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Great topic, and great set of coilovers you're putting on your car.
Have you added a rear wing? Have you taken rear aero into consideration for this decision?
Hey Aon19, No rear wing yet. I am thinking down the track to add the under body Aero. I like that the GTS is a sleeper. I debadged mine.
Originally Posted by Riz
How does the Carrera T fit in?
Not Sure. Sorry. I will try and look a bit later. I am intereste as well. If it has S-PASM and Sport Chrono, one would assume its the same as S/GTS and not just base.
Originally Posted by tgavem
4 point 0:
Great write up. Your modifications will for sure help some of the compromised behaviors Porsche have to make on a car designed for the street but will also see track duty. Sounds like you track quite a bit and if you do and you become very fast and good driver, a stock GTS will show its weakness.
The other key element is tires, the springs and shocks needs to be adjusted for tire side wall stiffness. Race cars have much stiffer springs but they may also have a taller tire and softer sidewall. So if you were to change the tires you use on the track, this can have a significant affect on the car behavior.
Keep up the good work.
Hey Tgavem, Agreed. I run MPSC2 same as GT3. I absoloutely love them for the street. best all round tyre in my opinion. However I m starting to be disappointed at the track with them. (I don't want much lol) I think the side wall is a little soft. I want to try TrofeoR next. I assume I will love them at the track, but lets see how long they last on the street. MPSC2 have 180 tread and I am fine with how long they last. But TrofeoR are only 80 tread. I am a bit concerned they will only last a track day and 5,000km. If I can get 10,000 km and three track days, I may run them all the time, if they are what they promise.
Originally Posted by reacher
I tried a 991.2 C2S that I am pretty sure had PASM, and it felt really soft to me. I guess my 991.2 GTS cab has the same spring rates, but it feels a lot better. I wonder if it's the PDCC that makes the difference? Or maybe I was mistaken and the S didn't have PASM. The S was definitely much, much too soft. I wasn't even pushing it because it was a test drive at the dealership, but just making normal turns in traffic and getting on the freeway it felt wobbly and sloppy. The Turbo I drove right before it was a lot stiffer than I had thought, and that felt so much better. I'm very sensitive to soft suspensions, I'll take a stiff ride any day of the week.
My GTS feels extremely planted at all times, granted I don't push it super hard, but for most everyday and spirited backroads driving it feels perfect. Incredibly comfortable, but no body roll, the front doesn't feel soft, etc. Porsche really nailed the suspension setup on that car.
Hi Reacher, Yes Porsche did an incredible job. But everything can be improved. Kaizen. I was really impressed with the setup at first. But as the confidence grows and you push harder and harder, the cracks begin to appear.
First it was the tyres. MPSC2 really made a huge difference. Now I am really noticing the soft front springs. Look at the pic below. I was horrified when I saw some footage of my car at the skidpan how much the car pitched.
Originally Posted by AAK GTS
Here is the prime example of what we want to dial out. This picture clearly shows how soft the front suspension is whether it is the sway bars or shocks/springs that can fix this or the combination of both. My car has stock suspension and P-Zeros.
Its all about solving for pitch, roll and yaw - sway bars (anti - roll bars largely deal with roll), springs and matched dampers largely deal with pitch and both plus COG/roll center and weight distribution govern yaw. Understanding yaw rate limitations are the key to optimising the performance of a 911.
Anyhow what problem are you trying to solve?
If the front is to stiff you push towards understeer, a softish front end in terms of roll bars and springs reduces the tendency to understeer and optimises grip during hard braking (e.g. balanced weight transfer from rear to front). In fact the whole purpose is to optimise weight transfer and ensure all tires are generating grip by maximising the contact patch at all times.
Honestly, I have not found the suspension set up on the series II to be a limiting factor governing the generation of a lap time e.g. you can consistently generate a yaw rate of +/- 35 degrees per second and +/- 1.6 g (lateral) on MPSC2 which is outstanding.
Hey Hog, We have rough roads here. Even some of our tracks have unsettling bumps at high speed corners. The car does not inspire confidence through some of the super high speed turns, being turn 1. I saw some footage of my car on the skid pan and the car was bouncing up and down. Seriously looked horrific. You cannot believe how much the car dives under brakes and raise under acceleration. It looked like one of those mexican jumping cars lol.
A few track guys are saying I went too stiff on the rear. I went 75/150. They were saying I needed to go a lot stiffer in the front and less in the rear. But I think I made something special. Its not a 100% track car. It will do more tarmac than track. I'm just testing at track at present. But its road stability I'm after. Here is a little teaser. I haven't fitted all the Elephant stuff as yet as they never included the spacers as you can see from this shot. They are in the mail. This just a fitting test teaser. Correct Spacer needed before Anti-dive anti-squat bar fitted to adjustable control arm.
Anyone know what the spring rates are for a 991.1 Turbo S?
I have Eibach Pro-Kits on my 991.1 Turbo S. Eibach says the Pro-Kits are progressive with spring rates of fr: 25/32 and rr 70/118. Does anyone know what the stock spring rates are?
I have Eibach Pro-Kits on my 991.1 Turbo S. Eibach says the Pro-Kits are progressive with spring rates of fr: 25/32 and rr 70/118. Does anyone know what the stock spring rates are?
Interesting as Stock 991.2 GTS is 33/108. Sorry I don't know stock rates for Turbo. I would think they are softer than GTS?
Some more Elephant Racing adjustable bars for your viewing pleasure.
Just a few goodies from Elephant Rear adjustable lower wishbone.
i think initial spring rates in h&r and eibach are softer than stock. Maybe that is why you feel they are a little bit too soft
Whaat. Even for fixed H&R Sportlines (which is what I have)? I don't think mine are adjustable. If so, what sense would that make (not denying you're right, it's just so odd that they'd do that)? I always assume lowering springs supposed to be stiffer. Anyone know exactly how the stiffness rating of the H&R Sportline (the blue ones) compare to stock PASM springs?
Originally Posted by reacher
I tried a 991.2 C2S that I am pretty sure had PASM, and it felt really soft to me. I guess my 991.2 GTS cab has the same spring rates, but it feels a lot better. I wonder if it's the PDCC that makes the difference? Or maybe I was mistaken and the S didn't have PASM. The S was definitely much, much too soft. I wasn't even pushing it because it was a test drive at the dealership, but just making normal turns in traffic and getting on the freeway it felt wobbly and sloppy. The Turbo I drove right before it was a lot stiffer than I had thought, and that felt so much better. I'm very sensitive to soft suspensions, I'll take a stiff ride any day of the week.
My GTS feels extremely planted at all times, granted I don't push it super hard, but for most everyday and spirited backroads driving it feels perfect. Incredibly comfortable, but no body roll, the front doesn't feel soft, etc. Porsche really nailed the suspension setup on that car.
I felt the exact same thing with the standard suspension 991.2 I drove. Felt quite soft to me. It turned where I wanted it to, but it felt anything but "tight and visceral." All 991.2's have PASM which is why it surprised me so much. The GTS I drove after indeed felt MUCH more buttoned down and tight. It didn't feel any less comfortable or luxurious in ride either (compared to my car the ride practically felt cosseting, not at all in the sense that it's floaty or aloof, just that it's so incredibly refined and filtered from jarring elements yet tight and sporty). PDCC definitely will make a difference too, absolutely.
Originally Posted by AAK GTS
Here is the prime example of what we want to dial out. This picture clearly shows how soft the front suspension is whether it is the sway bars or shocks/springs that can fix this or the combination of both. My car has stock suspension and P-Zeros.
991.1 with stock suspension. Note the front lift.
Wow, that's a GTS too. I'm really curious how the spring rate of H&R Sportlines compares to that....
Here is the prime example of what we want to dial out. This picture clearly shows how soft the front suspension is whether it is the sway bars or shocks/springs that can fix this or the combination of both. My car has stock suspension and P-Zeros.
991.1 with stock suspension. Note the front lift.
looks like weight transfer backwards lifting the front to me, making the front stiffer will do zero to change that. Look at the compression rear left.
Yes, I agree there is weight transfer to the back when on the throttle, which unloads the front but this seems excessive. Look at my previous track car (see picture) where the suspension is much tighter. Motons with 750/850 Eibach springs, F/R sway bars, 285/18 at each corner, etc. Of course this is an M3 with 50/50 weight distribution so hard to compare. My GTS is a keeper and will eventually get around to suspension modifications after brake mods and I believe this will greatly transform it to handle track duty better. I would like to do as little changes as possible so wondering if starting with GT3 sway bars first or coilovers and that would do the trick to settle the GTS down.
BMW and 911 are much different cars and require different driving style. I like the rear springs in the 911 to be a little soft (mix between factory and race), so under acceleration the weight transfer and grip goes to the rear. Combine this with a good differential, I can then accelerate very hard on the exit as I straighten the steering wheel. When i get it right, the 911 is a rocket ship exiting the corners.
I would like to do as little changes as possible so wondering if starting with GT3 sway bars first or coilovers and that would do the trick to settle the GTS down.
I also bought the GT3 Sway bars from Elephant racing. They DON'T FIT a 991.2 GTS. They are a completely different shape. You would need really short end links, and the shear angle would be dangerous. I'm sending them back. Waiting on BGB to see if Tarett or someone has one that is for a GTS.
Correct, the 991 GT3 suspension is significantly different in back, so the rear bars are not interchangeable. We have a rear bar and drop links designed specifically for your application. Give John a call at BGB and he'll set you up.
Correct, the 991 GT3 suspension is significantly different in back, so the rear bars are not interchangeable. We have a rear bar and drop links designed specifically for your application. Give John a call at BGB and he'll set you up.
Ira
Thanks Ira, I will wait until he has it all sorted. I already have the Elephant End links, as they are fitted, they would be Stock length. The rear bar will be less important. I really need a very stiff front one. If the GT3 bars had of fit safely without modifications, I would have ran the front full stiff and the rear full soft.
^^^^ what diameter sway bars did you fit front and back plus are they hollow or solid?
Hey GH, I haven't fitted anything yet. Keyword being "FIT". I ordered the OEM GT3 sway bars that Elephant Racing told me would fit. Apparently they fit older models, so someone assumed they would fit a 991.2 GTS. They don't fit.
I have been under the car with the mechanic. They are even a different shape. Different mounting spots. Different width. They don't fit. So they will be sent back, after it cost me $500 pulling the car appart to find out they don't fit and putting it back together again.
Now I find out that USPS will not ship the Tractive Shocks to me that I bought from another member here. I ordered and received the custom springs that cannot be returned. The tractive coilovers travelled across the states only to be returned a week later, saying they wouldn't ship them. A gas filled metal cannister? So now I have to buy Brand new ones. Great! That will take 6 weeks to have them made. Delay Delay Delay. I'm getting frustrated.
09-20-2018, 06:46 PM
Anyone know exactly how the stiffness rating of the H&R Sportline (the blue ones) compare to stock PASM springs?
