Rear axle subframe bolted directly to body? (Like M’s and 911’s?) ?

[Mark5]

Does anyone know if the rear suspension is directly bolted to the subframe (with no bushings)? I know it is on the red M cars and some 911’s to accentuate that purist red feel and control.

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[Mark5]

?? just checking to see if anyone here would know this..

 

[zamm3k]

They are not. I've had to unbolt the rear axle for the rear sway bar install and they do indeed use a bushing.

 

[Mark5]

They are not. I've had to unbolt the rear axle for the rear sway bar install and they do indeed use a bushing.

Damn... Thanks!

 

[Lorre]

They are not. In fact, I think this is the cause of the "bump steer" as what some people are experiencing when pushing the car hard on track especially with sticky tyres.

Speedengineering - a german engineering company that frequents the Nurburgring highlighted the soft rear subframe bushings are the issue which makes the rear axle less predictable than it should when pushing hard on track. They highly recommend solid bushes in place of the factory soft ones even on a stock car.

 

[FLtrackdays]

They are not. In fact, I think this is the cause of the "bump steer" as what some people are experiencing when pushing the car hard on track especially with sticky tyres.

Speedengineering - a german engineering company that frequents the Nurburgring highlighted the soft rear subframe bushings are the issue which makes the rear axle less predictable than it should when pushing hard on track. They highly recommend solid bushes in place of the factory soft ones even on a stock car.

Recently replaced mine

Another member who changed his?

The ones we bought

It didn’t say bushings plural so I bought two boxes, 4 bushing total, lol. Now I have 2 extra.

 

[Lorre]

Recently replaced mine

Another member who changed his?

The ones we bought

It didn’t say bushings plural so I bought two boxes, 4 bushing total, lol. Now I have 2 extra.

I think these are the diff mount bushings. The ones I'm referring to are the 4 large ones surrounding the entire subframe to the body of the car.

I'm sure the ones you posted are a good change as well as i can clearly see one of y'all have already torn the factory one. ?

 

[Todday1]

I went to solid ones. But they are not easy to change. Here are a few pics.

 

[FLtrackdays]

I think these are the diff mount bushings. The ones I'm referring to are the 4 large ones surrounding the entire subframe to the body of the car.

I'm sure the ones you posted are a good change as well as i can clearly see one of y'all have already torn the factory one. ?

You are absolutely right. Thanks for clarifying Errol!

I went to solid ones. But they are not easy to change. Here are a few pics.

I’ve got some but haven’t put them in yet. How’s the ride & noise difference?

 

[Todday1]

My car is a dedicated track car and changing to solid mounts just added more to the noises etc. if you want a street friendly feeling you may not want to do this. You definitely feel more drive train vibrations and sharp edges to the bumps. It is still drivable on the street however not for someone who wants a normal feeling ride. I already had all solid control arm bushings so while I think it did help a bit on overall set up and turn in stability etc. I am not sure if it made that big of a difference.

 

[FLtrackdays]

Yeah, you're not kidding about them being tight! We got a set of Verklines rear spring wishbone bushings squeezed in after doing the Powerflex differential mount ones.

Rear Spring Wishbone Bushings with lockout kit Toyota Supra A90 A91 – Verkline USA

However, wasn't as successful with the rear knuckle bushings. Will tackle that another time.

Rear Knuckle Bushings Toyota Supra A90 A91 – Verkline USA

Another question for the subframe gurus - assume it's best to change the bolts after dropping the subframe more than once. Especially if they are torque to yield. I started looking up the part numbers to replace them. Then saw Verkline's subframe. They come with the bolts and might be more conducive/ flexible/ easier for inspecting & replacing parts (such as bushing, lol).

Rear Lightweight Tubular Subframe Toyota Supra A90 A91 – Verkline USA

Any thoughts or feedback on it?

 

[lucky phil]

Yeah, you're not kidding about them being tight! We got a set of Verklines rear spring wishbone bushings squeezed in after doing the Powerflex differential mount ones.

Rear Spring Wishbone Bushings with lockout kit Toyota Supra A90 A91 – Verkline USA

However, wasn't as successful with the rear knuckle bushings. Will tackle that another time.

Rear Knuckle Bushings Toyota Supra A90 A91 – Verkline USA

Another question for the subframe gurus - assume it's best to change the bolts after dropping the subframe more than once. Especially if they are torque to yield. I started looking up the part numbers to replace them. Then saw Verkline's subframe. They come with the bolts and might be more conducive/ flexible/ easier for inspecting & replacing parts (such as bushing, lol).

Rear Lightweight Tubular Subframe Toyota Supra A90 A91 – Verkline USA

Any thoughts or feedback on it?

If you buy one new std bolt and measure the under head length against a removed one you will be able to tell if it's a TTY bolt. Generally TTY bolts have a preset torque and then to an angle. A lot of bolts called for replacement in the manual these days aren't due to being TTY fasteners but because they have factory thread locker applied to them. They don't trust dealer techs to apply locking compound so they call for the fasteners to be binned after removal and new ones fitted.
Phil

 

[FLtrackdays]

If you buy one new std bolt and measure the under head length against a removed one you will be able to tell if it's a TTY bolt. Generally TTY bolts have a preset torque and then to an angle. A lot of bolts called for replacement in the manual these days aren't due to being TTY fasteners but because they have factory thread locker applied to them. They don't trust dealer techs to apply locking compound so they call for the fasteners to be binned after removal and new ones fitted.
Phil

Thx Phil & why I just want to buy em & replace em. Master Fuzz @FuzzyRev might know which parts I need to order. What I found so far:

Also 90118-WA280 and 90118-WA504. Before I call the Naples dealer, I‘d like to have the parts in mind steering them in the right direction of what else might be needed/worthwhile.

 

[FuzzyRev]

Another question for the subframe gurus - assume it's best to change the bolts after dropping the subframe more than once. Especially if they are torque to yield.

For fuck's sake, never re-use TTY bolts!

They lose 25-30% holding capacity if installed again. Would you re-use TTY bolts when installing a cylinder head? NEVER. So it's the same mindset with the major chassis components, and it's even worse to re-use them on stiffer, upgraded mounts, because even more load forces are transmitted to the bolts without the gummy rubber to dampen it. It's basically a downgrade at that point. The notion of subjecting them to maximum stress on a track compounds the issue.

Bite the bullet, buy the replacement fasteners.

EDIT: Mark, those part numbers are for the FRONT subframe. Aren't you looking for the rear?

 

[rwense]

Recently replaced mine

Another member who changed his?

The ones we bought

It didn’t say bushings plural so I bought two boxes, 4 bushing total, lol. Now I have 2 extra.

Oh hey I was looking at these, how's the NVH afterword? I was considering doing these as well as the subframe inserts.

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