Tranny Mounts vs. noise

[Humble]

I've run the stock rubber transmission mounts then switched to the urethane mounts and now I'm going to a solid mount. Has anyone run a solid mount before and how much more noise should I expect in the cab? Previously with a 2L type4 and a stripped interior running urethane mounts I would almost have to shout to talk to the passenger. With solid mounts am I going to go deaf driving this thing?

[ricola]

Not sure about noise, but I've heard problems of nuts coming loose from the increased vibration!
Rich

[Bruce2]

Urethane are very noisy compared to rubber. For me, long highway trips required earplugs. Now that I am back to rubber, earplugs are not needed.

I would say that urethane are 50-80% of the noise of solid mounts.

[Bugat5speed]

Hi,

what would concern me much more than the noise is the fact, that your gearbox housing won´t stand a solid mount very long. We had customers in the past that monted their 901 gearboxes solid into the chassis. Some of them were completely destroyed (housing, bearings).

Besides, take care that your dental fillings won´t fall out due to the vibrations (-:

Martin

[Humble]

Thanks for the replies guys. This is a race car first and formost and it will see occasional street use because I'm a glutton for punishment Actually there are a lot of fun roads to drive around here and I want to take it on a cruise once in a while. I noticed a lot of vibration in the cab with the urethane but i never had any nuts loosen up on me that's not something I want to worry about either.

Martin, is a built 091 bus tranny going to hold up any better than a 914 tranny? I can accept a rebuild every season to every other season but any more than that would be too much.

[Tedzbug]

what about a rear trans strap (padded) same issues? and rubber mounts?

[Humble]

I had a padded mid mount and bellhousing strap kit before but that was with the urethane bushings. I don't think the straps would help the noise at all, if anything I would think it got worse with the strap kit.

[Twystd1]

If you launch hard in first consistently and often with a 914 tranny (901)

First gear isn't going to last long.

With slicks... fugetaboutit.

With a Quiafe or spool. Dragging?

First gear won't last ya 2 nights of running hard with slicks.

MORE THAN LIKELY.

The reason is that the 914 wasn't made to use 1st for anything other than getting the car moving. Thats why the next 4 gears are in a H pattern.

Road race cars don't really use 1st on the track. Therefore the 901 has a long shaft for first that only has two bearing surfaces at close to the ends of the shaft. So the gears start to climb each other when exposed to large amounts of torque and become un-meshed and chew each other to pieces.

Thus sending gear metal through the tranny.

Billet intermediate plates and spray bars (for heat) help a little. Yet they still don't fix the inherant issue with using a 901 as a drag transmission.

By the way. You ever try to shift a 901 tranny FAST from 1st to 2nd?
It takes some serious practice.

On the flip side. I know of MANY guy's with 901's behing Porsche 6s, suby's and V8 Chey's that don't blow up the 901s very often.
First they don't launch hard ALL THE TIME. Second they use street rubber and third they launch in second (V8) if they wan't to save the trans.

If they abuse it. They can and do blow up 1st with amazing regularity.

You can get many differant gear sets for the 901. Some are cheap Some are like gold.
A full 901 rebuild using the existing gears and shafts. Installing new synchros, sliders, dogs, forks, etc, all new bearings.

I bet ya a perfectly rebuilt 901will cost ya more than than most of the engines you see on this forum. If ya blow one up.

Differant R&Ps are scarce to some degree ($s) and you still have to find someone with the tools to change it.

Bottom line. For a competitive drag car and occasional street car. Find sumpin else.

You knoiw what I do? I collect 901s. I keep at least 4 at all times. I just swap parts and make good trannys out of broken or m3ediocre ones. it's cheap and effective. I just don't mess with the R&Ps.

Thats my opinion anyway. Yours may be differant.

regards,
Clayton