While at the track the other weekend my instructor mentioned he could tell the cars suspension needed some tweaking/tuning. He didn't tell me what (so I could do it on my own) but honestly I don't know what I should be looking for? Im only doing DEs right now and know I shouldn't be worrying about adjusting suspension but anything I can do to make the car feel better is a plus.
So, main question, when on the track what should I be looking for that are signs the suspension needs adjusting?
Second, I am running 500f/500r Springs (swift Springs in the front on my coilovers). These were sent standard.
I've read that a 100-150 split is best. Would it be a noticeable difference with putting 600-650 springs (possibly swift to match the front) in the rear?
The car: 97 M3 sedan. Rear is gutted with a 4 point bar welded in. Feal Suspension coilovers 500/500. 30mm front bar, 24 mm rear bar. 17x9 wheels, Federal RS-R 255/40 tires, Xbrace, f/r strut bar. Will post exact alignment specs but front camber is around - 3.2, rear is -2.0
Car is still registered and street legal but primarily driven on the track. Not really worried about comfort.
Any advice would be great.
Last edited by GG Emerican; 05-16-2017 at 04:56 PM. Reason: Added alignment
First, what do you and the instructor think the suspension is doing poorly that adjustments are needed? For DEs seat time is more important unless the suspension is horribly set up, and from what you describe I don't think that's the case.
100-150lb/in spring rate stagger is the standard advice, with the rear being higher. Spring brand is not important at all, spring rate, inner diameter, and length are what is important. Spring brand makes such little difference so long as you buy a reputable brand (Eibach, H&R, Hyperco, Swift are four of the well proven solid choices)
Alignment, sways, all seem fine...what are your bar settings?
What adjustments do you have on the Feals-- rebound only? Individual rebound and compression? Where are these set?
I would adjust shock settings before messing with springs first, to see if you can dial it in better.
----
As for what to look for -- The car's responsiveness to changes in direction, how much and where in a corner the car under/oversteers, whether it's riding on the bumpstops, etc.
Last edited by Bimmerman535i; 05-16-2017 at 09:37 PM.
"Fear disturbs your concentration" -Sabine Schmit
1995 BMW M3/2/5-- S54 + Mk60 DSC, California Smog Legal (Build Thread)
1998 BMW M3/4/5 Alpine/Modena, Z3 Rack, otherwise stock-- DD without burbles
2017 Chevy SS, Orange Blast Metallic, 6MT -- DD with burbles
There were no mechanical issues with the suspension and it felt fine (to me). Car wasn't pulling or drifting directions and no major under/oversteer that was causing any issues. Granted I don't have much experience and wasn't looking for these things.
I guess my instructor (with a lot more experience) picked up on a few areas that could be adjusted. Not major thus the reason for not telling me what to fix and letting me learn/feel it for myself.
Next event I want to start paying more attention to the car and getting faster. Just looking for a few pointers on what signs/scenarios to look for while on track.
Edit: the Feals are 1 way adjustable, rebound only. I forget what I set the sway bars to but believe the front is full stiff and the rear is full soft. Would it be advantageous to set the rear to full stiff to make up for the lower spring rates?
Last edited by GG Emerican; 05-17-2017 at 08:52 AM.
If the springs came stock with the shocks i'd just run the shocks at the manufacturer's recommended settings. Definitely don't run the shocks full firm, or full soft for that matter.
Nothing you mention is out of the norm. If the car behaves predictably, I'd leave it alone. Focus on solutions to problems you actually have. :-D
^ This. Don't fix it if you don't know what's wrong. And there's no way for us to know/guess how the car is handling.
That said, springs are for big adjustments, everything else if fine tuning (ARBs, damping, etc). Get more info from that instructor, or someone else that knows what their saying/doing, before doing anything other than minor tweaks...and always one at a time.
Also, just because someone is an instructor does not automatically qualify them to give advice on YOUR car. Does he have experience with BMWs or suspension tuning? It makes me suspicious that he would say something doesn't feel right and not offer a solution or at least a little guidance. There are hundreds of different setups for the E36 chassis. It comes down to your driving style and comfort level.
This x100.... Instructors are most often well intentioned and should be highly respected for what they bring to the hobby, but not all of them have suspension tuning on their resume....
No need to tune or tweak suspension settings, except to set to a middle ground, until you have advanced enough in car control to feel what tweaks need to be made.
Then come back and start a thread once you have specific issues. The folks around this forum are much more highly knowledgeable on your chassis and setup..
^^These also! I thought it was obvious, but it's not. That instructor isn't necessarily the best input for suspension changes.
Hi there, guys! It is a very useful and important thread, I have to say. I am looking for new springs for me, and I need some suggestions on a good spring manufacturer. I would like to get my car slightly lowered but not too much. Which brands to you prefer?
Last edited by Kohin; 05-19-2017 at 05:03 AM.
Thanks everyone for the advice. I agree with what everyone has said. I don't believe he had a BMW or was an expert in suspension. He simply knew more about the sport and was giving some advice. And it wasn't given as "the car sucks, change the suspension" but more as if you want to continue to go faster there are a few tweaks that (he thinks) can be made. I'm sure he would have told me if I asked but I want to learn the car and what's going on with it.
Which brings me to the question about feeling the car and what I should be paying attention to.
Im going to keep the shocks the same unless I change the spring. But, forgive my ignorance, would making the rear sway bar stiffer make the car behave similarly to if the rear springs were stiffer?
Last edited by GG Emerican; 05-17-2017 at 01:39 PM.
Remember, your instructor is a DRIVING instructor, not a setup guy/gal. An instructor should not be giving setup advice on cars unless (1) the student's driving talent has surpassed the car or (2) they are an EXPERT on the chassis they are in.
Did you ask what he thought needed improving? That would make it easier to tell if he was full of BS or knowledgeable.
The main things you need to look at in terms of telling if things need changing
* Tire wear
* Tire temperatures across the face
* Car handling, ie tendency to understeer or oversteer, mid corner grip, ability to get power down, handling under braking, high speed stability
Things you can adjust relatively simply
* Tire pressures
* Alignment
* Ride heights
* Sway bar settings (if adjustable)
* Shock adjustment (if possible)
Then it starts to get harder
* spring rates, shock valving
* Different tires, size, make, compound
* Body aero (spoilers, diffusers etc)
* Suspension geometry eg track, control arms etc
It will never be perfect. Have you ever seen a race team go to the track and not change anything?
Bottom line is you have to be a good enough driver to understand what the car is doing, analyse it and be able to interpret changes. That is a pretty big task, and in all honestly is the difference between some of the best drivers and the next level, even in F1 etc
Hmm... I had to go look up "Feal" suspension. As soon as I saw the price and colors I knew where they were built...
So don't put a whole lotta faith in the shock knob settings. Having dyno'd Chinese coilovers they are usually pretty inconsistent in their adjustments. You might as well be turning the knobs on a potato, sorry.
If you are totally new to HPDE don't try to tune your way out of perceived "handling issues". Honestly if you are very new its probably the "driving" that needs the most work. don't take offense at that - we all start out somewhere - but forum setup advice is going to you little to no good at this point.
If you know/trust your instructor, and the HPDE group allows it, ask them to drive your car. If you have a lap timer/camera use them both to capture the differences between their driving and your's. Don't be surprised to see 5-10+ second a lap differences, just from experience.
Sure, get tire pressures "in the ball park" but don't start chasing pyrometer numbers. I always ask my students about their pressures, which should be checked hot, so they don't shred a tire in one session or one day (see below). Federals on the wheel sizes you stated? Probably 34-38 psi hot will get you close. Sure, get the camber and toe closer, but don't break out a real time tire temp array to fine tune these settings.
Having instructed with hundreds of HPDE students over the past 29 years shock knobs and other suspension fine tuning is the last thing I tell them to worry about. Your instructor should be able to look at your tires and give you some pressure numbers that are fairly close. The rest - save it for when you are faster/more experienced.
I just did a driver / setup coaching session with a W2W racer last week. We went to a dedicated test day and found close to 3 seconds on setup and driving changes. So if/when you get to the point that you are looking for lap times, work with a coach or setup guru to get the car more dialed in. But for the next 1-2 years, just keep brakes and tires from falling off and drive, drive, drive.
Cheers,
Terry Fair @ Vorshlag Motorsports
^ Damn good post.
Good thread! The long and short of it is, keep wheelin. As you progress, the problem (if there really is one) will show itself and you'll have an "a-ha!" moment.
To put it into perspective, every driver has their own preference of vehicle setup. What it comes down to is, setting the car up so the DRIVER is comfortable, thus making the whole package FASTER. Everyone is different. For example, your "instructor" may have sensed an excessive amount of oversteer, something that could get you in trouble as a novice, but is essentially faster and more controllable as your driving skill evolves. So in reality, if you learn to drive the car as it is setup, you could potentially be faster than other drivers at your level.
lots of what-ifs and speculation in this post and not enough time to really elaborate, but thought it is worth mentioning.
I have an idea what your instructor was thinking, but I'm not going to tell you to change your setup. Try playing around with throttle application in different parts of the turn and pay attention to the attitude of the car and where the nose is pointed by the time you exit the turn. Once you get comfortable, you realize that you can actually steer the car with the throttle.
Last edited by heeltouge; 05-24-2017 at 12:14 PM.
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