Good fun!

Mine will remain a 3.6 as I intend to make a run at GT4.

Just found out he has ordered a raft of fancy pistons at 100mm...first time for that. The cool thing is the fact that I already have the required plenum, ECU, ITBs, exhaust and a few other things so the massive $$ required will be reduced considerably.

 

Bill,

Too be honest I have no idea. I picked these up on a whim. The price worked better than buying new even if I have to swap out barrels. I plan on using these until I can budget for new wheels and use these as spares. they appear to be factory assembled by Fikse.

I don't have the time now to layout the wheel. I will try later to use a height gauge and do an accurate layout.

I am posting pictures of some quick and very poor measurements. Didn't consider that the measurements would be off on the wheels.

It was next to impossible to hold the gauge and the phone to take pictures never mind lining things up by eye but this should give you an idea. I will get you better measurements but I would venture to guess they are all off by a good margin. I would put the outer lip at .375 I think my hand twisted. Inner lip is somewhere closer to .440 Outer lip is measure to the radius so I would venture to guess 3" to bead seat and 9" from bead to split in the rim. The measurement is very rough and taken from the outside not the bead. Also I have 14mm of spacer just to see how they fit and you can see it is still too tight.

I have to run will be back later if you read this I would be interested in your opinion and I will try to layout the wheel on my kitchen counter (surface plate ) for more accurate readings.

Whatever help you can offer is always appreciated.

So do you have a thread to what you are doing I would love to read up on it.

I purchased the trailing arms with the ERP bushings already installed. Keeping on budget is tough front and rear everything including new hardware cost me less than the rear bushings new.

I was planning on swapping out the big reds and 964 rear turbo calipers over from my C2 to the track build. I am not sure if I will use the backing plates or not. I had eliminated the fronts on the C2 and retained the rears. I was contemplating eliminating the rears. Although I was considering the heat shielding from the engine despite the fact that the headers will not be close like the cat on my C2.

I also was considering swapping everything out to 993TT offset front using the 993 carrier and I have one rear 993TT caliper need to source a second if I go this route. I am not sure the gains are adequate over the 964 turbo rears what are your thoughts on this. BTW this was a C4 so it does have the electro-hydraulic brake system.





Thoughts.

 

for the backing plates w/ big red font and the small 4 piston rears I'd use backing plates, it's true that I went bare for a few years and never had an issue but it was always a concern. The ABS sensors are a possible issue as are the rubber joints covers in the vicinity of the rotors

I went w/ aluminum 993RS backing plates in front and stock steel ones in back

I also have a set of 964 Cup aluminum ears and 993RSR cut down steel ones for the back
993RS front on left 993 on right


964 Cup ears


993 bottom 993RSR cut down top


993RSR installed

 

What advantage is there using aluminum fronts? The turbo has aluminum front backing plates so it should be easy to source. For now I will go without I haven't had any issues and it can be added later.

As far as cutting the rears what is the advantage? I also see you have your ABS sensors wrapped in some form of insulation. Did you do both front and rear or only rear?

As far as the wheels I had a chance to do a quick layout. I am sure my kitchen counter does not measure in the millionths as my surface plate did but these are as accurate a measurement as I can get. Dimensions are based off surface plate.

inner flange .460
overall barrel 9.460
top of gasket 9.535
upper bead 12.460
overall height 12.890

outer flange .350
outer lip 3.350

back side of hub to inner barrel outer edge 8.225

So I am curious if you have insight why the outer flange is different than the inner? Does this pose a problem it appears to be consistent to all the wheels.

I am seeing an outer lip measurement of 3" and inner barrel of 9". With a measurement of 8.225 to the outside of the barrel flange would make this an ET 44.

I see where I screwed up my calculations. If I reduce the barrel to 8" or by roughly 25mm it would change the center-line and give me an ET+30 if I go with an 8.5" barrel or an 11.5" wheel an ET of 25.

I believe i might be able to fit an 11.5" wheel with an ET25.

What do you think?

I never laid out wheels before so am I doing this correctly?

BTW thanks as always you are a huge help.

 

Aluminum is just lighter(~.3# vs .75#) and conducts heat better, and won't rust.

The advantage of cutting them away is better air flow for convective cooling and lack of a barrier for radiative cooling. But leaves some protection at the vulnerable rubber boots and ABS sensors

Firesleeves on the ABS connectors

Instead of measuring all the little pieces it's best to just measure the total overall and either the front or backspace as accurately as you can normal to the face plane. For backspace A small carpenters square laid on the mounting face gives you a guaranteed normal path and a 2' level a place to measure. For overall lay the wheel on a flat surface and lay any straight rigid object(2' level say)across the back flanges, measure the normal distance between the floor and the 2' level. Those 2 measurements are all that is needed. to fully define the wheel.

The bead is always going to be in .5" increments, so if the overall measures say 12" it is an 11" bead w/ 2x .5" flanges, A BBS 11" would measure 11.875" OA and would have an 11" bead and 2x .4375" flanges

 

I used a starret 24" square across the back side of the wheel and measured from the hub to the bottom face of the square. . I calibrated the gauges prior to measuring.

I laid out sand castings to close tolerances for years. I would guarantee all dimensions but the gasket which I believe is .005" off but that is unimportant Which leaves me.

So obviously an overall length of 12.890 is not normal. The outer flange is 0.110" less than the inner and neither are 0.5". So 0.350 flange is a problem? Is that too narrow?

Since the overall width is 12.890 or 0.110" less than 13" I would have to assume the outer flange might have been turned down at one point but these look as though they left Fikse this way and have a coating on the surface that has not been disturbed all 4 wheel flanges measure identically.

Meanwhile I guess I should contact the PO and see what he has to say.

I am curious if you are running 12's in the rear I know they are different in many ways.

Thanks again. I see you have been busy helping others out as well not sure how you find the time.

 

I did some research and came up with several sites claiming the new Fikse rolled outer lip can measure roughly 0.100" less than the cast barrel. I will contact Fikse and see what they say I have to consider what barrel size I need though first.

 

12.89" OA is a 12" bead w/ 2x .445" flanges, not far from the expected .5"

what is the backspace now? from that it can be determined the backspace w/ either a 1" or .5" narrower wheel 1/2 and then the resulting o/s

Let us know what Fikse has to say, all the specs I have are 15-20yrs old, they may have changed specs since those days.

 

I run without backing plates but wrapped my sensor cables with heat insulation as on the Cups.

Thomas

 

Sorry been busy Mother-in-law is in and out of the ICU it has been a crazy weekend.

Back spacing is 8.225" Someone PM'd me and said Fikse cuts the outer flange down more than the inner to set the flange deeper into the tire as to prevent less chance of curb rash. I checked my other 2 sets of Fikse's and they appear to be the same.

I will contact Fikse and see what they say and get back to you with the info.

Thanks

 

That's interesting and if true complicates things a little and makes my ss calc off a little

for instance my ss gives the current ET w/ 12.89" OA and 8.225" BS as ET45.2 but if the outer flange is asymmetric wrt the inner flange that would explain the difference from the claimed ET44.

Anywhooo, if you change the inner 1/2 to be 1" less the overall should be 11.89", bead 11" and BS 7.225" which gives an ET32.64 the F/S will remain the same @~4.67"

If you have 1" wheel spacers available you can judge the relationship between the wheel and the trailing arms pretty well, it will throw the outer clearance off by the same 1"

 

No word yet but I will keep you posted thanks for your help.

Paul from Protosport is stopping by Saturday we will go over the sizing and see what we can do. It looks like making these and 11" or swapping the inner to the 8" makes most sense.

I was considering slicks now since any R compound are not available in the sizes I need and cost about the same. The slicks come in the sizes I need and are a bit cheaper so we shall see.

Meanwhile I made a tow hook for the front. It was pretty simple and easy. Took a few hours. I had a 3/8" hardened steel bar I used and bent it around an old 3" cam gear. It took a bit of force. I was going to use a smaller dia. I was contemplating using a 2.5" gear but the material was too hard to bend with the tools I have. I used a vise which was easy enough and a long pipe to bend it around the gear. The vise allowed me to finish off the bend without any strange shape.

I drilled through the tub and I used a 12" long piece of bar stock up against the inner wall and a short plate on the outer. I also added spacers and a piece of aluminum angle ground to fit the contour of the tub. When bolted together it made for a very strong attachment. Not sure how strong but it held my entire weight without moving a bit. Assuming the car is just being towed in it should be fine.

I tried painting it red but it looks like the car is sticking its tongue out at you. So for now it is black and I will add a tow sticker near it. this may change.

 

Looks great! Nice work!

 

Sadly I have not made much progress. We lost my mother-in-law last week who moved in with us 3 years ago. Very sad times.

I have been trying to keep myself busy so I have been focusing on finishing touch stuff while I wait for parts to come in.

I made some door cards to cover up the exposed sheet metal left over from gutting the doors. I also took the easy route and used rennline cable pulls for door releases. After adding up parts to make my own it was cheaper to just use the rennline product. Easy enough to do it took about an hour per side. I used all the factory mounting points except the bracket I needed to make to attach the cable end. Easy pull up on the blue loop and it releases the door. You can't see any of the hardware once the cards are in place. cable runs along the bottom inside of door and the bracket supplied by rennline just needs some minor elongation of the slot to allow me to bolt it onto the window frame.

Heading over to Stable Energies later today to swap some parts. It is scary to think I remember when Laurette was born which seems like yesterday. I will have the passenger seat and steering wheel installed soon that will complete the interior. All I need to finish is the front suspension and it is set for the engine install.

No way I will be ready for end of March so it might not be until May or later by the time i have to shake this thing out.

 

Thanks for the update. I'm sorry to hear about your loss. I wish you and your family the best.