basic666

groundhog

Which tarmac guys did you talk to? I have run my 981 GTS in targa events and had zero problem with stock PASM which is ~ 30N/mm front and 50N/mm rear (Vs GT4 45 front 80 rear) - 100N/mm front and 160N/mm is 10kgf and 16kgf respective which I would consider brutal on a road car even with exceptional damping.

Speak to the guys at Porsche Melbourne - they look after the Cup cars and Matt Closes car - discuss what you are trying to achieve and which events you are getting set for and they'll put you right. One option is to get in touch with Proflex (Alister McRae is in Oz at the moment) they do great set ups ~20k and there is a group out of Brisbane that do the set up for about 50% of the Australian Targa Series cars (Murray Coote at MCA Suspension - gold series 5k to 10k). Also I know the Manthey generally uses and prefers KW set ups (I think the last Adac winner was on the new 4 ways).

The GT3 set up would be as far as I would go - and that is a very, very well set up car (although there is a difference in weight distribution that needs to be considered). The critical variables are the ratio of the thickness of the front and rear sway bar and the ratio of the front spring rates to rear spring rates assuming damping rates and valving are paired to the spring rates.

Have a look at the sway bars and end-links before the springs/coil overs. Keep in mind the Porsche S-PASM is very very good - in terms of Porsche suspension I'm of the frame "if it ain't broke don't fix it"

BGB Motorsports

According to my 991.1 bible, rates for the 991.1 Carrera in n/mm were as follows:

Basic Carrera Chassis: 24 / 48
Carrera / Carrera S PASM Chassis: 28 / 62
Carrera / Carrera S PASM Sport Chassis: 33 / 108

There is no specific mention of spring rates in my 991.2 bible which would leave me to believe they're carried over because that's how these books are usually written. Your numbers would confirm this so for this argument let's assume that the 991.2 GTS is still 33/108 in n/mm or 188/617 in lb/in, like the 991.1; given that you told me that your car is way too loose, you're going to want more FRONT springrate on your car. I understand that the GT3s are set up differently, have aero and different bars but some of these things can be close enough to the window to improve the overall balance of the car. I personally don't think that the front bar on the 991.1 GT3 is beefy enough but we run it on some cars because it's an improvement over stock and that's what i will run on this car but since i don't think it's stiff enough, I am going to want more front spring rate. Those 100/160 rates on the .2 GT3 and RS cars are big numbers but if im not mistaken, those cars also run "tender" springs which allow you to run big rates for the main spring while still maintaining compliance over bumps and harsh curbs. The 991 is rather well balanced and i don't think you'd create too much understeer or tighten the car up too much by increasing the front spring rate without a proportionate increase to the rear. I am going to try this H&R VTF kit at Sebring in 3 weeks and report back but i already know that the front rate isn't stiff enough.

H&R VTF Adjustable Lowering Springs for 991 PASM

arter

I passed the 90 db limit at Laguna Seca with PSE and Soul 200 cell cats.

4 Point 0

I spoke with the guys at TT Suspension. They are basically the OZ outfit associated with DSC Sport in the states. They said the softer your front spring rate, the more separation you need. I believe the Cup cars are 260/260. 33/108 GTS - 45/120 GT3 - Thinking 80/150 that is 2.4htz.

I have all the Elephant racing adjustable bars. As well as the End links. I still haven't fitted the OEM GT3 adjustable anti-sway bars yet, But I have them and the upgraded bushings. So by the time I upgrade the Springs, my car will be more RS than S. I am thinking 80/150

Thanks John, Its only the new 991.2 GT3-RS that has the 100/160. The 991.2 GT3 is still the usual 45/120.

Seeing as though I will have the same OEM adjustable sway bars and I have all the elephant stuff, I don't think I need 100/160 or 100/180 . Whilst that would be great on the track, I think it would be too harsh for a street Porsche.

I am considering the Tractive Active coilovers. So that they use upgraded software on my DSC module. (They react 17x faster than GT3-RS, and it is the only shock that can adjust mid stroke. Impreseive stuff.) But I really want to get the Spring rates right.

That's why I am going with AKRA. They are 300 Cell cats. (No engine lights)

4 Point 0

Oh Hey, I just noticed your number 355, I usually run 357 LOL. Great minds.

He John, What spring rates are those H&R's?

Whilst I want to get the full tractive coilovers, I thought about just up grading the front springs to 80 N/m as a test just to see if I like it? Thoughts?

flsupraguy

So what's the latest BGB? I enjoy reading your updates

BGB Motorsports

I just ordered the kitchen sink with the intention of taking the car to Sebring in 2 weeks and then COTA in October for a DE where it will sit with a FOR SALE sticker. I'm at 6K on the odometer.

Car will have:
Cobb Stage I Flash
IPD Plenum
Cargraphic catless or catted bypass pipe
BMC Filter
PWR Radiators
AMS Intercoolers

H&R VVT Springs & Coilovers
Tarett Monoball everything
Upgraded GT3 sway bars & drop links
DSC PASM controller
MSI Wheel Studs & Lug Nuts
15mm / 7mm wheel spacers

BGB 4-point harness bar (yellow)
Schroth enduro belts (black & yellow)
Porsche GT2 carbon fiber bucket seats

I'm sure I'm forgetting something but if you know anyone looking for a track oriented 991.2 GTS with 5-lugs, no sunroof and RAS delete, there might be a commission in it for you.

4 Point 0

I have tint, PPF and MPSC2.

Any pics of the tarett monoballs?

flsupraguy

Or if you ever want to return it near to stock I know someone that would buy nearly all your mods, is somewhat local, and has a near stock gts to switch parts out with

BGB Motorsports

Are you sure? I feel like it would be really hard to find someone like that, especially in the state of Florida.

JAhmed

Just thought I'd chime in and mention that I've done ~1000 track miles/15.75 hrs of track time in my 2018 Carrera C2 (PDK/PSE/SC)

Have done the above + 3900 street miles on the stock tires...with careful pressure management they are somehow still holding on.
One set of rear pads roasted, but to be fair I ran the car in "SPORT PLUS" with PSM ON up until the last two track days. I started turning PSM OFF at that point to try and save the pads a bit.
Front pads roughly at 1/4-1/5 OEM thickness now.
Car has been solid in terms of temps...as far as what I can see on the stock gauges is concerned. Rear brake calipers are starting to discolor a bit.
Plenty of rock chips and a nice 2 inch road rash scrape on the front pass. fender from a chunk of tire...for those who care about those things

Looking forward to 2 more track days this season...and then winter prep for next season! (Caliper/wheel studs, fresh fluids (again) and researching some more tires!)

groundhog

Why would you delete RAS, it (in effect) delivers an extra 1.5 degrees of slip angle. This is the reason why the GTS is competitive with GT3/RS through corners. The only reason to do this is to add smaller diameter wheels mated with substantially better rubber. This in turn impacts on oiling in the absence of a true dry sump......

Four point harness? (potentially very dangerous if not fitted correctly which is common e.g. buckle too high) - just go straight to a six point.

Brakes?

Suspension - stiffer/lower is not better - this is a major fallacy with the modding scene. When you start using adjustable sway bars and adjustable coil overs you waste more time trying to work out which is the best setup for any given track than you do racing. SPASM is very, very effective.

The only items on this list that resonate with me are the cooling mods (intercoolers and radiators) and, even then I haven't run into cooling problems as yet (although I'm not involved in endurance wheel to wheel).

What were you trying to achieve and more importantly has it worked e.g. significant change in lap times?

BGB Motorsports

Ha ha ha ha...question, did I insult your dog or something? Anything else with which you don't agree?

I purchased the car used from Porsche and it didn't have RAS. I'm not a fan of tuning on cars with rear axle steering nor do I like driving them on the race track so I saw it as a plus. I don't doubt it's faster...within 102% of the limit of the car, computer aids will always produce better lap times. I'm not some purist hater of vehicle aids. I like them.

As for the harness, it's a 4-point bar NOT a 4 point harness. I don't agree in referring to 4-point bolt in bars as "roll bars" so I call them 4-point harness bars given that they're bolted to the rear shock towers AND lower sheet steel rocker. I really only believing in weld in cages to be honest.

I do agree 100% with you that if that stuff isn't installed properly it can be dangerous but I'd never suggest anyone's using less than 5 points and I know the harness bar height is right because I oversaw the design of it. We made it in house and it's in several 991 GT3s around the country. Car owners have a responsibility to select the correct sized seat slider / mount combo to always double check appropriate shoulder harness angles based on seat back height.

Cheers mate!

groundhog

^^^ RAS delete your words not mine.

Why don't you like driving RAS, it delivers, free of charge 1.5 degrees of slip angle - thats a lot. I'll take that plus SPASM over unmatched sway bars and coilovers.

I suspect harness bars will be banned (unless built into a cage, obviously) - too many poorly installed - delivering the wrong angle at the shoulders.

So you have modded a car, all of which is unproven through testing on the car, will drive it at Sebring and then sell it?

Where is the track testing in all of this? The feed back loop?

What happened to the BGB approach as applied to the GT4?

To deliver a much improved suspension set up that delivers results on the clock requires a lot of work and testing - slap it in and hope is not the way I would do it.

Not trying to be a PITA, just curious as to why the apparent change in direction and the spray and wipe approach.