Drilling Holes in Prothane Mounts

[drewbird91]

I searched first, but my question is has anyone drilled a few holes in the prothane mounts to allow it to flex and not cause as much vibrations? Just holes straight through in the same direction as the bolt. You think it would help alittle? I don't mind the vibrations that much, but my bolts that hold the turbo to the manifold come loose I think the vibrations are what is causing that, along with the heat. Just an idea. I don't want to swap the prothane motor mounts out, neither does the girlfriend, she likes the vibrations, Let's discuss.

 

[staticbrainwash]

If it's that big a deal really, just swap to stock mounts. If not, sounds like you have other problems, OR they're not torqued down enough to begin with. Maybe some temp locktite is what you need, or new bolts.

 

[kahl23]

Hmm. Well you could theoretically drill holes in the mounts, but it defeats the purpose of having prothane mounts. As for the turbo bolts coming loose, special washers are used for those four bolts. If you look at them, they have dimples on them that act as springs to keep tension against the bolts. After 50k miles or more, they wear out. Slowboy sells these washers. Good luck.

 

[AuntiesTSI]

Do you have the correct washers on the turbo bolts and installed the correct way? The washers should be curved and I believe that they should be installed with the "cup" facing the manifold and turbo.

 

[drewbird91]

If it's that big a deal really, just swap to stock mounts. If not, sounds like you have other problems, OR they're not torqued down enough to begin with. Maybe some temp locktite is what you need, or new bolts.

I don't want the stock mounts in there because those things flexed alot. I need to get some high temp 1500 degrees loctite.

Hmm. Well you could theoretically drill holes in the mounts, but it defeats the purpose of having prothane mounts. As for the turbo bolts coming loose, special washers are used for those four bolts. If you look at them, they have dimples on them that act as springs to keep tension against the bolts. After 50k miles or more, they wear out. Slowboy sells these washers. Good luck.

I don't think it really defeats the purpose of having the prothane mounts at all. These are obviously stiffer than stock and if you were to drill a few holes through it would allow the mount to flex more, not as much as stock but not as hard as the solid prothanes. So you'd end up with something right in the middle of that range which was what I was thinking. Either way the solid motor mounts are tolerable but this was just a thought.

Do you have the correct washers on the turbo bolts and installed the correct way? The washers should be curved and I believe that they should be installed with the "cup" facing the manifold and turbo.

Thinking about it no I don't have the right washers in there. MR187848 is the part number you are refering to and JNZ tuning has them for $1.10, but I'll go to the dealer ($1.20 with discount) after work and get them right away and put them on. I bet that will help. Which way is the correct orientation? http://www.dsmtuners.com/forums/showthread.php?t=222822&highlight=Turbo+Bolt+Washer

Anyone else have input on drilling the motor mounts to get that middle of the road compromise? Has anyone tried this?

 

[Locke]

I filled the mounts on my old LT2 Sunbird. That old car almost vibrated itself apart. (really, interior panels fell off) I did exactly as you are thinking and cut four 5/16" holes into it. It did help a lot, though I wish I would have cut 3/8" holes instead.

 

[AuntiesTSI]

Just like they said, I'd go with Number 4. I was also having this problem on my car before I took it apart as well as my brothers. Then my uncle and I were putting back together my aunt's 1g and he showed me, I felt dumb . Her car also has prothanes.

 

[nightspeed87]

Take some stock motor mounts from the junkyard and fill them up with window weld.
Do it slowly and not cake it on, and let it dry in sessions, and this will give you most of the benefits of the prourethan motor mounts without all the vibrations. Theres a write up on this window weld trick somewhere. I Did this considering I have balance shafts removed and no sound deadner in my interior.
But if your just doing this just for that one bolt then find a way to keep the bolt tight like suggested before because the prourethans are helping the car alot whether you think so or not, there the best way to go....

 

[romeen]

http://www.dsmtuners.com/forums/showthread.php?t=222822&highlight=Turbo+Bolt+Washer[/url]

Anyone else have input on drilling the motor mounts to get that middle of the road compromise? Has anyone tried this?

The correct orientation is #2 in that thread.

In theory the holes should work to give you an end result somewhere between the stock rubber and the Prothanes, but I don't know of anyone who has done it. If you do it you may want to consider where to drill the holes relative to the stress placed on the particular mount. For example, the stock mount may have the openings at 12 o'clock and 6 o'clock depending on which mount and how it relates to engine movement. Or you could drill holes spaced evenly around the entire mount. Just something to think about.

 

[AuntiesTSI]

The correct orientation is #2 in that thread.

Actually now that I think about it, he may be right.