E90Post
 


E92 Lighting
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Suspension | Brakes | Chassis > STILL understeering at limit - there is more in the car I know it



Reply
 
Thread Tools Search this Thread
      04-15-2011, 12:23 AM   #23
zsapphire7
Colonel
 
zsapphire7's Avatar
 
Drives: 08 e92 M3
Join Date: Oct 2007
Location: SF Bay Area

Posts: 2,293
iTrader: (21)

Quote:
Originally Posted by DaFish View Post
lol... you crack me up man. I'll respond when I have a bit more time. Thank God you sugar coated it...
haha yes... Hack has a nack for sugar coating doesnt he ? but all that aside, what hes written down is absolutely right.

Hack, on a side note, if your suspension frequency/spring rates (front)are higher in this case, does that mean you can turn the steering wheel faster without experiencing this "understeer"?
zsapphire7 is offline   United_States
0
Reply With Quote
      04-15-2011, 09:52 AM   #24
The HACK
Garland Operator 7G
 
The HACK's Avatar
 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

Posts: 3,463
iTrader: (1)

Quote:
Originally Posted by zsapphire7 View Post
Hack, on a side note, if your suspension frequency/spring rates (front)are higher in this case, does that mean you can turn the steering wheel faster without experiencing this "understeer"?
Someone once accused me of typing out these long ss answers that doesn't technically answer anyone's question, so here it goes...


Yes.

My long and convoluted answer follows.

No it doesn't mean you can move your hands faster. It does mean that the rate of movement will need to be adjusted. Sometimes when you increase your wheel rate without matching damper rate, you may actually have to move your hands even SLOWER to prevent either end from losing grip. A better way to look at it is if you add more grip up front, you can potentially increase the rate of movement (but still not move your hands FAST). Another way to look at it is, you can start your turn-in later and turn in the wheel MORE in when you have more grip up front. But it still needs to move as slow as possible.

Which in turn introduces another issue in this complex equation. When you increase grip up front, and not increase grip in the rear, your vehicle can go from a understeer state in the specific situation you're trying to resolve, to oversteer if you move your hands TOO fast. So, like my typical answers, it's probably not going to really answer anything. At the end of my long winded post, my true answer to you is, IT DEPENDS.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
The HACK is online now  
0
Reply With Quote
      04-15-2011, 11:05 AM   #25
DaFish
2008 335i E92, Almost full mods
 
Drives: 2008 335i E92, Procede V5
Join Date: Mar 2009
Location: Ontario, Canada

Posts: 1,077
iTrader: (0)

Garage List
2008 335i Coupe  [3.00]
Quote:
Originally Posted by zsapphire7 View Post
haha yes... Hack has a nack for sugar coating doesnt he ? but all that aside, what hes written down is absolutely right.

Hack, on a side note, if your suspension frequency/spring rates (front)are higher in this case, does that mean you can turn the steering wheel faster without experiencing this "understeer"?
He certainly does... after reading it, I felt like I should be using crayons, driving a nerf pedal car and wearing a hat with a propeller on it....

I think he may have some sort of Tourettes Syndrome... lol

From his Avatar, no wonder he knows everything... he is old... maybe his son from his Avatar can help him with some proof reading...

Uh oh, I maybe getting a "Your not going to like this. " coming. Just kidding HACK - all good fun !!

There was lots of good stuff in there for sure on driving. Some assumptions I didn't feel were applicable though.

1) I was not accelerating in the turn, the turn was initiated, and I was on balance and on the line I wanted. Then at about 90 or 180 degrees in the constant radius turn it THEN overwhelmed the front and started to plow (I won't use the word understeer - because I maybe retarded).

This probably is classic fast in, slow out as he mentioned... BUT my original post and point was that I felt the CAR can do better - and it can. This was what I was hoping for feed back on, what MODS can I do so the nut behind the wheel can get higher G forces?

For example: before I did my mods the car plowed a lot more at a much lower speed. Since the mods, I can certainly go faster around corners now with better balance. I have made progress. I feel there is further progress that can be made and hence the reason for the post and what I put in it.

Quote:
Originally Posted by The HACK View Post
Starting from the most simple and most basic, 99.95% of "understeer" is human error.
Agreed, you can't take corners at 400 mph.... even someone as retarded as me can "get" this. But as stated above and proven on the skid pad and slalom course.... you can make mods to the car that will improve grip, and speed in these 2 tests and that translates into higher capacity/handling in this car all round - IMHO. I have proven this with the Dinan suspension mods listed in my SIG.

Quote:
Originally Posted by The HACK View Post
Once you fix that part, the rest of the .05% of understeer can be fixed in the following manner: Add grip to the end that looses grip first, or take away grip from the end that still has it. And then, you have to figure out if the understeer happens at corner entry, corner exit, under throttle and HOW MUCH under throttle. If you can pin point where and when it's understeering and how, then you have a shot at fixing it.
This is what my original post was about and what I am asking for: E90Pilot stated and proved on his car that all square rims/tires increases front grip, and may reduce rear grip - equalizing and balancing the grip where it is needed to round out the balance. I can just feel another lecture series coming on this statement, but this is how I relate to it... hang on, let me get my flame suit on - bring it on HACK....

What I also gained from this thread is that the strut bar won't assist on front grip - I thought it would keep the geometry in place more firmly on hard cornering assisting front grip on a staggered setup. I won't waste my money - and thank - unless this is not true.

I will explore all square setups on rims I like. The problem is, I LOVE the look of the car, the 19" and the "stagger" look. The car is just beautiful.

I also don't really want to spend another 5k on rims/tires. I paid cash for the car and I would prefer the 5k go toward savings for my next car in a few years - which will be expensive. That said, I want the best handling I can get now.
__________________
2008 335i E92 Black, Procede Rev 2.5 (11-1 map), BMS DCI, AR Catless DPs, AMS FMIC, Procede PWM Meth, Forge DVs, CDV delete, 230s w/ 235/265 Michelin PSS, Dinan S3 susp w/ front/rear M3 arms (4), Wavetrac LSD, Subframe bushings, Dinan Rear Sway, Rogue toe arms, Stoptech Slotted rotors, Stoptech Street pads w/ steel lines
DaFish is offline   Canada
0
Reply With Quote
      04-15-2011, 11:51 AM   #26
The HACK
Garland Operator 7G
 
The HACK's Avatar
 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

Posts: 3,463
iTrader: (1)

Quote:
Originally Posted by DaFish View Post
...I still don't get it...
Here's what you need to do. You need to take some high performance driving schools. Stat. You are still missing the majority of the concepts I'm trying to explain, and at this point you're definitely one of the cases where you're bright enough to think you understand the concepts, but without the actual application of the concepts, there's absolutely no way to connect the dots.

The two men in my avatar...The old dude is the greatest teacher of man in the history of sports. The younger dude is probably one of the best coaches in the country right now. If I'm EVER 1/10th the teachers they are, then I would have a very successful career in teaching. And I'm sure both of them will tell you that, in any sport, just as life, the number 1 thing you can improve upon on performance, is yourself. If you still haven't gotten that, no amount of dissertation from me is ever going make it all of a sudden make sense for you.

What I am going to say, one last time, and if this still doesn't make sense, I will gladly bow out of wasting my time here. The car still has a ton of grip. So much so that adding grip at this point is a pure waste, since you still haven't comprehend how to add grip up front with YOUR HANDS. If you come to grip with the fact that the slower you move your hands on turn-in, the higher your turn-in speed therefore the faster your speed through the turn and at exit...You will have at least understood why I kept telling you adding more grip isn't going to help you.*

And to E90Pilot's point...I've driven my fair share of E90s. There ARE ways to add more grip up front via the driver. Not disputing his point that these E90s will eventually understeer (just as I pointed out earlier, all cars will at some point), and not disputing that these car's limit to understeer comes much faster than last generations of BMWs...I am, however, pointing out that there are ways to cure that through the driver, and that's still far more effective than trying to cure it through mods. If you haven't trained yourself to actually squeeze the last bit of performance out of the stock system, say, at current skill you can only get about 3/10th of the actual speed upon entry, making it that much more capable...You're still only taking advantage of only 3/10th of the grip that you will add. Making yourself capable of taking that turn at 8/10th will be worth FAR MORE than adding another 3/10th via mods. But again, to his point, that these cars do understeer? Sure, adding some grip up front IS going to help the driver. Only if the driver is capable of taking advantage of that added grip.

*p.s.: I am getting way ahead of myself here. And I hope you read this last part before attempting to add speed through your hands...And this is why I say you absolutely need to take a couple of high performance driving schools before you proceed.

You can't move your hands slower and still make the turn without looking way ahead to figure out when and where you need to move your hands. High speed and high performance driving is COUNTER INTUITIVE. The only thing that makes perfect sense is the most basic of high performance driving. You need to look as far ahead as you can. For example, on a track I am easily looking 3-5 turns ahead, if not already thinking 3-5 turns ahead mentally, when I approach each turn. Because at the speeds you'll be capable of traveling, if you're thinking and looking at the turns you're approaching, you're already TOO LATE. But that visual skill comes from constant practice. And that visual skill will allow you to time your turn-in and hand motion and speed right to allow you to manually maximize grip all around. But none of this can be read and understood, from my experience. This stuff needs to be experienced, because without actually doing it RIGHT, you will never if you're doing it RIGHT.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
The HACK is online now  
0
Reply With Quote
      04-15-2011, 11:57 AM   #27
zsapphire7
Colonel
 
zsapphire7's Avatar
 
Drives: 08 e92 M3
Join Date: Oct 2007
Location: SF Bay Area

Posts: 2,293
iTrader: (21)

No worries about being convoluted . I think I forgot to add properly matched dampers. I kinda assumed increasing spring rates would go hand in hand with dampers but i forgot... thats not always true here!

but in a more concise way:
you can turn in as fast as your car can settle? (given same max grip)

Quote:
Originally Posted by The HACK View Post
Someone once accused me of typing out these long ss answers that doesn't technically answer anyone's question, so here it goes...


Yes.

My long and convoluted answer follows.

No it doesn't mean you can move your hands faster. It does mean that the rate of movement will need to be adjusted. Sometimes when you increase your wheel rate without matching damper rate, you may actually have to move your hands even SLOWER to prevent either end from losing grip. A better way to look at it is if you add more grip up front, you can potentially increase the rate of movement (but still not move your hands FAST). Another way to look at it is, you can start your turn-in later and turn in the wheel MORE in when you have more grip up front. But it still needs to move as slow as possible.

Which in turn introduces another issue in this complex equation. When you increase grip up front, and not increase grip in the rear, your vehicle can go from a understeer state in the specific situation you're trying to resolve, to oversteer if you move your hands TOO fast. So, like my typical answers, it's probably not going to really answer anything. At the end of my long winded post, my true answer to you is, IT DEPENDS.
zsapphire7 is offline   United_States
0
Reply With Quote
      04-15-2011, 12:06 PM   #28
zsapphire7
Colonel
 
zsapphire7's Avatar
 
Drives: 08 e92 M3
Join Date: Oct 2007
Location: SF Bay Area

Posts: 2,293
iTrader: (21)

Quote:
Originally Posted by The HACK View Post
You need to look as far ahead as you can. For example, on a track I am easily looking 3-5 turns ahead, if not already thinking 3-5 turns ahead mentally, when I approach each turn. Because at the speeds you'll be capable of traveling, if you're thinking and looking at the turns you're approaching, you're already TOO LATE. But that visual skill comes from constant practice. And that visual skill will allow you to time your turn-in and hand motion and speed right to allow you to manually maximize grip all around. But none of this can be read and understood, from my experience. This stuff needs to be experienced, because without actually doing it RIGHT, you will never if you're doing it RIGHT.
hah you know... I finally learned that I wasn't looking far ahead enough on my last trackday and it definately affects your line a lot!
zsapphire7 is offline   United_States
0
Reply With Quote
      04-15-2011, 03:48 PM   #29
ATB09
Enlisted Member
 
Drives: 335i
Join Date: Apr 2011
Location: MA

Posts: 32
iTrader: (0)

Hack,

What is your racing experience? Interesting post for sure. I probably would have just told him to 'add some rear bar'...lol. But understanding WHY the carvis doing what it is doing is surely the first step.
ATB09 is offline  
0
Reply With Quote
      04-15-2011, 09:28 PM   #30
The HACK
Garland Operator 7G
 
The HACK's Avatar
 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

Posts: 3,463
iTrader: (1)

Quote:
Originally Posted by ATB09 View Post
Hack,

What is your racing experience? Interesting post for sure. I probably would have just told him to 'add some rear bar'...lol. But understanding WHY the carvis doing what it is doing is surely the first step.
Does K-1 karting count?

I'm just an internet hack that can write slightly more elegantly than the next hack and pretend I know what I'm talking about by putting down random posters.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
The HACK is online now  
0
Reply With Quote
      04-15-2011, 09:56 PM   #31
e90pilot
Freight Dawg
 
e90pilot's Avatar
 
Drives: E90 325i
Join Date: Jul 2005
Location: Oakland, CA

Posts: 2,105
iTrader: (3)

Adding rear bar isn't as easy as just going a few clicks forward on the lever like in a nice racecar. It can be kinda expensive in the e90.
__________________
--Marcelo
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here! | Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors
e90pilot is offline   United_States
0
Reply With Quote
      04-15-2011, 10:33 PM   #32
ATB09
Enlisted Member
 
Drives: 335i
Join Date: Apr 2011
Location: MA

Posts: 32
iTrader: (0)

An adjustable rear bar (and end-links) would allow the OP to do some tweaking that could result in the handling characteristics he desires on the street.

But I'm still not sure if all we are trying to do here is make his car more balanced for off-ramp time-attack or if there are bigger issues at play.
ATB09 is offline  
0
Reply With Quote
      04-18-2011, 07:50 PM   #33
CT310
Private
 
Drives: 2002 Porsche 996
Join Date: Jul 2009
Location: SoCal

Posts: 74
iTrader: (1)

Quote:
Originally Posted by The HACK View Post
The old dude is the greatest teacher of man in the history of sports. The younger dude is probably one of the best coaches in the country right now. If I'm EVER 1/10th the teachers they are, then I would have a very successful career in teaching.
Great compliment for Mr. Howland, but if we keep losing the 1st round of the Tourney, he'll go the way of Lavin!

'Going Faster' is also a great read with a lot of pages devoted to understeer/oversteer. Completely agree that few of us will use the grip the cars have to offer in any of the set ups...but we'll spend the money like we're Red Bull Racing.
CT310 is offline  
0
Reply With Quote
      04-19-2011, 05:29 PM   #34
DaFish
2008 335i E92, Almost full mods
 
Drives: 2008 335i E92, Procede V5
Join Date: Mar 2009
Location: Ontario, Canada

Posts: 1,077
iTrader: (0)

Garage List
2008 335i Coupe  [3.00]
"Quote by the HACK on post #26:
Originally Posted by DaFish
...I still don't get it... "

I just re-read my posts... I never actually said this, nice trick though - I'll have to remember this one. I could put one in for you too... but I won't.

Quote:
Originally Posted by The HACK View Post
You need to take some high performance driving schools. Stat.
You are right, I am on it. One of my friends is an instructor -drives Turbo cup cars (he has a 944 turbo cup). I plan on having him instruct me at Mosport - in my car... I will start reading up on it too...

BUT, I think you are making a huge assumption on my driving skills as they are now. You didn't see my line, or how fast I was going... nothing but my description of what I was doing. Pretty thin.

Quote:
Originally Posted by The HACK View Post
You are still missing the majority of the concepts I'm trying to explain, and at this point you're definitely one of the cases where you're bright enough to think you understand the concepts, but without the actual application of the concepts, there's absolutely no way to connect the dots.
I am NOT missing the majority of the concepts. I get it already. Your descriptions are clear, concise and being "bright enough", I completely understand your additional condecending comments. I welcome NON condecending comments though.

I understand what understeer is. I understand fast in slow out. I understand moving hands too quickly.... I understand high performance driving instruction would allow me to perform better, and enjoy it more.

I also understand that stock, the car needed help to increase the handling to a point I would enjoy it more. I turned to Dinan and didn't try to "fix" this myself - and wreck a really nice car. It worked. The car defintely performs MUCH better than it was. It has more steering feel, quicker turn in and more balance - it is way more fun and capable.

Is there more performance to be had? YA there is.

I have the LSD, the matching rear dinan bar coming and the subframe bushings coming. I have already paid for those, so I can't wait to feel the difference with those.

Anyway, I am having a lot of fun doing this, and my pleasure at driving the car has gone up 10 fold.

I am looking into track days now in my area too - I'll try to line my instructor up.
__________________
2008 335i E92 Black, Procede Rev 2.5 (11-1 map), BMS DCI, AR Catless DPs, AMS FMIC, Procede PWM Meth, Forge DVs, CDV delete, 230s w/ 235/265 Michelin PSS, Dinan S3 susp w/ front/rear M3 arms (4), Wavetrac LSD, Subframe bushings, Dinan Rear Sway, Rogue toe arms, Stoptech Slotted rotors, Stoptech Street pads w/ steel lines

Last edited by DaFish; 04-19-2011 at 05:44 PM.
DaFish is offline   Canada
0
Reply With Quote
      04-19-2011, 06:50 PM   #35
cvc 22349a
Colonel
 
cvc 22349a's Avatar
 
Drives: 335i
Join Date: Sep 2007
Location: SF Bay

Posts: 2,231
iTrader: (8)

You're kinda taking a beating; maybe you should disengage him
I guess everyone on this forum should be a racecar driver
__________________
2007 E90 335i, TiAg, 6AT, ZPP, ZSP, ZCW, 6FL, HD
Quaife lsd, ETS fmic, GIAC s/w, Dinan intake/exhaust/oc, KW/M3 susp, Apex Arc 8, Mich PSS
cvc 22349a is offline   United_States
0
Reply With Quote
      04-19-2011, 07:06 PM   #36
e90pilot
Freight Dawg
 
e90pilot's Avatar
 
Drives: E90 325i
Join Date: Jul 2005
Location: Oakland, CA

Posts: 2,105
iTrader: (3)

Just to elaborate on my point a little, my E90 in stock form (I'm not sure if they changed it over the years) promoted bad driving habits. Yes you could manipulate it to get more front grip, but what you had to do was really drastic. If you hopped in a properly balanced car, you would spin it in the first turn doing what you needed to do in the E90. And it wasn't really the fact that it understeered that bothered me. It was how it understeered. Once the front lost grip it was like a switch. The car would go wide abruptly and would not easily recover. A touch too much gas on corner exit would send the front wide and lifting and backing out steering wouldn't get the nose back. The car has a "soft-lift" to prevent you from getting into a classic understeered to oversteer situation. And you can shut it off. The only thing you could do was brake. Or wait until the car finally lifted hopefully before you hit guard rail.

The way I have the car set up now, I can be subtle with steering, brake, and throttle inputs. That promotes good driving habits. It rewards being smooth. Being abrupt will cause it to understeer. In stock from you really had to monkey it around to do what you wanted which is bad if you're trying to learn.
__________________
--Marcelo
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here! | Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors

Last edited by e90pilot; 04-19-2011 at 07:16 PM.
e90pilot is offline   United_States
0
Reply With Quote
      04-19-2011, 08:01 PM   #37
MKE_M3
Lieutenant Colonel
 
MKE_M3's Avatar
 
Drives: 2011 e90 M3
Join Date: Feb 2009
Location: Milwaukee, WI

Posts: 1,679
iTrader: (0)

I would consider my car extremely balanced with stock sport tires, Dinan stage1, m3 lower control arms and LSD. The LSD really helps in control of over/understeer. I wouldn't change the balance of my car at all.

You may want to consider autocross. It is the best/cheapest way to learn how to balance your car at the limit. I think it is even more instructive that track time, at least it was for me.
__________________
MKE_M3 is offline   United_States
0
Reply With Quote
      04-19-2011, 08:45 PM   #38
jbass524
Captain
 
Drives: 1995 E36 M3
Join Date: Mar 2007
Location: Norcal

Posts: 983
iTrader: (2)

Realization will take place when you ride with someone who can do it better than you and can explain it in a way that makes sense to you.

Funny how someone wanted to know if Hack could drive. Good question but immaterial as what he is saying is true albeit with some frustration sprinkled throughout.

I've read many times "suspension tuning is a black art". I believe it. As Hack said (in so many words) there is no one setup for every driver. He used the words dynamic and variable.
jbass524 is offline  
0
Reply With Quote
      04-20-2011, 04:25 PM   #39
The HACK
Garland Operator 7G
 
The HACK's Avatar
 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

Posts: 3,463
iTrader: (1)

Quote:
Originally Posted by DaFish View Post
You are right, I am on it. One of my friends is an instructor -drives Turbo cup cars (he has a 944 turbo cup). I plan on having him instruct me at Mosport - in my car... I will start reading up on it too...

I am looking into track days now in my area too - I'll try to line my instructor up.
Good for you. That's the FIRST step in curing your understeer.

And one more thing. Book mark this page. After your first events or two at the track with a qualified instructor. Come back and re-read it. I'll accept your humble apologies then.

Trust me on this. Getting proper instructions on track is an eye opener, and without it, you won't understand. Really.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
The HACK is online now  
0
Reply With Quote
      04-20-2011, 05:33 PM   #40
MKE_M3
Lieutenant Colonel
 
MKE_M3's Avatar
 
Drives: 2011 e90 M3
Join Date: Feb 2009
Location: Milwaukee, WI

Posts: 1,679
iTrader: (0)

... don't forget to try autocrossing

It's kind of like reading Maxim (auto crossing) vs. nailing the model in Maxim (track time), but if the first experience you have is with Megan Fox. It will likely be a little awkward for 2 minutes and then your OH! face
__________________
MKE_M3 is offline   United_States
0
Reply With Quote
      04-22-2011, 03:53 PM   #41
spicish22
Private First Class
 
spicish22's Avatar
 
Drives: 2005 X3; 2010 335i M Sport
Join Date: Mar 2011
Location: PA

Posts: 100
iTrader: (1)

Garage List
posts like this is why i love reading the forums......

we should have to pay for such quality information!!
spicish22 is offline   United_States
0
Reply With Quote
      07-03-2011, 09:01 PM   #42
DaFish
2008 335i E92, Almost full mods
 
Drives: 2008 335i E92, Procede V5
Join Date: Mar 2009
Location: Ontario, Canada

Posts: 1,077
iTrader: (0)

Garage List
2008 335i Coupe  [3.00]
Well, I have had some more wheel time in.... and I am about to get my Wavetrac, subframe bushingins, Dinan rear bar and M3 upper and lower control arms in the rear next week.

The car is still not right at this point, the steering feels not as sharp as I feel it should be even with the front M3 arms, the Dinan springs. I am hoping the rear end work, sway and LSD will fix things but I fear the only solution will be the matched rubber all around.

Once I get set on the corner (mid corner - equally on the front and rear rubber), the car is balanced beautifully - the mods are a real treat then - lovin it. It is the initial entry in the corner that is the issue.

What I experience now isn't from driving at the limit either - it isn't driver error.. It is the general feel of the car going around a round-a-bout. Not even fast.. the front seems to be plowing (or fighting) a bit (even with my mods).

My question is: How do you know the front rubber is undersized? What qualities are apparent when a 3600 lbs car is driven with too small a front tire?

(lets see if we can avoid the driving lessons this time)
__________________
2008 335i E92 Black, Procede Rev 2.5 (11-1 map), BMS DCI, AR Catless DPs, AMS FMIC, Procede PWM Meth, Forge DVs, CDV delete, 230s w/ 235/265 Michelin PSS, Dinan S3 susp w/ front/rear M3 arms (4), Wavetrac LSD, Subframe bushings, Dinan Rear Sway, Rogue toe arms, Stoptech Slotted rotors, Stoptech Street pads w/ steel lines
DaFish is offline   Canada
0
Reply With Quote
      07-03-2011, 09:57 PM   #43
e90pilot
Freight Dawg
 
e90pilot's Avatar
 
Drives: E90 325i
Join Date: Jul 2005
Location: Oakland, CA

Posts: 2,105
iTrader: (3)

As far as the fronts being undersized it's not really a matter of weight but a combination of many things. I drove a Lotus Evora which has the same rubber as the 328 sport: 225/255 front rear tire width. While it's not ad heavy as 328 you would think it would understeer. Not the case at all. You can make it do pretty much whatever you want. Yes it does understeer under certain situations as it should; cars that oversteer everywhere can be fun, but are slow. What makes a car understeer excessively in my mind is how it responds to inputs that should make it oversteer or how it responds to corrections to understeer. What I couldn't stand about my car stock is the fact that you had to be so drastic just to get the rear to start working let alone slide. Also when it did understeer lifting and backing out steering seemed to do nothing. It's not really a matter of weight and tire width but how the car as a whole utilizes the tires. I drove a no-option 328 with 16" wheels and that thing didn't feel at all like the fronts were undersized and all its tires are smaller than the sport cars. In fact I found the non-sport car more fun than the sport.

Ok here come the driving lessons. I'm not a profestional driver but I have learned a few things from pro instructors. The Dinan suspension is very stiff up front. Along with the m3 arms it's even more stiff. What you are describing on turn-in is attributed to asking the front tires to do too much all at once. Simply put, you're turning the wheel too fast. A larger front tire will help, but even then, the Dinan setup rewards smooth driving. You need to load up the tire before you really ask it to corner. That's why it feels better mid-corner.
__________________
--Marcelo
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here! | Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors
e90pilot is offline   United_States
0
Reply With Quote
      07-03-2011, 10:30 PM   #44
DaFish
2008 335i E92, Almost full mods
 
Drives: 2008 335i E92, Procede V5
Join Date: Mar 2009
Location: Ontario, Canada

Posts: 1,077
iTrader: (0)

Garage List
2008 335i Coupe  [3.00]
Quote:
Originally Posted by e90pilot View Post
As far as the fronts being undersized it's not really a matter of weight but a combination of many things. I drove a Lotus Evora which has the same rubber as the 328 sport: 225/255 front rear tire width. While it's not ad heavy as 328 you would think it would understeer. Not the case at all. You can make it do pretty much whatever you want. Yes it does understeer under certain situations as it should; cars that oversteer everywhere can be fun, but are slow. What makes a car understeer excessively in my mind is how it responds to inputs that should make it oversteer or how it responds to corrections to understeer. What I couldn't stand about my car stock is the fact that you had to be so drastic just to get the rear to start working let alone slide. Also when it did understeer lifting and backing out steering seemed to do nothing. It's not really a matter of weight and tire width but how the car as a whole utilizes the tires. I drove a no-option 328 with 16" wheels and that thing didn't feel at all like the fronts were undersized and all its tires are smaller than the sport cars. In fact I found the non-sport car more fun than the sport.

Ok here come the driving lessons. I'm not a profestional driver but I have learned a few things from pro instructors. The Dinan suspension is very stiff up front. Along with the m3 arms it's even more stiff. What you are describing on turn-in is attributed to asking the front tires to do too much all at once. Simply put, you're turning the wheel too fast. A larger front tire will help, but even then, the Dinan setup rewards smooth driving. You need to load up the tire before you really ask it to corner. That's why it feels better mid-corner.
I had a loaner 323 with square tire setup.... it felt so balanced and just fun ! Like my car with the snows on for balance. Once I am set on corner, it is really nice.

I'll play with the quickness in the steering.
__________________
2008 335i E92 Black, Procede Rev 2.5 (11-1 map), BMS DCI, AR Catless DPs, AMS FMIC, Procede PWM Meth, Forge DVs, CDV delete, 230s w/ 235/265 Michelin PSS, Dinan S3 susp w/ front/rear M3 arms (4), Wavetrac LSD, Subframe bushings, Dinan Rear Sway, Rogue toe arms, Stoptech Slotted rotors, Stoptech Street pads w/ steel lines
DaFish is offline   Canada
0
Reply With Quote
Reply

Bookmarks

Tags
sway bars, understeer

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 06:10 PM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST