Stiffer Motor Mounts

[jemartin144]

So, I don't think Festiva Motorsports is available anymore and I'm looking to stiffen up my motor mounts.

For the front mount I'm just gonna make the inserts, because I have a lathe and it should be easy. In fact I'd be whiling to make them for anyone else once I figure out a price.

The rear seems trickier though. Without having a place to buy high durometer mounts I'm not sure of a way to stiffen them up. I can't make it solid metal (and I wouldn't want to anyway), so does anyone have any ideas?

The only real idea i have right now is just to just try and epoxy a polyurethane block to the plates, but I'd be really afraid it would come apart.

[eurotiva]

Even with solid mounts, you can't really tell because the crossmember is rubber mounted

[jemartin144]

I probably wouldn't really mind either, but for autocrossing it cant be solid. But that's another good point that i hadn't thought about, I wonder if i could eliminate those crossmember to chassis bushings. That would help stiffen up the engine. I'd probably have to make some spacers or something to hold the crossmember in.

[Movin]

I had a solid rear for awhile until my new one arrived. Even with the rubber in the
cross-member it was way too noisy and vibrated the dash bad! It sure was nice
getting the new mount in place. More recently I dropped and rolled the transmission
by making a 3 inch thick rear solid cross-member mount. I noticed no change
in noise or vibration. I left the rubber front in place to allow the new angle.

[gauge_half_inch]

You could use poly bushings like swaybar endlinks, and drill through the metal and rubber on the rear mount use 2 holes, on either side of the stud. After the holes are drilled rip the old rubber apart and grind it all off both sides. Using a pair of bolts and lock washers bolt the two pieces back together using the two poly bushings in place of the rubber. Don't over tighten them, the Polly will crack if compressed to much, but make sure their good and tight. The conquest/starion guys fix their trans mounts this way and they have a similar design only theirs used two rubber blocks, one on each side of the tail shaft housing .

[fastivaB6TG25MR]

You could use poly bushings like swaybar endlinks, and drill through the metal and rubber on the rear mount use 2 holes, on either side of the stud.

you mean like this?

[gauge_half_inch]

Not quite. The stock rear mount. Basically removing the rubber chunk and replacing it with two of those bushings between the original metal halfs.

[Movin]

Because the poly is so much stiffer four might be preferable?
assume that the poly has a sleeve to prevent bolt contact
with metal..

[jemartin144]

guage, I could see something lke that working. I wonder if it would be enough material. Maybe making a block the size of the original out of poly and bolting it in? Id think anything with a bolt wouldnt give enough without isolating it from the metal brackets.

[gauge_half_inch]

If the conquest and its 2.6L turbo charged engine is fine with just 2, I think it should be just fine for ours.

[fastivaB6TG25MR]

i think i still have a stock cross member laying around some where that i could check to see what is needed to make a set of these if someone is interested.

[jemartin144]

I've been looking around and I found this aftermarket Miata motor mount that I think the same concept may work for stiffening up the festiva mount. It would take some fabricating, but it doesn't look like it would be too hard. I'm gonna try and mock something up like it.



Also, I finished the front mount. I'll try to get it in later today and I'll report back. It's a bit heavier than OEM, but it should be much stiffer. I've got enough material to make a few more. So, if anyone's interested let me know and I'll come up with a price. (btw, I went with the amber over black because it has the same properties, but its cheaper)

[Safety Guy]

I might be interested in a poly front mount.

Waiting to see your modded Miata rear mount idea shape up, too.

Karl

[Advancedynamix]

For the front and engine mount I would (and did) fill a new stock replacement with two part polyurethane epoxy. I suggest the URS 2050 (50A durometer) polyurethane system from Forsch polymers.
No lathe necessary, it hardens in hours and firms the engine mounting without sacrificing traction or drivability. I have this same resin in the stock engine mount and the custom rear mount on tweak, it's held up to over 20k miles of my abuse.
Just google forsche polymers, they are in CO, nice people, and they supply a lot of the polymers to many aftermarket suspension companies.

Also, an idea for the rear mount that I don't think anyone has mentioned is to swap out to an Aspire mount and that can also be poly filled.

If you are more comfortable buying local, and have some time to wait, the black loctite brand polyurethane roofing sealer sold at hardware stores is a great mount filler, but it takes lots of thin applications and lots of drying time. A properly done mount using this technique will take a couple weeks. The two part resin cures ultra fast, but the loctite solution is cheaper and only requires a trip to home depot.

[jemartin144]

I assumed the rear aspire mount is the same as the festiva mount. Are they different?