camlob

Some of you guys know that I have tried my brothers 997 GT3 RS gen 1 in a track and I want my car to handle like his

His car has motons, sway bars, not so sure about the tires but better than mine.

I have JIC's w/ 8 and 10 kg springs, TRG sway bars and a front strut brace. I have 8.5 and 10x18 HRE 540 wheels with Sumitomo HTRIII's. My front camber is - 1.5 and rear 1.3. Zero toe on both ends. My ride height is a little like MO30. It was at RS spec but I didnt like the bump steer. My LSD, I think is toast.

I also have elephant racing toe-control arms and walrod bushings in the front.

My car initially was set at the middle for my damper settings, then moved them up to stiffest, then am now -4 clicks from stiff for the front and -2 clicks from stiff at the rear. My sway bars are set at soft. At this setting, I think its soft.

The RS handles beautiful. It can maintain higher speeds at turns etc. I know the chassis is stiffer.

I just came from the track yesterday, and a friend who has a lot of experience with Honda's and VW's told me that my car was well balanced. I think he didnt know how Porsches handled But he knew the track well.

Now I noticed I tend to oversteer a bit, even on - 2 from stiff damper setting. I was thinking it was the LSD. My car has 4l kit with ITBs etc.

After reading numerous threads here on suspension tuning, I will experiment more like on tires pressures and damper settings.

So will it be possible to make my car handle like a GT3 RS or even similar to it? I was thinking of having my chassis seam welded, to have it stiffened, but decided not to since it will take too much time and money.

Steve Weiner-Rennsport Systems

JMHO,

You are comparing two totally different chassis as well as suspension systems and such comparisons are not really valid.

Its possible to make a 993 handle as well as that GT-3RS in the right hands, however you need a very different suspension that what you currently have to help bridge that gap. Further, you'll need some aero changes to offer the downforce that the GT-3RS has.

The right components really go a long way toward leveling the playing field.

You'll start the process with:

MCS double-adjustable shocks with a custom main/tender spring package tailored to your current driving skills.

EVO uprights and tie-rods

ERP rear toe, camber, and kinematic links

ERP front camberplates and rear upper monoball mounts

ERP rear solid subframe mounts.

A properly functioning LSD; Guard or PMS that's properly set up.

Provided all these items are correctly install and adjusted, you'll have a KILLER 993 that in the right hands, gives a 996 GT-3 or Cup a real good run for the money. Naturally, there is a power difference, however that can be easily addressed as well,.. .

camlob

Steve, are you referring to Elephant Racing? Their website only has the monoball cartridge kit for the rear, 8 pcs total.

So you think that chassis stiffening is not the way to go? I figured that the RS had a seam welded chassis, hence part of the stiffness feeling that I wanted. It also had a rear cage.

Regarding the EVO uprights, I cant have my car too low because of our roads over here, like speed bumps etc.

But if you feel its necessary then maybe I should Maybe Ill do the Guards LSD first and the rear subframe mounts, and the rear control arm cartridges.

winders

ERP = Eisenlohr Racing Products and is owned by Cary Eisenlohr.

http://www.erpparts.com/porschesuspension.html#993

Scott

333pg333

Where's 'over here'? Do you not have a cage as well?

camlob

Still in the process of deciding what custom cage to put. Looking at the old 993 cup car full cage or maybe a 997 cup car cage design perhaps?

camlob

Thanks Scott!

Paul

camlob

Here is a vid on a track that we go to. Its about 1:50 to 60 mins per lap. This was sort of a tempo lap just to get my lines correct. The car with the camera is a 997 GT3. The reason I am showing this is to show you guys what type of track that I use. I hope its relevant.

At this time, damper settings were at full stiff with no TRG sway bars. Hot tire psi was at 37

http://www.youtube.com/watch?v=y9uj8...=youtu.be&hd=1

85Gold

Couple of comments

1. Sumitomo HTRZIII are really not track worthy. You are leaving seconds on the table just in tires.

2. Rear toe at 0 of course the car I'd going to be loose. Need some rear toe in

3. More neg camber front and rear -2.5 front and -2.0 rear check tire temps and adj

4. Try that 1st then listen to Steve as he is the MAN.

Peter

camlob

Of course not to compare but my brother's RS doesnt use neg camber that extreme. I know that -2.5 and -2.0 rear is the way to go but it will eat too much rubber. I am hoping for the best compromise

Ill use up the sumi's for practice and save up for better rubber. Meantime, Ill spend on components if needed. I mean, I wont rush in and order parts right away, but at least I know the direction I have to take

utkinpol

If you have nice clean 993 with full interior I doubt the rationale to convert it into track only car. As of what to do - 993 can be done to run faster than stock RS car, you need full track conversion - strip it, put in full cage to make it stiff, replace front fenders to fit wider rims, roll rear fenders and put rsr like aero kit.
There are cars like this on a track.
Imho nice mint 993 car is a collectable item, it is worth more in its stock form than in a track only, but it is up to you.
It also may cost less now to buy 996 cup car than to build 993 street car into 993 'rsr' replica.

mhm993

I dunno. You don't even have a cage yet. Take the conversion slowly since each step can significantly change the car. Get used to the incremental alterations and make sure that everything works together. I've seen way to many cars that have taken giant steps in mods and then go, boom!

You can make a 993 into a great 993 but if you need a GT3-RS you are going to have to buy one.

-- mindy

Flying Finn

Well of course it is.

Steve Weiner-Rennsport Systems

The very LAST thing on a handling improvement program would be seam-welding. You won't feel the difference compared to all the other items on my list of upgrades. A proper cage will certainly help and thats noticeable, however proper dampers are tops on the list.

EVO uprights and tie-rods are needed to correct bump steer issues found at RS ride height and thats where your car should be.

I did prioritize my list of suggestions to make assessment easier and thats where to begin. You can install monoball cartridges, however the ERP adjustable links are MUCH better as they permit a wider range of adjustability. This is critical for bump-steering the rear suspension to get better kinematics.

trophy

Hey Paul,

Some good advice here all around. A good starting point would be to get rid of the rubber in the suspension, it moves around alot and doesn't allow you springs and shocks to work effectively, namely;

ERP links (toe, Kinematic Toe and Camber link), As Steve says this will ensure you can get an accurate alignment that will hold.

To get the height and geometry right at a good low height (RS or lower) you will need to get a set of RS/GT2 uprights and GT2 Tie Rods. This will correct the bumpsteer you are experiencing when you go lower.

Next would be the A-arms, you already have the Walrods in the front, I would replace the super soft rubber bushing in the rear a-arm with a monoball (the rear a-arm has a monoball at the front of the arm already and a rubber one at the rear, this is to allow the Kinematic toe effect for the rear end). What this will do is eliminate the Kinematic toe effect in the rear of the car, makes it more balanced and predictable when pushed.

The last bit would be solid side members, this will then eliminate the movement in the rear suspension carrier, further planting the rear of the car.

Next step would be to get a good track specific wheel alignment:

Camber: Will be dependent on the tires you run, less on street tires more or R-Comps etc, the resulting camber settings will depend on tire temperatures, this will be a trial and error process. Even with my car running -3+ on the front and -2.6 on the rear I actually get pretty even tire wear. (last sept I drove 1500km to Salt lake city, 900km on the track and 1500 km back with the above alignment and perfectly even wear)

Toe: As has been said, 0 on the front and some toe in on the rear. I run 0.7 degrees toe-in each side and has worked very well for my car. These cars need toe on on the rear or they can be quite diabolical. Especially the way you have it set now with 0 toe and stock rubber links.

The above will get you quite a long way to matching the performance of a GT3 in the corners, you could do this with your current JIC's and notice an amazing improvement. After this would then be some dedicated track coilovers, as per Steve's suggestion, however the above will be very noticeable.

A note on Tires: The Sumi's are a great tire, for the street. If you are wanting to match your brother you will have to select a better tire. If you are stuck with a street/track type tire I have always had great success with the Dunlop Star Specs, wear pretty well, stick well, and pretty easy to set the car up on. Sizes Front 235 40 r 18, Rear 265 35r 18. These cars can run some pretty wide rubber without modification to the body. (there is no need to put wider front fenders on these cars I have had 255 35 r 18 on the front of my car on 9" rims with absolutely no rubbing at below RS height).

If you want to go to a dedicated track tire like the Hoosier then I would go for the 245 35r18 front and 285/295 30r 18 on the back.

Of course the alignment settings for camber will be different between the Dunlops and the Hoosiers.

Oh, get your diff fixed with parts from Matt at Guard

Hope this helps.