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Hey guys,

Today I had a great opportunity to check out a super nice JPS Speedster Coupe, at a reseller in the S.E.

See, touch, and closely inspect every detail over the course of about an hour,  I was very impressed overall with the total package.  Didn't get to drive, but was able to crank it up, listen and rev her up a little bit.....

And that is where my question begins... Between 2000-3000 RPM,  I was rather surprised at how much engine vibration made its way thru the floor and seats and overall structure of the car.  (Wasn't gonna rev higher than that in the showroom.)

Is this normal for a Suby powered setup?  I expected a higher level of smoothness and refinement, where vibration isolation is concerned.  Ive driven a VW powered Speedster before and it was quite isolated, much like any Beetle.   

The only support and isolation I could find for the engine is where it mounts up to the transmission, in the transaxle cradle/pan there are a couple rubber isolators.  That whole engine is hanging by the cradle.  

Can any Subaru-powered Speedster owners comment on this vibration/isolation  please.

BTW, my hat's off to JPS for producing such a nice Coupe.  Beautiful fit and finish, outstanding paint,  marvelous interior,  attention to detail, etc.   I'v looked at many of the reproductions in the last few years, and this was the finest I have seen. 

Last edited by G-man
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I'll give it a start. I'm no engine expert but I do have about 30 , maybe 40,000 miles just frigging and sorting out my own Soob conversion in an older IM Speedster. 

Your engine / frame vibes are not typical in my experience. What would make it vibrate while standing still ? I ran a 2.2l  Soob for thousands of miles with  a bone stock VW tranny where many said I should not go. What ever tranny mounts were in my existing runner, I just went with.

I finally built up a very nice Frankenmotor and then upgraded to Genuine German front and rear HD tranny mounts for the tranny and supplemented that with an "aux" rear end ( back of the engine compartment ) mount made up of
"Small Car"  Soob engine mount cradle parts . Aft of that, a very rear end shock mounted transverse bar designed, built and installed by this kid. It works. I don't know what doesn't work. I don't know what others have done. 

I'm not aware of what pro shops do for Soob engine mounting  and give no advice herewith other than stating what works for me. The vibes you are describing could just be an ignition or fuel issue. Ask the seller to get a Soob tech give it a looksee. Probably quite minor. 

Last edited by David Stroud IM Roadster D

I have no vibration issues with my JPS Subaru EJ25.  Of course, there is a fair amount of vibration that goes with the territory.  As you know, these are not Accords and Camrys.  Additionally, I previously owned a 1600cc VW Speedster, and it vibrated SIGNIFICANTLY more than the EJ25.

That said, I did have a 3rd party mechanic remove and replace the trans mount.  Not sure I noticed a difference, but they swore there was some questionable fabrication underneath the car.  Paid $85 to have that mount redone.  Further down the line, we completely re-engineered the motor mount, but that was for clearance rather than vibration issues.

I would echo the comments from Bruce, Ray, David, Bill, and PBH:

1.  Insist on taking it to an independent shop to look it over (preferably someone who knows both Subarus AND VWs, and a race shop is all the better).

2.  Insist on a test drive.

You won't save any money buying from a reseller -- only time.  Last bit of advice is to be patient, and either wait for the right car to come along or spec/build your car with one of the reputable coach builders.

Good luck!

It is a striking creation.  I saw a few things that need attention, but easily corrected.  Some poor wiring crimps, one door latch that drags the striker as it is closing before it latches (the other door is perfect), one window won't roll up fully with the door closed but will with the door open,  larger than necessary hole in the firewall for plumbing, etc.   I know these things happen, but for the money I have high expectations.  Wish they'd put me in charge of detail quality control.  There is a simplicity to these cars,  and I don't see why attention to detail has to be omitted.

Also, I'm not sure I'd drive it in the rain,  i saw too many ways for water to get into the interior.

Last edited by G-man

I agree with Tom Murtaugh.  I rode around for the Carlisle weekend last year in Tom Marantz' JPS Suby coupe and didn't notice any abnormal vibration from the right seat. Felt a little 2'nd and 3'rd gear growl but that could be a lot of things and not especially pronounced.

Tom also mentioned that he had personally fixed a lot of questionable stuff "under the covers" on the mechanical side of his car.  The fit and finish of the body and interior was first rate.  The pan-related drive-train?  Not so much first rate, there.  Typical JPS in that regard.

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