I put a poly mount on the driver's side, and I like it. I had a new mount that didn't even last a season, and it was ripped apart. Maybe the hard launches?? Well, I refuse to put a factory style in if the car is going to be beat on, so I went poly. There is no way that I will break that one. I do have regulars in my GN, but I don't plan on 25# launches, so it should be ok.
Does anyone regret installing the poly motor mounts ?
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Just checked out their site: http://www.hrpartsandstuff.com/, and they have something about them using softer rubber now to help avoid vibration.
chrisgarrett
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91Bird305 said:Hmm, wonder if those are the ones I picked up? Eh, I doubt it. I think I picked mine up in early 2005.
Wasn't the design improvement made two or three years ago?
HRpartsNstuff
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Someone e-mailed me asking how many times we changed the mounts, so I searched & found this thread. Here is the skinny on all that:
We have made several improvements over the years, but they were all basically subtle in the overall design of the mounts. The poly stiffness started with all that was available. Since the start, we have custom ordered many prototypes for testing & softened them up best we could. Even the softest ones ever are WAY better than the stock rubber, and handle any HP level thrown at them.
We started with a black 93 duro poly on all mounts back in the beginning, only had TR mounts back then. As stiff as they were, only about 5% ever said a thing about them (vibration-wise). The original ones sat the TR motors a little bit higher, but wasn't much of an issue.
Years ago, we went to an 88 duro in black, made a little improvement. Stage mts got the 93's, prod mt's got the 88's. Can't remember if early TTA mounts got the 88's or the next softer 80's (below). We wrote on the mounts what was in them, but didn't document a lot back then.
A couple years ago, we went to an 80 duro (originally in black, but changed to red), which seemed a lot softer & really did the trick getting rid of vibrations on TR's. About that same time, we changed the TR mount design to have a pin that contacted the frame pedestals instead of that welded brace. I still have some 93's left, but don't use them anymore. Stg got 88's, prod got 80's. Some got 88 dr & 80 pass, but only special situations.
We did a few of TTA's with 88's dr & 80's pass when we had matching colors, and eventually went to 80's both sides. The frame pedestals stayed 88's cause they only had 1 set to take the abuse compared to the mounts having 2 sets. We kinda weened ourselves off the 88's in the frame pads on the TTA's, and went to 80's all around once we proved they would hold up.
Just over a year ago, we finally got some 70's in black that we were waiting on for over a year. They were tested at over 1000hp & held up fine. The softer issue wasn't needed for TR's at that point, but we got them going for the TTA's & also used them in prod TR mounts. The TTA's went to 70's in the mounts & 80's in the frame pads for a while. Some got 70 pass frame & 80 dr frame. We just kept softening things up AFTER they were tested & proven to hold up at appropriate HP levels.
Last year, we got one step softer rubber pad for under the frame pedestals too. Probably not a big issue, but figured it might help.
NOW, we put 80's in the stg TR, T/A, and stg TTA mounts, 70's in the prod TR & TTA mounts, and 70's in the TTA frame pads. ANYONE that has a stg setup (TR/TTA) that isn't thrashing hard can custom order the mounts with 70 duro at NO extra cost for best street use. We haven't heard ANY negative issues with ANY of our mounts in the last 6 months +, basically since the 70's started to be used.
Bottom line, if you have black poly in a mount purchased in last 1.5 years, it's 70 duro. If it's red, it can either be 80 or 88 depending on how old & stg etc. It *should* say on the back with a paint marker, but didn't do them all over the years. ALL cars reacted differently, and overall, less than 5% of TR's complained, and less than 15% of TTA's complained. Those are tougher because of unibody, and had to use stiffer poly in the beginning. Get a lot less bothered by vibrations now. Our poly motor mounts usually "soften up" in the first couple weeks, NOT just get used to it. They get a set in the car after moving around a little, and the clearances in them further reduce vibrations. Motors sit higher & lower from car to car too, no 2 the same. For most, it's not an issue.
Trans mt's are a slightly different story. We DON'T make them for the TTA,s and they DO vibrate & bother a lot of people. The ones we DO offer for TR's are OK for most, but 10-15% say it's a bit much for them. Racers going fast just have to use them no matter what, but not a big issue. It varies by opinion, AND car (even with same setup). The poly BODY bushings transfer a bunch too, but not bad on all cars I hear. All depends on too many variables.
FYI, Old mounts are a pain to upgrade poly to new softer ones. Best bet is to sell old ones on e-bay or other place, and just get new ones. Ends up close to same $$ but lot less work. A few reported making a profit, but can't say that will happen to anyone else
Hope that helps explain & lessen the fears of what it will be like for those not yet started the motor Definitely try it, for a few weeks at least, and you probably will be fine with it.
We have made several improvements over the years, but they were all basically subtle in the overall design of the mounts. The poly stiffness started with all that was available. Since the start, we have custom ordered many prototypes for testing & softened them up best we could. Even the softest ones ever are WAY better than the stock rubber, and handle any HP level thrown at them.
We started with a black 93 duro poly on all mounts back in the beginning, only had TR mounts back then. As stiff as they were, only about 5% ever said a thing about them (vibration-wise). The original ones sat the TR motors a little bit higher, but wasn't much of an issue.
Years ago, we went to an 88 duro in black, made a little improvement. Stage mts got the 93's, prod mt's got the 88's. Can't remember if early TTA mounts got the 88's or the next softer 80's (below). We wrote on the mounts what was in them, but didn't document a lot back then.
A couple years ago, we went to an 80 duro (originally in black, but changed to red), which seemed a lot softer & really did the trick getting rid of vibrations on TR's. About that same time, we changed the TR mount design to have a pin that contacted the frame pedestals instead of that welded brace. I still have some 93's left, but don't use them anymore. Stg got 88's, prod got 80's. Some got 88 dr & 80 pass, but only special situations.
We did a few of TTA's with 88's dr & 80's pass when we had matching colors, and eventually went to 80's both sides. The frame pedestals stayed 88's cause they only had 1 set to take the abuse compared to the mounts having 2 sets. We kinda weened ourselves off the 88's in the frame pads on the TTA's, and went to 80's all around once we proved they would hold up.
Just over a year ago, we finally got some 70's in black that we were waiting on for over a year. They were tested at over 1000hp & held up fine. The softer issue wasn't needed for TR's at that point, but we got them going for the TTA's & also used them in prod TR mounts. The TTA's went to 70's in the mounts & 80's in the frame pads for a while. Some got 70 pass frame & 80 dr frame. We just kept softening things up AFTER they were tested & proven to hold up at appropriate HP levels.
Last year, we got one step softer rubber pad for under the frame pedestals too. Probably not a big issue, but figured it might help.
NOW, we put 80's in the stg TR, T/A, and stg TTA mounts, 70's in the prod TR & TTA mounts, and 70's in the TTA frame pads. ANYONE that has a stg setup (TR/TTA) that isn't thrashing hard can custom order the mounts with 70 duro at NO extra cost for best street use. We haven't heard ANY negative issues with ANY of our mounts in the last 6 months +, basically since the 70's started to be used.
Bottom line, if you have black poly in a mount purchased in last 1.5 years, it's 70 duro. If it's red, it can either be 80 or 88 depending on how old & stg etc. It *should* say on the back with a paint marker, but didn't do them all over the years. ALL cars reacted differently, and overall, less than 5% of TR's complained, and less than 15% of TTA's complained. Those are tougher because of unibody, and had to use stiffer poly in the beginning. Get a lot less bothered by vibrations now. Our poly motor mounts usually "soften up" in the first couple weeks, NOT just get used to it. They get a set in the car after moving around a little, and the clearances in them further reduce vibrations. Motors sit higher & lower from car to car too, no 2 the same. For most, it's not an issue.
Trans mt's are a slightly different story. We DON'T make them for the TTA,s and they DO vibrate & bother a lot of people. The ones we DO offer for TR's are OK for most, but 10-15% say it's a bit much for them. Racers going fast just have to use them no matter what, but not a big issue. It varies by opinion, AND car (even with same setup). The poly BODY bushings transfer a bunch too, but not bad on all cars I hear. All depends on too many variables.
FYI, Old mounts are a pain to upgrade poly to new softer ones. Best bet is to sell old ones on e-bay or other place, and just get new ones. Ends up close to same $$ but lot less work. A few reported making a profit, but can't say that will happen to anyone else
Hope that helps explain & lessen the fears of what it will be like for those not yet started the motor
Definitely try it, for a few weeks at least, and you probably will be fine with it.
turbojimmy
Supporting Member
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- May 26, 2001
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- 5,560
Mine are old - maybe that's my problem. Like 2002 or 2003.
Jim
Jim
turbojimmy
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HRpartsNstuff said:
So the new ones have the engine sitting at the right height? My engine definitely sits higher with the old poly mounts. It's not a big deal, but it caused me issues with interference between my THDP and my heater box, vacuum-block to hood insulator, up pipe to hood-insulator and I had to tweak my V4 scoop (it wraps around the sway bar). More recently I had pipe fitment problems with my RJC Megacooler.
If the new mounts are indeed softer than I'm willing to move to new ones but only if the engine sits where it's supposed to. I've always been confused as to why people say that there was no change in vibration when mine was so severe. Now it all makes sense - thanks for the explanation.
Thanks,
Jim
HRpartsNstuff
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- 844
We haven't changed anything to lower engine position, haven't had any requests or issues on that until here now. Couple things you can do to help out:
Leave out 1/4" thick rubber pad on one side or both from under frame pedestals. That will drop it a little, and not effect vibrations a whole lot. They do a little, but not a big deal.
Also, could put old stock long bolts back in, they are smaller. It will drop motor a little more.
Those 2 suggestions are safe & fairly easy.
========
On Vibrations on old ones that seem too stiff, they are not rebuilt very easy. BUT, you can very easily change the red ones out of the frame pedestals (especially with motor out - pictured above) and put in new soft 70 blacks. That will help out pretty good. Got new tubes to press in them too, that are less likely to be a problem clamping side plates against it. Some said the sides start to press onto the tubes, instead of clamp against it. We reduced unnecessarily high torque setting for the long bolts to help too. Just e-mail me for pricing etc for parts if interested.
Leave out 1/4" thick rubber pad on one side or both from under frame pedestals. That will drop it a little, and not effect vibrations a whole lot. They do a little, but not a big deal.
Also, could put old stock long bolts back in, they are smaller. It will drop motor a little more.
Those 2 suggestions are safe & fairly easy.
========
On Vibrations on old ones that seem too stiff, they are not rebuilt very easy. BUT, you can very easily change the red ones out of the frame pedestals (especially with motor out - pictured above) and put in new soft 70 blacks. That will help out pretty good. Got new tubes to press in them too, that are less likely to be a problem clamping side plates against it. Some said the sides start to press onto the tubes, instead of clamp against it. We reduced unnecessarily high torque setting for the long bolts to help too. Just e-mail me for pricing etc for parts if interested.
