drag racing John, that is what did it!

What are all the possible mounts we can upgrade to?

I remember someone selling some X-73 tranny or motor mounts??
does anyone know about these?

Marty K

 

The mount has been upgraded to a 997 part number and was about $200. I got a low mileage, like new shaft that was removed from a RWD conversion for about $200.00, also...

Part # for tranny mount = 997 375 033 03

I did not get a number for the front shaft - just had it shipped...

Marty, X-73 is a motor mount. I have them and like them...they tighten up the handling a bit when hard cornering...and overall make the car feel tighter, more direct in general...slightly, though - nothing major, but you can feel it.

 

Thanks John! You're a wealth of info, as ever.

 

Haven't had that experience at all. When you're creating that much torque and etc. solid mounts are the way to go, period, IMO. Consider this as well.... you're running a light flywheel, kevlar clutch, huge cats and an open exhaust system PLUS PSS9's or motons. you ask about vibration?

Honestly I have felt no difference with exception that when I am on boost, the car does feel a bit more linear and seems to track a little better. The concern SHOULD be that the solid mounts subject the driver to more engine vibration through the chassis. I have not found this to be the case at all, and as above, who would care about the marginal increase in vibration (if you could detect it) since the mods here create a very loud and stiff car to begin with relative to a turbo on stock trim.

 

Brett,

Here are the pictures:










With no tension, it is hard to see...



With the new transmission mounts, new front shaft, new PP/flywheel/clutch, 4 new tires and an alignment...the car felt nice today. Finally, I'm ready for the 2008 season.

 

John this may be one that the drag strip is harder on than us track junkies!! Sorry to hear about it but sounds like 08 will be a good season for you!!
thanks for pointing this out, we will all check now!!

 

Wow that looks really bad, never had anything like it. I think it does have to do with drag strip like Tom mentioned.

 

Jean/John, you should have seen the condition of mine, will post pics later, rubber was badly shredded. I think it's a common issue that not a lot will know about, don't think it will cause any issues apart from the odd vibration etc.

 

For those who are not ready for the solid mounts. There is a happy medium on stiffening engine and tranny mounts. Start with new OEM mount and use
windshield installation urethane...3M has an excellent product.
Clean new part with lacquer thinner, then inject the cavities around the
rubber until full and flush with bracket. Allow to set up for 24-36hrs
(depending on volume of urethane) this will minimize any movement
without transfer of vibration using solid mounts.
This modification eliminates the weak link of the drive train.

 

Jean, both sides had the same type of break and it went all the way through the rubber making that rubber section totally useless. My title says one year at 700HP, but I think I may have had this for a little longer. Last year my driveline had a lot of "backlash" and we looked for the problem, but couldn't find anything. On a guess, I had the rear CV joints changed and it effectively cured the problem, but a tiny bit of the backlash remained at times. My tech thought the rubber coupler of the front drive shaft looked like it may be cracked, so I purchasd one then, but hadn't put it in yet. When we took it out for the clutch, he discovered it had also failed and was indeed cracked. Now with the new CV joints, new Transmission mounts (which some said a broken mount can cause excess driveline slap, but it didn't appear broken when we looked at it) and new drive shaft, the car is really tight in the drive train. Feels like new.

It is very possibly the drag strip. The last time I went, I was on the PS2's and they made my car axle tramp badly, whereas the PS1 or PS ribs do not. I have gone back to the PS Rib, as I prefer it to the PS2. When I go to the 1/4 mle again, I will shut down at the first sign of axle tramp from here on...as I thnk that may be the cause of the rubber failure - it feels really rough on the drivetrain when it's happening...and once it begins, you know that run is not going to be any good, anyhow.

 

That's not a bad idea and one we've done for years with aftermarket Urethain bushings! Best part is, it works!

Mike

 

John, Stevo

I recall a couple of years back I took my car to a small racing shop in Germany, the guy is a guru who used to work for years for Supercup and is until today almost impossible to get hold of.

He took a look at my car's suspension which I thought was great after having installed Moton and checked everything etc.. He came back with a HUGE bill for parts, basically every single arm, link, sway bars etc.. + some additional parts from GT2 cars.

When I went to see the control arms, which he said where "****e", I could not see anything wrong with them, he took a screwdriver and moved the rubber around, and it showed some cracks, albeit small. I tried arguing with him, he told me he would not touch the car unless I changed those, as his alignment work and corner balance would be worthless, and this car would never handle well as is. It was enlightening, because of how seriously they take this stuff.

With that put into perspective, I know that you cannot have a good handling car unless all these are in perfect condition, you cannot hold toe settings that's for sure, and any corner balance will be worthless after 5 minutes driving the car.

I ended up having to replace every single arm in my car (I put RS ones at once), I could have sold the old ones easily as "almost new" this is how good they looked, and no he was not ripping me off, it was as a favour to one of his biggest race customers and labour costs were very reasonable.

 

John, Jean and others,
I also am getting ready for the road racing season (and maybe one "6bling drag racing
adventure"), what are the part #'s for the CV joints (are there (2) or (4) of them,
and what are the X-73 motor mount part #'s?

thanks guys, this info makes this site very useful!

Marty

 

i've got 30k miles on my GT700 and, while i shift like a maniac, i don't drag race. replaced the clutch 2-3k miles ago and no issues.

the x-73 mounts are going in sometime soon...

- chuck

 

Chuck, which clutch were you using before? and what did you put in recently?

thanks