MRAMG1

Okay gentlemen, it is time for some basic handling facts. All of this information is taken directly from books such as “How to make your car handle” William Mathis’s “Mustang performance book 1 and 2, which my crew chief assisted in writing” etc, etc.

To start with 99% of all STREET cars sold on the planet have some degree of under steer built into them. That is the car push’s also known as “Tight” in the racing community, i.e. does not have enough steering. This is a MUCH safer condition for the average driver as if you exceed the cars handling limit around a corner, it will simply push to the outside.

Conversely, the FEW cars sold that have a degree of over steer also known in racing as “loose”, such as the Nissan 240Z, Porsche 911, when pushed to the limits will have there tail end spin around on an average driver. Not a very fun thing to have happen in traffic.

Here are some BASIC tips that you can do to correct these two conditions on ANY car.

I will start with an Under steering car as that IS what a C32 has. To reduce the amount of under steering you can:

1. Use a LARGER rear sway bar
2. INCREASE the REAR spring rate
3. Use a SMALLER front sway bar
4. Use a Lower FRONT spring rate
5. Use a STIFFER rear strut
6. Use a Looser Front strut.
7. Use a Lower rear tire pressure
8. Use a Higher front tire pressure

Note: These Items were put in this SPECFIC order as the first item IS the most effective way to REDUCE under steering/Push/Tight. Each item has drawbacks/advantages. Example A larger Rear sway bar will cause the car to have a tendency to Lift the inside Rear wheel around corners, thus REALLY stressing your differential. Higher spring rates can REALLY make your car ride like a truck. Stiffer Struts will also have this effect, but to a lesser degree.

If you have a car that Over steers, simply reverse the above information, example
1. Use a Smaller rear sway bar
2. Decrease the rear spring rate
3. etc
4. etc
5. etc

I know there has been a lot of confusion regarding Handling about our cars, and I post this to try and clear up some issues from the past. It is not an ANSWER all questions or to be used as a Bible. It is simply some facts from books and track experience that I hope will help in attempts to make are Toys a BETTER handling, i.e. more neutral ride.

Yes there are other ways to cure these issues; I have just tried to list the EASIEST/Cheapest ones
See yeah at the track!!!

AWDman

4/21 @ shenandoah?
http://emraracing.org/Emraeven.htm

MRAMG1

[QUOTE=AWDman;2084870]4/21 @ shenandoah?

Sorry cann't make it. vacation with the wife.

How about Nelson's on 6/12?

See yeah

Oh yeah, thanks for the website

AWDman

[QUOTE=MRAMG1;2086422]maybe i can attend. can you give me details? i have to be in cinnicinati that week anyway.

MRAMG1

[QUOTE=AWDman;2086429]Mercedes Benz / National
Monday, June 11, 2007
Tuesday, June 12, 2007

go to nelsonledges.com for schedule.

PS: I don't know how you get into this one as there is no phone #

mbenzman

Other cheap ways of affecting handling is through weight control. Taking mass off, obviously will make the car faster, quicker, less hard on tires and brakes, corner faster and stop shorter.
But relocating weight will help if you can't get rid of it. Move weight from front to rear, such as battery relocating, will reduce push, and vice versa. Relocating weight down will reduce the center of gravity and reduce body roll which will help the car go through the corners faster by maintaining more traction from the inside tires. Lowering the ride height lowers all the sprung weight and will make the car stick better.
Light wheels, tires, brakes and suspension parts will reduce unsprung weight which will make the car easier to handle and stick better by allowing the suspension to react faster and follow the road.
If there is more left turns than right, you can shift weight to the left side to help plant the left tires and gain an advantage, but this will slow you in the right turns. (Track specific mod)
Adding caster angle in the front end will cause camber changes in the front when the wheels are turned during corners which will help keep the tires planted through the corners, this can be used in conjuction with additional neg. camber or w/o.
Stiffer bushings such as urethane allow less suspension deflection keeping the alignment settings more accurate.
These are more general handling tips, not specific any one model.

Fifth Ring

Good info. One add-on though relates to air pressure.

As a general rule, you can increase slip angle by REDUCING tire pressure making that end of the car "looser" but at some point INCREASING tire pressure will reduce the contact patch efficiency and have the same result.

As another post recently pointed out, it's all about achieving the optimum hot pressure to maximize the contact patch. Reducing air below that optimum will give slip angle, but so will increasing it.

dsC32

I will post the contact and registration info re June 11-12 at Nelson Ledges this evening. It is a MBCA event that starts on Sat. June 9, with track events Mon & Tue., and is headquartered out out of The Bertram Inn & Conference Center, Aurora, OH.

dsC32

Go to the mbca.org cite for information on Gemutlichkeit at Nelson Ledges in June. The contact person is John Morrison, email at Gobenzing@aol.com. He can take your registrations. Hope to see you guys at the event. Should be great fun.

///AMG4EVER

I'm going to the track Thursday afternoon (www.msrhouston.com) for a few laps. This is my first time and I'll like to get some feedback from the experts here. What is the optimum tire pressure? It looks like I need more in the front tires... Did you guys turn your ESP off the first time? Sorry for the newb questions.

Regards - Carlos

Fifth Ring

ESP should be off unless it's wet. I would set tires at 29 to 32 cold, all around, depending on air/track temp. Check pressure right after each session. Your tires are going to get HOT and that will increase hot pressures to 40+. Fronts will heat up more than rears so you could start with 29 front, 32 rear, and go from there. If my tires are much over 40 when hot, I back out pressure. There's no science here. Tire brand, age and driving style will all influence things.

///AMG4EVER

Thank you Fifth Ring. I'll follow your recommendations.

AWDman

what tires do you have? PS2s will roll sidewall at 29psi. c32 will kill pretty much any street tire due to heat buildup (if you're pushing it). take some white crayon to mark the sidewalls.


if this your first time -best thing is to take it easy, enjoy using all the road, hitting your apexes, following the racing line etc......you can rotate car if you're not careful suggest running with esp on at first, epecially if track is smooth.

may want to consider high temp brake fluid, i boiled mine on my first event and i was taking it relatively easy.

good luck, post feedback. ...and welcome to the gold caliper club.

AWDman

[QUOTE=MRAMG1;2086422]how 'bout mid ohio may 28-29th? chinmotorsports, may be pricey @ ~$650 but i plan to be there (have to be in columbus that week).

///AMG4EVER

AWDman - I have PS2s on AMG 18s. I've read about the chalk/crayon trick. So basically I mark the sidewall all around at a determined cold pressure, go for a spin, if I see some of the marked area 'touched', that means I need more air... is this right?

Take it easy and have fun is my plan, the C32 is my daily driver and I don't intent to push it to the point that I'm going to need new tires and/or brakes.

I'll take pictures and post my experience. Thanks for tips man.

Fifth Ring

The "spin" needs to be long enough to heat up the tires since you'll increase pressure as they heat up. You might rub off chalk on the first lap, but once warm, you are no longer rolling the tire over.

You should be able to see scuffing without relying on chalk. Don't worry about it so much. Just have a good time, and don't baby the car. Driving in bumper-to-bumper traffic is harder on the car than driving at a track. (At least that's what I tell myself.)

///AMG4EVER

OK cool. One last question... do you decelarate down shifting or just braking in auto mode? I guess the most logic answer is BOTH. Any advice as far as transmission/shifting goes? I have the Behr radiator and the freaking jerk. My only performance mods are green filters and renntech springs.

Fifth Ring

I use the stick to pre-downshift into turns. Downshift as you brake so you are in the preferred gear through and out of the turn. Don't downshift to decelerate - that's what brakes are for. Just downshift to get into the gear you'll need exiting the corner. Upshifts happen at redline anyway so there's no need to upshift manually.

PS: It will not hurt if you do the first few laps in fully automatic mode. It lets you get comfortable without thinking about shifting. What you'll learn is that the automatic will not downshift until you are starting to accelerate out of the turn, and the delay/lag time is upsetting.

///AMG4EVER

[/QUOTE]What you'll learn is that the automatic will not downshift until you are starting to accelerate out of the turn, and the delay/lag time is upsetting.[/QUOTE]

I know exactly what you mean. It is most likely that I have to punch the gas pedal to accelerate out of the turn. I'll varied my driving with ESP on/off and downshift/automatic style to learn more about the behavior of the car.

Fifth Ring

What you'll learn is that the automatic will not downshift until you are starting to accelerate out of the turn, and the delay/lag time is upsetting.[/QUOTE]

I know exactly what you mean. It is most likely that I have to punch the gas pedal to accelerate out of the turn. I'll varied my driving with ESP on/off and downshift/automatic style to learn more about the behavior of the car.[/QUOTE]


The auto-stick on the Benz is pretty lame compared to systems available on Audi and BMW. The programming makes it hard to really select a gear you want since it gets overridden so easily. And even if you are changing the gears, it is very difficult to know what gear you have actually ended up in. The dash readout is ridiculously small.

///AMG4EVER

Tell me about it... my cluster fades in the heat. I'm replacing it with a CLK cluster April 14th. Expensive but it's the only thing that I don't like about the car.

Now my track event will be pushed to next week... my friend's porsche won't be ready, bad rear bearing and hub. He is the one with the passes so... gotta wait! He has a Boxster S and another friend that's coming has a Corvette C5. All pretty much stock newbies.

OPM

Carlos, do not worry about all that. Focus on the important things. Get some sleep the night before. Relax and stay relaxed. Drink a lot of water and **** as much as you can. A day prior to the even skip salty and other dehydrating foods like potato chips or sushi. Also skip alcohol, including glass of wine or bottle of beer at the diner. It has nothing to do with being drunk and everything to do with being dehydrated. Dress in layers. Some tracks require long sleeve shirts and pants so make sure you have those with you. Obviously, wear comfortable driving shoes. You do not need to buy anything, but if you already own comfortable narrow shoes with thin soles, wear them. Clean inside of your car and trunk by removing anything that is not bolted down. Put everything you need inside a sports bag. When you get to the track just remove the bag and your car is ready to go.

When you are driving at the event – listen to your instructor as though he/she is a god. Do not think you know better. If he says brake or brake harder, do not assume he does not know your car and he is forcing you to decelerate prematurely. He might be seeing something that you do no (like a flag). Instructors rarely scream, “oh my god we are going to die”. They usually will try to instruct you on how to save the car until the last minute, so do as you told when you told. If you can, let your instructor drive the first few laps. This will help you understand what your car is capable of and will give you an opportunity to start learning which turn is left and which is right. Some clubs will run first 2 or 3 laps under yellow flag. If that’s the case you should drive those laps then switch with you instructor under green then after few laps switch again. He/she only need to drive a few laps (about 4min) for you to understand what’s going on. Also at some point in the day you will be given an opportunity to be a passenger in your instructor’s car during his run. Do not miss that. During your first run focus on memorizing where left and right turns are. Do not worry about flagers (during that run you won’t be able to see them, but your instructor will, so do not worry about that), or driving line, or good turn in, or trucking out, or looking ahead, or anything else for that matter. Just focus on getting yourself oriented. If the track is long like lets say Watkins Glen it might take the whole first run. Just breathe, pay attention to your instructor and drive. You might want to let your instructor put his left hand on your steering wheel and guide you the first few laps. Trust me there is no shame in asking for his help, at that moment, I guarantee he has a bigger dick than you, even if he happens to be a she. So relax and enjoy the ride. As soon as you get comfortable start looking into your rearview mirror. Second run - pickup pace, start pay more attention to the driving line and look into your ****ing mirror. Third run – do as you did during the second run, but if you can pickup pace a bit. This is the run where you should be comfortable enough to start finding flagers. These people are your eyes and they might save your life so seeing them every time you pass-by is crucial. However, during your first event it is unlikely that you will be able to see them every time, but give it a try. Do not forget the mirror. Forth run should be the same as third.

For you tires, esp, shifts, etc., are not relevant at this point. Having said that, I would leave esp on and tranny in auto. When you feel comfortable you will change those things, but for now it should be one less thing to think about. 30PSI cold sounds too low, but I never tracked my C55 so I would take Fifth’s word on that. Maybe your pressure will go up by 10 degrees. Yet, I am sure you’ll be ok if you start with your normal street pressure. Just make sure it’s the same in each side. If it’s a clockwise track, check your front left first. It is likely to read the highest. If you own a torque wrench bring it with you and check your lugs after each run.

You might get hooked or it might be your one and only. Either way, relax and enjoy the event. I am sure you and your car will be fine. AND keep looking into your rearview mirror!!!

///AMG4EVER

OPM man! That was TRACK 101 right there! Thank you very much for taking the time to explain all this. I went through it twice to make sure I got the scoop.

To be honest, one of my goals is taking that speed-bug out of me in public streets and highways. I don't drink, but I'm no angel either. Tracks supposed to make street racing/speeding lame. So I hope this will make me take it easier out there.

I'm left-handed and I drive with both of my feet. Is this something instructors will point out to you? For me, driving with one foot is like throwing a baseball with your wrong hand...

dsC32

AMG: Give us a report about your 1st track experience.

AWDman

think he said event got pushed to next week.

good words opm.

fifth you are not familar with the ps2s construction and behavior......i run my ps2s at 37 psi on street now. if i had to do it over again i would start 40 psi cold for track. as i said i had sidewall wear on my 1st track day - my advice is run tire hard say 40 psi but observe pressure as soon as you come off track.

my yoke a048s are fine starting out 21 psi cold, massive stiff sidewalls. if only the compound was more sticky.