Softer springs for Ohlins R&T?

I’ve got the Ohlins R&T’s on my 996.1 and, like so many others, I find the spring rates way too high for our roads. They seem to work a lot better at higher speeds, but are extremely crashy at low speeds. With the dampers set fully soft the springs seem to overpower the dampers. I’ve looked at the various options and there seem to be a lot of opinions out there… I spoke with CG, and they recommended Eibach 40/80 springs which (I think) are 39/78 N/mm Then 9e spoke with Ohlins, and they recommended either 40/100 or 50/110 N/mm The standard Ohlins R&T springs are 60/123 N/mm For reference, 996.1 GT3 springs are 35/65 N/mm There seems to be quite a disparity between what CG are recommending and what 9e/Ohlins have suggested. Especially at the rear. I appreciate that spring rates are matched to damper valving, but the 9e/Ohlins recommendation at the rear is much higher than either the original GT3 rates, or the CG rates. I need to get all the coffin arms changed and wanted to do everything at the same time. It would be an absolute pita (and £££) to do the whole lot and then find I’d made the wrong choice and have to do it again.. I was wondering if anyone had had theirs changed, and to what (and how you find them)? Thanks.

I went down this rabbit hole when replacing the suspension on my 996 turbo, both Bilstein and Ohlins said spring rate could be reduced by 10% without revolving the dampers. I ordered PSS10 from CG along with their recommended springs, the guys doing the install (lots of 996 turbo / gt2 experience) said the CG springs were too soft and the rear would squat under power. We went with the stock PSS10 springs which actually work pretty well on the road, for reference the PSS10 springs are 45/90, standard Porsche are 33/60, and the CG were 49/59. When I was researching KW and Ohlins had much higher spring rates than the Billy’s.

That’s interesting. I’ve had the PSS10’s on my 993’s and rate them really highly - tbh, I prefer them to the Ohlins, but that might be just because they feel so harsh right now. CG are supposed to be the gurus in all this, but they seem to prefer much softer springs for the rear (as with your experience) compared with what Ohlins suggested to 9e. On the other hand, the CG spring rates are still quite a bit higher than the standard GT3. I know, I know, damper valving etc. etc….

Just to add, the car is quite a bit lighter than standard; Recaro PP’s Fuchs wheels Full stainless exhaust Carbon ducktail So, perhaps the lower spring rates maybe workable….?

Ive done a lot of research in this area and had multiple kits. Out of the box, the Bilstein are great and perfect for UK roads. Im not a fan of Ohlins, but if you have them, i would swap to the 40/80, or even 40/70 (but you maybe at the limit of the valving and end up with the damping over-powering the springs). I ended up with a Prepworks Nitron kit. Thats 40/80 with custom damping to match the rates (on a GT3), there Carrera based kit is 30/70 iirc.

30 / 70 springs is the one, I ran feal 441 plus with 3.5ish and 7.9ish rear and it was good. the nitrons are an improvement which was greatly appreciated on the drive to leman and back this year

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CG spring rate will work fine i have ran these spring rates, its the highest spring rate i would go on a any road biased 996. I have ran alot of spring rates, 6/12, 5/10, 3.6/7.9 - 4/8 and now 3/7. 3/7 for me is the spot but its all subjective to your personal preference. I have 4 pairs of nitron springs here from working with nitron and Ian at prosport to get it right on my c2 all at my cost mind!

Thanks, folks. Hugely helpful! I was edging towards the CG 40/80 recommendation, but was slightly concerned by the fact that Ohlins were recommending higher spring rates at the rear. At the same time, tempering their recommendation with the fact that what they fit as standard to the R&T kit is a bit too harsh for UK roads. Great to hear first hand experiences. Makes me rest easier with my decision to go 40/80. I think that’ll be a happy medium between a softer spring rate and damper firmness without getting to the point of a mismatch. Thanks again

So just putting that list together from previous info I've got, as I'm going through the same thing. Rear H&R GT2 - 150 N/mm = 857 lb/in Ohlins GT2 - 140 N/mm = 800 lb/in H&R GT3 - 130 N/mm = 743 lb/in C2 Ohlins - 123 N/mm = 702 lb/in Ohlins TT - 120 N/mm = 686 lb/in 9e Ohlins - 110 N/mm = 628 lb/in 9e Ohlins - 100 N/mm = 571 lb/in PSS10 TT - 93 N/mm = 515 lb/in CG Eibach - 78 N/mm = 445 lb/in Stock GT3.1 - 65 N/mm = 371 lb/in Stock TT - 60 N/mm = 343 lb/in Front Ohlins - 70 N/mm = 400 lb/in H&R - 60 N/mm = 343 lb/in C2 Ohlins - 60 N/mm = 343 lb/in 9e Ohlins - 50 N/mm = 285 lb/in PSS10 TT - 45 N/mm = 257 lb/in 9e Ohlins - 40 N/mm = 228 lb/in CG Eibach - 39 N/mm = 222 lb/in Stock GT3.1 - 35 N/mm = 200 lb/in Stock TT - 33 N/mm = 188 lb/in

Can't help with Ohlins rates but my 996 C2 is currently having the Nitron elec-TRON Roadsport kit fitted and advice from Nitron for a road car was 40/80 spring rates. Will be interesting to see how it all comes together with the adaptive damping

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How much are you paying for those? I was tempted with the tractive, but for 6k, I've never been able to tell the difference in cars I've had adaptive with, well, not enough for 6k. That's on a C63s, M135i, Golf R, GTR, GLB 35, so I've had a few.

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4k + vat total supplied, installed, geo and corner weight. About 2700 + vat of that is for supply of the kit.

Gotta ask a general question has anyone tried adjusting the dampers ? I have Ohlins R&T on my 987.2 and asked the workshop to keep on the softest setting initially the handling on the car was a vast improvement apart from at lower speeds on London roads (which are awful) the rear was just to jolty and awful on the soft setting so I stiffened the the rear dampers 11 clicks from maximum which is stiffer end of “street” and the results were superb. Obviously it’s all quite subjective and a different porsche architecture with front springs on 70 Nm and rear springs on 80 NM from Ohlins, but I thought the damper would be the first place of adjustment on other cars the general adjustment is in the damper, anyway it worked for me and my local roads are atrocious.

@kazoom ; I’ve tried various damper settings, none that really worked. It’s interesting that your rear springs are 80’s, which is pretty much the softest springs I’ve seen recommended for the Ohlins. Maybe that could be the reason you’re damper adjustment did the trick?

Just to add to this, I’ve got a couple of thousand miles on the PSS10 on the turbo, my first thoughts were that they work really well on the road in terms of ride quality, I started to think that they could be a bit stiffer, so had a twiddle, but they were already close to full hard, which tbh was a bit disappointing as it would have been nice to have a little more adjustment, I did experiment softening them and the steering felt less direct and a little soggy. By coincidence I started to lose boost pressure, so put it into West Tuning to investigate, they noticed that the inside edge of both rear tyres were down to canvas, geo was checked and was still correct (camber adjustment is a bit limited) Ray has seen this before caused by squat on lowered tuned turbos wearing the inside edges, which is why he had originally recommended stiffer springs (it was a bit frightening the spring rates he had on his 700 bhp track car). Anyway, long story short, it looks like my options are to fit stiffer springs to the Billys (cheap option) or go with another damper with stiffer springs (like Nitrons), and sell the Billys ….