I just put solid motor mounts on my 308

I only swapped the 2 rears ... I couldn't wait to try them out ... I still have the urethane mounts on the front. At first I thought it was too much but I'm hooked. The feeling coming thru the steering wheel reminds me of a motorcycle ... in fact the whole car reminds me of that more and more. Shifting at high rpm is so solid ... I luv it!

cheers
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Thanks ... I have solid mounts on my 911 track car. Some guys in the P club put them on their Boxsters and had some serious resonance issues at low rpm which made driving in traffic unbearable I was told. There is quite a bit of extra bzzz at 1500 rpm but I never drive there .

I originally made up some urethane ones but the rears haven't been holding up. When I first switched to urethane the difference was night and day ... the swap to solid is another magnitude of "night and day".

 

probably ... is it going to fall apart you think? ... my 911 is a 1973 and I still drive the **** out of it

 

no worries ... I don't have teeth .

I hope it doesn't do something to my brain though ... probably too late since I already don't think its that harsh LOL ... door fell off though .

cheers

 

It's interesting ... now it just seems louder and not that harsh at all. The engine is all warmed up and idles really smooth so that helps. When the engine was cold and idling it felt pretty. Like I posted I only have 2 solids in there right now ... all 4 might be too much ... I'll take the wife for a ride and see if she notices any difference. I think if I'm looking at things right the front ones get pulled up for the most part under load so maybe just 2 solids in the rear is a good compromise.

Here's a pic of the urethane deformation. Only the right rear is getting hammered like this. They've seen 30,000 miles and several track days. Hopefully they'll last like 10 years with typical street driving.

The top pic is comparing the right side to left side compression. The bottom pic is showing the deflection on both pieces from the right mount ... I'd rotated the urethane from top/bottom and machined new pieces when the first side started to collapse. They've both pretty much got the same permanent set now.
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Yeah I could of just hogged all the meat off the back side of a stock pan but had this one that I made up for a different dry sump style. It has windows/openings in the sides for external scavenge pickups (can't see them in this pic). I figured I might as well use it instead of cannabalizing a factory part. All I had to do was put the 2 mangetic drain plugs in which are right under the pipes of the pickup tubes.

I've got to do a few more things to the car that this motor is going in but was just dieing to try the solid mounts. I went for a few more romps yesterday eve and the worst vibration is at 1500 rpm. The rest of the "experience" is really more noise related ... it seems like you can really hear everything ... a lot more gear whine and wrrrr.

 

another pic
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Hmm you got me wondering about that now ... I thought for some reason the mounts weren't symmetrical but they are. The exhaust is still pretty close on the left mount. Maybe the fact that the crown gear is offset on that side in the gearbox puts more load on the bearing on that side thus the mount, or it's just that I don't sandbag on left handers like I do right handers 'cause of the oiling issues ... maybe that's it?

On the front mount on the right side the "puck" is loose on the top like the motor is pulling up which makes sense ... just real interesting all the load appears to be greater on the right side than the left ... any more thoughts about that? I really thought it was the geometry of the mounts relative to the engine but now I'm not seeing that now.

cheers

 

Hey Pete ... PM'd you back. I absolutely luv these solid mounts. I was watching one of my autoX videos and I shifted right in the middle of a corner under heavy cornering load. I don't think I was able to do that even with the urethane mounts. I've also got this "feeling" that the motor is actually boxing in the entire rear end structure. I've also got solid suspension bushings on the rear ... that helps .

 

FWIW ... a fellow engineer (Mke) was 'splaining me about possible problems with only running two solid mounts. He's absolutely correct of course but I just wanted to install two in the beginning because it was easy and I wanted to make sure my teeth didn't rattle out.

I still need to swap the other two and probably go to a solid bushing arrangement on the top dog bone strut that connects to the rear cam cover.

Yes ... those Hill pieces are pretty reasonable in price. There's pics of what I made up above ... much ligther than what Hill's part looks like and you don't need the extra steel ballast/spacers that the stock mounts use ... I made the front mounts the correct length without the need for the extra spacers.

Be interesting to see if that is a part they stock now ... looks like a rendering in the pic.

It's good they offer them ... they should start offering EFI conversion packages .

cheers

cheers!

 

Yes they are working great. It's interesting I noticed something on the rear suspension that I would have never picked up if I wasn't installing such precision pieces. Without getting into a long explanation that belongs in the other thread it seemed both upper control arms were shifted forward or back (can't remember) because I had to change the stack order of the thrust washers ... rubber/urethane just distort the .04" difference that it was "roughly" ... think it was creating a bit of caster?

I am really excited about getting my CNC lathe running to do the bushings for the front. If I do them on that machine it will literally be minutes to make extra ones. When I make them manually making extras isn't "fun" . That lathe will be running one day. I'll post on that thread when I get closer to doing the fronts.

Hans, dude! ... still can't get my ITB car to pull to redline (7700 rpm) like your car seems where it makes sense. Right now if I shift right at 7100 rpm the tq in the next gear is higher than where it was in the previous gear, meaning I should've shifted at a lower rpm ... we're talkin 1st/2nd/3rd. Going to 7700 rpm just seems like it makes "no sense". On my plenum EFI car I can pretty much go all the way to 7700 rpm and the shift "makes sense" because the torque in the next gear just about equals where it fell off in previous gear. I rambled about this I think in the ITB thread ... plan on playing with the cam timing but if I'm going to do that I'm going to make belt covers that let me get to the adjustable pullies.

Hi jacking my own thread ... too much coffee .. .cheers!

 

Yeah I was concerned about what could be "bad".

My 911 track car has 'em first off so that inspired me. I had cause and effect that led to them though.

When I would drive hard I could not shift in mid corner, which is why I made the urethane mounts initially. That made things a lot better but still had issues with 3/4 in mid corner. When I put in the solids all that went away.

cheers