LT's are beating up my floorboard.
 

So I got some kooks LT's installed, and just like I've read on here, they hit the floor when I get in it any. I've read the common fix is the poly motor mounts. Just wondering if anyone has done this with success. Ive heard installing those will fix the headers hitting the floor problem but makes the car shake terribly (with a cam, I have a cam).

On the other hand, is there any risk/issue with just dealing with them hitting the floor?

Motor mounts will NOT make your car shake. That is only if you do the poly trans mount as well... and even then its not that bad, i have all poly mounts on my car and it isnt bad. Tho I do not have a cam, so im not sure if that makes a difference. Maybe someone running poly MM's with a cam can chime in.

The trade off to NOT doing it is your headers will begin to separate from one another and yank the threads out of the cylinder heads.

Also: If your trans mount is still pretty good, and it's most likely not, you are killing your poor bell housing! :)

Here's a temporary fix. I did it because I'm going to replace my motor mounts and install headers after my deployment, and wanted to get rid of the banging until then.

Think it would be that dangerous to NOT replace the motor mounts? seems a little extreme but, I guess its possible. Someone with a cam and poly MM chime in about the shake plz.

ive had KOOKS for yrs with stock mounts and theyve never hit my floor.

Poly motor mounts will transmit more vibration than stock mounts, but it's actually very mild, and that's with having poly trans mount also (modified ES mount).
This is with a 227/231 111 lsa cam.
FYI, unless run a stealth cam plenty of negative overlap your going to get some engine shake in a cammed car. :nod:

try solid mounts instead

lol, Or replace them with stock rubber mounts if the mounts are bad

You are probably bumping some of the stiffening
bosses under there. First thing to try is rehanging the
pipe with 1" shims between pipe and any close under
car feature.

My last bind was the driveshaft loop, I zip-tied a
pad of high temp silicone foam rubber to it.

I fixed mine with poly motor mounts and did not replace the trans mount. You will feel a little more vibration in the car with the poly mounts but it isn't much worse than with the factory mounts, and it solves the y pipe banging issue. I tried many other solutions before going to the poly mounts and later wished that I had just installed them first.

Also be aware the poly mounts will break in and soften up a bit you drive the car a couple hundred mile and smooth out more. seriously you want even notice and vibration after a short time. Its better to use the Headers to move exhaust gases rather than use them as motor mounts.

Working for me.

Yeh I was hoping that by buying kooks I wouldn't have this issue, but my mechanic said its the worst fitment he's ever had with kooks. Just my luck I guess.

Just from looking under the car and feeling around it seems that the place its touching is on the passenger side between the header and this heat shield right before the header straightens out under the car (many technical terms there I know..)

if you enjoy wasting time and money

I thought the passenger side header should torque away from the floorboard when the revs increase not into it? On my LT's the Y pipe was a little too close to the floor on my drivers side causing my noises. I could actually see where it was rubbing through the paint. You may need to look a little closer for contact marks.

That's a good point. I guess I didn't think that through. Im re-doing my exhaust this weekend so I'll inspect it more. And as cheap as poly mounts are, I guess I'll just buy some..

I saw on here before, I can't remember who makes it or what thread its in sorry, that someone makes what looks like a band clamp that has an exhaust hanger on it.

Get some poly motor mounts that will fix it case closed!

I made sort of a diy version of this and it worked well I had it one for almost 2 yrs until I recently did a motor swap and put poly's in I havent started it up yet so I cant comment on how much different the vibration between the 2 is although I will say that the motor does sit a little higher with the polys.