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Hi Awrryan, I think we need to put this in context. I am absolutely positive 70/120 would be a dream on the street and be more than enough on the track for 98% of the population. These guys are Pro race car drivers pushing the car at 10/10ths. At 7/10ths your car would be a sweet heart all day long. I just wanted a little more up my sleeve as I push harder and harder. But not that much difference between 70/120 and 75/150. I will need a really big front sway bar upgrade soon, before I push above 7/10's.
If this Tractive setup is as good as I believe it is, I can turn the front up full and the rear a little to make the car "FEEL"like 100/160 at the track and turn it down to "FEEL" 70/120 for the street.
Where can I find a 70/120 setup which will also lower a .2 GTS with SPASM?
Where can I find a 70/120 setup which will also lower a .2 GTS with SPASM?
Are H&R springs any good?
Hi Psorcery, once fitted, the Tractive Coilovers are fully height adjustable. So Whilst my springs are 170mm long, you will need to do your homework, to find out how long your stock springs are. Unfortunately its not just a matter of then saying I want springs one inch lower so I will deduct an inch off that length. If only it were that easy. When changing springs, you capitalise on the opportunity to stiffen the rates and make the car handle better.
So a 70/120 being much firmer than your stock setup, would sit higher at the same length spring as your stock setup, because they would not compress as much.
I personally don't read into one brand of spring is bad. What they really mean to say is, Those particular springs, were supplied at a spring rate that did not play nice with your dampers.
So as they guys said above, it is a dance of matching dampers and valving and having spring rates that play nice in that range. That will give you balance and feel and control. It probably why, Techart and H & R don't want to reveal their spring rates when they offer a lowering spring. They may have done a lot of homework to work out something that works. To have someone say, Oh I just need a X length spring at a Y spring rate.
I do have a GTS and whilst it seemed awesome at first, I did start to notice when I pushed it, that the front is very soft. 75/150 is not crazy stiff at all. Most track guys would say its far too soft. As I said, I had to fight off all the recommendations to go 100/180. With the advanced valving of Tractive Coilovers that react 17x faster than PASM, and have a much broader range, you get the best of both worlds. So I never felt the need to go track Stiff. I still want to drive most days in the car and take it out to dinner. Don't quote me but I believe (i read somewhere) PASM range is 500-1500 whereas tractive is 500-2400. So it can go a lot stiffer. They make all sorts of custom maps for you to download.
PASM is just the start. Porsche did a great job of collecting all sorts of data that PASM does not fully use. Whereas the Tractive says, Thank you very much, I know exactly what to do with that data that Porsche already collected.
Stiffening the front shocks when you stand on the brakes. Stiffen one side of the car when turning in. It is PASM on Steroids. The guys that made it have PhD's LOL.
Agree 75/150 is not crazy stiff...have driven 911s with something like 200/450 and/or 300/600. Now that's stiff, but brilliant dampers made them work. Curious to try Tractive, and I am a big fan of TPC suspension setups. All that said, I'd hate to see people move away from factory 991.2 Carrera/T/S/GTS suspension unless they really know what they're doing and want—and will get. This is some of the best suspension for a Porsche road car in memory, imo. If track work is the primary focus, I can easily see getting to work. Carry on!!
Agree 75/150 is not crazy stiff...have driven 911s with something like 200/450 and/or 300/600. Now that's stiff, but brilliant dampers made them work. Curious to try Tractive, and I am a big fan of TPC suspension setups. All that said, I'd hate to see people move away from factory 991.2 Carrera/T/S/GTS suspension unless they really know what they're doing and want—and will get. This is some of the best suspension for a Porsche road car in memory, imo. If track work is the primary focus, I can easily see getting to work. Carry on!!
Hey Stout, are you still in N/mm or lbs/inch? I have 75/150 N/mm so that in American lbs/inch is about 425/850. Let me speak in American for a bit as you may be more used to it.
M4 Comp pack Stock is 200/550 lbs/inch
M4 GTS is 400/600
My M4 was 628/1,028 (But m4 in rear spring and shock separate, so .6 ratio, brings that back to 628/617
That was track stiff.
Back to Porsche and my speak in N/mm.
A Porsche Cup car is 260/260 That is insane. A serious street car used for many track days setup is 100/180
So I was a little more reserved at 75/150. I could have gone 80/140 but I explained my reasons in original post. I still wanted a firm street ride. (Some comfort.)
Also Porsche having rear engines, they are stiffer in the rear.
Remember all GT3 and RS have been 45/120 for years. But now the latest 991.2 GT3-RS will be 100/160 to put it in perspective of how good the dampers are now.
My C2 has H&R’s and PASM and PTV+, and it STILL feels somewhat soft for me SOMETIMES (often it also feels absolutely genius in that it corners flat when I want to corner and also feels comfortable and not too rough at all when I’m just normal driving.... it’s a nearly flawless balance between both, even with the lowering springs). I don’t know how guys with C2’s on stock springs and no PASM do it. Just seems like it’d be too soft for me.
My C2 has H&R’s and PASM and PTV+, and it STILL feels somewhat soft for me SOMETIMES (often it also feels absolutely genius in that it corners flat when I want to corner and also feels comfortable and not too rough at all when I’m just normal driving.... it’s a nearly flawless balance between both, even with the lowering springs). I don’t know how guys with C2’s on stock springs and no PASM do it. Just seems like it’d be too soft for me.
It's funny, I just got back from a quick half day Track day. Thought I would squeeze one last one in before fitting the new Coilovers and springs. I am really aware how soft the front spring rate is now.
The DSC has really improved the car, and the COBB Tune (LOL) but the pedal was getting long fast. I have CSF, but I definitely need steel lines and to fit the Pagid RS29's. After that its a BBK.
Driving home, the GTS is beautiful on the street. But still could use more front spring.
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.
My C2 has H&R’s and PASM and PTV+, and it STILL feels somewhat soft for me SOMETIMES (often it also feels absolutely genius in that it corners flat when I want to corner and also feels comfortable and not too rough at all when I’m just normal driving.... it’s a nearly flawless balance between both, even with the lowering springs). I don’t know how guys with C2’s on stock springs and no PASM do it. Just seems like it’d be too soft for me.
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
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.
My C2 has H&R’s and PASM and PTV+, and it STILL feels somewhat soft for me SOMETIMES (often it also feels absolutely genius in that it corners flat when I want to corner and also feels comfortable and not too rough at all when I’m just normal driving.... it’s a nearly flawless balance between both, even with the lowering springs). I don’t know how guys with C2’s on stock springs and no PASM do it. Just seems like it’d be too soft for me.
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.
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.
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.
09-19-2018, 07:06 PM
