Ok, I did a search and found some good info, but wanted a couple more individual thought answered. I believe my ASM Y-Pipe hitting the floorpan problem is a combination of my new 355 setup and some saggy abused 108K mile stock motor mounts. Reason I don't believe I had the problem before is because they had never been touched until the motor R&R. So.....

Poly or Solid. Reason I ask is because ride isn't going to matter to me and I want to make sure it doesn't flex to the point of the Y-Pipe banging the pan again. The car will see lots of track time and sporadic street time. The cam is a very healthy Joe O cam, which is VERY lopey at idle. Both have their ups and downs, and I just wanted some opinions.

Second, if I were to go with the solid mount, how prone would that be coupled with the lopey cam to throw false knock indications. I have a 93 so I can't use a LT4 KM, and given the compression ratio I'm running don't want to tune out or desensitize my stock KM.

Thanks for the help, this is new territory for me.

 

I suggest the poly mounts. I put them in my new motor, and it does shake the car a little more if you have a bigger cam, but not to the extreme. Compared to the stock mounts, they are a TON more sturdy.

If you do go solid, you have to do a solid trans mount too. At that point you will have to get a different tq arm that relocates it to the body also. Pretty rough set up for a street car, and I wouldnt recomend doing it that way unless you are seeing drag strip only.

 

Another vote for poly mounts. Have them in my car and they work great with a somewhat big cam and LTs.

 

Ok, THAT I did not know, nor would I have thought of. Looks like it's going to be Poly mounts for me as I just don't have the cashola for a new TQ Arm.

Thanks for the heads up on that. Anyone using anything of preference??? I know I've seen the Energy Suspension mentioned.

Madwolf, what was the clearance of the Y-Pipe to your floorpan, if you happened to notice. My issue isn't even with Long Tubes, just a mid. My flange for the Y-Pipe collector is only sitting about a half inch to three quarters of an inch max from the floor, and you can see that's where it's obviously hitting. Think the poly will take care of that??

 

Who says you have to go to a solid tranny mount? I know plenty of people running poly tranny mounts w/ solid motor mounts w/ no problems on either stk or after market TA's. Fastbird how soon you need those motor mounts? I've got a set of poly's on the car that are new less than 200 miles that I'm planning to swap out for solid's. The poly's cured my flex but not enough to the point I'm satisfied so solid is the only way to go. Y-pipe hitting the floor board syndrome.

 

What ya want for them?

 

Ditto. I figure I'll give the poly mounts a shot first, then if they don't work out move up to the solid. Gives me something to do.

 

another vote for poly, have the energy suspension's here. little rougher than stock....

 

Well I am curious to know whether you need a solid tranny mount or or if you can use a poly one with solid motor mounts. This is for a blown, not yet caged 87 el camino.

 

my poly mounts are pretty new, they might have a 'break in' time, but damn is it rough! feels like fricking solid mounts! and i bet the poly tranny mount just adds to this

i really hope they break in and sit in and stuff, cuz i'm going crazy! lol

and my ypipe is still hitting my cross member oh well, guess i gotta live with it...

 

But Ypipes hitting metal causes KR

 

I just put the energy suspension poly motor mounts into my car. I had the same problem as you with the stock mounts, the y pipe was hitting the floorboard with my long tubes. After the new mounts the problem is solved. I didnt notice any more vibration either. I also have poly trans mount and tq arm mount.

 

so where can i get some poly.... motor mounts.... THX

 

not with mine...

 

Oh jeez, you mean the y pipe flange hitting the crossmember will cause KR? Dammit, I just had a shop help me put new y pipe/header gaskets in, and when I wasn't looking, the shop guy tightened the y pipe down, and the flange turned, and is now hitting the crossmember. Will it really be that big of deal? Please don't tell me I have to try to loosen and spin that flange with the car on ramps in my driveway.
I also was looking into new motor mounts, and everyone I talked to said to go with poly mounts, especially ES brand.