I'm pretty sure you didn't pull a car or two once we were going full steam...cause I was checking in occasionally in the side view mirror to see where you were at.

Anything past the time I nailed the brakes (so anytime you were in front) means nothing, cause I shaved off a good 10mph when I hit the brakes, then started again. We also got to a speed where I eventually let off and gently got on the brakes.

I nailed the brakes about the time you flew past me...heehhe...it wasn't let off, wait, squeeze on the brakes...it was let off, maybe a second at most pause, then hit the brakes...i think.

Will have to do a better run, purely technical purposes of course ...must compare chipped, test pipe 26/8 car to MAF, dual port wastegate, 3" downpipe back exhaust, forge CBV car

I'm running ~16-16.5 psi in 3rd.

 

[quote] Will have to do a better run, purely technical purposes of course <hr></blockquote>

Yes, I agree. Now I’m very interested in gathering all the empirical data for our study. Sometime before the next AX season preferable. <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />

 

[quote]Originally posted by jvc951:
<strong>

Yes, I agree. Now I’m very interested in gathering all the empirical data for our study. Sometime before the next AX season preferable. <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" /> </strong><hr></blockquote>

Hells yeah... Probably not for a while though, this little problem will take till december/january to fix. No time till winter break.

 

Well, right now I'm in the process of going to mech's and getting opinions...

Problem: car shakes badly on full boost (only full boost) in 2nd gear (only 2nd gear).

So far mech #1 who has test driven says trans fluid, change to what redline recommends (in this case mt-90)...right now mobil 1 is in there because it was available, done a few hundred miles on it.

mech #2 who hasn't test driven says torque tube, i say he's wrong because it wouldn't only shake in 2nd gear, it would shake in all gears at X through Y rpm's. I'll be taking the car to this mech in a few days after I change the trans fluid.

mech #3 I'll be going to see on saturday...so we'll see what he has to say.

Perry, Why do you say wheel bearings? Wouldn't it shake if I boost it in 3rd at the same speed as I'd be going in 2nd?? It doesn't...

The rubber cap on the back of the trans slides into a bolt...someone on the e-mail lists suggested that maybe this bolt came loose and pushed the cap out...right now the cap is back in but it is not fitted into the bolt. If the bolt is tight, can fluid leak out the back? Does the rubber cap just keep dust out or what?

The problem here is that to tighten that bolt...or check its tightness I'd need to drop the trans at least an inch or 2 or 3. Is this just as involved as dropping the trans completely or is it any easier??

TIA for any advice...

--adrial

 

I have the same problem with the shudder. Its the Flywheel. Your Flywheel is warpped you may need to get a new one or have yours re-surfaced. Problem solved.

Evan

 

Your car shook only in an individual gear and at WOT with a warped flywheel???

 

I say wheel bearings because I have replaced just about everything else! IIRC... and it has been a while since I drove the car... mine was most noticible in 3rd, but was apparent in all gears. 1st and 5th yielded just a small vibration, but 2 and 3 felt like you were driving on square tires. The vibrations increase with wheel speed.

No... it was not the tires because I ran 2 diffrent sets, 1 of them new rims/tires and a fresh balance.

Torque tube does not make sense since it rotates at the same RPM as the motor, so it would happen at each RPM range no matter the gear.

Since yours is 2nd gear only, you may have an issue with that gear alone. Hard to tell without feeling it myself.

 

It's the Flywheel.... Have it re-surfaced. After i had it done the shuddering was gone. No matter what gear i started in the shudder was there.

Evan

 

Well Evan might have your solution there Perry....did you have that done with all the recent work??

edit:

Well after a few more seconds of thought...Evan's problem doesn't quite describe yours either Perry...I dont think it does anyway.

 

I had the flywheel turned when I did the 1st rebuild... shudder sill there. Had it checked again this last time and it was 100% true. I prepped it for re-install, but nothing major.

Mine is definately from the rear end. It feels like an out of round tire. The frequency of rotation is far less than the motor. (say 6 grand in 2nd gear, the "vibration" is not happening at 6000 times a minute.)

Again, mine increases with wheel speed. I initially thought it was my CV's, but after a flip and repack, no change.

 

the round rubber thing is a cap/seal that seals the end of the case where the input shaft bearing is tightened. the little gear thing is connected to the seal and sticks into the end of the input shaft, which is hollow. Unless the gear thing is the bolt on the end of the shaft, which is also hollow and takes a 12 point or triple square socket to fasten.

 

I have had the same problem for at the past 2 years without it getting better or worse, even after replacing the cv's. I find it worst when under WOT going up a hill in 2nd. It relates to the amount of rear end squat. My vote goes for the wheel bearings. Luckily for me it harmonizes with the rattle from my hatch

 

The back of my car was lowered an inch somewhere in all this...I think the start of the vibes and the lowering weren't TOO far apart...I'll have to think about that some more.

MHT, I kind of understand what you said...but to clarify....fluid CAN leak out if the 12pt bolt is tight and the cap is off?

thanks,
adrial

 

Just to make sure everyone understands what happened here...

I estimate fluid started to leak out of the transmission at least a month before we noticed it. After an autocross and high speed driving 90% of the fluid dumped out the back. So... the car was driven for at least 200 miles and autocrossed with insufficient &lt;50% transmission fluid. In my opinion this will cause damage to any transmission, hence the shuddering.

Adrial - i thought it shuddered in 1st gear too, at least that is what i remember. I also thought the shudder occured in higher gears, but not as badly.

This automatically rules out torque tube and flywheel since it is gear related. Hopefully once some new redline is dumped in there and the bolt retightened everything will be fine. But in case that does not work what else could be wrong?? LSD doesn't seem to be functioning properly, but this could be due to Mobil 1 trans fluid instead of Redline MT-90??

 

bump. New Redline MT-90 fluid didn't change anything.