Sketch_hs

Hello all,

I've recently installed ohlins dfv coilovers on my rx7. I find for my preference the rear of the car is just a little stiff while the front is almost perfect. (For comfort, handling is amazing already)

I was considering going back to a stock rear sway bar from the racing beat 2-way I have on now.

Or

Switching the rear springs to 10k or 9k from the 11k

Or both.


Wanted to see if anyone else has run a lower rear rate on the Ohlins or what sway bar you're using with them.

Car is 99% street driven. Santa Cruz mountains area (tons of very fun roads with a lot of poorly maintained roads thrown in)

HadaVette

iTrader: (3)

When I put the Ohlins in I ended up removing the rear sway bar. Seemed better balanced that way, and easier to get power down coming out of corners - notable with autocrossing. My front bar is a Tri-Point med bar, set about mid way. Feels very nice on the couple of track days I've done too.

I was considering a little stiffer front springs...not sure if it's worth it though.

j9fd3s

iTrader: (3)

i think i'd try the stock sway bar

Brekyrself

iTrader: (30)

The stock sway bars are also different diameter throughout the years. I believe the 94-95 base/touring is the smallest diameter. I'll grab my notes when I get home.

Stock 94 rear sway bar and the Ohlins are amazing on track.

Brekyrself

iTrader: (30)

Try changing the sway bar first and tweak the shock settings before swapping out springs.

0.68 --- hollow --- Stock Rear 93 only (17.3mm)
0.63 --- hollow --- Stock Rear 94, 95 (15.9mm)

ZDan

The Ohlins coilovers are fantastic, but the spring rates are kind of out to lunch. 11kg/mm all around results in ~4.1kg/mm front wheel rate and ~5.2 kg/mm rear wheel rate. Too much rear bias.

I track my car, so to get better handling balance and drive out of the corners I went to 13 kg/mm front springs and kept the 11kg rears.

For a street car I wouldn't hesitate to go to 8kg or 9kg rear springs and run them with the Ohlins 11kg fronts.

FWIW I run a Speedway front bar, currently on the 2nd stiffest of 5 settings, and stock '94 rear bar.

lOOkatme

iTrader: (19)

I just did some canyon runs this afternoon. I had 40-80MPH corners and high speed run up the mountain topping out at 140mph, the road is somewhat smooth but has all sorts of bumps, cracks etc in certain spots.

My findings.

I initially ran the ohlins at 10/10 recommended around the street first. Too stiff, I backed off the rear to 15 clicks from stiffest and was much better. Took this setting up to the canyon roads.

I found the rear was planted, front was too stiff, it was skipping over bumps, mid turn bumps would skip the bump and you could hear the tire. I went softer settings in the front with a 15/15. This cured MOST of the harshness over bumps, car felt MUCH better with the softer settings. I still think the spring rate is too stiff. Not just the rear but all around. I will turn the front settings a hair softer and retry again before changing the springs.

The car still feels like it wants to skip the bumps, not absorb them. Feels like the spring rate is too much for the roads. I didn't have this skipping problem at the lower speeds with my 8/6KG set up and ARK coilovers. The ohlins suck up bumps better for comfort, but it still skips over them at high speeds. Perhaps going that fast over the bumps just isn't possible to absord them, just too large going too fast.

I am reluctant to go any softer as I am already at 15/15. To me it feels like the spring rates are too high. Perhaps my speeds with these are just that much faster and I am not noticing just how fast I am going over the bumps to begin with?

I don't mind the rear being as stiff as it is compared to the front, just overall it feels too stiff. Does anyone know how much travel front and rear the shocks have? Could someone grab a measurement of the complete "free travel" (subtract the bumpstop out). I was wondering if I could swap back to my softer springs as long as I am not bottoming out the suspension.

ZDan

Weird, pretty much exactly the opposite of my impression of the Ohlins. I found 10/10 a bit soft even for the street, I run 8/8 on the street an stiffer at the track. I found I wanted stiffer springs for street/track work and did feel that the stock spring rates gave too much rear roll stiffness, so I went to 13k front springs and kept the 11k rears. With these spring rates I wound up with damping settings of 4/6 at the track, still 8/8 street. Never experienced anything like "skipping" over bumps, even at 4/6 damping settings they've always done an incredible job of soaking up road and track irregularities, better than any other dampers I've experienced.
Way way WAY smoother and better-controlled than the 9k/7k Tein SS coilovers I had before.

lOOkatme

iTrader: (19)

Went out again today, front damping set to 17 clicks from full stiff and 15 clicks from full stiff in the rear.

It didn't skip at all, soaked everything up, roll wasn't bad at all, everything composed very well. I had a second passenger in the car with me and perhaps that did something? I don't know, but it did well this morning.

My experience with 10/15 was the front would jump/skip over some stuff, and the rear would hook. now at 17/15 the car soaks things up pretty good.

BLUE TII

iTrader: (9)

So you are turning the Ohlins full clockwise to where the adjuster stops and then backing off counterclockwise back toward soft 17 clicks?

That seems so soft!

I now run my Ohlins 6 clicks from full stiff on the street/auto-x and 3F/4R clicks from full stiff on the smooth track. Your wheels/tires are heavy like mine too right?

lOOkatme

iTrader: (19)

My wheel and tire combo weighs 48lbs. The car ran well today, perhaps one of the problems I had was I tried 10/15 and that difference in damping really upset the way the car handles. Perhaps if I try a 10/10 or 8/8 or keeping the valving very close to each other I will have different results. I don't really have a preconceived notion of what damping setting to run, I just keep trying different values till I like where the car rides and handles well. I also like soft spring rates, I never really had problems with driving fast on soft springs as they seem more forgiving and have more grip. I seem to adapt to better to the softer feelings. I also like having a stiffer spring rate or roll rate in the rear of the car. I think the matched 11/11 rate is actually good. perhaps the rate is a little high but having the front and rear matched seems good to me. I will stick with the 11/11 set up as the whole kit is designed to it. It does ride better than my last set, I just wish it were more like a 8/8 or 9/9. I do think with the DFV that those rates are probably not a good idea to run as the shocks seem to need the higher rate spring to keep from bottoming/off the bump stops.

I might try a 10/10 even match for a run and see how I like it. perhaps matching the damping up front to back is the key.

when I did have 10/15, the rear of the car under braking was all over the place. it was moving left and right and swaying around. When I went 15/15 that cleared up everything under braking but still a hair too stiff in the front. 17/15 was actually really good. Yes, full stiff, 17 clicks counterclockwise.

I will keep trying different settings and will report back what i find. I am running a 1993 stock sway bars, stretched 285's front and rear. I was pushing the car damn hard as well

j9fd3s

iTrader: (3)

you kind of did this, but try full soft, and then full stiff, and then half way, it calibrates the seat of the pants. we've found that too hard, is a, very easy, and b, hard to drive, so its less consistent.

another thing you may wanna check is for bottoming out. you can just lightly bottom out, and the car just gets twitchy. you might try raising the car, or end, a turn or two and see if it gets way better.

ZDan

Definitely seems like something's screwy. Even at 4 clicks, they should be doing a very good job of soaking up bumps. If anything, I find myself thinking of getting them revalved with more high-speed damping since they seem so plush! Skipping across bumps and losing/regaining contact with the road is NOT what you should be experiencing at any setting.

Sketch_hs

Now running 13k / 9k springs with 94 bar. Feels pretty good. Really think switching from 18s to 17s would help everything

lOOkatme

iTrader: (19)

We have a local here running 9/8 on his ohlins with larger sway bars front and rear and he loves the way the car rides and performs.

The difference I think between most of the people on this thread and us is our roads are too choppy to go much above a 9KG spring. this is the outer limit for us and being able to use the car as a street car here.

On the track where it is smooth compared to our streets here I can understand why you might want the car to be stiffer, especially low speeds like autoX. totally get it. anyway street car we like 8-9KG front and 6-8KG rear.

time trails small course stuff I could see 11/11 or 13/11 rates doing great on a nice flat track.

ZoomZoom

iTrader: (2)

Rule of thumb is tune it with the spring rates or sway bars. Messing with combinations is going to set you back from dialing it in. You can do it either way. Just pick one.

If the rear doesn't roll enough, you can actually go bigger away bar up front. There are so many ways to attack this problem. There are chassis shops that can tune this for you, you can study up and read some books from the pros or keep throwing parts at it until you find something you can work with.

j9fd3s

iTrader: (3)

+1. my long answer is race car specific. race cars are simple, all we care about is lap times, unless the drive sees double or something. this one time we put solid motor mounts in the honda, and it vibrated so much that the driver couldn't see, and then weird stuff started falling off the car...

anyways, good rule of thumb is to do one thing at a time. however you do actually want to play with all of the adjustments. we see a lot of people that buy all the fancy adjustable bits, and then never adjust anything.

its also good to write this stuff down, putting a white board in the trailer was the best thing we've done in a while, paper works great too. simple and quick is better here than fancy.

izanami

I also have Ohlins and am looking to change to softer rear springs before i go for my next alignment. Does anyone that has done this have any feedback about how it worked out. I know some people have changed out fronts and had good results, but I haven't heard first hand from anyone with softer rears. I am thinking Swift Z65-178-090, which are 9kg or possibly the 8kg. Also, would you set the preload the same as the regular setup (2mm from free length)?