Spyerx

I'll post a full "phase 1" build list once complete. It continues to evolve but the end state for this part I have pretty well defined in my head at this point.

Cost? Who knows. Mid 5 figures plus the car. But who is counting. I will post that too to scare people away. LOL and same again for the engine build.

Let me put it another way. I have driven the 991 gt cars and I'm not a fan. Faster, "better" sure. But the feel is gone. Maybe it gets right on 991.2gt3/rs.

But for now my $ is going into an "antique" that I think will be much more fun and teach me a lot more as a driver. Cost may end the same. But that is ok by me.

FLYT993

killer, just absolutely killer! love it.

bobaines

I like what you are doing, and LOVE your attitude!

Spyerx

MORE PARTS

these are the BMW brake lines that allow you to connect the 993 master cylinder to the abs unit. 10mm on one side 12mm on the other. Part 34326752405 $15 each and a local dealer actually had them in stock. On shelf since 2009 he said! Other option is an adapter or fab new lines or tweak current lines to work. Lines must be bent to match current lines. Easy job.

Other pic is all the shifter mechanism bushings, washers, o rings, clips and any other part in the shift chain. All will be replaced with rothsport shifter install.

Texas RS

We can get you fixed up on an air cooled 3.9L, with more torque than your 7.1.

Bill Verburg

The reason Spyrex is able to retain the parking brake w/ the hats is that the caliper he has are radial mount. This allows the caliper to be spaced out a bit more than on the 993RS rear 322mm rotors. The parking brake requires rotors in ~330mm. This is also done on Cayman, Boxster and 996, 997.

It could be done w/ 993RS if the calipers are converted to radial mount and a bigger rotor is used
like this

On left stock axial mount 993RS rear caliper, on right 993RS rear caliper converted to radial mount w/ caliper adaptor

Bill Verburg

always a good idea, but the 6 speeds have a lot of flexibility
here is a comparison of some of the 993 6 speeds that have been used
Tee /30s use a different mainshaft that laaows 1 -6 to be altered easily, the /20s all have a fixed 1 and mostly all have fixed 2 as well. Here is the break down on the #s where the loose 2 ended, M220 is w/ lsd
G50.20 - 02693
G50.20 - 02174 (M220)
G50.21 - 05072
G50.21 - 03094 (M220)

I have the /30 in mine it is great for both street and track, the RS /31 or /32 have much taller 6 for more relaxed highway use. Other differnces will be found in the choice of internal components, the /30 and /34 are pure race transmissions w/ all steel syncros and more robust build, the /32 and /31 are slightly less robust, w/ the /31 least so. The /20s are street trans which will tend to have more issues w/ track use. Among the issues that will be found are brass syncros and plastic bearing shells

Spyerx

Bill - Benefit of a 993 trans vs. modifying what I have with steel synchros and the like? Obviously the additional ratio... but I think the stock 964 gearing is a bit nicer than the 993 gearing?

Bill Verburg

Ther are several way s to look at it and the torque curve of the motor has a huge influence on what way you go

Just for instance I did this comparison for a friend the engine is a very healthy 993 non vram in a 964 RSA. The trans choices available were g50/03/ g50/05( these are 964 5speeds) and a g50/20 from a US 993. The thrust curves take unto consideration the aero resistance of a stock RSA


Except for 3rd the /20 is better, but the /03 3rd is fabtastic in comparison to the other 2 if the car is driven between 60 and 110mph. This is likely to be the most used gear on most race tracks. AFAIK the 964 g50 come w/ steel syncros stock, don't know about the bearing shells or other internal components.
Now compare the 2 964 trans to a g50/30, same chassis and engine


here the 03 still has better thrust in 3 between 70-105, but the 30 has a smaller drop into 4 and even 5 for the speed realms above 110mph. Here the smaller drops overall in all gears are the big advantage.

Spyerx

^^ Great info. My car has the G50/03, this gives me something to think about.
My driving style/use is canyons which are mostly 2-3 and track which will be 2-3-4 with 3-4 being most common. 1 track here, auto club speedway 5th would be used, but I rarely drive there.

Do you have a way to do something similar with the G50/03 tranny but changing just the final drive ratio to (I think ? 3.89?)

Bill Verburg

Sure, but all it does is move all the blue lines up a bit, you still have the same big drop from 3 to 4 and 4 to 5 3 now goes from 60 - 95 and 4 is 178-122 and 5 is 98 -152 some what less w/ shorter tires

In the thrust charts note how the /20 at he end of 3 kisses 4 and the end of 4 kisses 5 etc. That is a good thing compared to the drop from 3 to 4 and 4 to 5 etc in the /3 or .5, even w/ 3.89 or shorter tires.

kos11-12

Hi guys, As a stock box I quite like the gearing of the G50/01 , What do you think From what I understood It's not a straight fit, The front case needs to be changed plus an LSD to be fitted, I came across one for 2500 € with 70000 km ...

Spyerx

Thanks for the info as always Bill!
I've traded some notes with Matt (GT Transmissions) and his feeling is similar with the 5spd, keep it and address a bit shorter on the higher gears, to tighten up the spacing but it's pretty good as it sits.
Ugh I think my tranny is going to be seeing Bill Rader sooner rather than later for some GT Gears updates :-)

Jjm4life

After looking at An endless number of charts, I decided to regear a six speed this winter instead of doing the 5 speed. No matter what ratios, the 5 speed always had a compromise to it. Not the case with the extra cog.

Bill Verburg

The /01 is the same as am /03 but w/ shorter 4 & 5 the drops to 4 & 5 are 25% & 27% vs 30% & 25% for the /03.

You might be better off just regearing a /03