Dougs951S

I'm thinking about moving to solid engine mounts in an attempt to solve what feels like a bit of driveline lash when getting on the throttle hard from low rpm, hitting the throttle hard while cruising with light throttle, or downshifting and then stepping on it. Also feel it when I let off the throttle, mainly if I just let it snap closed and less so if I ease off it. It feels like something is moving slightly, it just doesn't feel as solid as my 84 when I jump on it. There is a split second of "squishiness" before the power feels like it connects. I don't hear any strange noises (hard to hear much at all with a side exit exhaust ) and the idle is smooth enough, its not ridiculous anyway! Its fine once I'm on the power and stay on the power but I do notice the same bit of slop on hard upshifts when I'm on the power. I think its worse in the lower gears but I could be imaging that. Does this sound like a motor mount issue? I have a solid polyurethane trans mount that I love and it was one of the best things I ever did to the car. I'm thinking about taking some old stock mounts and filling them with 75 durometer polyurethane; it'll be solid but not as solid as a stiff piece of aluminum. Has anybody tried this? People tell me this is going to rattle my teeth out, but the car is used 90% on smooth texas highways with track use and autoX in its future. I'm on 300 lb coilovers and 28mm T bars so the ride is already a bit stiff for a street car, plus I'm young and I don't think I would mind a little more roughness in trade for a stiffer chassis. Thoughts gentleman?

thingo

I have the semi solids, they really do help with what you are talking about, some people cannot abide the increase in vibration, but I found it either settled down after a while or I got used to it, mine is a track car and I am old, but for me they were an improvement. I have the tranny mount filled as well. Filling old mounts should work fine I would think if you can come up with a decent method.

Dougs951S

Good feedback, I think the poly filled mount will be closer to a semi solid than a true solid mount and I think I could include a round rubber bushing set inside the block of poly to help dampen vibration a bit. My plan is just to stretch out the rubber baffle after slicing them open and draining the oil, then insert rubber bushing and fill the rest of the void tightly with 3M window weld, which comes in ~80 durometer and cures at room temp in 48 hours.