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      06-12-2008, 09:20 PM   #23
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Feel can mislead a lot of drivers. Since the springs and not the shocks control how a car sets, rest assured both sport and normal have the same amount of movement to them.

A lot of people think a car they have to fight feels fast. Usually its not but because they as the driver are busy they conclude the result was better.

This will be easy to test once we have data logs from the cars on a track.
That is not totaly true as the shock does contribute to the dynamic spring rate in cornering especially on a bumpy track which the majority of tracks in North America are.Beleive me as I have done lots of suspension testing on both racecars & streetcars in a previous timeframe and we have had enough variation in shocks that we could control how much suspension travel was being used without ever touching the springs,only shocks and settings.
Beleive me it is quite easy to see when the suspension is working at its best,if you have reference points that you know your RPM at those points to be able to compare to previous laps with a different setup.It comes with experiance and feel is a very large part of going fast.
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      06-12-2008, 09:29 PM   #24
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That is not totaly true as the shock does contribute to the dynamic spring rate in cornering especially on a bumpy track which the majority of tracks in North America are.
...
Beleive me it is quite easy to see when the suspension is working at its best,if you have reference points that you know your RPM at those points to be able to compare to previous laps with a different setup.It comes with experiance and feel is a very large part of going fast.
You said, more movement before the car takes a set. The set point for a car is determined by the springs, not the shocks. The shocks determine how a car transition and handles bumps, not where the suspension eventually settles.

I have seen a lot of very good drivers that were terrible at car setup. Feel is not a substitute for hard data. ideally you want both.

My expectation is the results (normal / sport) will vary with surface conditions.
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      06-12-2008, 10:14 PM   #25
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We can sit and argue about suspension setup theory for an awful long time:

Facts;
My tire setup is about 1" shorter overall height than my factory 19" setup with less stagger difference front to rear

The Toyo R888's are much less precise feeling tire than the PS2's that came on the car.They are a very good track tire however with extremly friendly breakaway and they they are very easy to bring back into the zone once you overdrive them.They heat up quite fast and only started to fall off after about 10 laps.

But on this one track that is fairly tight and that is fairly rough and I prefered the sport EDC setting and went about 2 seconds a lap quicker in the afternoon with more track & car familiarity than using the normal setting in my first couple of sessions.I was using my bike lap timer to keep an accurate track of my lap times.

Yes I would like to do some data logging but for myself in these conditions the sport setting was faster and much more controlable.
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      06-12-2008, 10:47 PM   #26
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We can sit and argue about suspension setup theory for an awful long time:
So you are opposed to talking about suspension theory in a thread about suspension settings?

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Facts;
My tire setup is about 1" shorter overall height than my factory 19" setup with less stagger difference front to rear

The Toyo R888's are much less precise feeling tire than the PS2's that came on the car.They are a very good track tire however with extremly friendly breakaway and they they are very easy to bring back into the zone once you overdrive them.They heat up quite fast and only started to fall off after about 10 laps.
Having driven on 888s before I didn't have the same feeling. What size tire & rim combo were you using?


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But on this one track that is fairly tight and that is fairly rough and I prefered the sport EDC setting and went about 2 seconds a lap quicker in the afternoon with more track & car familiarity than using the normal setting in my first couple of sessions.I was using my bike lap timer to keep an accurate track of my lap times.

Yes I would like to do some data logging but for myself in these conditions the sport setting was faster and much more controlable.
I highlighted the important part above. If you were still learning the car and track then we really cannot use the data. Too many factors changing at once.

My initial response to you was simply to point out that your perception of events (amount the car moved to take a set) was not in line with the real events (its the same sport or normal). For the purpose of showing how unreliable driver feel can often be.
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      06-12-2008, 11:05 PM   #27
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So you are opposed to talking about suspension theory in a thread about suspension settings? No because its my bedtime ,been up since 5.00am!


Having driven on 888s before I didn't have the same feeling. What size tire & rim combo were you using?

[b]255/35-18 on 8.5 265/35-18 on 9.5

What car did you use them on?




I highlighted the important part above. If you were still learning the car and track then we really cannot use the data. Too many factors changing at once.

My initial response to you was simply to point out that your perception of events (amount the car moved to take a set) was not in line with the real events (its the same sport or normal). For the purpose of showing how unreliable driver feel can often be.
I have been hired for testing in the past because of my feedback and ability to turn extremly consistant laps so I know I have the ability to discern what works in a track situation.

The fact that you cannot argue is that on this particular situation is that both the timer and SOP confirmed that the firmer setting was better ifor my needs!
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      06-12-2008, 11:12 PM   #28
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I have been hired for testing in the past because of my feedback and ability to turn extremly consistant laps so I know I have the ability to discern what works in a track situation.

The fact that you cannot argue is that on this particular situation is that both the timer and SOP confirmed that the firmer setting was better ifor my needs!
You said you were still learning the track. How can you seperate car setup from driver change under those conditions? Its normal to drop time as you learn a track even if nothing else changes. If you drove 3s faster but the car was 1s slower you wouldn't know based on timer alone.


I have run the 888s on two different E46s and an Elise. The Elise comunity uses them for street tires to replace the stock 048lts

[edit] The 255 on the 8.5" would be pinched quite a bit which would hurt response.
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      06-12-2008, 11:24 PM   #29
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You said you were still learning the track. How can you seperate car setup from driver change under those conditions? Its normal to drop time as you learn a track even if nothing else changes. If you drove 3s faster but the car was 1s slower you wouldn't know based on timer alone.
I think that by the end of my second session I had found most of my speed due to the car & track unfamilarity.I was playing with the EDC setiings and I cannot honestly tell you the lap time differences due to the settings as I was carrying students around with me on quite a few runs.I just know that I liked the car better on the sport setting.
I have run the 888s on two different E46s and an Elise. The Elise comunity uses them for street tires to replace the stock 048lts

[edit] The 255 on the 8.5" would be pinched quite a bit which would hurt response.
I would really like to have 9.5 & 10.5's on the car with this tire setup but the budget will not allow that right now.These wheels will be for my snow tire setup or that is what my wife has been told

Am I replacing Footie in your argumenitive world
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      06-12-2008, 11:29 PM   #30
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I would really like to have 9.5 & 10.5's on the car with this tire setup but the budget will not allow that right now.These wheels will be for my snow tire setup or that is what my wife has been told

Am I replacing Footie in your argumenitive world
Nope, you seem to have both driving skill and car knowledge leading to actually productive discussions.

I have a set of 9.5x18 for the front and rear for when my car gets here. I am curious how the front suspension deals with the extra grip of dot-r tires. i.e. will it use the full tread width or just roll over onto the outer half.

I'm running 275/35-18s on the 9.5" rims. (just 3 more weeks to go)
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      06-12-2008, 11:42 PM   #31
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Nope, you seem to have both driving skill and car knowledge leading to actually productive discussions.

I have a set of 9.5x18 for the front and rear for when my car gets here. I am curious how the front suspension deals with the extra grip of dot-r tires. i.e. will it use the full tread width or just roll over onto the outer half.

I'm running 275/35-18s on the 9.5" rims. (just 3 more weeks to go)
The front needs a lot more camber,which I am unwilling to do as I enjoy the normal street manners of this car so much.The rollover was not bad but the temps were quite a bit warmer at the outside of the tires.On my C5 Corvette I ran 315'/40 -17 all the way round on 11's and that was a great setup.I think the M3 would probally work oK also with a square setup but I do not have the time or money at this point to really start experimenting with different wheel & tire setups.I am moving in less than a week to another house that we have renovating for the last year.
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      06-12-2008, 11:45 PM   #32
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The front needs a lot more camber,which I am unwilling to do as I enjoy the normal street manners of this car so much.The rollover was not bad but the temps were quite a bit warmer at the outside of the tires.
I am going to try just sway bars. Since we cannot really add lots of camber witout other issues I figure that sway bars may help control the dynamic camber losses. i.e. keep the whole car from leaning over as much since the struts cannot deal with that well.

Also since they don't affect ride quality much it should have a minimal impact on street comfort.
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      06-12-2008, 11:52 PM   #33
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I am going to try just sway bars. Since we cannot really add lots of camber witout other issues I figure that sway bars may help control the dynamic camber losses. i.e. keep the whole car from leaning over as much since the struts cannot deal with that well.

Also since they don't affect ride quality much it should have a minimal impact on street comfort.
I am still awaiting the pics from the day,but the car does not seem to roll very much,especially on the sport setting

I am not a big fan of big bars on the road because any cars that I have done that to, the side to side motions become rather unbearable in normal use,but I am sure our roads are crap compared to yours.
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      06-13-2008, 11:57 AM   #34
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I Tried both the firmer settings on track and I found that the hardest setting(sport?) worked the best for myself.I found that in the normal setting the car was floaty over a 90-100 mph bumpy rise when turning at the limit and felt much more buttoned down with the firmest setting.That was probally the only place where there was a dramatic difference between the 2 and to be frank,I do not think there was much a difference between the settings elsewhere on the track speedwise but I did like the feel better on the sport setting.

I do not how you could spin one of these cars with MDM engaged as it really does kick in early and even with no stability system engaged I think you would have to have zero car control skills in order to loop it!You can get this car very sideways and have no problems catching it IMO.
I agree with your assessment on the EDC setting; however I do need more track time with this car to test Normal vs. Sport. Sport was the setting I felt more comfortable with as well; and I did feel more confident at speed and prior to turn in. I should add thogh, the Sport setting reminded me of my old e46M3 on GC coilovers, so this could aslo be a one of the reasons I felt more at ease with the setting as well.
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      06-13-2008, 01:53 PM   #35
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I agree with your assessment on the EDC setting; however I do need more track time with this car to test Normal vs. Sport. Sport was the setting I felt more comfortable with as well; and I did feel more confident at speed and prior to turn in. I should add thogh, the Sport setting reminded me of my old e46M3 on GC coilovers, so this could aslo be a one of the reasons I felt more at ease with the setting as well.

Some of you asked for my feedback prior to the track event...if you have not already seen the post, here it is:

http://www.m3post.com/forums/showthr...ghlight=laguna
I hope you realize you will be getting flamed by Enigma from now on
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      06-13-2008, 02:15 PM   #36
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I hope you realize you will be getting flamed by Enigma from now on
Why, he didn't say anything that was factually wrong.

I don't care if someone tells me they prefer sport, I suspect I will end up using it on some of the lots around here. Just don't tell me it makes the car lean less or squat/dive less, it doesn't

Transitional behavior != steady state behavior

You seem bitter that someone corrected your posts when you posted bad info.
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      06-13-2008, 02:22 PM   #37
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Why, he didn't say anything that was factually wrong.

I don't care if someone tells me they prefer sport, I suspect I will end up using it on some of the lots around here. Just don't tell me it makes the car lean less or squat/dive less, it doesn't

Transitional behavior != steady state behavior

You seem bitter that someone corrected your posts when you posted bad info.
I am only bitter when my posts are corrected with less than correct real world information.You do not even have your car yet!
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      06-13-2008, 02:40 PM   #38
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I am only bitter when my posts are corrected with less than correct real world information.You do not even have your car yet!
Do you need one to know that sport mode doesn't change the static spring rates?
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      06-13-2008, 03:05 PM   #39
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Do you need one to know that sport mode doesn't change the static spring rates?
I never said that as i was talking about dynamic spring rates which are a very different thing to static spring rates.While in motion a shock that has more compression damping will increase the dynamic (wheel)spring rate as the suspension is in motion being compressed as it will provide more resistance to the spring being compressed over its travel.A shock setup change can often result in what amount of wheel travel is being used in cornering or bumps.If you soften a shock in compression you will always use more wheel travel than a harder setup.Then we could start a discussion on the using bump rubbers as part of the springing package.
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      06-13-2008, 03:31 PM   #40
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I never said that as i was talking about dynamic spring rates which are a very different thing to static spring rates.While in motion a shock that has more compression damping will increase the dynamic (wheel)spring rate as the suspension is in motion being compressed as it will provide more resistance to the spring being compressed over its travel.A shock setup change can often result in what amount of wheel travel is being used in cornering or bumps.If you soften a shock in compression you will always use more wheel travel than a harder setup.Then we could start a discussion on the using bump rubbers as part of the springing package.
You are correct, the shocks will have an effect on how the car moves WHILE its taking a set. However,

You are wrong in implying that the shocks will change where the car takes its set. Unless you are playing games with mismatched compression and rebound on the shocks it will set the same way regardless if it gets there in a controled way or a sloppy way.

The part I highlighted is staight up WRONG. Take a picture of the car in a sustained sweeping turn and both the hard and soft shock car will be leaning the same. They will have the same wheel travel.

Now if you are driving along and suddenly yank the wheel, the way the car moves while taking its set will be different.

Shocks only have an effect on the suspension while the suspension is in motion. At a steady state they have no effect since their sole purpose is to provide resisitance to movement, not support weight.

Perhaps you are more like footie than I realized, ugh.
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      06-13-2008, 03:48 PM   #41
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You are correct, the shocks will have an effect on how the car moves WHILE its taking a set. However,

You are wrong in implying that the shocks will change where the car takes its set. Unless you are playing games with mismatched compression and rebound on the shocks it will set the same way regardless if it gets there in a controled way or a sloppy way.

The part I highlighted is staight up WRONG. Take a picture of the car in a sustained sweeping turn and both the hard and soft shock car will be leaning the same. They will have the same wheel travel.

Now if you are driving along and suddenly yank the wheel, the way the car moves while taking its set will be different.

Shocks only have an effect on the suspension while the suspension is in motion. At a steady state they have no effect since their sole purpose is to provide resisitance to movement, not support weight.

Perhaps you are more like footie than I realized, ugh.
Have you ever worked on a shaker rig? Well I have and learned an awful lot about the dynamics of suspension.Even in steady state cornering you still have suspension movement happening unless you are dealing with a high downforce car with extremly high spring rates.A totaly smooth corner does not exist in my world,but I forgot that I am dealing with somebody on the left coast and you guys invented it all!
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      06-13-2008, 03:56 PM   #42
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Have you ever worked on a shaker rig? Well I have and learned an awful lot about the dynamics of suspension.Even in steady state cornering you still have suspension movement happening unless you are dealing with a high downforce car with extremly high spring rates.A totaly smooth corner does not exist in my world,but I forgot that I am dealing with somebody on the left coast and you guys invented it all!
Worked on a shaking rig, no.

As to the surface question. Here is a pic from the location where the local BMW club runs their autocrosses.
http://www.alternaterealities.info/v...autox_hell.jpg

Laguna is pretty smooth now after all the work they did to it.

Thunderhill, not so much.

Reno, so bumpy I though I was going to break the car and had to go off line to look for smoother pavement.

Do you have pictures or in car video? If so put a level on them for your sport laps and normal laps. I'm willing to bet you won't see a difference in the lean of the car. (provided you were driving both laps at the limit).

[edit] I'm not a native left coaster. You are right though, they are nuts.
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      06-13-2008, 04:18 PM   #43
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Laguna is pretty smooth now after all the work they did to it.

Thunderhill, not so much.

Reno, so bumpy I though I was going to break the car and had to go off line to look for smoother pavement.

So are you suggesting Normal would be the preferred for rough track surfaces?

Will be headed to Infineon and Thunderhill over the next two months, will be interested to see how the EDC works on these two tracks.

I have a suspicion I may use Normal more at Thunderhill(long sweepers) and Sport at Infineon(technical slalom like turns)...who knows...we'll see.

Can say, that I did prefer Sport at Laguna....at least on that day
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      06-13-2008, 04:30 PM   #44
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In theory, yes.

In practice I cannot say yet. I am guessing for a place like Laguna or the autocross site I showed you woudl want sport mode. For reno I would bet on normal. The other, I have no idea.


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So are you suggesting Normal would be the preferred for rough track surfaces?

Will be headed to Infineon and Thunderhill over the next two months, will be interested to see how the EDC works on these two tracks.

I have a suspicion I may use Normal more at Thunderhill(long sweepers) and Sport at Infineon(technical slalom like turns)...who knows...we'll see.

Can say, that I did prefer Sport at Laguna....at least on that day

Curious to know, how does the compression and body lean look in these pics?

http://www.m3post.com/forums/showthread.php?t=147091
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