Spiffing up for the twisties..

[BimmerWill]

I took the car for a spirited drive the other day and took a well known mountain road in my area. I stayed within the speed limits of the road which was 45 but was determined to make it around the corners at that speed while staying well in my lane and controlled.

She handled the corners fairly well but I'm a little uneasy to push too hard due to the fact that the only non factory parts in regards to the suspension have been lowering it on fk coilovers, fcabs, and rtabs. The rtabs were replaced with urethane but that's the only real "upgrade" to the suspension besides the coils. Everything else is bone stock with 211k on them.

I rarely push the car but if I were to find myself with the desire to go 8/10 with it on some corners I'd like to have the peace of mind that it would hold. That being said I was able to get traction control to kick in on one corner and from what I could tell it was the outside drivers front tire that broke loose but was quickly corrected by the traction control so not entirely certain.

For you autocross gurus out there I was wondering where I should look at in regards to checking her out and ensuring everything is ship shape. Camber is set at - 1 degrees and I'd like to not mess with that too much to preserve tire life as this is my DD.

I've never ridden in one of our cars that is in top shape as far as handling goes so i only know from my own car what a BMW feels like in the corners. I know they are well known for handling them quite well but have this feeling in the back of my head that I've neglected to replace some needed parts over the years that could be having a negative effect on the cars handling. Any advice or help is appreciated I hope that my questions are not too vague.

Sent from S4

[Newjack]

Control arms. ZHP control arms specifically.


Everything after that is going to be about your coilovers. The stiffer the spring the less body roll through corners and essentially better grip.


Also just a tip. DSC on the e46 is a LOT more invasive than you might think. It will go off and correct your wheels even if the DSC light doesn't come on. If it starts blinking it's going into the "oh shit" mode.

Turn off DSC and ABS every once in a while and don't be stupid about it. But push your car a little bit. You will be surprised as to how much harder you can drive you car and still control it than you had realized.



Oh, and tires. Good tires make all the difference on a vehicle. As anyone here with dedicated summer and winter tires will attest. I'm running Michelin Pilot Sport A/S plus all seasons, and they were night and day compared to my contis. I can take a 90 degree turn hard enough to break a Honda in half.

[BimmerWill]

Now that is think about it I did replace my control arms before with the meyle replacements for my car. What's the major change in the zhp ones?

Yeah I've just got cheap tires on it right now. I really don't feel much body roll but I could be ignoring it or just not noticing it.

Sent from S4

[saace7]

With 211k I bet all your suspension bushing are shot. My car has 107k and I am in the process of getting all 17 rear bushings replaced. U can get a kit i think for about 350-500 bucks from turner. You can get upgraded anti roll bars to.

Like you said though, your not feeling much body roll, so that means your not pushing your car to its limits. Get better tires! You seem to be breaking grip to easily.

[BimmerWill]

I've crawled under and looked at them and they don't seem to be bad but that could be because they aren't under stress while sitting up on jacks. Bushings may be what I tackle next as my main bushing on the diff is definitely shot.

Sent from S4

[M0nk3y]

Control arms. ZHP control arms specifically.


Everything after that is going to be about your coilovers. The stiffer the spring the less body roll through corners and essentially better grip.


Also just a tip. DSC on the e46 is a LOT more invasive than you might think. It will go off and correct your wheels even if the DSC light doesn't come on. If it starts blinking it's going into the "oh shit" mode.

Turn off DSC and ABS every once in a while and don't be stupid about it. But push your car a little bit. You will be surprised as to how much harder you can drive you car and still control it than you had realized.



Oh, and tires. Good tires make all the difference on a vehicle. As anyone here with dedicated summer and winter tires will attest. I'm running Michelin Pilot Sport A/S plus all seasons, and they were night and day compared to my contis. I can take a 90 degree turn hard enough to break a Honda in half.

I don't agree with the spring rate statement at all.

With your statement, you imply that throwing on 1000 lb springs will help you corner better than say, 400 lb

This is completely false.

You need weight transfer for grip. The factor is now determined by how much

The money is in the dampers, not the springs. You need to CONTROL your body roll to effectively load and unload your tires.

Single adjustable, and more expensive double adjustable are key if you want to dial in your car. You'd be amazed at how a click in adjustments can change the character of a car.

As well, I will never turn of ABS. You're asking yourself to lock up wheels and go off the road.

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[saace7]

I've crawled under and looked at them and they don't seem to be bad but that could be because they aren't under stress while sitting up on jacks. Bushings may be what I tackle next as my main bushing on the diff is definitely shot.

Sent from S4

Yea I have a split going through the middle of one of my Diff bushings. This is what pushed me to get it changed at first. Once I spoke with my indy and he recommended if I wanted to change that one then I might as well change them all while the rear end is pulled out. Ya he'll get a little extra buck but personally I know it will be completely worth it in the end. I bought my car used at around 100k miles with original shocks.. So the bushings got a little extra abuse.

[BimmerWill]

I don't agree with the spring rate statement at all.

With your statement, you imply that throwing on 1000 lb springs will help you corner better than say, 400 lb

This is completely false.

You need weight transfer for grip. The factor is now determined by how much

The money is in the dampers, not the springs. You need to CONTROL your body roll to effectively load and unload your tires.

Single adjustable, and more expensive double adjustable are key if you want to dial in your car. You'd be amazed at how a click in adjustments can change the character of a car.

As well, I will never turn of ABS. You're asking yourself to lock up wheels and go off the road.

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I see what your saying. Unfortunately I went with non adjustable dampening when I bought my coilovers and don't really have a desire to completely change out the suspension again so was hoping to make do with what I already have.

Sent from S4

[Katu]

Turn off DSC and ABS every once in a while and don't be stupid about it. But push your car a little bit. You will be surprised as to how much harder you can drive you car and still control it than you had realized.

I think you mean DSC and TC?


As well, I will never turn of ABS. You're asking yourself to lock up wheels and go off the road.

Does the Z4M have a similar system to the E46's DSC/TC (single push/push and hold)? If so, do you turn both off for autocross? So far I've only disabled the DSC but never both systems.

[M0nk3y]

I see what your saying. Unfortunately I went with non adjustable dampening when I bought my coilovers and don't really have a desire to completely change out the suspension again so was hoping to make do with what I already have.

Sent from S4

And there is nothing wrong with those kits. The damper is designed with the spring rate in mind. Don't change your spring rate because the damper will fail.


I think you mean DSC and TC?



Does the Z4M have a similar system to the E46's DSC/TC (single push/push and hold)? If so, do you turn both off for autocross? So far I've only disabled the DSC but never both systems.

Kinda.

Our DSC on is the E46 Ms track mode. That is DSC pressed once.

There is no press and hold with our cars. You press the DSC once and everything is disabled.

So I run my car with DSC and TC off at autocross and track. DSC is too intrusive.

Helps rotate the rear around and keep on the throttle. Of course an LSD helps here as well.

This video shows it pretty well how you can use the throttle to get around a corner (At the end of the slalom and crossing over the road into the braking zone with the hard right hander especially), and how if you push too much it'll bite you in the butt.


http://www.youtube.com/watch?v=QoXqTzrCx2g

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[Newjack]

I don't agree with the spring rate statement at all.

With your statement, you imply that throwing on 1000 lb springs will help you corner better than say, 400 lb

This is completely false.

You need weight transfer for grip. The factor is now determined by how much

The money is in the dampers, not the springs. You need to CONTROL your body roll to effectively load and unload your tires.

Single adjustable, and more expensive double adjustable are key if you want to dial in your car. You'd be amazed at how a click in adjustments can change the character of a car.

As well, I will never turn of ABS. You're asking yourself to lock up wheels and go off the road.

Sent from my XT907 using Tapatalk 2




OK let me rephrase my statement. Stiffer springs, combined with shocks that are meant to be used with those springs, along with stiffer sway bars will make a large improvement in your overall cornering capabilities. It's not just the springs per say that give you better handling. It's the entire suspension working together that helps.


As for turning off ABS. on the E46, at least the ZHP, you can't completely turn off DSC without turning off ABS as well. 1 press of the DSC button lets you get a little stupid with the traction before DSC will kick in. Holding the button down for 5 or 10 seconds will completely turn it off, when you do this ABS turns off as well.

[Katu]

As for turning off ABS. on the E46, at least the ZHP, you can't completely turn off DSC without turning off ABS as well. 1 press of the DSC button lets you get a little stupid with the traction before DSC will kick in. Holding the button down for 5 or 10 seconds will completely turn it off, when you do this ABS turns off as well.

I agree with everything above except the part about it disabling ABS as well, I have never read that anywhere.

After a bit of googling I found the following:

http://www.bmwtech.ru/pdf/e46/ST034/13%20P1%20Traction%20and%20Stability%20Control%20I nternet.pdf

Short press Only
Only the yaw control of the DSC is deactivated. The ADB and DBC functions remain active. A higher slip ratio is allowed up to 42 mph for the purpose of improving traction in slippery conditions. ASC uses different thresholds.
DSC light illuminated

Long press
All ASC, ADB, DSC, GMR (yaw control) and DBC control functions are deactivated. Used for service and use on dynamometers.
DSC light and brake warning light (yellow ABL) illuminated.

[Katu]

Our DSC on is the E46 Ms track mode. That is DSC pressed once.

There is no press and hold with our cars. You press the DSC once and everything is disabled.

So I run my car with DSC and TC off at autocross and track. DSC is too intrusive.

Helps rotate the rear around and keep on the throttle. Of course an LSD helps here as well.

This video shows it pretty well how you can use the throttle to get around a corner (At the end of the slalom and crossing over the road into the braking zone with the hard right hander especially), and how if you push too much it'll bite you in the butt.

Great information and video, thank you!

Have you heard of people disabling DSC but keeping the TC (push & hold) active because E46 non-m's don't have LSDs?

[M0nk3y]

I agree with everything above except the part about it disabling ABS as well, I have never read that anywhere.

After a bit of googling I found the following:

http://www.bmwtech.ru/pdf/e46/ST034/13%20P1%20Traction%20and%20Stability%20Control%20I nternet.pdf

Short press Only
Only the yaw control of the DSC is deactivated. The ADB and DBC functions remain active. A higher slip ratio is allowed up to 42 mph for the purpose of improving traction in slippery conditions. ASC uses different thresholds.
DSC light illuminated

Long press
All ASC, ADB, DSC, GMR (yaw control) and DBC control functions are deactivated. Used for service and use on dynamometers.
DSC light and brake warning light (yellow ABL) illuminated.

+1. This is what I know.


Great information and video, thank you!

Have you heard of people disabling DSC but keeping the TC (push & hold) active because E46 non-m's don't have LSDs?

No, most people turn it off regardless. If they are in a turn they'd rather have a wheel spin and keep power going instead of throttling the engine and bogging it down

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[Newjack]

I agree with everything above except the part about it disabling ABS as well, I have never read that anywhere.

After a bit of googling I found the following:

http://www.bmwtech.ru/pdf/e46/ST034/13%20P1%20Traction%20and%20Stability%20Control%20I nternet.pdf

Short press Only
Only the yaw control of the DSC is deactivated. The ADB and DBC functions remain active. A higher slip ratio is allowed up to 42 mph for the purpose of improving traction in slippery conditions. ASC uses different thresholds.
DSC light illuminated

Long press
All ASC, ADB, DSC, GMR (yaw control) and DBC control functions are deactivated. Used for service and use on dynamometers.
DSC light and brake warning light (yellow ABL) illuminated.

So even though the ABS light is illuminated yellow, it is still working? In just figured it was off since it lit up.

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[derbo]

So even though the ABS light is illuminated yellow, it is still working? In just figured it was off since it lit up.

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Holding the DSC button till the parking brake light on the cluster turns yellow will fully disable DSC. This has nothing to do with disable ABS. You cannot disable ABS as simple as a button.

[Newjack]

Holding the DSC button till the parking brake light on the cluster turns yellow will fully disable DSC. This has nothing to do with disable ABS. You cannot disable ABS as simple as a button.

Ok. I guess the ABS light lighting up yellow is solely an indicator that DSC is fully off. I always just assumed that ABS was off.

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[LivesNearCostco]

And AutoX, some track days, and skid pad practice! Not sure if it's better to leave it on for wet track days... thoughts?



Long press
All ASC, ADB, DSC, GMR (yaw control) and DBC control functions are deactivated. Used for service and use on dynamometers.
DSC light and brake warning light (yellow ABL) illuminated.

[derbo]

But back on topic,

With your setup with no adjustability for dampening you can focus also on performance tires. My pilot sports are wonderful but my star spec tires are on another level of grip.


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[M0nk3y]

But back on topic,

With your setup with no adjustability for dampening you can focus also on performance tires. My pilot sports are wonderful but my star spec tires are on another level of grip.


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Yea. Star Spec ZIIs will have a stiffer sidewall and much, much more grip.

I'm not sold on the new tread design, and I'm still sold on my Hankook RS3s. I'm down to the wear bars and they are still fast, and keep on getting faster

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[derbo]

The re11 tires were awesome


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