+1 what i'm thinkin and felt no difference at all! this AM. so it all comes out next week since i'm back under the car for clutch again. any advantage ( or downside other than no electronic nanny? ) to running rwd without an lsd? other than weight loss? thats reason enough though.. as i'm happy with power levels, so less weight is where im hopefully headed now. i blame pwderhound

 

+1 what Tim said. For anyone contemplating the conversion, in the next month or so, I will have a complete JRZ RS1 suspension assembled ready to bolt on with JRZ upper mounts, extended Tarett drop links, and a choice of 600/800 or 700/800 rates. This set up can be installed on either a GT2/3 or a TT as I have both the TT and GT front upper mounts including the front JRZ shock sleeves if you are retaining the TT uprights. Suspension is only a year old with 3K miles on it and will be priced at $4K shipped CONUS. I'm replacing this set up with JRZ Pros..

 

99672116390

 

These are the pieces to convert the front suspension to GT2 spec. Different front brake rotors are needed as the GT2/3 offsets are different from the TT.

 

Yes, it comes from GTA. I will checkout Magnus also. Its great to find someone local with local references.

 

what did that bundle of parts cost?

 

Plenum isn't needed at your power level. Will help with throttle response a tad, but no real power gains. Blow off valves aren't needed either.

If you are looking for a simple way to do it, take your front diff out by searching for the DIY RWD conversion threads in this forum. Or have a shop do it. It's really not that hard, probably take 2-3 hours or less if you are a little bit mechanically inclined.

What you will need though, especially on the ring (or wet roads) is an LSD. Guard or OS Giken will do the trick.

Probably want some better coilovers, PSS9 are limited in track usefulness. They will suffice, but just not a great setup. Ohlins, JRZ or Motion Control should provide supple street ride and great track performance.

You can patch up the geometry issues with toe arms with bumpsteer control. Use spacers to lower the pickup points and save $$$$$. Oh and for bumpy tracks, almost certainly some locking plates for the toe arms.

You might just need a clutch, so it may be best to get the power work done first and drive it some. You will save money on the labor to switch the clutch when the gearbox comes out for the LSD (or plenum if you still decide to get one). Might save money just to do it now, because it's almost a certainty to start slipping at some point with the added power and torque.

6 piston brakes will help alot slowing the added power, add some Castrol SRF brake fluid and PFC 08 brake pads. But depending on the tracks you run, stock with some cooling ducts and those pads and rotors may work too. Just get some Girodisc,PFC, Brembo or Sebro rotors for the TT. They last a lot longer than stock which might crack in a day. Get slotted, not cross drilled.

Oh, and you can unplug the PSM cable from the booster pump in the trunk. Disable PSM without disabling ABS. Problem solved. $0.

 

It was right at $1400, give or take...

 

Right on, bought mine (through Brent) at GTA as well.
Magnus told me $1500 for tune, done on dyno.

 

Can you go more in-depth about what makes the gt2's LSD so bad? This is the first time I've heard of someone calling it bad. I've had many people say its very capable.

 

^the internal clutchs go bad quicker than Guard, Porsche Motorsports due to their compound, can be upgraded. 996 GT diffs are otherwise a good differential from my knowledge, 997 variants have bigger issues, Matt at Guard could lend much more knowledge on this subject.

 

I think guard does rebuild oem LSD though.

 

The OEM street GT2/3 LSD comes from the factory with a super light preload on the order of less than 10 lbs or so, compared to around 60lbs for a Guard and even higher on a CUP LSD. A preload is what "ties" the rear wheels together and the amount is the force it takes to break the rear wheels apart under static condition. After running the OEM LSD for a couple of track days you are essentially left with an open diff under braking. The OEM clutch packs are also inferior to the Guard or CUP. The OEM LSD will still lock under accelaration but it's useless under hard braking resulting in tail wag. You can easily check this by putting the gearbox in neutral, jacking up a rear corner of the car and very easily spinning one rear tire. With a Guard or CUP LSD, you will need to exert 60-100lbs of force to spin the wheel due to the much higher preload. You have to realize that the OEM LSD was designed with the average buyer in mind majority of whom live for cars & coffee and will not track their car anyway, and if they do, they won't drive the car hard enough to tell a difference. The goal of the OEM LSD was not so much best performance but rather an LSD that is quiet and transparent to the average end user. You can take the OEM diff and send it to Guard to have it rebuilt and reshimmed with new guts. Cost is under $2k. That's what most guys that track these cars do. Hope that helps explain it..

 

after a few days of running canyons with psm off/on alternately i'm having difficulty feeling much of a difference but it isn't for lack of trying ( eg i can trigger the psm nearly at will when pushing it in corners esp downhill..
...or not pushing the car but it STILL sticks like friggin glue w/ freshly scrubbed ps2's
so i'm figuring in spite of the fact the difference at this stage is minimally noticed, it can't hurt to eliminate all that extra front weight which i've so far only lessened by removing tools and spare lol..

so my question is.. is this an efficient way to run the car even absent the lsd conversion rear? ( though taking out the axles and diff next week )and is the only thing i'm sacrificing being the awd? ( which i'm confident has helped to save my *** more than once! but mostly while i was "new" and eliminating weight! ( GOOD! ) because that's reason enough to go forward with rwd for me! any advice is appreciated!

..and again to the op. thx for the timely thread! go for it and let us know if and when you fully lsd it!

 

You'll be fine on the street with an open diff as you won't be pushing the car at the limit like you would at the track. You won't tell much of a difference driving up to 7 or 8/10 but it will become apparent past that. PSM is essentially a poor man's LSD because it tries to keep the rear wheel with the least traction from spinning. While an LSD does this by routing power to the wheel with the most traction, PSM does this by cutting power and applying the brake to the wheel with the least traction, the result of which is a reduction of forward momentum. This is why it is very easy to cook the rear brakes when tracking these cars with PSM because the rear brakes are constantly working overtime keeping the inside rear wheel from spinning. You'd be amazed how much harder the car will hook up on corner exit with an LSD than with PSM. LSD is putting power to the ground while PSM is cutting power and applying the brakes. Also, even when PSM is "off" with the dash button, it comes back on automatically under braking and when certain slip angles have been exceeded. The only way to truly turn off PSM is to disconnect the PSM pump.