Ohlins DFV Discussion

[andrewhake]

Yo! Here is a dedicated topic to one of the best dampers available for the S2000. The Ohlins DFV!

Please feel free to ask any questions on DFV related parts or setup here. To start I will include my original impressions post I made a few years ago. Keep in mind a lot has changed with my setup since then so take everything with a 2 year old grain of salt and feel free to ask any questions!

01-26-2014 - Ohlins DFV









01-25-2014 - Ohlins DFV Driving Impressions (Street/Touge)

[andrewhake]

Here are my posts related to my current DFV setup with custom valving and 13kg/13kg Swift springs.

Ohlins DFV (custom valving) + Swift 13kg/mm springs



Ohlins DFV (custom valving) + Swift 13kg/mm springs installed

[garyw116]

I love this setup. I'm running 14kg swifts. Had the shocks re-valved at PSi and just tried them out at Sonoma recently. I wish i can describe how it felt but i can't (I suck at describing how it felt). I just know that i slashed 3 secs off my PB time.

[alSpeed2k]

I'm running Ohlins with the 10kg/8kg springs on my '07, currently on staggered OEM tires (225/255). I will be going square (17x9 +60, 255/40/17), thoughts on running a beefier swaybar?

[TsukubaCody]

^You may want to add whether you mean front or rear.

[andrewhake]

I love this setup. I'm running 14kg swifts. Had the shocks re-valved at PSi and just tried them out at Sonoma recently. I wish i can describe how it felt but i can't (I suck at describing how it felt). I just know that i slashed 3 secs off my PB time.

Very nice!

[andrewhake]

I'm running Ohlins with the 10kg/8kg springs on my '07, currently on staggered OEM tires (225/255). I will be going square (17x9 +60, 255/40/17), thoughts on running a beefier swaybar?

I ran with 10kg/10kg on OEM 06 sway bars (same as 07) and I think the car is very well balanced with 255/255 with this setup. I am on ASM sway bars now but the front/rear bias between the sway bars is still very similar to stock just stiffer overall.

Definitely avoid just putting on a stiffer front sway bar without trying out the new setup first. A neutral / mild oversteer S2000 is easier to drive than an mild understeering S2000 in my opinion.

[JamesD89]

Any thoughts on preload/ride height settings? I currently have my shocks setup per the Ohlins recommendations and my rear end can be skittish over rougher roads or sharp bumps at higher speeds. I've been reading a bit about the lack of travel and riding on the bump stops over at S2Ki so I'm thinking I can probably do some tweaking to get the rear more planted on rougher roads.

I'm running Ohlins with the 10kg/8kg springs on my '07, currently on staggered OEM tires (225/255). I will be going square (17x9 +60, 255/40/17), thoughts on running a beefier swaybar?

Still learning the ropes as far as car control goes but I felt like my car was fairly snappy during autocross with the stock sways (2007, 245 square setup). However, it did feel fairly neutral on a more open go-kart track and was an absolute pleasure to push to my own limits. I could be wrong here, but it seems like the front bar helps tame rear end during the fast transitions you'd see during auto-x that you might not see on a wider, faster track. This is probably why most of the top level STR guys (SCCA auto-x) run a larger front bar. If you're not autocrossing, or do and are still learning the ropes I think sticking with the stock sways is the best route.

Also running the standard 10k/8k setup.

[andrewhake]

The thing to keep in mind about adjusting the preload is that you can't add compression travel without sacrificing rebound travel and vice/versa. More compression travel can be nice, so the damper can compress effectively, but if there isn't much rebound travel the rear end can still react in a way that is difficult to deal with after the compression stroke is done.

With the S2000 there just isn't a lot of travel in the rear period, with the way the subframe and everything is designed in the rear. As the ride height gets lower, you can only get so much compression travel before the tire makes contact with the body. In practice the bump stop should be there to keep that from happening.

As far as the car being snappy, Making the car stiffer in the front just makes this worse in my experience. It is fine as long as you just ride it on the limit of the front grip and understeer, but the "curve" of grip in the rear gets more exponential. It works the same if you were to make the rear significantly stiffer. It would be hard to get the front tires to loose grip, but the moment they do you will just get "snap understeer". Best to get rid of all the "snap" while still having the car be very quick to react to all the inputs. Make all of the transfer from grip to no grip as linear as possible.

This all depends on driver style too, some drivers might prefer a setup that isn't neutral, so really comes down to driver testing.

[MikeRT4]

I recently fitted my Ohlins, where I opted for SBG's recommended 10k rear springs and 10mm preload. Due to time constraints and vacation over the Christmas period, I fitted the rears first. OH. MY. GOD, What a revelation, the ride quality AND comfort with the mixture of Ohlins rears and OEM front dampers was brilliant. No more hitting the bump stops, it was just joyful in the way it ironed out road imperfections and was everything I imagined and had read about (and was indeed MORE comfortable than standard). On this basis, I couldn't wait to fit the fronts and finally did so yesterday. Naturally I was expecting the same improvements and although the handling seems to have been firmed up even more, it has lost some of ride comfort quality it had with the OEM fronts.

It now "feels" aftermarket, where with just the rear Ohlins fitted it felt OEM+ (as in what I felt the S2 should have been from the factory). Unfortunately the roads here in the UK at the moment are cold, wet and greasy, so I have been unable to push the car and can only comment on the ride quality at the moment. With all four Ohlins dampers fitted it is now firmer than standard and with a reduction in ride comfort over the OEM springs and dampers and with the mixture of the two (although the rears don't hit the bump stops).

However, my reason for this post is that I "think" Ohlins have got the spring rates spot on, just the wrong way round LOL . The 8s should be on the front and the 10s on the rear. Given my experience of running the mixture of the two set-ups, I believe that this "might" be the fix for the ideal ride handling / comfort compromise. At the moment, I am going to leave as is and see what it is like on dry roads, but I will probably do the swap when the weather improves.

I have since seen that the original Amuse car actually runs this kind of set up (harder rear springs than on the front, albeit stiffer F12k R14k) - although I appreciate it has a rear wing.

Has anyone tried running the Ohlins springs swapped in this way?

[JamesD89]

There was some discussion on S2ki a while back about rebuild intervals for the DFV with Ohlins officially stating 20k miles, but up to 40k if the car is street driven. I recently got my shocks revalved by Doug Brenner in SoCal and had him rebuild the shocks while everything was apart since my set was just over 30k with the prior owner spending a decent amount of time on track.

In Doug's words (Ohlins USA recommended him and PSI for California rebuilds), they looked absolutely fine. My rear bump stops were fairly chewed up though:


Wasn't necessary to spend the money, but I definitely feel better knowing I have what are essentially brand new shocks . Took the car out for a drive with 12k/10k springs last night and F/R RCAs and it rode great. Looking forward to getting the new setup back out on track.

[JagoBlitz]

Hi,

congrats on this nice forum. I like it.

I am currently running Ohlins with the 10k/8k setup.
How much would the handling and balance change if I switched to 10k/10k?

Thanks.
JagoBlitz

[andrewhake]

Hi,

congrats on this nice forum. I like it.

I am currently running Ohlins with the 10k/8k setup.
How much would the handling and balance change if I switched to 10k/10k?

Thanks.
JagoBlitz

Thanks! In my opinion it would change only for the better and make the car much closer to neutral. The 8k rear springs just aren't stiff enough with the travel in the rear of the S2000 being quite small.

[andrewhake]

There was some discussion on S2ki a while back about rebuild intervals for the DFV with Ohlins officially stating 20k miles, but up to 40k if the car is street driven. I recently got my shocks revalved by Doug Brenner in SoCal and had him rebuild the shocks while everything was apart since my set was just over 30k with the prior owner spending a decent amount of time on track.

In Doug's words (Ohlins USA recommended him and PSI for California rebuilds), they looked absolutely fine. My rear bump stops were fairly chewed up though:


Wasn't necessary to spend the money, but I definitely feel better knowing I have what are essentially brand new shocks . Took the car out for a drive with 12k/10k springs last night and F/R RCAs and it rode great. Looking forward to getting the new setup back out on track.

Good to know and also a good example of why to avoid the standard 8k springs in the rear I think. When I pulled off my original DFV setup with the 10kg springs in the rear the rear bump stops looked just like the front ones.

[JagoBlitz]

Hi,

congrats on this nice forum. I like it.

I am currently running Ohlins with the 10k/8k setup.
How much would the handling and balance change if I switched to 10k/10k?

Thanks.
JagoBlitz

Thanks! In my opinion it would change only for the better and make the car much closer to neutral. The 8k rear springs just aren't stiff enough with the travel in the rear of the S2000 being quite small.

You were right. As expected, 10/10 gives way more neutral handling.
At least for the AP2 10/10 is the way to go IMHO.