Mk-1 GT3 suspension vs. 1999 Carrera, Q's >>>

What are the major differences in the Mk1 GT3 suspension versus the stock Carrera? I know they offered an H&R based coilovers versus the Carrera's Macphereson struts and springs. My questions are based on reinforced parts, different hubs, etc. Are the control arms more robust? What is different mechanically? Mr. C4 (Johannes) can you offer any feedback on this? Thanks! Chad

Chad: I have put GT3 hubs/carriers on my 996. They are larger and stronger with larger bearings. The GT3 also has adjustable lower control arms that, with shims, give more camber and caster. I have those on my car also and am running 2.3 degrees of camber with 6mm of shims. The GT3 also has larger and adjustable sway bars. Much better than the euro sport bars IMO. Alex

Is there more?? Control arms? What else is different on the GT3? C.

some of the major differences between the MK1 GT3 and the early 996s: different bodyworkm, engine, suspension based on C4 chassis instead of C2 chassis. <--- big difference! less soundproofing, etc.

Please explain the differences on the C4 chassis. Chad

it is stiffer, more reinforced, a little heavier.

Alex - did you do just the fronts? Also can you post or PM me your parts lists for the hub conversion. I am going to start down that road pretty soon - Also did you use the MK.1 Hubs or the MK II (04') parts.

You might want to rethink the upgrade as the benefits are offset by the MUCH greater increase in unsprung weight. There is a brembo kit that is ligter, performs better, and consequently is the better alternative Everyone notes the advantages, save maybe $$ I highly doubt that the gt3 runs the same chassis as the c4 as well as the c4 v. c2 difference in terms of rigidity etc. The weight issue is from the 4 wheel driveline What evidence do you have that the gt3 runs a c4 chassis? The gt3 uses the gt1 block which mounts are vastly different than the c2/4 I could be wrong but I have never heard anything of that nature of what your claiming. The chassis rigidity change occured in 02 and up

actually i believe Moogle is correct - the GT-3 uses the C4 body shell - the difference is in the front structure. the 4 wheel drive system of couse is not used. I need to verify this - on a side note why would using the GT-3 parts weigh more - the difference would be a few grams if any in fact i think the 04' parts are lighter than the stock 996 hibs - as far as brakes go i was undecided between the GT-3 04' system or the brembo 380mm 8-piston kit - the problem with the brembo's is that they use an adapter to fit the caliper - which i do not like. not to mention the cost of the kit itself (4.3K for the fronts & 2.5K for the rears) in this example the brembo bbk's are the heavier kit. just some thougths....

Compare the kits the addition of the GT3 carriers, disc, calipers v. the two Brembo kits They are aboslutely heavier by a bit, not a few grams. I was told this personally by Barry at Race Technologies. I also have friends who have had the gt3 brakes and called them a waste because of the increase in unsprung weights offsetting the benefits. There is no question. Further the brakes are the same c4/c2 as well as boxter S only color is different. I am sure that's not want you wanted to hear but it is fact.

Rob: So much bad info and so little time. First, I will PM you the part numbers, they are at my office. Second, SPR, the GT3 calipers accept TT brakes NOT red painted 996 calipers. That is the fact. I have the parts on my car and do not have to rely on anyone telling me second-hand information. I think that they are well worth the price if you track your car. You are correct, if your car is only driven to 7-11 and back, TT calipers would be a total "waste". I stick with Porsche parts therefore I would never go with Brembo "adapters". With regard to 996 V. GT3 frame parts--from my PET: 996 501 911 01--it is the same part number for both cars and it is the entire front clip. 996 501 551 00--it is the same part number for both cars and it is the entire floor. 996 501 551 00--it is the same part number for both cars and it is the entire rear seat mould. 996 501 978 00--side frame rails same for both. etc etc. I rest. Alex

Who said anything about using 996 parts???? You completely misready what I stated, please read more closely. I said ALL GT3 PARTS, not 996 calipers etc. Rediculous. I was stating that the c4/c4. and boxter S brakes are all the same, NOT GT3 which are akin to the turbos! Thanks for inferring that I have bad information when you have poor reading comprehension. Rediculous.

I guess i should have clarified - i was speaking of the hub's being the same weight. the disc's and calipers do weigh more (increased diamater and thinkness). Currently my plan is to upgrade to the MK II uprights and brakes. For me the advantages are - better stronger bearings and hub carriers larger brake diamater = more heat disapation 6 piston caliper = greater sweep area - good to excellent pad choices currently (which to me is the real decider in braking preformance) more bias to the rear brakes (must change the brake propotion valve to GT-3 RS type) the same applies for the rear - I will not be looking at the PCCB system. Also i will not be using the MK I calipers (4 piston) or the turbos. I do not want to jump into a flame war -

I was stating that the c4/c4. and boxter S brakes are all the same, NOT GT3 which are akin to the turbos! Thanks for inferring that I have bad information when you have poor reading comprehension. the front brakes (both w/ iron rotors) on a 996tt and gt3 are completely different. fwiw, i was told by at least two vendors, that 15" brembo 8-pot system weighs the same as the 6-pot pccb.

I can help clarify... The GT3 does use a C4 tub. This has been documented in both Excellence, Panarama, and other sorces. The additional reinforcement of the C4 chassis makes it a stiffer platform (along with the sunroof delete). The TT and the GT2 also use the C4 chassis. The brakes on the Mk1 GT3 were straight off the turbo and are considered a weak point. The front brakes (rotors and calipers) on the Mk2 GT3 are larger than the turbo (350mm 6piston v 330mm 4 piston). The rear brakes on the Mk1 and Mk2 are the same units used on the turbo (330mm 4 piston). The PCCB rotors on the Mk2 are all 350mm rotors with the 6 pistons in front and 4 piston in the rear (rear caliper is same as turbo with different spacing to accomodate the larger rotor). The GT2 uses the same setup as the GT3 (PCCB only). The Boxster S, C2, and narrow body C4 all have the same rotors and calipers. The C4s uses the brakes from the TT. HTH.

The/my narrow body C4 has silver calipers, is this just for aesthetics?

Its just for looks. The same brakes are red on the Boxster S.