Motor mount options? (Page 1/1)
TurboGN APR 21, 09:42 AM
I have a 1988 Fiero GT with the L32 swap. It looks like the mounts they used might be poly mounts. At idle, in gear, it's like being in a giant vibrator which made me think at first that they used solid mounts until I looked.
Is there anything else that can be done to stop the vibration?
If I power brake to bring it up to 1,000 RPM's the vibration is much less but I doubt that would be a good solution to change the RPM vs Gear at idle that high.
Gall757 APR 21, 10:06 AM
Is just the engine swapped or did the transmission come with it?
olejoedad APR 21, 10:20 AM
It's a hot rod, it's supposed to have a bit of an edge to it.
Dennis LaGrua APR 21, 11:49 AM
My swap has poly dog bones, engine and transmission mounts as well and they do vibrate at idle. If you want a smooth idle you buy a luxury car. If you want POWER, you live with what comes with it. The benefit of poly mounts is that they limit drivetrain movement. This is advantageous for improved axle and transmission life. If you must have a vibration free idle then you set it up with custom rubber mounts like the Grand Prix uses but that would also require two dog bones to hold the powertrain in place.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

theogre APR 21, 07:35 PM
I'm guessing Auto Trans....
Is little you can do w/ this problem.

87-88 Fiero L4 w/ auto can have same problem because of mounting and dog bone covered in my Cave, Torque Strut in this case. soft bones can make other parts to fail. polly is harder but will get more vibration.

Change bigger V6 etc to soft mounts etc can cause same breaking stuff problems.

For long traffic lights could put in N to unload the trans but doing this is illegal in many places.
(Same as coasting down a hill w/ a car is illegal too.) If you stall going into Drive or otherwise cops sees you then can get a ticket.

If someone use wrong Flywheel for the engine... will be worse and break stuff too.
some v6 are external balance, other are internal balance and many install wrong flywheel.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

fieroguru APR 21, 07:36 PM
You might want to look closer at the mounts and see if they are round poly bushings. If they are, you might be able to find some rubber bushings to install in place of the poly.

TurboGN APR 21, 08:45 PM

quote
Originally posted by Gall757:

Is just the engine swapped or did the transmission come with it?



The engine and transmission were from the same donor.
TurboGN APR 21, 08:48 PM
I guess I'll just live with it. I thought if there was an easy fix I would do it. I don't want to have stuff breaking....lol.
When I switched my GN to poly mounts there was more vibration, but nowhere as intense as this.