Check Rosepassion, the price was quite good last winter I bought a new one to RH side.
You can use your present rotors with 1.5 mm space between the rotor and the hub. Ask Antti for those. For upper mounts go for OEM GT3 parts. Antti has quite nice track rods etc too. While there you can add some more parts to the bankruptsy, like GT3 (lower) control arms and stabilizers... Remove rubber from rear subframe and upper control arms.

You can test mine at Alastaro, if you wish.

 

As I drive also on high speed bumpy tracks (=Nordschleife) etc it could be I end up with heavychevy's statement that I just cannot improve times with RWD, but let's test it properly first and I like the challenge!!

pwdrhound, thanks for info, but am not going yet for a proper GT3 upright conversion as I do know few pro drivers who feel it shouldn't be that big issue. Let's see when I get more miles.

In rear, I don't have much rubber left. Newest addition will be subframe bushings to uniball. Dog bones are still OEM rubber, just like in RS 4.0 and GT2 RS that are quite fast in right hands. All others are uniball already.

Pete, really hope we can do some driving together on Alastaro track next week. Not sure if car ready then! Should be...

As mentioned, I am far from being a RWD fan boy, and would indeed think it would be less than 0.5 sec 60-130 (like 0.2-0.3 sec depending on various parametres), but here's couple different mentionings I have spotted:

https://www.6speedonline.com/forums/...ml#post2569595

https://www.6speedonline.com/forums/...ml#post4178464

 

My confirmed AWD to RWD 60-130 mph times on the exact same ground, same weight and tune is 0.4-0.5 seconds

 

It's legit, mine were like that too (.3-.4). The drag from the front is pretty big.

Kai,

Give it some time bro, you need to get those spring rates right first and spend some time tuning. Like any other major change, you'll need a while to tune it right. It will take a few events.

However, the problem with the TT is lack of decent aero dynamics. It's slippery, but produces quite a bit of lift. On a track like the Ring, you may not be able to put all of the confidence in RWD with the lift and bumps at high speed. AWD mitigated a lot of that adding some extra confidence.

The same times will be a lot scarier in RWD. You will have to white knuckle it sometimes.

 

Interesting! Was thinking of turning my 997tt into RWD .. But not anymore !

 

I have now changed the springs from KW's original 70/190 N/mm to a more even 100/150 N/mm setup.

Rear grip better, apart from some corner exit oversteer, but that may be unavoidable with 600hp RWD.

Front grip worse, especially in low-speed corners. Don't have exact data for high speed corners as visited a different track.

Had also braking issues, couldn't stop the car well. Main problem can be the brakes, as it was during my earlier attempt, but perhaps the 43% stiffer front springs with less grip in front didn't help it either.. Car has Brembo GT 380/380 kit from 997TT, 997 master cylinder, Brembo's race pads and rotors, race fluid, steel lines, techart air channels and GT3 Cup air ducts. Next will install the 997 vacuum pump. Interesting...

Will continue to finetune.

 

I like to add a bit of rake to the chassis to help with braking and turn-in. It can possibly add some mid corner oversteer, tune that out with the sway bars starting first on the end with the problem (rear) and going softer and then I turn ***** on the dampers.

Learn how to play with rake angles at the track and save yourself a lot of time, trips back to the shop. It's super easy to do. You can get away with about 2 turns in either direction before messing up the alignment. I did a lot of that this weekend myself.

 

What sways are you running Kai? I think I'll take a little to get used to the different feel of the car. You'll need to rotate the car more under braking compared to your old set up. My spring rates are 245/263NM and I have no issue with front end grip. On NT01s my GT3 sways are on the middle hole in the front and 1 hole from full soft rear.

Ever take rotors and caliper temperatures as you come off the track? That would be good to know to get an idea what is going on with your brake system. What kind of ducts are you using in the rear? I am using front 996Cup ducts along with 996GT2 fender liners and 997GT3 upper radiator air guides. The GT3 radiator air guides funnel a ton of radiator air directly over the rotors. In the rear I just installed 997GT2RS brake ducts which are a huge improvement over the old 996GT2 units as they funnel air directly to the eye of the rotors as well as the rotor itself. I also have a 997GT2 belly pan which has NACA ducts in it to direct air to the rotor via air guides attached to the thrust arms. My rotor temps coming of the track are rarely over 500F coming off the track. Fronts and rears are virtually the same temperature

Rake is good. I found 25mm to work well. 997GT3 tires sizes work well as it gives you a taller rear and induces rake into the chassis.

 

Thanks for comments.

This is a bit difficult as I am trying to achieve the total maximum performance of the car, e.g. no one here with these cars drive nearly as fast, but I know setup is not optimum.

For clarification, I am missing only 1.0 second on a 1:25 minute track so it's not totally awful, but I have driven much better setups.

All slow corners are done with trailbraking. Must be, won't rotate else..

Sways are stock, I understand everyone may suggest a stiffer rear bar for better balance, but I like to focus on the end that has the grip problems. And even with my current setup I have to countersteer the fast corners in exits...

Thanks John for mentioning the brake temps! I'll measure the brake temps next time. I am sure my cooling is OK (as it was with 996 GT3 brakes) but I believe I will rebuild these Brembo GT calipers just in case they get someway stuck when hot.

 

Stock sways dude? Like non adjustable? You are missing out on a lot of fine tuning bro. No wonder you are under steering. That's what the stock bars are tuned for.

I'm surprised you managed to get the AWD to turn in with stock sway bars.

You have to also realized you took 75 lbs out of the front of the car. That means less weight on the lightest end of the car. It's going to push until tune it out.

 

Really happy with the feedback!

Yep I will buy adjustable sways again, when I have entered the right ballpark.

But I sold them earlier as my KW Clubsport was optimized for stock bars and AWD. That's why it had the crazy spring rate split. This was decision by Manthey-Racing, the well known race team. My car was faster with stock bars compared to H&R bars in any setup I tried, when I was AWD with KW Clubsport. Still holding one street legal Porsche lap record with that setup, even though tuned 997 GT2's / 997TT's are coming close and expecting them to break it during next year or so.

But thanks for the comments; That's true I have now considerably less weight in front with RWD. Seems I'll change back to softer front springs, they may not be too soft as I have a 35 profile front tire (less sidewall, so less flex?) and I could next install a 3lbs lithium battery as well.

Hope it won't be too soft...Actually the softer spring rate choice is the same that KW uses with good results on the 997 GT3 RS, so they shouldn't be that much off. Even though 70 N/mm is nothing compared to spring rates used by US tuners...Please don't convert it to lb inch as you think I'm a fool

BTW. My brake upgrade has been a disaster, had 996 GT2 brakes, was not happy with the pedal feel (due to 996 master cylinder), then switched to 997TT Brembo GT 380/380 brakes. Had to go to 19" wheels while would prefer 18", and now the brakes are mysteriously not performing as expected (I won't risk buying another 18" wheel set without first trying, bought one 18" set, that should have had the space but it didn't...). As I wrote earlier, will try a 997 vacuum pump next, if doesn't help, I send the calipers to Brembo for a rebuild.

 

997GT cars have different roll center than our cars that is why you can get away with softer spring rates on them. Doesn't translate to our cars though.

Tough to go wrong with the stock 7GT3 380/350 brakes and all the associated hardware like MC and Vacuum pump. Rear brake utilization is also greatly improved which will help turn in under trail braking as you have much greater rear brake bias. Absolutely phenomenal brakes all around.

 

I like your approach. I am the same way. Get back to where you were, then add mods so you know for sure where the speed came from. Hard to argue with Manthey. There is no one setup that works. You have to find what works best for you and gives you the most confidence in the car. You seem to know what you are looking for, so I'll leave it at that.

I have heard poor reviews of H&R sways several times before. I would consider trying GT3 bars if you get new ones.

 

Buy one of those cheap infrared temp guns so you can easily get a temp readout on your rotors and calipers. It'll tell you if you have any problems like a dragging caliper for example. I take rotor and caliper temps at the end of each run and if I were to see a spike on one rotor or caliper I'd know right away something is up. Useful for tire temps too although not as good as a pyrometer. GT3 sways are good. No need to reinvent the wheel there..

 

That's a tall statement.