Pics & Review of My Bilstein PSS10 Lowered Red Turbo by cannga

12 minute(s) of a 612 minute read

One more pic to whet your appetite :-). The central portion is perforated, similar to Ferrari's and other high-end steering wheels, for good reasons (more grippy, etc.). For those who bought the Turbo used and with high'ish mileage, keep in mind in well-used Turbo's, the leather of that steering wheel is no longer what it used to be when new. With time original steering wheel's leather has worsened considerably: became "hardened"/stiff (used to be supple) and very slippery. A change to this Techart wheel does a large part in making the car feel new, all over again :-). 

Look guys, just do it. Don't think of it as an $1800 mod, think of it being *ONLY* around $900 more than the alternative LOL, to get you a seriously better steering feel, hand made in Germany by a highly reputable German tuner. Lastly, as mentioned, I am a very picky person (extreme OCD type really :-)) and I don't say anything is great unless I have considered all the pro's and con's. No con here.

OT: Chris are you back, though you sold your fantastic low mileage Turbo?

2-12-2016

Hi, congrats on your new car. Not only I have a slightly different suspension (my Bilstein is not the Techart version and doesn't have the front lift feature), I have no idea what the road you described is really like, and what your car feels like, so following are my best guesses.

1. The answer is no, the "travel" of the Bilstein shock should be normal and very similar to stock assuming you have set it up correctly and did not LOWER the Bilstein beyond spec. In general I would not advise any lowering beyond 1 inch or so, from stock height. To best of my knowledge, the risk of too much lowering is that you would hit the internal bump stop - and that would be quite an adventure at speed, in the curve. Go here to see how to measure car height and see how much you have lowered from stock: https://www.6speedonline.com/forums/...ml#post2758673. Please measure your car and let me know what numbers you are getting - once you know where to measure, it takes 5 minutes, literally.

Assuming your car's setup is otherwise correct, the tires are good (what tires are you using?) and not over-inflated (should be about 32/38 psi "cold" in 70 degree F weather), I would add that when road surface is imperfect, all bets are off and speeding would cause problems regardless of what suspension you have. Pardon me if you already know this, but in case you are new to a 911: more so in a rear engine 911 than in any other car - slow in fast out is the order of the day, even for professional drivers. I agree lifting throttle at high speed in mid curve is something that would require an underwear change after.

Whether you should de-tune the car to stock suspension only you could decide. But let me warn you that once you have tasted the stiffer Techart Bilstein, going back to the the soft stock suspension may make the car feel like a ponderous and lazy grand tourer. (The suspension change, for me, is THE single most important mod for 997 Turbo's.)

2. Having listened to quite a number of Porsche Turbo exhausts, IMHO and in my experience all exhausts have a resonance at low RPM, if you are an audiophile with good ears :-). It sounds like engine lugging and you would also hear it with the stock exhaust, around 2200 to 2600 rpm. This low rpm resonance is a problem not just in Porsche, but across several car makers if you google the topic (Toyota Highlander has it LOL - looking to buy this for my son and can't help but have a chuckle reading people losing sleep over it.). My thought on this topic: An engine, any engine, is simply not meant to be driven at 1500-2000 rpm.

Why this resonance is never a problem with several Turbo owners? At least, in a manual car, we drive our car at 3000 rpm to keep the car in the sweet torque range and therefore inherently avoid the problematic 2000 rpm range. Also possibly unconsciously we keep the gear that will maintain 3000 rpm to prevent the resonance. So... the result is that in normal driving, it is not a problem. As for automatic Turbo's, I do not have any idea - have never driven one.

BTW aftermarket exhausts with the least resonance are likely to also be on the quiet side, relatively. It likely would have very little of the extremely satisfying low V8 frequency rumbling. The good thing then for quiet exhausts is lack of resonance, the bad thing is if your personal preference (no right or wrong) is for a louder, more sporty sound, it might be too quiet of an exhaust for you. My Cargraphic for example has resonance at 2400 rpm like the stock exhaust, but it also absolutely, positively sings, loudly, and is perfect for me for the past EIGHT (!) years while passing stringent California smog test. So keep your excellent Capristo and enjoy it! BTW to hear it best, have someone else drive the car with you standing on the sidewalk (exhausts sound better - the full frequency range and loudness - when you are outside the car), or take your car into a tunnel, lower windows and sunroof, and listen to the firework. Hope this helps.

I like it that you are using all top notch components in your car. May I suggest also the Techart wheel. Please TRUST me I didn't expect it at all but the muscular Techart wheel transforms the subjective steering feel. A new steering wheelalso makes the car feels new LOL.

With street tires like Michelin PSS, 32/34 psi cold (meaning you measure before driving the car - before tires heat up) is LOW for the rear tire. I would think 32/38 are more in line with recommendation. In fact I am surprised your TPMS did not show alarm warning at 34 psi rear?

IN GENERAL and with a street suspension, the rear of 997 Turbo tire should be about 6 psi higher than the front. This is primarily because of the rear weight bias of 911 rear engine platform.

2-15-2016

If you haven't done so yet use tire gauge with digital readout. I could sense differences in street driving feel with as little as 1 psi change. Also note that reading from the car's TPMS could be off by as much as 1-2 psi when compared with a reference tire pressure gauge (Tpms tends to read LOWER than actual btw, ie good tire gauge reads 33, tpms reads 31.). I use a good quality Longacre tire pressure gauge.

I understand for others outside the car the sound from a good after-market exhaust could be quite terrifying (literally like a jet). My first traffic ticket was the first day that I had my Cargraphic. The cop was quite upset at me - "didn't you hear my siren!?"

I don't make my recommendation lightly, and the Techart wheel is recommended without reservation. Over time, the stock steering wheel's leather becomes smooth and hardened, making grip difficult and feeling not so nice. Not only the Techart wheel gives you new leather, the increased front-to-back thickness at 3 and 9 o'clock position is terrific. It makes a huge difference.

Be clear as to exactly what you want when you order the wheel - there are multiple options/variations and in my case Techart Germany had to make and send 3 steering wheels before they got it right (First one got a badge, second one they forgot I wanted the perforated leather in the mid section for better grip, etc.). It was a semi fiasco and my dealer ended up with 2 extra wheels LOL.

https://www.6speedonline.com/forums/...per-now-4.html

2-17-2016

Hi, should not present a problem at all as the install is all outside the car's cabin. Great install thread here: https://www.6speedonline.com/forums/...b-g-rides.htm

2-23-2016

Hi, very interesting but sorry no knowledge of this product. I do trust TPC, an excellent and reputable tuner, and what they have to say.

BTW & IMHO if you are that serious about improving the car's soft suspension (yes stock 997.2 Turbo feels pretty soft also, to me anyway) the next thing would be stiffer spring or coilover. Cup tire has very stiff side-wall and using a stiff tire with the very soft stock spring, while a good improvement, could be further improved, by matching it with appropriately stiffer spring. No hard and fast rule but you kinda want the the spring and the tire to be evenly matched in their behavior (not one super stiff, the other soft).

A while back Porsche was racing GT3 at the 'ring and IIRC Walter Rohrl mentioned a similar concept: road condition caused them to have to de-tune to softer tire, and as they did that they switched out to softer spring as well. If my memory serves me right.

Similarly, DSC is only software change of stock damper - there is only so much this could do, and changing the actual hardware (the damper itself + spring) would bring even more improvement. Besides "better" spring rates, just lowering the car's center of gravity is of huge benefit with car dynamics and this could only be done by actual spring or coilover change.

3-4-2016

Regarding Tractive - thanks for the explanation. Very interesting and now the cost of the system makes sense to me. www.tractivesuspension.com

Back to DSC for Bilstein: would you please explain why the number of modes is cut back to 2, from previous 3? Is it a matter of how much memory the module could hold? Memory is cheap, no?

I would think more is better, 3 to me is a good start, or even 4, as it allows user to compare the modes instantly (COMPARISON - very important for us amateur drivers IMHO) and gives more choices. At the least, it doesn't cause any harm to have more choices, does it?

3-6-2016

Some spring rates for comparison (thanks Changster and TPC/Harris) for fun, nothing else :-). Note that multiple factors, ie both the damper and the spring, and multiple other components (sway bar, drop link, etc., etc.) determine suspension behavior. That said, IMHO the spring is THE most "important" component to look at if you want to have an idea what the tuner is thinking and what his intention for the car is. I converted TPC spring rate to lbf/in - please correct me if I made any error.

When competent pro's like TPC do something, I like to learn from them. The first thing to notice is the differential between front and rear springs of Tractive DDA system. No matter what the front spring rates are, the difference between front and rear remains a fixed 50 n/mm or 285 lbf/in. This is consistent with other numbers I've seen, around 200 between front and rear.

3-7-2016

Excellent questions. IMHO (any expert/pro please correct me as needed - I don't mind):

1. Up to a point only. Two key components make up the suspension system: spring and damper. To make the system stiffer, you could stiffen dampening rate, but this only "works" up to a certain point. Eventually and ideally, you will have to go up on spring rate, and THEN tune the damper to fit that spring rate.
What happens if you do jack up the dampening rate instead of changing to stiffer spring? This is the problem with 997.1 stock system: Porsche/Bilstein engineers increases the dampening force so high in the Sport mode that the system has no compliance whatsoever. This is why it's so jittery and so un-useable, and why TPC DSC is a great solution.

2. Spring is the key of any suspension system. The 3 spring rates used by TPC is expected and nothing abnormal- see 1 above. Pro and expert tuners such as TPC would pick a spring rate, then tune the damper to fit it. Comments below are my opinions.
TPC Tractive DDA for Turbo
1. Road & Track version with 343/628 (60/110 n/mm) springs (similar range to Bilstein Damptronic)
2. Intermediate version with 457/742 (80/130 n/mm) springs (now we are talking - this takes the Turbo to GT3 level and this is where I would try if I have the $)
3. Extreme track version with 571/857 (100/150 n/mm) springs (GT3 killerKidding)

The beauty of using coilover such as TPC's Tractive is that the springs could be easily exchanged as your needs and taste change. This is no big deal and the spring costs about 100 each. You could do the same with your Techart Bilstein's springs; change them to softer or stiffer springs as I did. BTW above discussion is why I've told Changster that DSC is great, but eventually if you want to get "serious" you will have to deal with the soft spring of stock Turbo(200/450 range): by changing to either stiffer lowering spring, or to a coilover with stiffer spring.