Technically, a non adjustable coilover.

Mike from AWE was able to get the data on the Bilstein's...

Front Main Spring - 285 lbs.
Front Tender - 115 lbs.

Rear Main Spring - 570 lbs.
Rear Tender - 145 lbs.

Not sure what stock 997s are, but for track use, not that impressive.

 

I was wondering, I know that dampeners and springs are made specifically for each other, but wouldn't it be possible through good engineering to create a set of springs that had a different ride height and spring rates that wouldn't dramatically worsen the life of a dampener? Is that just wishful thinking?

 

hey buddy, go directly for the pss10's and a 1.5inch drop !!!! you will love life and your car even more. good luck.

 

Mike,

Are you referring specifically to the A Arm Monoball? Did you have this on your 996TT? If so, comments please?
http://www.gmgracing.com/porsche_suspension.shtml

 

Hello Bobby,

1. Are you referring to the Bilstein's spring rates when you wrote "not that impressive"? If yes, I assume it's because they are on the low side?

2. I got the spring rates for the Bilstein already. It's the stock spring rates that I can't find. I drove briefly a car with the PSS10; it *felt* stiffer, but still I think it would be interesting to see how the 2 compare.
I recall reading an old post where someone was asking about replacing the spring of the PSS9 with a stiffer one!

 

Hi Can...my comment about impressive was in reference to dampers with higher spring rates for the track. On my 996, I think my 996's coilovers were around 450 and 650 on JIC dampers...pretty similar to the Bilsteins. I thought it was a reasonable compromise for street, but for serious tracking, they weren't enough especially with the weight of the car.

I think the Bilsteins are nice, but it's popularity right now are due to the limited choices, and the ability to use the electronically controlled PSM with it.

I'd bet Fabryce at GMG probably knows the data on the stock suspension.

 

From what I've gathered so far, bilsteins are better than the stock suspension, but the springs may be a bit soft for the track. The bonus is that they are EDC and wont throw faults.

The springs, are getting good reviews, but then there's the question of how long the stock dampeners will last.

And in my particular case, since I will be doing alot of street driving and I am in NY with ****ty roads, I dont know if I can really run stiff springs without wanting to kill myself.

So its really a decision between the PSS10s or the springs.

I was also wondering, if the PSS10s have 10 clicks of adjustment to the dampeners how does that work with the EDC since thats only one click (on/off) if Im not mistaken. Do you get to select the presets that you want it to goto when its activated/deactivated ?

 

for those worried about doing springs alone, consider that even if the stock dampeners wear out prematurely (unlikely in a newer shock, more likely in an older shock which has had the seals wear into the shock piston) you can send the worn dampeners to Bilstein in California for a rebuild for about $100 a corner. They can also change the rates to better match the new springs. Peanuts in costs.

 

Would you please explain the part about the "seals wear into the shock piston"?

So if I am to use Spring alone, it's better to change it early? How early in general is early? Less than 10k?

I am still trying to understand: I assume technically as far as the driver is concerned, the 2 main numbers of any coilover to be concerned with are the spring rate and the damping rate? Outside of perhaps durability and adjustability, are there other factors that make Moton "better" than Bilstein, or Bilstein PSS10 "better" than stock?
In other words, if one is to set a Moton's damping rate and spring rate equal to a PSS10, does a typical amateur driver ever notice a difference, on street OR track?

 

The biggest problem is that springs & shocks are always designed together to make them perfect.

This is the biggest problems when changing the springs to stock coilover's- the original designed travel in shock is shortened, therefore they are not working as they are supposed to.

This could also cause other issue's like premature wear, but only thing that worries me is that dynamics isn't there anymore.

So for the track use- I would not even consider lower springs to stock shocks, they are more for the looks!

 

Hello Brad,

Interesting points & I am also following your other thread to see your opinion of the KW. Not being argumentative here for the sake of arguing, just probing for answers.

Let me play devil's advocate and ask the question this way. If 2 experienced tuning houses use lowering springs (and let's assume they are trust worthy), and the cars are reviewed by a third party, an experienced reviewer and competent driver, to be outstanding, than is there REALLY a problem with using springs?
http://www.rennteam.com/showflat.php...rue#Post426128
I am aware of the theories of why the lowering spring shouldn't work and it may fail prematurely (as well as the possible counterpoint as eclou points out above, that failure may not be a problem if spring is replaced "early"). But what if practice doesn't follow theory? What if the spring setup by Champion or GMG feels "better" than the Bilstein?
Obviously I am discussing not from the view point of serious professional racing, only the weekend tracking that most readers here are involved with.

 

cannga, You make very good points there!

This is very difficult world, first of all everybody wants to make business and therefore neutral opinions are hard to get, especially in this kind of forum's where we, the owner's, have very subjective opinion defensing the choices we have made.

Secondly, I must point out that even we are not professional driver's ( at least most of us aren't- me including), we are driving one of the world's most powerful sportscar, which has been designed to very high standards.

As many of us has felt that stock suspension is not for what we think it should be for, many of us has been opting different improvements for the suspension. It is a very difficult to say, which set up is the best, even when trying/ driving other's 997TT with different set ups, cause every modified car has very different approach and also many of us are not capable of tuning coilover's etc for its prime level, and also we have many different targets for the suspension ( track, road/ track, only road, bumpy roads etc...) The stock set up is propably the best for above mentioned use, but it is a compromise.

As I am not an engineer, I have only kept my ears wide open over these years. Suspension manufactures have always clearly pointed out that shocks & spring are or should be always designed together, not separately. Lowering the car without knowing or caring it's affects to the cars performance could cause serious dangers, and this is not wise way to go if You only want to have the looks i.e lower the car.

I am not saying there are not good springs-manufacturers that are able to even improve some set up's- but hey are the one's usually working in very close co-operation with the shock manufacturer.

You could meet cars/ setups with changed springs, which are tremendeous- but odds against it are maybe little too high- therefore it is good to choose full kit (springs/shocks) to make the odds the best they can!

 

Can this be right? Why would Moton's damper systems I have seen are sold separately from the various race springs.

 

No, it can't

It is more like talking about stock suspension, which is not adjustable.

If You there fit lower spring, the shocks are not working as they are original designed for.

But anyway, this is a infinite debate, we will have many different opinions on this.

When suspension is adjustable, it gives a variety of choices "springwise".

What comes to Moton, I think as them beeing top manufacturer, many do close co-operation with them ( still, beeing a non- professional driver, I would go for their Clubsport set up with their springs).

I believe I have in my "new" 997 GT3 Cup car H & R Springs and Sachs dampers.

 

So far it looks like the only thing that I have decided is that Im not going to rush this decision.

I'm also probably going to stay away from springs, because in all likelihood I will continue tuning the suspension and adding bits, so overtime I would probably go with coilovers.

One concern I do have is that one of the reviews I read, said something to the effect that as you make the overall suspension stiffer, not just coilovers, but sways, and upgrading all of the linkages, it becomes more difficult to determine when the car will lose grip. The one thing that I do like a lot with the stock setup is I can feel the oversteer coming up, and the car gives me a lot of feedback, so I can recover very often, or no where the limits are and avoid them. Would a very stiff setup make this more difficult to determine?