too long. I don't know if it was 150 or not but it was 6800 in 5th. All that matters is it was too fast for my car and I don't plan on doing it again.

I'm with most of you with thinking my rotors warped for the few moments. Maybe at that speed even no brake effort heats the rotors?

 

OK,grandma driving is relative around here.I still get on it going up freeway onramps,and there are plenty of windy roads in the back country where I push a bit.But in comparison to the yuppie idiots and ricers around town,I drive like a granny.These guys are taching each gear on surface streets and doing 100 on the freeway.Im work directly across from an on-off ramp and I watch the same morons speeding through town and on the freeway,every morning and evening.Its amazing some of them still have licenses'.Probably the worst offenders are the guys in hopped up diesels(OK I have one too,but I dont pull a smoke screen at every light!)

 

Yeah,

Only 3/4 lights!

Actually, I usually am pretty easy on my new RX-7, I've only got on the gas a few times to get on the on ramp, she definitelyruns, I usually get up to about 5k RPM before I shift to the next gear.

If I were to race, what should I shift at? It's got about 110k miles on it, and I'm about to go through all the usuals (oil change, etc).

Thanks,
Eric

 

If your tires are not rated for those speeds, or are just old, they may go slightly out of round at high speeds. I ran across this issue in a '73 Z that I had years ago.

 

For those that think the 20 year old tinney 1st gen can't run fast safely, look at these trap speeds from this past september. http://www.scca.org/_Filelibrary/Fil...n-traps-ep.pdf

Now these are race prepped cars with full cages and race tires, but these old cars can still run.