964 RSA Suspension upgrades

[Chakka71]

Just looking for some input. Currently, car is below RS height, bilstein cup suspension.
I'm looking at doing the following:

Front Monoball kit
Rear Monoball
Rear Spring Plate
Bump Steer
Roll Bar F/R changed to Urethane

The first two are a huge difference doing Monoballs vs. Urethane

My car is used 75% track/25% street.

No racing just DE's. Planning to keep the car for many years to come.

A) Any other upgrades to think about while doing these(i.e. f/r toe links from tarrett or the like)
B) Are the monoballs worth the big expense vs. new Urethane. Does the choice of material make a big difference or just longevity(consistancy)?

[Bill Verburg]

Originally Posted by Chakka71

Just looking for some input. Currently, car is below RS height, bilstein cup suspension.
I'm looking at doing the following:

Front Monoball kit
Rear Monoball
Rear Spring Plate
Bump Steer
Roll Bar F/R changed to Urethane

The first two are a huge difference doing Monoballs vs. Urethane

My car is used 75% track/25% street.

No racing just DE's. Planning to keep the car for many years to come.

A) Any other upgrades to think about while doing these(i.e. f/r toe links from tarrett or the like)
B) Are the monoballs worth the big expense vs. new Urethane. Does the choice of material make a big difference or just longevity(consistancy)?

W/ Bilstein Cup suspension I assume that you already have the mono-ball shock top mounts and camber plates in front

for a pure track car mono ball suspension arm pivots are the way to go, for some track and some street I much prefer hard rubber bushes over urethane, the objection to urethane is mostly related to noise issues but urethane bushes can also wear quickly too.

Elephant Racing has some sport rubber front A arm bushes that work great for what you are intending to use the car for.

As for the rear I don't have enough experience w/ 964 rear suspension to have much of an opinion but again the pure track cars will usually have mono-balls.

Rennline has some sealed monoball cartridges for the strut top mounts that might be interesting but afik nothing for the rear trailing arm.

964 does't have the need for the mono-ball toe links that a 993 would need

[Chakka71]

Actually I don't have mono-ball top mounts and camber plates. On the list of possibilities but now can come back to the list if I go with the Sport rubber. MUCH less expensive than Mono-balls. I'm not doing more than 6-7 events per season and just can't justify going with mono-balls.
I appreciate the help!

I did notice you went with the sport rubber when you did your car awhile ago. I'm assuming you're pleased with your choice?

[Bill Verburg]

Originally Posted by Chakka71

...

I did notice you went with the sport rubber when you did your car awhile ago. I'm assuming you're pleased with your choice?

Very, the mono-ball strut top mounts and front camber plates would go well w/ the sport rubber A-arm bushes

A friend has the same setup but his is a daily driver, he puts lots of street miles and has had to replace the front mono-ball cartridges in the strut tops

[Chakka71]

I like the idea for the sport rubber. Seems to be a perfect fit for my driving and wallet!

So,
new list :
ERP - Front Sport Rubber Bushings
Bump Steer Kit
Monoball top mount/camber plates
Rear Trailing Arm (not sure what to do, I gather only choice is OEM or ERP monoball) I'm guessing the better choice is the monoballs on the trailing arm?
ERP - Rear Sport Rubber Bushings

Leaving out :
Rear Spring Plate($750)
Drop links ($500)

[911boost]

Not to hijack, but can you take a picture of the strut towers for me, from the inside, in the front trunk? Specifically, the metal brace that towards the rear of the car?

Thank you very much!

Bill

[sml]

what is in the 'bump steer kit'? where from? any links?

[Chakka71]

Originally Posted by BSiple

Not to hijack, but can you take a picture of the strut towers for me, from the inside, in the front trunk? Specifically, the metal brace that towards the rear of the car?

Thank you very much!

Bill

My car is in a friends garage hibernating. Nothing I can do currently.

[Chakka71]

Originally Posted by sml

what is in the 'bump steer kit'? where from? any links?

From Rennsport Systems :
Tuning the bump steer inherent in every 911 can be as simple as installing a Bump Steer Kit to using spherical rod ends, instead of tie rod ends (ERP Bump Steer Kit), to position the steering arms precisely. This is only necessary when the car has been lowered from the stock ride height. The Bump Steer Kits are comprised of two steering rack spacers and longer bolts to accommodate the higher position of the rack. The spherical bearings that replace the OEM tie rod ends offer a much greater range of adjustment, albeit at higher cost.

[Bill Verburg]

Originally Posted by Chakka71

From Rennsport Systems :
Tuning the bump steer inherent in every 911 can be as simple as installing a Bump Steer Kit to using spherical rod ends, instead of tie rod ends (ERP Bump Steer Kit), to position the steering arms precisely. This is only necessary when the car has been lowered from the stock ride height. The Bump Steer Kits are comprised of two steering rack spacers and longer bolts to accommodate the higher position of the rack. The spherical bearings that replace the OEM tie rod ends offer a much greater range of adjustment, albeit at higher cost.

A 964 won't use rack spacers as part of a bump steer kit, that would only be for 911s

afaik the only bump steer kit for 964 involves the use of 993RS front wheel carriers both Smart Racing and Tarrett have tie rod ends w/ o/s connections to the wheel carriers.

the 993RS wheel carrier is in itself a bump steer modification as it relocates the tie rod mounting points and uses it's own special tie rod ends.

you can use the 993RS wheelcarriers w/ 993RS outer tie rod ends or w/993GT2 spherical tie rods or w/ the Smart Racing/Tarret o/s ends

[Chakka71]

I see it in the description. I just looked at the fact it says 993/964 bump steer kit. But, reading on further you need much more to make it work.......off the list it goes then. I probably drop it then, but look to add poly-bronze control arm/spring plate bearings.

What would be used to replace the anti-roll bar stock bushings.......is urethane the only option? And what are track rod bushings for. They are listed below the sport bushings in Elephant Racing?

[Bill Verburg]

Originally Posted by Chakka71

I see it in the description. I just looked at the fact it says 993/964 bump steer kit. But, reading on further you need much more to make it work.......off the list it goes then. I probably drop it then, but look to add poly-bronze control arm/spring plate bearings.

What would be used to replace the anti-roll bar stock bushings.......is urethane the only option? And what are track rod bushings for. They are listed below the sport bushings in Elephant Racing?

again I'm not all that up on 964 rear suspension but afaik the poly-bronze is only for 911 suspension not 964

for sway bars either rubber or urethane are usually used though there are mono-ball versions too, Tarrett has some nice mono-ball drop links for 964.

trackrod would be for 993/996/997 rear suspensions but not 964 or 911

[Chakka71]

Thanks for the help Bill! I'm learning something about my car every week it seems. It is really helping me in making educated decisions going forward.

[Bill Verburg]

Originally Posted by Chakka71

Thanks for the help Bill! I'm learning something about my car every week it seems. It is really helping me in making educated decisions going forward.

No problem

here's what a 964 rear suspension looks like


there are 2 bushs on the semitrailing arm that can be replaced

you can use mono-balls or and RS bush on the 1 circled in red



the RS bush is just stiffer than a normal one

[Chakka71]

Would the RS bushings work better than Mono-ball if I am doing Sport Bushings on the front control arms or will it not really make a difference. I'd be curious to see the price difference. Sport Bushings are appreciably less than mono-balls so i'm assuming the RS bushings are the same.
Who sells the RS bushing? I didn't see it listed with Pelican, EPR or Tarrett.

[sml]

If you were considering (although now cancelled) the bump steer kit, how low were you planning to drop the car?

Apparrenly RS height -10mm is still ok with minimal bump steer.

My car is RS-10mm at the front and there was some bump steer albeit it did not bother me. After a wheel alignment with RS specs, it feels perfect with no bump steer.

Maybe cranking in the max caster or -2 degrees negative camber reduces bump steer?!

[Bill Verburg]

Originally Posted by Chakka71

Would the RS bushings work better than Mono-ball if I am doing Sport Bushings on the front control arms or will it not really make a difference. I'd be curious to see the price difference. Sport Bushings are appreciably less than mono-balls so i'm assuming the RS bushings are the same.
Who sells the RS bushing? I didn't see it listed with Pelican, EPR or Tarrett.

Unfortunately the RS bushings only come w/ RS arms.

have you read thru Jeff Burgers's thread?

Cup car replacement? Jeff sold his Cup car nad built a replacement from a street 964, it's well worth reading.

There just dosen't seem to be a lot available for the 964 rear supension other than mono-balls

[Chakka71]

[QUOTE=sml;5711179]If you were considering (although now cancelled) the bump steer kit, how low were you planning to drop the car?

My car is lowered currently in the same area as yours. I hadn't had any noticeable issue's with bumpsteer, but it was a suggested change. I think i'm going to stick with replacing, upgrading, what I have currently with sport rubber(front), mono-ball(rear), urethane for the sway's and mono-ball shock top mounts and camber plates in front.

If I don't find an issue with bump-steer no reason to change it.

Winter gives alot of time to think......maybe too much! But, I'd rather ask, digest and make a well-informed decision.

[jpachard]

My car is very low as it was corner balanced and aligned by Dan Jacobs and I have no bump steer issues.

As far as front camber plates I would suggest looking at Mode Design. Pelican carries them and they are a very nice copy of the factory RS mounts. I went with Bilstein RSR dampers on all 4 corners but you will need to get lower shock mounts for the rear since the RSR dampers have a monoball end, not rubber. Mode sells these as well. As far as the rear goes as Bill indicated the only option is monoball. In the front ERP are a good option for the A-Arms but all of these companies haven't really done their homework and their tolerancing is all over the place so be prepared to do a little massaging to get these parts to fit in correctly. Dan and I have had a conversation about this and being an ME myself I have half a mind to make these myself and not pay someone 600$ for 100.00 worth of parts and some poor engineering.

Cheers, James

[Chakka71]

James,
Mode Design. Didn't find it in the search on Pelican?