BOOSTED TTS

Hi guys,


Wanted to get some feedback on what other suspension mods are out there for high speed pulls, 1/2 and 1 mile events...Mexico too


Current mods
Stock PDCC
H&R Sport Springs
991 Cup Car upper wishbone (Solid mounts)
991 Cup Car Trailing Arm (Solid mounts)
991 Cup Car Upper control arm
RSS front control arms


After 180mph, I would like the car to feel tighter.


Thanks,


Manuel

Jean

Manuel, high speed stability has to do with aerodynamics more than suspension. By tighter you mean more planted, so more downforce. Some quick improvements without spending much.

- Lower the car, you can do this with springs only. You will reduce lift at high speeds and reduce drag
- Or Better..adjustable height suspension, KW, Billstein, Ohlins, etc.. or cheaper, visit the Elephant Racing website, they sell a kit to turn your stock suspension into a height adjustable one. Then lower the car
- With adjustable ride height suspension, increase the rake on your car, lower the front more than the rear
- Or without adjustable suspension, fit taller tires in the rear, it will increase rake
- Fit a good quality rear diffuser, not a cosmetic one. if you have the $$$, get yourself a 991 R / 991.2 GT3 rear diffuser
- Set your front toe to zero

You can always go the extra mile and change the front bumper or add a guerney or large rear wing but your top speed will be reduced by a few mph, which is not what you are looking for I assume.

worf928

I agree that downforce is solution. Aero is tricky.

... make sure you do both, not one or the other.

Have to keep aero balanced. Big rear wing, only, will cause progressively-increasing-with-speed understeer. Too much front downforce not balanced by rear downforce, will make the tail 'happy' at high speed.

More downforce needs to be balanced with stiffer springs. And then, of course, dampers may be too weak.

At 200 mph, you want engineering, not experimentation, unless you have a unlimited supply of new cars and new drivers like F1 in the early days

Jean

Definitely correct about balancing downforce.

But you don't need to go stiffer springs than stock or worry about understeer for a high speed run, these cars are tested at top speed and beyond safely from factory. We are not talking about a road course.

Lowering the car and setting additional rake take care of increasing front downforce. A rear diffuser would be a great add-on. That's all thats needed for stability with the right alignment..

Obviously a large rear wing (cup style) without front balance is a different story but then again why would anyone wanting max. top speed do it, it will easily shave >15mph from the top speed in a mile run.

BOOSTED TTS

Thank you so much for the feedback, going to go with the rear diffuser. I see you are suggesting the 991R or the 991.2 GT3...I would have to change the rear bumper? Any other options?


Regards,


Manuel

ace37

Underbody aero is about the only way to gain downforce without a significant drag penalty. If you can reduce your drag coefficient you'll even gain top speed.

Diffusers, nose splitters, and side splitters are best considered as a package rather than as one-off items to add to a car. The whole package interacts and changes the underbody airflow - since it works as a system you have to think of it that way.

The suggestions above such as rake, ride height, and alignment are easy to get right so I'd start there and see if you're happy before getting too far into aero. But aero could help your performance quite a bit if you want to go down the rabbit hole.

BOOSTED TTS

Thank you...one thing that has not been mentioned and I had it on my 997.2 TTS was the GT3/GT2 bumper insert...that was a good help on the 997

Cicio Performance

H&R springs are awesome but in my experience they for sure can make the car feel a little less stable at speed.

I completely agree with the others that aero will help a ton but it will also put a bit more stress / weight on the spring which in my theory isn't going to help you a ton and might hurt you.

I would recommend a good setup and either a fun shock or a KW Sleeve kit.


That all said when is your next event? I'm going up to the NC WGF event in two weeks then will be at the Ocala one this fall as well.

stealthpilot

The elephant racing height adjustable coilover conversion for existing PASM sounds great. However can you adjust the height at yourself, or do you need to take the car into a shop so they can lift it to adjust the coilovers? If you can do it electronically that would be awesome. I like the height of the TTS for city driving, but on highway I do wish it was lower. Ideally I would like an air suspension.

Jean

If you haven't done it before, it might take you several hours (or days), you need to have corner balancing scales and a lot of patience to get the diagonal corner balance correct at the desired rake and ride height.

Take all measurements on four corners before and after conversion, measure rake before and after, adjust height to your specs, corner balance again, fine tune height to get diagonal weight balance within spec, measure rake again, adjust height, corner balance, measure rake, etc.. Sounds difficult but it's not, just time consuming, having the scales, some tools and the target values.

After all the above you still need to readjust all your alignment settings and corner balance again.

For a street or highway only driven car at legal speeds definitely not worth it.

Take it to a shop

BOOSTED TTS

http://www.sharkwerks.com/products.php?pid=424

DSC Sport

I'd recommend going with one of our DSC Sport controllers, which will allow you to tune the stock dampers by a variety of inputs, including speed. I think you'll find that our stock tune will provide the "tightness" you're looking for as it is.

You might also want to look into getting a set of sway bars, such as the TPC Racing Pro Race Adjustable Sway Bars (NOTE: DSC and TPC are affiliated)