But it still bites!


We just got a wirehair dachsund. Long wheelbase, high rearward polar moment... he oversteers pretty bad.

 

Nice, IP?

 

Sorry. Don't mean to hijack the thread but I'll answer these questions real quick.

Yes, my M3 is an IP car. But not fully matured yet. But getting close. Still a lot of possible legal upgrades available.

I've been playing at a private karting Club with a Tony Kart shifter, and a CRG DD2. Just bought a Birel(R-31SE with Parilla Leppard engine) to compete locally outside the club (TAG class).

Back to the subject. I agree with S2Kretard that the "increasing bump in the rear increases rear end grip" statement does not apply to every situation.

But we are here dealing with the basics of shock and car tunning. When at the track, alignments, swaybars, tire width, ride height and other things like that are more difficult to adjust/correct. Therefore my post stated "let's talk about shocks" implying the other variables be fixed.

There are a multitud of car behaviors that you can tune in/out by just adjusting your shocks. It takes less than 1 minute and it can save you about two seconds a lap (depending on the track) if you know what you're doing.

I was just trying to give him a simplified explanation on how and where to start. Book knowledge as you call it. Experience comes only with time, and that's something that neither of us will be able to teach him but time itself.

 

Okay guys, I just got back from Buttonwillow running Race #1 (CCW) for the first time. After correcting toe-in by setting it to 0 degrees in front and 1/16 degrees in the rear, and making the settings on my dampers stiffer up front and looser in the rear (increased front by 2 clicks and decreased rear by 2 clicks) the car felt much better.

With these changes I was able to accelerate a lot harder without the car feeling squimish and/or oversteering as much as last time. Although I couldn't push the car as hard as I usually do because the track config was backwards (it took me 3 sessions to learn the track), I definitely felt more confident through Riverside (went 90mph around there and I usually maintain speeds of no more than about 84-85mph). I also had an easier time through the Bus stop as the bumps weren't as bothersome.

Next step will be to remove the rear ST sway and replace the OEM unit. If all goes well I will be back to Buttonwillow in May.

BTW, I really appreciate your help. Your tips made my day a lot more enjoyable. I'm really taking in everything you guys tell me and will be trying my best to improve.

What did you guys think of the adjustments I made?

 

Impossible


Jk... Glad to hear you were able to improve the car! To really learn what the dampers do, you just have to play around with them. Try various front-to-rear combinations, try keeping one end constant while going increasingly stiff or soft on the other end, etc etc. Be careful when doing this though, they can have a drastic effect and a big change may require a significantly different line/style through a particular corner.

Don't know what tires you're on, but an apex speed of 90mph is pretty quick through Riverside... I was an indicated ~95mph apex in the Berk car, so that's pretty close

 

[QUOTE=S2Kretard,Apr 12 2008, 01:21 PM] Impossible

 

How far is your car lowered?

 

This is the only picture I have that'll show the ride height.

 

Doesn't seem too low. When you the lower car more than 3/4 inch to an inch you throw the roll center way off which changes the dynamics quite a bit.

I would put a 255 on the back next time you change tires.

Also at get at least a spoiler in the back.

and better a full wing in the back and a splitter in the front.

 

Well, I meant that if you mage a BIG change to the dampers, take baby steps up to the limit of the car because it might not be where it was last time... and you may be required to adjust line/technique to compensate for the change. Like, if you set the rear to full stiff to see what that feels like, don't go charging into Riverside at 100%

Ah. Cool, those are similar to the Yok Neova AD07's we were on, right? Anyway, CCW vs CW will make a small difference because with CW, the apex is late in the corner and the last half of the corner tightens up a bit; whereas with CCW, that slightly tighter part is your entry. But if you felt an improvement with the car, that's the biggest factor IMO.