HELP/965 to 3.8 RS clone, trailing arm conversion and Brake and suspension mods

[heliolps2]

Hey guys

I'm gonna need some help and advice with my suspension and brake mods,maybe Bill V will chime in,

Here's what I'm thinking , I'm will be trading my 993 Cab for my brothers 1992 965,

Building a 3.8 RS clone street, using 18 inch Speedlines wheels , with deep dish rear wheels , What will I need ?

FRONT

Speedline 18x9 inch wheels

1, Aluminum carriers ? does the 965 have steel or alum ? do I need to upgrade to 993
2, Bilstien PSS10 uprights?
3 BIG Reds front or keep stock 965 Calipers ?
4 Will I need 322mm two piece Rotors or keep the stock 322mm 965 rotors?
5 I also wanted to add adjustable sway bars and drop links ?

What do you think this part would cost?

REAR

Speedline 18x11 rear wheels, deep dish

1 N/A trailing arm
2 Elephant racing spring plates and bushings
3 What Calipers and Rotors? Can I keep the 965 rear brakes ?
4 Bilstien PSS10
5 Adjustable Rear Swaybars and droplinks

Please let me know if I forgot something?

I'm gonna look into a Patrick Motorsports built 3.8 NA engine

Please help with info and part numbers or if you have parts to sell, It would be very appreciated .

heliolps2@yahoo.com
Helio

[heliolps2]

This what I'm talking about

[heliolps2]

The first million dollar 964

https://www.classicdriver.com/en/article/cars/will-porsche-911-38-rs-become-first-million-dollar-964

[Bill Verburg]

Originally Posted by heliolps2

Hey guys

I'm gonna need some help and advice with my suspension and brake mods,maybe Bill V will chime in,

Here's what I'm thinking , I'm will be trading my 993 Cab for my brothers 1992 965,

Building a 3.8 RS clone street, using 18 inch Speedlines wheels , with deep dish rear wheels , What will I need ?

FRONT

Speedline 18x9 inch wheels

1, Aluminum carriers ? does the 965 have steel or alum ? do I need to upgrade to 993
2, Bilstien PSS10 uprights?
3 BIG Reds front or keep stock 965 Calipers ?
4 Will I need 322mm two piece Rotors or keep the stock 322mm 965 rotors?
5 I also wanted to add adjustable sway bars and drop links ?

What do you think this part would cost?

REAR

Speedline 18x11 rear wheels, deep dish

1 N/A trailing arm
2 Elephant racing spring plates and bushings
3 What Calipers and Rotors? Can I keep the 965 rear brakes ?
4 Bilstien PSS10
5 Adjustable Rear Swaybars and droplinks

Please let me know if I forgot something?

I'm gonna look into a Patrick Motorsports built 3.8 NA engine

....
Helio

oe 964 3.8RS used Speedline
9ET49 x18 235/40
11ET5 x18 285/35 you will need to swap in 964 n/b trailing arms to use these

964t has steel wheel carriers, but they aren't the same as other 964 steel wheel carriers as they have radial mounts for the calipers instead of the 964 axial mounts. You can retain the stock 964t wheel carriers as they are the same as was used on the 3.8. That said 993RS aluminum carriers would be a preferred up grade.

The stock 964t brakes are fine as is, both front and rear. If you use 993RS wheel carriers the rotors would need to be swapped to 993tt rotors which are the same size as the 964t but have an o/s that is correct for the 993RS carriers. 964t front calipers bolt right up to the 993Rs carriers The 993tt front rotors are a lighter 2 piece design compared to the heavier 964t.

If this is a street car PSS9/10 are fine, they just aren't very stiff and would only be appropriate for casual track day use.

For adjustable sways some research will be needed, It probably depends on whether the outer or inner front suspension mounts are used.

[Spartan993tt]

I did that conversion to my 91 turbo.

For the front I did the 993 RS/GT2 uprights with 993 turbo calipers and rotors. For the rear NA arms (and axles) use 993 C2 calipers (painted red) with 968 rear M030 drilled rotors from sebro. Everything bolts up and works great. I had to ditch the erp rear spring plates and go back to stock as the most camber I could run at this ride height was around 2 deg which is unacceptable for a street car. Stock still makes me run more rear camber and toe than I want but its manageable. Susp is mcs two ways but you can run whatever you wish to get the ride height you like. Rear sway is 964 RS and front is stock 91 turbo.


Wheels are RH replicas and were the standard 993turbo fitment in the front and in the rear I changed out the outer barrel to a 4.75 inch. You can source RH barrels online. Only reason I went this route was that RH takes forever for a custom set of wheels and I found a cheap 993 turbo set in perfect condition. The rear is now 12.25 unfortunately and I had to run a 5 mm spacer to keep the inside tire from rubbing. The rest is easy with the rear wing and the small front splitters.





Since these pictures were taken I've put on a slightly thinner front tire to stop the rubbing on the liner. Those are all the basic mods to get you to a 3.8 RS conversion from the outside. Now my car also has a built motor with a motec conversion but that's a different story!

[Vandit]

Originally Posted by Spartan993tt

. I had to ditch the erp rear spring plates and go back to stock as the most camber I could run at this ride height was around 2 deg which is unacceptable for a street car. Stock still makes me run more rear camber and toe than I want but its manageable.

You probably needed to flip them. When I first installed them I had the slotted hole downward and it would not camber more than -1.3. I flipped the plates and could manage up to -3.0 but settled at -2.0 once it was aligned.

[Spartan993tt]

Originally Posted by Vandit

You probably needed to flip them. When I first installed them I had the slotted hole downward and it would not camber more than -1.3. I flipped the plates and could manage up to -3.0 but settled at -2.0 once it was aligned.

I was talking about getting less negative camber not more if that makes sense. I wanted close to 1 deg neg and had to settle at 1.3 neg with the stock plates back on. With the erp plates the least amount of camber I could get was neg 2 ish which is too much for street only car imo. Obviously you could get just about as much neg camber as you want with those plates which is their intended purpose.

[Bill Verburg]

Originally Posted by Spartan993tt

I did that conversion to my 91 turbo.

For the front I did the 993 RS/GT2 uprights with 993 turbo calipers and rotors. For the rear NA arms (and axles) use 993 C2 calipers (painted red) with 968 rear M030 drilled rotors from sebro. Everything bolts up and works great. I had to ditch the erp rear spring plates and go back to stock as the most camber I could run at this ride height was around 2 deg which is unacceptable for a street car. Stock still makes me run more rear camber and toe than I want but its manageable. Susp is mcs two ways but you can run whatever you wish to get the ride height you like. Rear sway is 964 RS and front is stock 91 turbo.


Wheels are RH replicas and were the standard 993turbo fitment in the front and in the rear I changed out the outer barrel to a 4.75 inch. You can source RH barrels online. Only reason I went this route was that RH takes forever for a custom set of wheels and I found a cheap 993 turbo set in perfect condition. The rear is now 12.25 unfortunately and I had to run a 5 mm spacer to keep the inside tire from rubbing. The rest is easy with the rear wing and the small front splitters.





Since these pictures were taken I've put on a slightly thinner front tire to stop the rubbing on the liner. Those are all the basic mods to get you to a 3.8 RS conversion from the outside. Now my car also has a built motor with a motec conversion but that's a different story!

Unless you just want red calipers and don't want to paint, there is no good reason to change either the front or rear 964t calipers
front
993RS/tt 'Big red' brake torque is 2306nm, at the same line pressure the 964t is 2381nm. The reason is that 964RS/t has a larger effective radius on the same size 322mm rotors

back
993 rear is designed for a 24x299mm rotor, 964t rear is designed for and uses a 28x299mm rotor. Other than that they use the same pads and have the same pistons and develop the same brake torque curve. The only real rear upgrade, other than after market, is 993RS rear w/ it's much bigger pads(same as 964t front), bigger pistons)gives better bias) and bigger 28x322mm rotors(better thermal characteristics). The down side of the 993RS rear brakes is that in a 964 application you lose the parking brake.

[Spartan993tt]

It was a couple of years ago but I recall an issue using the rear 964t calipers with the NA trailing arms. Might have been the rotor offsett? The combo I used was bolt on and works. The 3.8rs had red calipers so I wanted red calipers. When you go with 993RS/GT2 uprights in front its kind of a no brainer to use 993tt rotors and calipers especially back when the calipers were $400ish new. Needed new front rotors anyway. None of the brake mods were for performance as the stock brakes were great. Its just part of what I did for a reasonably accurate conversion.

Anywho that's what I did for my 3.8rs conversion so hopefully it helps the OP.

[Cobalt]

Originally Posted by Bill Verburg

Unless you just want red calipers and don't want to paint, there is no good reason to change either the front or rear 964t calipers
front
993RS/tt 'Big red' brake torque is 2306nm, at the same line pressure the 964t is 2381nm. The reason is that 964RS/t has a larger effective radius on the same size 322mm rotors

back
993 rear is designed for a 24x299mm rotor, 964t rear is designed for and uses a 28x299mm rotor. Other than that they use the same pads and have the same pistons and develop the same brake torque curve. The only real rear upgrade, other than after market, is 993RS rear w/ it's much bigger pads(same as 964t front), bigger pistons)gives better bias) and bigger 28x322mm rotors(better thermal characteristics). The down side of the 993RS rear brakes is that in a 964 application you lose the parking brake.

Bill I made this mistake as well on his thread on rennlist. If you convert to 964 Narrow rear trailing arms you have to use 993 rear brakes and 24mm rotor if you want to retain your handbrake. The turbo rears only fit the turbo or the RS rear trailing arms which are different and impossible to come by. I went with the 993RS rears on my widebody narrow arm conversion (thanks to your suggestion) and lost my rear hand brake. It works great on track with the added weight of the 993 Varioram and huge IC but IMO the bias would be off if he stays with a N/A motor which weighs a couple of hundred pound less.

[Bill Verburg]

Originally Posted by Cobalt

Bill I made this mistake as well on his thread on rennlist. If you convert to 964 Narrow rear trailing arms you have to use 993 rear brakes and 24mm rotor if you want to retain your handbrake. The turbo rears only fit the turbo or the RS rear trailing arms which are different and impossible to come by. I went with the 993RS rears on my widebody narrow arm conversion (thanks to your suggestion) and lost my rear hand brake. It works great on track with the added weight of the 993 Varioram and huge IC but IMO the bias would be off if he stays with a N/A motor which weighs a couple of hundred pound less.

ok, that does make sense. The rotor o/s for the 28mm 964t rears is different from the 964 n/a.

Anyway, only an issue w/ the n/b trailing arms where you would wwant either the 993 w/ stock or 968 M030 rear rotoors or 993RS rear calipers w/ 993RS rear rotors

I still wouldn't mess w/ the fronts.

[Cobalt]

Originally Posted by Bill Verburg

ok, that does make sense. The rotor o/s for the 28mm 964t rears is different from the 964 n/a.

Anyway, only an issue w/ the n/b trailing arms where you would wwant either the 993 w/ stock or 968 M030 rear rotoors or 993RS rear calipers w/ 993RS rear rotors

I still wouldn't mess w/ the fronts.

I agree 100%. It is one thing when we are talking stock but swapping from NB to WB and or WB to NB adds to the confusion. Getting old doesn't help either. LOL

[panzerfaust]

Originally Posted by heliolps2

Hey guys

I'm gonna need some help and advice with my suspension and brake mods,maybe Bill V will chime in,

Here's what I'm thinking , I'm will be trading my 993 Cab for my brothers 1992 965,

Building a 3.8 RS clone street, using 18 inch Speedlines wheels , with deep dish rear wheels , What will I need ?

FRONT

Speedline 18x9 inch wheels

1, Aluminum carriers ? does the 965 have steel or alum ? do I need to upgrade to 993
2, Bilstien PSS10 uprights?
3 BIG Reds front or keep stock 965 Calipers ?
4 Will I need 322mm two piece Rotors or keep the stock 322mm 965 rotors?
5 I also wanted to add adjustable sway bars and drop links ?

What do you think this part would cost?

REAR

Speedline 18x11 rear wheels, deep dish

1 N/A trailing arm
2 Elephant racing spring plates and bushings
3 What Calipers and Rotors? Can I keep the 965 rear brakes ?
4 Bilstien PSS10
5 Adjustable Rear Swaybars and droplinks

Please let me know if I forgot something?

I'm gonna look into a Patrick Motorsports built 3.8 NA engine

Please help with info and part numbers or if you have parts to sell, It would be very appreciated .

heliolps2@yahoo.com
Helio

luv your car... especially with a NA motor. i had a 930 now prefer my black lighten slightly mod M491. so if you EVER want to sell that NA turbobody please let me know!

[Cobalt]

I believe he has purchased a 3.3 turbo motor for the car instead and has decided against the narrow trailing arms.

The speedlines are prohibitively expensive and impossible to come by using the RH's is the only feasible option. I hear RS sets are selling for as much as 24,000 euro.

[panzerfaust]

Originally Posted by Cobalt

I believe he has purchased a 3.3 turbo motor for the car instead and has decided against the narrow trailing arms.

The speedlines are prohibitively expensive and impossible to come by using the RH's is the only feasible option. I hear RS sets are selling for as much as 24,000 euro.

thanks for the heads up... it would have been interesting for somebody to do a NA on a factory wide body. I would still love to do one one day

24k for a set is ridiculous. we had pcars in the family for 35 years and i can say all this recent upmarket is bad for the enthusiast more akin for investors and speculators.

[Cobalt]

Originally Posted by panzerfaust

thanks for the heads up... it would have been interesting for somebody to do a NA on a factory wide body. I would still love to do one one day

24k for a set is ridiculous. we had pcars in the family for 35 years and i can say all this recent upmarket is bad for the enthusiast more akin for investors and speculators.

I am with you. I had to build mine out of a C4 I had been looking for a wide body donor but no luck. It looks like factory but took a lot of work and a lot of luck.

As far as the factory RS/RSR speedlines. When you consider a new set from Porsche will cost you easily $10k finding a set of some of the rarest speedlines at reasonable price is not going to be easy. The inners are different than the stock Speedline as well. There are no published part numbers for the 11 x 18 ET5 wheels. So unless you have a set you wouldn't know how to verify if they are real or not. There were probably 100 sets made and most are on the original cars. I got lucky with the set I have. Same goes for other rare items like the 94 turbo S tail. They were $6k new in 1996 so if you can locate one prices like $10k or more are not unheard of.



My friend is building a street 962 so imagine what parts for that are like sway bar drop links can run as much as $10k if you can find one.

I have been around these cars since the 70's. IMO I am surprised the price increases didn't happen earlier. These cars were all undervalued for far too long but some prices have become ridiculous no doubt.

[panzerfaust]

on the speedlines... im sure they can be easily made since they are split rims and not like a mg forged wheel which involves large molds. hell i might even convince braid to do some since i see him every other weekend.

the problem is getting a real one in hand for a scan to make sure they are close to the real deal. are the originals mg or an alloy mix?

for me i wouldnt necessarily want to do an exact 3.8 copy since its nearly impossible with the umpteen bespoke parts. I just want a much lighter and simpler car than the 964T... sort of a hybrid of a wide body with elements of RS/RSA/NGT. I have some even rare wheels in mind than those speedlines which some of the cup cars ran with. :-)

[Cobalt]

Originally Posted by panzerfaust

on the speedlines... im sure they can be easily made since they are split rims and not like a mg forged wheel which involves large molds. hell i might even convince braid to do some since i see him every other weekend.

the problem is getting a real one in hand for a scan to make sure they are close to the real deal. are the originals mg or an alloy mix?

for me i wouldnt necessarily want to do an exact 3.8 copy since its nearly impossible with the umpteen bespoke parts. I just want a much lighter and simpler car than the 964T... sort of a hybrid of a wide body with elements of RS/RSA/NGT. I have some even rare wheels in mind than those speedlines which some of the cup cars ran with. :-)

Considering I am a retired third generation manufacturer of magnesium aluminum sand castings for the defense, aerospace, race car, restoration and commercial markets. I can tell you exactly how easy and how much liability is associated. I have no doubt I could make you a very nice exact replica. I have done so for restorations of some of the most significant cars in racing.

It was a lot of work and a huge learning curve to figure the slight but numerous differences etc associated with using original parts where I could building my track car.

The originals are aluminum alloy and are quite heavy but are durable and some of the best looking wheels they ever used. They can easily be made in mag but Porsche added material to the back side of the mag wheels adding more material and weight than if just made from the same tooling as the Al centers.

No doubt you can sink a lot of money into these cars some are willing to go for the real deal and others an RH replica is perfect. There are even ways to etch the SPEEDLINE for PORSCHE etch and offset info. But to the trained eye there are differences and to some it means something. I guess if you have an RSR you're restoring to original and want the proper speedlines 9 & 11 for the RS and 9 1/2 x 11 for the RSR you may have to pay up for the few that come up for sale.

The best Porsche is the one you can afford to drive. If you can afford to drive a million dollar plus original 3.8 RS you can afford the real deal. I got lucky and somehow these found me otherwise I would never consider owning them at market price.

Build a nice driver and drive it. I would consider a fikse or bbs for you if you want light weight even the RH's are heavy but they give you the feel of driving something similar to a great car and some will pay a lot of money to experience that.

[panzerfaust]

Originally Posted by Cobalt

Considering I am a retired third generation manufacturer of magnesium aluminum sand castings for the defense, aerospace, race car, restoration and commercial markets. I can tell you exactly how easy and how much liability is associated. I have no doubt I could make you a very nice exact replica. I have done so for restorations of some of the most significant cars in racing.

It was a lot of work and a huge learning curve to figure the slight but numerous differences etc associated with using original parts where I could building my track car.

The originals are aluminum alloy and are quite heavy but are durable and some of the best looking wheels they ever used. They can easily be made in mag but Porsche added material to the back side of the mag wheels adding more material and weight than if just made from the same tooling as the Al centers.

No doubt you can sink a lot of money into these cars some are willing to go for the real deal and others an RH replica is perfect. There are even ways to etch the SPEEDLINE for PORSCHE etch and offset info. But to the trained eye there are differences and to some it means something. I guess if you have an RSR you're restoring to original and want the proper speedlines 9 & 11 for the RS and 9 1/2 x 11 for the RSR you may have to pay up for the few that come up for sale.

The best Porsche is the one you can afford to drive. If you can afford to drive a million dollar plus original 3.8 RS you can afford the real deal. I got lucky and somehow these found me otherwise I would never consider owning them at market price.

Build a nice driver and drive it. I would consider a fikse or bbs for you if you want light weight even the RH's are heavy but they give you the feel of driving something similar to a great car and some will pay a lot of money to experience that.

very good points you have made

i know a little about the manufacturing side too both here and in torino. thats what i do for a living

speedliness (italian made) have been known to make a stout wheel...perhaps a tad heavy because of it. you can reference the, ferrari, F40, 355 challenge and lancia integrale wheels mg race and rally wheels speedlines made during the same era as the 3.8rsr. lots of these cars ended up using tecnomagesio, enkei, oz casted/forged mg wheels as an upgrade. in fact the best wheels made these days most likely come from jpn, i.e mackin industries, enkei etc. they are current suppliers of many F1 teams. the coveted speedline RUFs are an absolute joke on how heavy they are. as much as iuv the look of that wheel i resisted of picking up a set.

i have a set of e50's already, not remotely interested in Fiskes since they arent period correct looking. I was in there manufacturing facility near tacoma washington 25-30 years ago (gez has it been that long?) to watch how they were being designed and made. they were big locally with the racers and were decent quality wheels. I believe they were sold or acquired by another company long ago

split rims in my view were a low cost practical way to produce race wheels with easy replacements of damage rims and flexible offsets. on the bbs e50's you were suppose to exchange your mg centers to be melted down and get new replacements for the each season. the E50 often takes credit for pioneering this concept for circuit racers but in the 60's they were on all sorts of F1 cars and sports racers. gotti was producing them since 66. smaller less complex tooling with thin centers along with spun rims were very affordable way to produce race wheels.

i couldnt agree with you more. I grew up with Pcars in the family before i even had a license. bros and sis had 3 of them at once. I never thought much as them as investments as folks do now. the recently upswing in prices driven by speculators and flippers hits hard for the enthusiast. I have an car but as you have mentioned, I will soon be bumping in to running cost i can no longer afford. Dam, I bought to car to be driven spiritedly and track and not just to polished for cars n coffee!

cheers pf

[Cobalt]

Originally Posted by panzerfaust

very good points you have made

i know a little about the manufacturing side too both here and in torino. thats what i do for a living

speedliness (italian made) have been known to make a stout wheel...perhaps a tad heavy because of it. you can reference the, ferrari, F40, 355 challenge and lancia integrale wheels mg race and rally wheels speedlines made during the same era as the 3.8rsr. lots of these cars ended up using tecnomagesio, enkei, oz casted/forged mg wheels as an upgrade. in fact the best wheels made these days most likely come from jpn, i.e mackin industries, enkei etc. they are current suppliers of many F1 teams. the coveted speedline RUFs are an absolute joke on how heavy they are. as much as iuv the look of that wheel i resisted of picking up a set.

i have a set of e50's already, not remotely interested in Fiskes since they arent period correct looking. I was in there manufacturing facility near tacoma washington 25-30 years ago (gez has it been that long?) to watch how they were being designed and made. they were big locally with the racers and were decent quality wheels. I believe they were sold or acquired by another company long ago

split rims in my view were a low cost practical way to produce race wheels with easy replacements of damage rims and flexible offsets. on the bbs e50's you were suppose to exchange your mg centers to be melted down and get new replacements for the each season. the E50 often takes credit for pioneering this concept for circuit racers but in the 60's they were on all sorts of F1 cars and sports racers. gotti was producing them since 66. smaller less complex tooling with thin centers along with spun rims were very affordable way to produce race wheels.

i couldnt agree with you more. I grew up with Pcars in the family before i even had a license. bros and sis had 3 of them at once. I never thought much as them as investments as folks do now. the recently upswing in prices driven by speculators and flippers hits hard for the enthusiast. I have an car but as you have mentioned, I will soon be bumping in to running cost i can no longer afford. Dam, I bought to car to be driven spiritedly and track and not just to polished for cars n coffee!

cheers pf

I don't meet many people who come from a foundry manufacturing background. It is not a business for many. I stayed with it my grandfather was head of Bendix Eclipse Pioneer in the 1930s with some 3000+ employees. An Italian immigrant with a foundry background. Pioneered the first Mag alloys in the US and helped create Dow metal or AZ92 turned over all his R&D and essentially won WWII due to his reducing scrap on a national level by over 40%.

I avoid making wheels since it is such a specialized market and difficult to make a buck, spent most of my years making key parts for the blackhawk, Chinook, Super Stallion and other critical aircraft used today. I have made replacement wheels for F1 cars using original Campagnolo tooling but these were rare earth alloys as are most of the F1 wheels today.

No doubt there are better wheels but so much has been learned in the past few decades. I recently worked with a local foundry and we have come up with a new sand system that makes the nicest mag casting I have seen. Hopefully something will come of it. There are literally no signs of the common issues associated with mag sand castings and is far more environmentally friendly.

Good luck with your build.