JP2002LS1

I just installed Prothane poly motor mounts and everything on the car is poly including trans mount. My Y pipe for my pacesetter headers still bangs the floor pan when I drive.

It is only 1/8" from the floor but I was hoping the poly motor mounts would keep it from moving. Is it common for the motor to still twist 1/4" with poly motor mounts?

I revved up the motor and it doesn't move much but still moves 1/4" and combined with the car twisting while driving the y pipe bangs.

99blancoSS

iTrader: (115)

Try repositioning the Y pipe. The poly mounts can only do so much, they cant account for the rest of the hangers in the system. Look for broken rubber hangers/mounts along the exhaust piping. Maybe some are stretched or eroded. Maybe you just need to twist a pipe a little to position and angle better.

5.slow99

you know thunder racing makes a really good bumpstop hanger for the y pipe. http://thunderracing.com/catalog/?ac...&vid=3&pcid=54

i know a lot of people that have used it and it has helped, it really helps with the banging and the knock sensor problem

JP2002LS1

I don't think I can move the pipe to a more favorable position. I may have to just wrap some silicone or radiator hose around the exhaust where it rubs. It seems to do it the most when turning and hitting bumps.

99blancoSS

iTrader: (115)

I would look at your hangers then, they're are just rubber and get stretched and loose resiliency (sp)

other than that the mufflex from Thunder Racing should work for you.

FNQUIKWS6

iTrader: (2)

try a free solution... i did this and it worked. remove the heat sheild above the y. all my banging was gone!

NHRAMAN

iTrader: (1)

I have EDELBROCKS and the y banged at first...got under there and yanked down like ****...no more....bet it is your hangers/mounts..as said above.

JP2002LS1

Thanks for the advice guys. I am trying everything but it is too close on the driver side of the Y-pipe and I can't bend it because of how it slips onto the header. I checked the 3 hangers and they all seem good. I even disconnected the exhaust from the y-pipe and the y-pipe is still 1/4" or less from the floor pan. The angle of header points slightly up and when I attach the y pipe it is close to the floor. The only thing I can think of is to use another hanger to keep it from moving or just put some rubber/silicone between the y pipe and floor pan.

I thought all my trouble of installing poly mounts would prevent this. I am suprised the motor can even move with the poly mounts much less move enough to cause banging. Maybe I can use a ratchet strap (torque strap) on the motor to keep it from moving at all.

JP2002LS1

Well I got under my car again and noticed that the 1/8" clearance was easily being used when the car twisted, braking, or just by prying on the exhaust I could get it to touch.

The motor still moves with the poly mounts but not nearly as much as it did with stock.

I fixed my banging problem by buying a silicone baking pan and cutting in and while I pryed on the exhaust I was able to slide it in between the floor pan and then I clamped it to the exhaust with hose clamps. I haven't heard any more banging but I do feel vibrations which I am assuming are from the motor mounts. The silicone sheets are soft enough that they should absorb the banging vibration and not cause knock retard and they should also withstand the heat from the exhaust since they are made to bake in an oven.

s/c'd cav

iTrader: (10)

loosen up the motor mounts and lift up on the pass side and that will drop the drivers side down

that should give you a little more room