Dinan Stage 3 suspension

[ScullyD]

Anyone thinking about going this route, since if it has the same setup as the 335i, it will have the Dinan front camber plates, which should completely eliminate the understeer. I wouldn't be one to go Stage 3 on a non track car, but it my work wonders for this car specifically. Just wondering what people's thoughts are on Dinan's camber plates?

[mikeo]

Seems like Dinan Stage 3 uses a fixed camber plate yielding only 1/2 degree more negative camber. The price for the system also seems aggressive for what you get, i.e., a non-adjustable OE type suspension.

The Motorforce adjustable camber plates should offer more value for the money.

[larryn]

.. and also, I think that you could get adjustable Konis, adjustable sways, matched springs, and adjustable camber plates for less money.

Adjustable konis/matched springs for the e90 are $910
Adjustable UUC Sways are $425
Adjustable (high end) camber plates are $550

That totals $1885, and you have adjustability on everything...

14.4 Hrs is a asking a bit much for that too (at how much an hour???), as I could even do that install in about half that time.

I don't see the value in that package. Granted, I would need to get a 4 wheel alignment, but that's not going to eat up the other $600 difference.

[BMWeber]

Originally Posted by ScullyD

Anyone thinking about going this route, since if it has the same setup as the 335i, it will have the Dinan front camber plates, which should completely eliminate the understeer. I wouldn't be one to go Stage 3 on a non track car, but it my work wonders for this car specifically. Just wondering what people's thoughts are on Dinan's camber plates?

DINAN stage 3 is in now way a track setup. actually very little(really non) DINAN stuff is track oriented. stage 3 adds more parts it really doesn't make it any more unstreet able. DINAN makes some nice street oriented performance parts. if you want something on the aggressive side you can get setups from Turner motorsports/tc kline type places that will run circles around DINAN cars for half the price.

[PrematureApex]

Originally Posted by larryn

I don't see the value in that package. Granted, I would need to get a 4 wheel alignment, but that's not going to eat up the other $600 difference.

For someone that autox's and tracks, you should be getting into doing your own alignments.

Seriously, one of the best things I ever learned how to do.

Free, easy, and spot on. I've checked the string method on racks at 2 different shops too.

[larryn]

Originally Posted by PrematureApex

For someone that autox's and tracks, you should be getting into doing your own alignments.

Seriously, one of the best things I ever learned how to do.

Free, easy, and spot on. I've checked the string method on racks at 2 different shops too.

I do my own.

I have these right angle boards, clamps, and a pile of string that my wife always wants to throw away. :smile: I was talking about if others want to forego the $2467 and save on 14.4 hours of expensive labor by doing the majority of this themselves. they could save a couple thousand dollars pretty easily, and have better equipment.

[FreeBMW.net]

I remember reading the one of the swaybar installs (rear) i think was a 8+ hrs job due to the need to remove the rear subframe as the swaybar is mounted to the TOP of the subframe and cant be removed without dropping the subframe. so the 14 hr quote might not be far off for a whole deal

[Akirasoft]

Originally Posted by FreeBMW

I remember reading the one of the swaybar installs (rear) i think was a 8+ hrs job due to the need to remove the rear subframe as the swaybar is mounted to the TOP of the subframe and cant be removed without dropping the subframe. so the 14 hr quote might not be far off for a whole deal

UGH, that is a bit disheartening considering that is likely one of the few suspension mods positively necessary on this car. Stiffer rear bar and a bit wider rubber out front and see where that settles things.

But man, that is a lot of book hours and I'm not so sure about removing subframes in my garage... But hey, it can't be THAT hard can it.

[larryn]

That's what friends and tech sessions are for! On the E9X, you fdon;t have to remove the rear subframe, you have to lower it an inch or two, and you can unbolt, slide it out.

You should only need another couple of jackstands and a friend to do that.

I'll be attempting it, soon. Anybody around the S. Shore of Boston want to help, and make a tech session day of it.. Maybe get some detailing in, or a first oil change?

[WAY]

Why does everyone assume that changing the rear swaybar will improve the handling? Wouldn't doing that result in a car with less traction on real roads (ie. with bumps mid corners etc - at least here in Oz)? My preference would be dialling in more camber at the front with slightly wider tyres. Can someone think of what the potential issue that would bring for day to day road use?

[larryn]

I like to have adjustability in my cars, so tha tI can dial them in for different situations, but you are right that for real roads, depending on spring rates and damping, you could be making the rear a bit jumpy. That's why it's important to have that adjustability though.

[mikeo]

Originally Posted by WAY

Why does everyone assume that changing the rear swaybar will improve the handling? Wouldn't doing that result in a car with less traction on real roads (ie. with bumps mid corners etc - at least here in Oz)? My preference would be dialling in more camber at the front with slightly wider tyres. Can someone think of what the potential issue that would bring for day to day road use?

Agree, Way. Anti-roll bars have a side effect of taking away grip at the limit (in most cases--why a big bar up front on MacStrut BMWs has the opposite effect is another story). Don't ask me to explain why--if you are curious read one of the many good books on suspension dynamics. I experimented with a stiff rear bar on my E36 M3 trying to get the car to rotate better at autocrosses. And it did, but the compromise was reduced ability to get on the power early during corner exit.

I'll say it again, racers say to work on the end that is having the problem. In the case of understeer ADD grip to the front--don't REDUCE grip at the rear.

To answer your question on daily effect of your front grip changes you would experience more tendency to tramline, and unless you were running very little front toe-in, more tire inside wear. Of course, a lot less understeer is the benefit.

[WAY]

Thanks for the response guys. I am not concerned about tyre wear or tramlining. However I am very time poor, so will wait for one of you experts to work out the best suspension/camber angle/tyre width etc combination and just copy it. In terms of suspension, I have had really good experiences with bilstein shocks and eibach springs combo, and PSS9 coilovers. So I will likely stick to one of the two...

[BMWeber]

Originally Posted by larryn

That's what friends and tech sessions are for! On the E9X, you fdon;t have to remove the rear subframe, you have to lower it an inch or two, and you can unbolt, slide it out.

You should only need another couple of jackstands and a friend to do that.

I'll be attempting it, soon. Anybody around the S. Shore of Boston want to help, and make a tech session day of it.. Maybe get some detailing in, or a first oil change?

well Larry if you were up for heading west a little I have my own rotary two post lift. just like all the shops have

[Orb]

Originally Posted by mikeo

Agree, Way. Anti-roll bars have a side effect of taking away grip at the limit (in most cases--why a big bar up front on MacStrut BMWs has the opposite effect is another story). Don't ask me to explain why--if you are curious read one of the many good books on suspension dynamics. I experimented with a stiff rear bar on my E36 M3 trying to get the car to rotate better at autocrosses. And it did, but the compromise was reduced ability to get on the power early during corner exit.

I'll say it again, racers say to work on the end that is having the problem. In the case of understeer ADD grip to the front--don't REDUCE grip at the rear.

To answer your question on daily effect of your front grip changes you would experience more tendency to tramline, and unless you were running very little front toe-in, more tire inside wear. Of course, a lot less understeer is the benefit.

The anti roll bar in rear will take away grip on the inside wheel so if you have open diff you gone light them up a lot easier. The opposite is true to LSD so you better grip on the outside wheel. The other limiting factor is how complaint your overall suspension is so a soft spring and stiff bar can produce good results for grip. It is fairly subject and one thing is dependent on the other things.

Racer say to work on the end with a problem given a good setup. Change your setup like LSD then you need to throw it out. At some point you have to be logical what you change and 90% of the info out there is too generic and not correct.

Orb

[mikeo]

For suspension setups in autocross, with its very low-speed corners, there are two schools of thought regarding the relationship between stiff springs and stiff anti-roll (sway)bars. Autocross is a very specific type of environment, but does have correlation with road racing and spirited street driving. The many variables of suspension desigh and setup all work together of course, but I will only discuss the relationship of springs and swaybars as separate components in the suspension.

The group of autocrossers that favor very stiff springs and relativily softer swaybars (referred to as the 'California Method') believe that best results are achieved without using exceedingly stiff bars as a spring to compensate for softer true springs. There are many SCCA National Champs in this school of thought.

Those that prefer relativily soft springs (and their 'soft' is still usually firmer than OE) and huge swaybars to control body roll (known as the 'Denver Method') like the compliance of a more supple spring setup. National Solo Champs exist in this camp as well.

I've tried both methods on a auto-x/street E36 M3 over three seasons of regional competition and ultimately was most competitive with a blend of the two methods. However, my experience proved to me that the stiffer spring setup provided the most corner exit grip by far (and my springs were not that stiff - 440lbs/in front and 550lbs/in rear) with UUC swaybars set to medium in front and soft in the rear. When I used H&R Sport springs with the UUC bars set to full stiff front and rear, the car was more tentative in mid-corner and could not put down power in corner exit nearly as early. The stiffer spring/softer bar setup was faster overall.

The M3 did have a LSD and a stiff rear bar did take away rear grip, so I don't agree that big rear bars won't reduce rear grip on LSD equipped cars. Some of the 'California' racers use extremely stiff springs on E36/E46 cars in the range of 700 front, 1000 rear and do without a rear swaybar entirely. Those springs rates are race-only as they would beat you to death on the street.

[white911]

tires ==> springs ==> shocks ==> sway bars

If you are going to stick with RFTs remove tires from the equation, springs and shocks at the same time. Shocks must be able to control the spring. Sway bars for fine tuning. Big rear sway bar to compensate for understeer is not helping the front turn better, it is removing rear grip by removing independence. Generally use the lightest sway bar you can after you get the rest of the suspension set up.

[mikeo]

Originally Posted by white911

tires ==> springs ==> shocks ==> sway bars

If you are going to stick with RFTs remove tires from the equation, springs and shocks at the same time. Shocks must be able to control the spring. Sway bars for fine tuning. Big rear sway bar to compensate for understeer is not helping the front turn better, it is removing rear grip by removing independence. Generally use the lightest sway bar you can after you get the rest of the suspension set up.

Agree. :w00t:

[Orb]

Originally Posted by mikeo

For suspension setups in autocross, with its very low-speed corners, there are two schools of thought regarding the relationship between stiff springs and stiff anti-roll (sway)bars. Autocross is a very specific type of environment, but does have correlation with road racing and spirited street driving. The many variables of suspension desigh and setup all work together of course, but I will only discuss the relationship of springs and swaybars as separate components in the suspension.

The group of autocrossers that favor very stiff springs and relativily softer swaybars (referred to as the 'California Method') believe that best results are achieved without using exceedingly stiff bars as a spring to compensate for softer true springs. There are many SCCA National Champs in this school of thought.

Those that prefer relativily soft springs (and their 'soft' is still usually firmer than OE) and huge swaybars to control body roll (known as the 'Denver Method') like the compliance of a more supple spring setup. National Solo Champs exist in this camp as well.

I've tried both methods on a auto-x/street E36 M3 over three seasons of regional competition and ultimately was most competitive with a blend of the two methods. However, my experience proved to me that the stiffer spring setup provided the most corner exit grip by far (and my springs were not that stiff - 440lbs/in front and 550lbs/in rear) with UUC swaybars set to medium in front and soft in the rear. When I used H&R Sport springs with the UUC bars set to full stiff front and rear, the car was more tentative in mid-corner and could not put down power in corner exit nearly as early. The stiffer spring/softer bar setup was faster overall.

The M3 did have a LSD and a stiff rear bar did take away rear grip, so I don't agree that big rear bars won't reduce rear grip on LSD equipped cars. Some of the 'California' racers use extremely stiff springs on E36/E46 cars in the range of 700 front, 1000 rear and do without a rear swaybar entirely. Those springs rates are race-only as they would beat you to death on the street.

You mention a lot about setup but it doesn’t really support anything technical so why mention it. A LSD will completely change the loading and unloading of the rear suspension and it is really not that trivial. Like I said, stiffer bar will reduce the inside normal forces on the tire. However, the normal forces on the out side tire and increase substantially; hence, a major increase in grip. When you accelerate from a stop, the rear suspension compresses and the normal force increase on the rear wheels. The forces act the same as mentioned for an LSD outside wheel so I hope you can see this then you see how it react on the suspension as a whole.

For the other person, a sway bar doesn’t remove inpendency at all. It simply effectively increase the spring rate of the wheel that compresses while simultaneously unloads the opposing wheel. The member that is in torsion is not as ridged as you think it might be but stating that too much of sway bars are not good thing but neither is overly strong spring rates or terminal over steer. BTW, your suspension setup reasoning is highly flawed. You’re solving problems you have yet encounter and no competent suspension tuner/engineer will tell you different.

[atr_hugo]

So Orb - what's your suspension tuning background? Give us a baseline.

[slipkmaggot]

idk I think I'm too scared to mes around with internal stuff like that, just the Golf tee and radr detector hardwire are gonna be my first mods, and probbly my only ones for a long time :iono:

As a note in GTR@ the sim racing game i try messing around with the cr settings like springs and stuff and the car starts handeling horribly, sliding all over the place

[Orb]

Originally Posted by atr_hugo

So Orb - what's your suspension tuning background? Give us a baseline.

Mechanical Engineer....worked for Ford many eons ago in suspension design.

Orb