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Motor mount cunnundrum

 
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Qik Nip  



Joined: 16 Jan 2015
Posts: 122
Location: Kentucky

PostPosted: Thu Oct 01, 2015 1:55 am    Post subject: Motor mount cunnundrum Reply with quote

I'm building a '79 924 to run the Salt Flats in a naturally aspirated 2 liter class and find myself wondering if I need to upgrade the motor mounts to accomodate the targeted 225 HP we expect the new engine to generate.

The stock mounts look amazingly sound, but as I recall (before the tear down began last fall) the engine rocked noticibly when the trottle was blipped. What are the experiences out there with stock (especially old) mounts? And what manufacturers / models are recommended assuming I opt to replace?
Rick
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Fasteddie313  



Joined: 29 Sep 2013
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Location: MI

PostPosted: Thu Oct 01, 2015 2:21 am    Post subject: Reply with quote

I believe stock motor mounts should take that power level just fine (in good condition), mine seem to..
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ideola  



Joined: 01 Oct 2004
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Location: Woodstock IL

PostPosted: Thu Oct 01, 2015 3:37 am    Post subject: Reply with quote

Or get a pair of these:


I have three sets of the fast-street and one set of the full-race versions in stock and ready to ship.

Click to purchase.
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CÚdric  



Joined: 27 Aug 2004
Posts: 1740
Location: Sweden

PostPosted: Thu Oct 01, 2015 3:48 am    Post subject: Reply with quote

The street ones would work well on your race car, torque response is much quicker than the stock squishy ones. I can't recommend the race ones, way to stiff even for a race car, ive tried both on my car. Even the street ones ads lots of vibrations..
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Qik Nip  



Joined: 16 Jan 2015
Posts: 122
Location: Kentucky

PostPosted: Sat Oct 03, 2015 6:43 am    Post subject: Reply with quote

ideola wrote:
Or get a pair of these:


I have three sets of the fast-street and one set of the full-race versions in stock and ready to ship.

Click to purchase.


Given Cedrick's comment (below) on the harshness of the race units, would you recommend the street units? Bear in mind this is a race car and I really don't care if the mounts transmit vibration.
Rick
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fiat22turbo  



Joined: 18 Jan 2006
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Location: Portland, OR

PostPosted: Sat Oct 03, 2015 6:56 am    Post subject: Reply with quote

Get the race ones for a pure race car, especially one that will live at WOT and high RPMs much longer than most of our street/race cars will.

Adding mixable polyurethane to the transaxle mounts can also help get power to the ground more efficiently and might reduce some strain on the torque tube, etc.
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ideola  



Joined: 01 Oct 2004
Posts: 15508
Location: Woodstock IL

PostPosted: Sat Oct 03, 2015 7:57 am    Post subject: Reply with quote

If it's an all time race car and you don't care about vibration, get the race units. If you plan to spend any time on the street, get the fast street.

My $.02
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CÚdric  



Joined: 27 Aug 2004
Posts: 1740
Location: Sweden

PostPosted: Sat Oct 03, 2015 6:49 pm    Post subject: Reply with quote

Like i said, the race ones are to stiff imo, things will only brake due to vibrations. The street ones are to stiff for a street car, especially since they seem to firm up a bit with time, imo opinion a better choice for a race car. Driveline response is very similar with both anyway, couldn't tell the difference on track..
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Sun Oct 04, 2015 1:50 am    Post subject: Reply with quote

They do seem they get harder over time (unlike the driver).
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Qik Nip  



Joined: 16 Jan 2015
Posts: 122
Location: Kentucky

PostPosted: Sun Oct 04, 2015 4:44 am    Post subject: Reply with quote

ideola wrote:
If it's an all time race car and you don't care about vibration, get the race units. If you plan to spend any time on the street, get the fast street.

My $.02

Since you're the expert, I'll take the race units. Placing order for them....
Rick
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