Which is better? Reaplcing rear diff bushings? or installing rear diff brace?
 

Hey everyone. I've been on here for a few hours looking into which would suit me better in regards to a lot of drive train slop I have when pressing/letting off the gas pedal. (its as if the entire drive train moves forward and backward while I sit still in my seat when Im quickly giving it gas or letting off the gas) Its required me to change my entire driving habits and honestly is taking away from how the car should be driven if everything were tighter. I have come across two solutions (so far) which seem to gear toward the issues I'm experiencing. The first option would be to replace the rear diff bushings with white line rear bushings, however the install looks to be pretty involved with presses and stuff. However the other option I came across was the "beatrush rear diff brace" which actually from what I understand, sit on top of the existing rear diff mounts and bolts to the rear diff frame itself to make it stronger. My question is if the rear diff brace would be better than the bushing replacement method? My main goal is to reduce as much slop in the drive train as possible. Ill most likely be doing the perrin motor mounts also. Anyone with any experience with any of these or with other successful options would be greatly appreciated.

Both. Do it once, do it right

I looked at a brace as well but as far as I can tell, its a backwards engineered reinforcement designed to imitate a solid type bushing. The brace will definitely stiffen up the differential, but for the cost of the Beatrush, I would just recommend purchasing the following:

http://www.ft86speedfactory.com/whit...nsert-846.html
http://www.ft86speedfactory.com/whit...n-kit-287.html

I installed these a few weeks back to reduce pinion angle fluctuations resulting in contact with my exhaust and I absolutely LOVE the driveline feel now. So much more responsive and predictable. Highly recommend as it is a WORLD of difference. The differential inserts include inserts for the two rear bushings (that you would be bracing) as well as inserts for the two front bushings. In addition to those, grab the subframe bushing inserts. Took me about 2 hours to install everything. Very easy upgrade and worth every penny. I dont feel the need AT ALL to have a brace with this current setup. but to each his own.

Cheers.

Also don't forget that too stiff of a drivetrain can hurt the components in the system. Just as bodyroll doesn't necessarily mean less traction, slop in the drivetain doesn't necessarily mean less power/efficiency.

I have subframe/outrigger/diff bushings ( referred to above, actually :D ), whiteline tranny bushing.. love it, but I feel the weak link is now the motor mounts. I'm also looking at the perrins. Definitely not going solid.

I understand completely though what you mean and I do agree that the slop should have been toned down a little from the factory. What are they trying to appease here- grocery getters and old mums?

I've noticed this problem as well, although I called it bad throttle response but maybe that was not the right term. Do you have any links for anywhere that confirms these bushings should fix it? As far as I can see from the description on them it just says they should help give less movement when cornering and help get rid of annoying noises... no mention of it improving anything when you get on and off the throttle

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Trying to find somewhere in the UK that I can buy these - is this the same thing as the subframe lockout kit you recommended? http://www.tuningdevelopments.co.uk/...oducts_id=1331

Also what effect does the positive shift kit have? As far as I can see it is only for improving gear change feel?

Yes, that's the same kit as listed above.

The positive shift kit is another insert for the rear trans bushing and firms up the drive line as well. It won't improve gear change feel, but a short shifter upgrade will do that. This just takes the slop out of acceleration/deceleration at the transmission. Notice how the shifter shakes left and right under heavy acceleration? This insert will greatly reduce that.

I have the subframe bushings already, and I am considering a differential bushing. Unfortunately, Whiteline has two different types that seem to do the same job. Why did you choose this one:

Rear Differential - mount in cradle & support outrigger insert bushing

Over this one:

Rear Differential - mount in cradle bushing


Also, Whiteline makes another product for the differential:

Rear Differential - support outrigger bushing

which is very confusing for me. I can't figure out from their graphic where this is installed and why I might want one.

Perhaps some of you could chime in with opinions on these three products.

I have the 925 insert bushing. I chose it instead of the 924 version.

To install the 924 bushing you have to remove the existing bushings, which involves cutting one of them out of the sub-frame. The 925 version is just an insert that fills in the existing gaps, so no need to remove the old ones.

The outrigger bushing is on the actual differential. If you download the install guide you will see a better picture. According to the install guide, you actually need to take the differential off to install that one.

^^ what he said.

This is what I installed. They are inserts and utilize the OE bushings and fill in the voids to firm up how the OE bushing behaves. This is an economical option that is easy to install. Good for daily driving/ mild track. For front AND rear bushings of the differential.

This is a well engineered bushing REPLACEMENT of the OE rear bushing ONLY. Might have to drop the cross member to press out the OE bushing for replacement. Good option if you are going to see a lot of track time.


This is a well engineered bushing REPLACEMENT of the OE front bushing ONLY. Will have to drop the differential to press out the OE bushing for replacement. Good option if you are going to see a lot of track time. I actually bought this with the insert pack and couldn't install without dropping center section.

The inserts are great and well engineered. Start there and if you want more rigidness in the future, you can upgrade piece by piece. Hope this helps.

Can someone with a brace installed chime in with performance feedback?

Give Mark at Abbey Motorsport a call, he'll be able to sort you out, knows plenty about which bushes are worth doing.

i have a cusco brace. It increases vibration as you drive and it has surface rust in the year and a half ive had it. i haven't tried the bushing inserts but if they were available when i got the brace i would have chose the inserts