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      12-07-2012, 08:18 AM   #23
kotik
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Quote:
Originally Posted by PrimeBMW View Post
Why can't the stock suspension handle the tires?

The stock suspension was calibrated using many factors but one was the grip of the Michelin PS2 or Michelin Sport Cup (special formulated with less grip). Most street tires will still work within the suspensions optimal range. The stickier the tire the more you are starting to operate outside that optimal range. At some point the cornering forces are too great for the spring and shock/damper to control. They start to loose control of the movement, may fall behind in correction, may over heat the fluid and basically start to flail. Plus you start to get unwanted body roll. This can cause you to ride on the bump stops, as the car rolls the negative camber starts to become more and more positive = loose you contact patch. In addition I believe the suspension geometry is less than ideal at full compression.
So an ideal set up with the stock suspension would be a less grippy tire. I would buy front camber plates and run 275 in the front.(AD08 or RE-11)
BTW Coilovers do not necessarily have to be harsh on the street. They can be set up for your individual needs and calibrated to the specific tires you want to run. KW has an ipod adjustable set up.

For reference: I have a 2700lb. E46 M3 with full aero running Yokohama race slicks. It takes 1000lb. front, 900lb. rear springs with MCS triples to control the corning forces that are near 2 Gs. The E92 M3 stock suspension + Yoko slicks wouldn’t even come close to controlling the motion. Its just not designed to do so…..
makes sense, thanks.

if I put H&R race springs, would it improve?
I did the pin removal, so my front is at about -2.5 i believe.


I have a lot of issues going into turns, it feels like the car weights 20 tons. Understeer is pretty bad, and when I try to correct, the whole car just plows all together. It leans sooo much! I rode in my buddies GT3rs with stock suspension, and that thing is like on rails. Also, i've been passed by some NA M3's, with full suspension, and their cars just go in turns so nicely.

Right now my best time is around 8 flat with small traffic, on a second lap, but I am greatly limited by my brakes... I really need something better, was thinking about stoptech BBK, stock size, but i heard they are much better. Also was reading somewhere about some upgraded rotors... it is my understanding that stock rotors have ventilation issues, thus are bad, so if i can just upgrade the rotors without calipers, i'd save $, right?
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      12-07-2012, 02:49 PM   #24
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kotik,

First, if you are hitting the limit of stock brakes, get a front BBK. Safety always come first. Spending $3k on a kit vs. losing your entire car + damage to the track ('ring guard rails are expensive . You do the math.

Second, changing EDC from sport to comfort will NOT change how MUCH your car rolls in mid-corner. It will only change how FAST your car rolls. Think of EDC as a timing device.

A good suspension optimizes the grip of your tires by controlling how your car reacts to bumps, turns, acceleration, braking, etc. It is much more than just roll. It is a combination of spring rates, damping, camber, toe, ride height among many other factors. A GT3RS feels like on rails because it has a combination of the factors I mentioned above, not just because of sway bars or stiffer springs.

As PrimeBMW suggested. The cheapest mods you can do to the handling of your car are tires and alignment. If you are experiencing understeer, get some wider front tires (you only have 245 vs 275 in the back). Get a more aggressive alignment by pulling the front alignment pins.

Quote:
Originally Posted by PrimeBMW View Post
Why can't the stock suspension handle the tires?

The stock suspension was calibrated using many factors but one was the grip of the Michelin PS2 or Michelin Sport Cup (special formulated with less grip). Most street tires will still work within the suspensions optimal range. The stickier the tire the more you are starting to operate outside that optimal range. At some point the cornering forces are too great for the spring and shock/damper to control. They start to loose control of the movement, may fall behind in correction, may over heat the fluid and basically start to flail. Plus you start to get unwanted body roll. This can cause you to ride on the bump stops, as the car rolls the negative camber starts to become more and more positive = loose you contact patch. In addition I believe the suspension geometry is less than ideal at full compression.
So an ideal set up with the stock suspension would be a less grippy tire. I would buy front camber plates and run 275 in the front.(AD08 or RE-11)
BTW Coilovers do not necessarily have to be harsh on the street. They can be set up for your individual needs and calibrated to the specific tires you want to run. KW has an ipod adjustable set up.

For reference: I have a 2700lb. E46 M3 with full aero running Yokohama race slicks. It takes 1000lb. front, 900lb. rear springs with MCS triples to control the corning forces that are near 2 Gs. The E92 M3 stock suspension + Yoko slicks wouldn’t even come close to controlling the motion. Its just not designed to do so…..
Well said! Any pictures of your beast?
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      12-12-2012, 04:58 PM   #25
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Quote:
Originally Posted by kotik View Post
makes sense, thanks.

if I put H&R race springs, would it improve?
I did the pin removal, so my front is at about -2.5 i believe.


I have a lot of issues going into turns, it feels like the car weights 20 tons. Understeer is pretty bad, and when I try to correct, the whole car just plows all together. It leans sooo much! I rode in my buddies GT3rs with stock suspension, and that thing is like on rails. Also, i've been passed by some NA M3's, with full suspension, and their cars just go in turns so nicely.

Right now my best time is around 8 flat with small traffic, on a second lap, but I am greatly limited by my brakes... I really need something better, was thinking about stoptech BBK, stock size, but i heard they are much better. Also was reading somewhere about some upgraded rotors... it is my understanding that stock rotors have ventilation issues, thus are bad, so if i can just upgrade the rotors without calipers, i'd save $, right?
H&R race springs: Will it be an improvement? I don’t know if it would be an improvement for the Ring. Either way it would only be a very slight difference……..it will not correct what you are experiencing.
Camber: Unless you have an extremely rare car you probably only getting -1.5 in the front. Don’t quote me but the H & R race springs might allow the car to sit lower thus allow more like -1.7 or -1.9.
If you don’t want the front to plow I would suggest the following:
1) Install camber plates. You can run -2.2 and still save the front tires. It will still push. You could try to run -2.5 or more but will have to run 40lb. on the street. Ideally you would run -3.0+ for the track.
2) Run 275s in the front in addition to the camber plates.
3) Turn off the TC and MDM, push down with your right foot and the rear will come around nicely Just kidding. Dont do anything you are not comfortable with.
A BBK kit (at least the fronts) would be smart.
You really need to find a shop that knows what they are doing. Fredy & Ralph @ Rent4Ring are the only people I have met over there. Good guys and they know how to set up a car for the Ring. Fredy loves BMWs and could most likely help. The KW club sport would correct your problems. Pay one of those guys for coaching. Fredy has done Bridge to Gantry in 8:06……….in a 140 hp. Suzuki Swift!!!

Richard: I will work on getting some pictures up. (she is only a few days from starting for the first time)
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      12-13-2012, 11:15 AM   #26
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thanks guys.

I'm prob mistaken on the -2.5 camber... I did remove the pins.
Ok, so camber plates then... I was thinking of doing dinan stg 1.
Some drivers told me that on the ring it's prob smart to go with Normal EDC mode as it's too bumpy in sport mode, and makes the car very jumpy. When I was at Spa, sport mode was perfect, but i still had lots of body roll.
The reason i was asking about H&R, is cause a buddy of mine had them, and I rode with him, the car felt A LOT more planted and gave more confidence going into corners.
Turning off MDM, yes I do feel very limited by it, there are some turns where I do want the back to come out more, and some places where there are bumps and I just want the car to feel free to spin a little... it's just that it's my baby, and bad things happen on the ring every day to very experienced drivers, u never know... and having that safety net (MDM) just makes me a bit more comfortable. I do have Euro MDM though.
BBK, oh yes, I would love to have it, lots of money though... plus, I need winter set up on the car, so i'd prob have to go with stock size rotors on BBS (hard to justify).
275 in the front, yes i thought about it, but i would need new set of wheels to fit those (i'm running A7's as my track wheels/winter set up). I'm also affraid that they will rub. My street tires 255/35/19 rub.
Yes, I do know Ralph and Fredy, they are the ones that keep my track tires. They just bought a very nice E46 M3, it's well set up, on semi slicks... They told me the fastest they got it was low 8's.

To be very honest, I saw Megan RS and mini's that were under 8 minutes... so there are some fast guys there, but most of them have well set up cars. Those swifts don't have interiors, have semi slicks, good brakes, full suspension, and full bolt ons... so off course they are much faster than me around the turn.

I've never done a clean lap, always some traffic or accident. Here is a lap i took with my GF, with 40% traffic... it's around 8:20... figure without traffic would be under 8. On stock brakes (60% worn).


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      12-13-2012, 11:16 AM   #27
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oh and i had a bit of a boost leak, and extra weight (she hates when i call her that!).
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      12-25-2012, 12:35 AM   #28
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That was fun! Hope you didn't end up in the dog haus after that run.
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      12-27-2012, 09:22 PM   #29
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Kotik! I spent this whole evening watching these vids! The good camera view, exhaust notes and the commentary (the one when you were following the white GT2) were entertaining. Honestly, if it didn't sound so good, I would skipped forward through them. What exhaust system is that?
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      12-28-2012, 02:02 AM   #30
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Thanks man!

I have stock catback, Fabspeed High Flow cats, and resonated xpipe. It makes the car sound like a muscle car (a vette for example). Some like it, some don't.
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