Phoenix64

iTrader: (3)

I have a set of pacesetter longtubes, I'm not willing to install poly mounts, so I'm wondering with stock mounts will the headers/y-pipe hit the bottomside of the car?

crazychucky8

iTrader: (1)

Mine weren't rattling against the bottom of the car. However, they were rattling on the crossmember. I fixed that problem by installing a hanger arm to my y-pipe. I have Jet Hots off road Y. They did not come with a hanger arm.

cabech984

iTrader: (11)

I did the mounts and it is a pain IMO, Seeing that your car is a 98, they may possibly be bad anyway. My mounts rubber wasnt even bonded to the metal anymore. My Y-pipe still hits my crossmember and also my torque arm. I couldnt even put that tunnel/d-shaft brace thing in after the swap.

FU_I_AM_UltraZ

iTrader: (20)

shouldn't if the headers were made to the correct specs and installed correctly...

jdiddyws6

iTrader: (5)

I had some clearance issues with the k member on the driver side. Fixed by sliding a piece of heater hose in between the header and the k member

Lithium

iTrader: (47)

Depends. Mounts will solve it most likely, but its a pain in the ***.

I never installed the mounts and didnt have one rattle with my pacesetters.

jmm98LS1

iTrader: (28)

Whether or not your exhaust hits the bottom of the car all depends on the condition of your stock motor mounts. Odds are they're pretty worn, if not completely trashed. My motor would rock over an inch back & forth at idle (lumpy cam) with the stock mounts, mine were trashed. If you want to tuck your exhaust up for the best ground clearance, you need to have mounts that keep the motor from rocking. You're gonna have the headers off anyway, there's never going to be a better time to put poly mounts in......do it, you'll kick yourself if you don't. My $.02

Tainted

iTrader: (9)

mine didnt

Luna

iTrader: (6)

I agree completely, just do the motor mounts while your doing the headers its actually really easy to do once the headers are off, its worth it for more than just keeping the ypipe hitting, it tightens the whole car up.

Poly motor mounts are cake while your doing the headers, just consider it part of the install.

As for whether they will hit or not, yes most of it has to do with how bad your stock mounts are. How many miles are on the car?

At about 80k miles my stock motor mounts were shot enough that the ypipe rattled quite a bit. There are alot of tweaks that can be done to keep the y from banging but NOTHING is as effective as poly motor mounts.

With the exception of course of solid motor mounts

Phoenix64

iTrader: (3)

79k I hated my poly mtrans mount. I have poly motor mounts, but I have no intent of installing them, Will stock mounts keep them from hitting?

What normaly hits the y-pipe or the headers?

RrCoX22

iTrader: (6)

the majority of cars will have no problems with rattles fat as the headers... the y-pipe and true duals is the problem getting them tucked up enough yet still not hitting the floorboard... nothing some poly motor mounts and bumpstops can't hurt for asurance

Tainted

iTrader: (9)

the floorboards

TheBlurLS1

iTrader: (8)

Poly motor mounts are nothing like a poly trans mount. My poly trans mount caused vibration, motor mounts did not.

My advice, install the mounts, then send me a thank you card.

00 pewter ws6

were can i get poly mounts and how much money are they

Cop Car

iTrader: (14)

if you do poly mounts, you really need to do both motor and trans at the same time so you dont end up with unforseen issues.

but no, LTs wont bump your bottom, the pacesetter y pipe will though, so dont get it

jmm98LS1

iTrader: (28)

For clarification, you can install poly motor mounts and leave the stock rubber trans mount without any problems. What you want to avoid is installing a poly trans mount and leaving worn stock rubber motor mounts in place. This can put stress on the tailshaft of the transmission and cause it to crack.

Phoenix64

iTrader: (3)

What kind of vibes to poly motor mounts cause? Low(thumps) or high(buzzing)?

Luna

iTrader: (6)

You can get them from our fantastic sponsor speed inc. http://www.ls1speed.com/catagory.cfm...%20/%20Chassis part #7-512 towards the bottom of the page.

And yes poly trans and motor mounts are totally different. You never want to install a trans mount more rigid than your motor mounts.

I thought it was more because of risking cracking the bellhousing not the tailshaft? Because the motor will move more on softer mounts and the trans won't follow?

and NO YOU DO NOT need to do trans and motor mounts at the same time .

TheBlurLS1

iTrader: (8)