My eyes are tired from reading books and going over old notes, so I am turning to you guys :)

What can I change to (in theory) make my E36 turn in better? When I drive and NSX, S2000, 911, etc one of the most outstanding things I notice is that the turn in feels much more presice, quick and accurate than my E36. I already have ALL the correct hardware, so maybe it is a set-up issue?
I am wondering about playing with the adjustment on my Koni SA's. Which way should I go on either end? I think I need to soften the rebound on the front? Any other ideas?

Thanks!

hmm sounds interesting....let hear so tips/advice...........

Two words: Steering Ratio

The M3 has the slowest steering of any car I've owned to date. My '98 Z28, '91 Integra, '87 Z28, and even my '79 Mercury Zephyr had quicker steering.

My old man has a 996 TT and it has extremely quick steering, making it feel like a go kart in comparison to my M3.

Using the stiffest sidewall tire you can find will help (I ran Hoosiers for the first time at my last event - unbelieveable turn in), but I think that the slow steering makes the car 'feel' like it has a sluggish turn in when in fact, it does very well.

I really wish there was a fix to this, as it is my one major complaint about an otherwise brilliant car.

Chris

Originally posted by rhl
I already have ALL the correct hardware, so maybe it is a set-up issue? I am wondering about playing with the adjustment on my Koni SA's. Which way should I go on either end? I think I need to soften the rebound on the front? Any other ideas?

First, what do you mean when you say you have all the correct hardware? Camber plates? Adj. front swaybar?

The thing I would recommend is to check the front alignment. If you have camber plates give yourself some more negative camber. Otherwise, a little toe-out can really help turn in...unfortunately, toe out will also wear the insides of your tires and cause tracking problems on the highway.

A good front swaybar can also help.

Also, what tires are you running (size, brand, type)

While I agree that steering ratio will effect the 'Quick' aspect of your quandry, it does not account for the 'Precise' and 'Accurate' portion of your quest.

First, you say you have all the correct hardware. Care to elaborate?

Things to look at:

1. Camber. More negative camber helps turn-in grip. Also looking at bumpsteer and the amount of camber you gain or lose during turning will effect your grip and accuracy.

2. Track. A wider track helps with turn in.

3. Toe. Toe-out helps a car turn in faster. It also eats the livin' hell out of your tires if you go too agressive. Zero toe is good for straight line stability (as is some toe-in).

4. Spring rates. Too high or too low a spring rate (f/r) can negatively effect turn in (oversteer / understeer).

5. Dampers - too much damper / not enough damper (see #4)

6. Driving style - too agressive... understeer.

7. Sway bars - too big / small (see #4)

Usually, a good (re: agressive) alignment will correct for most of your issues on a stock car.

When you start modifying things like springs, shocks & swaybars, then you have to start asking others and experimenting on your own to find out what works. No two combinations work the same.

My advice. Try some additional negative camber and some toe-out.

If understeer in, then snaps to oversteer on power application:

Front springs too soft
Front sway too soft
Too little bump

Also, could be:

Too much front toe-in
Too much castor

Use front spacers to widen track. Also, use tires with stiff sidewall. My new S03s have better turn-in than my old Pirellis. Could also be because I went from 235s to 255s.

Jay

Originally posted by negcamber
First, what do you mean when you say you have all the correct hardware? Camber plates? Adj. front swaybar?

Also, what tires are you running (size, brand, type)


Lots of camber (-2.8), zero toe, RD sway bars, 450# springs, 235 Kumho V700's, Koni SA's, etc. It isn't so much a corner entry understeer issue, but more a feeling that the car just doesn't bite and turn like the other cars I mentioned. No boubt it is partly an inherent E36 thing.

I have to agree with Cannon, I think the steering ratio play a large part in the 'feel' on the turn in. I am quite sure that different years and models of E36s had different ratio racks. Does anyone know?

RHL

Just having hardware won't improve crap, as mentioned earlier spend some time tuning all the adjustable stuff. Turn-in feel and steering ratio are two different things, IMHO.


///badmonkey

Here's a list of steering racks that i saved from a post on Suzy's E36M3 e-mail list...

Vehicle --- Ratio --- Lock-to-lock
1995 M3 --- 15.4:1-19.8:1 --- 3.0
1996 M3 --- variable (TBD) --- (TBD)
1997 M3 --- 15.6:1* --- (ND)
1998 M3 --- 15.6:1* --- (ND)
1999 M3 --- 17.8:1* --- 3.2
95 325i/is --- 16.8 --- 3.4
96,97 328i/is --- 16.8:1 --- 3.4
1998 328i/is --- 15.4:1 --- 3.2
1999 328i/is --- 15.4:1 --- 3.4
*variable ratio; figure given is mean ratio

Don't know about the validity of this list, but maybe it will help.

Originally posted by badmonkey
Just having hardware won't improve crap, as mentioned earlier spend some time tuning all the adjustable stuff. Turn-in feel and steering ratio are two different things, IMHO.



Uh huh, I know that. I have spent the last few years messing with these set ups and I am just searching to see if anyone has discovered something I haven't :)

Thanks,
RHL

Rob, have you had your car corner balanced? It may be that weight transitioning is what is making the car feel imprecise. I had this issue with my GC setup and street tires. I have not actually balanced the car with scales yet, because I am adding adjustable camber plates, but I did follow some advice from Jay and set the ride height at his recommendations. This helped turn in and precision immensely.

In addition to John's list, the x brace isn't felt a lot all by itself, but it does make those other big ticket items (negative camber, etc) work much better.

Here's another one to add to the fire --

I can tell a tremendous difference in turn in in my 318ti vs. my '97 M3, until recently the only major difference between the two was the amount of caster; that being the 318ti had stock measurements (not nearly as much) compared to the M3's caster-adding stock offset strut hats.

So less caster will make turn-in a lot faster, I suppose at the expense of high speed stability. I just installed adjustable camber plates on the 318ti so I'll have some adjustment to play with, but so far I can't think of any good reasons to increase it. :dunno

Thoughts on that? :devillook

Originally posted by rhl
So it looks like the '99 M3 rack might be the one to have? Can anyone else confirm this?

RHL

If you mean the 17.6 for a '99 vs. the 15.6 for a '97, then you would want the '97 rack. Lower number is faster steering. Some Corvette's have a 12:1 ratio, and possibly lower. I don't know if those numbers are valid or not, just that you want a lower number for faster steering.

Chris

Originally posted by Kos-motate139
So less caster will make turn-in a lot faster, I suppose at the expense of high speed stability. I just installed adjustable camber plates on the 318ti so I'll have some adjustment to play with, but so far I can't think of any good reasons to increase it. :dunno Thoughts on that? :devillook

I'm not up to speed on caster on E36s.... but on Mustangs, you want as much caster as you can get (because the front geometry sucks donkey nuts!). So... on my 86GT, the plates are all the way back to the firewall (max caster) and all the way in to the motor (max camber) with a smidgen of toe-out. Car now corners very well.

Anyone? Bueller?

John

PS- I'm still living with the Mustang.... haven't completely gone to the M3 side yet.

Originally posted by rhl
I have to agree with Cannon, I think the steering ratio play a large part in the 'feel' on the turn in.

I think you contradicted yourself earlier in that you cited the NSX as an example of a car with crisper turn-in, yet it has a MUCH slower steering ratio than an E36 M3. What the former does have is factory-spec toe out and specially designed, corner specific tires. As Badmonkey stated, turn-in and steering ratio are two different things. BTW, if you like quick steering ratio and decent turn-in, try a Viper GTS ACR. Pain to live with but fun to drive at the track.

Originally posted by Number9
I think you contradicted yourself earlier in that you cited the NSX as an example of a car with crisper turn-in, yet it has a MUCH slower steering ratio than an E36 M3. What the former does have is factory-spec toe out and specially designed, corner specific tires. As Badmonkey stated, turn-in and steering ratio are two different things. BTW, if you like quick steering ratio and decent turn-in, try a Viper GTS ACR. Pain to live with but fun to drive at the track.

Hmmm, I guess you busted me :D I better rethink this. I guess what I really notice when tracking an NSX is that it is much closer to having what I call "razor sharp precision". I can really aim the car and hit where I want to be inch by inch. The E36 really lacks this. Obviously the cars are totally different, the NSX has a low polar moment, etc, but here must be a way to make the E36 better. Yeah, yeah I know the M3 has been voted the best handling car and we all regularly beat NSX's at the track, but that doesn't mean they feel as good...

RHL

I can really aim the car and hit where I want to be inch by inch. The E36 really lacks this.

Speak for yourself RHL, maybe YOUR E36 lacks this ;) I have driven several NSXs and my M has the turn-in they have. It lacks a bit of feel but with my setup on r-comps, I can put the car where ever I want with very fast turn-in.

i can relate to the thread author. i've been driving my modded e36 for a while and every now and then i miss my old Rx7 turbo II or Miata b/c the steering just felt so right.

while the m3 handles extremely well, other cars namely the Porsche 911, NSX, Miata and RX7 (2nd and 3rd gen) have *REALLY* nice steering feel and turn-in characteristics. these cars are famous for their *steering feel*.

its really hard to duplicate, but maybe try a momo wheel to make it *feel* a little better. it sounds like you know how to set up your suspension already so i won't comment on that. it does make a difference having a steering wheel that has less inertia from the weight of air bag.

another thing i do when setting up my kart for racing is raise/lower the front end. it definitely bites a little better resulting turns in quicker turn in - provided my weight is correctly distributed on the chassis. maybe you can try scaling the car and see where things are...

good luck.

Originally posted by alberto_mg
i can relate to the thread author. i've been driving my modded e36 for a while and every now and then i miss my old Rx7 turbo II or Miata b/c the steering just felt so right.


Thank you!!!! Many cars out there do feel "just right", but IMHO the E36 is a bit lacking in the steering feel and turn-in. The European motoring press has made many negative comments about the steering feel/feedback of the E36 M3, but for some reason the N.A. guys love it.

You bring up an interesting point with ride heights. Raising one end of the car puts more weight on the higher end. Which direction do you think would help with turn-in feel?

Anyway, obviously I love the car and I know it handles amazingly well, I just wish I could make the steering feel more like a 911, or the like. BTW, I do have an aftermarket steering wheel.

Thanks,
RHL

Here is the short list of things to do that I have not seen listed.

1) BMW x-brace

2) Control arm bushings. The 96+ bushings suck nutz, but the 95 ones are a bit better (stiffer). Poly ones from BimmerWorld are better, next level are the Delrin ones (I have these), and the next is the sperical bearings from Ground Control. If you still have the stock CA bushings, then this is the first place you should start. Turn in response will go from somewhat numb to insane...

3) Caster, yes, more is better from what I am told, although I run less than most due to the orientation of my CA bushings. I sometimes wonder how is really necesarry on a fully tracked car with limited roll induced suspension travel.

4) Ride height (rake). BMW's experience better turn in with the front ride hieght slightly higher compared to the rear. Yes - this is true!

5) Springs - I used some nascar technology on my progressive rate springs (spring rubbers). You may notice the some H&R aftermarket springs come with a clear thin hose wrapped around some of the coils. I did this but a bit more extreme - got some black rubber reinforced hose from Lowe's and fed it onto the spring where the 'dead' coils are (about 1 full turn). This makes the first few coils bind quicker, leading to a higher initial spring rate.

6) Strut tower brace - some people debate about thier effectiveness, but go ahead and throw one in if you haven't already.

Don't forget the pink struts!!!

Originally posted by melmyers12

3) Caster, yes, more is better from what I am told, although I run less than most due to the orientation of my CA bushings. I sometimes wonder how is really necesarry on a fully tracked car with limited roll induced suspension travel.

I meant something more to the effect of. "limited steering angle turning" i.e. faster corners. I would think caster would be more inportant on an autocross car than a car set up for a high speed road course. There are only a few tracks in this country that I know of that have a 2nd gear corner for instance.

-Mel

p.s. - the pink struts do seem to help ;)

Originally posted by badmonkey
Don't forget the pink struts!!!

Sounds like badmonkey has been peeking under Mel's chassis. :stickoutt

After having extensively driven the finest US market NSX (Limited Edition Zanardi) and the top finishing BMW in the 2K One-Lap, my OPINION (only) is this: the Zanardi has much better feel, in part due to its non-power assisted steering and its great suspension setup. The Dinan S3 M3, with similar boosted power, also handles great, but feels a bit numb in comparison. The M3 steering is overboosted (and don't get me started on the E46). The NSX has no boost and the other, lesser NSXen have electric boost that cut out at higher (track) speed. Handling is an unrigorous term and has lots of components, but both M3s and NSXen handle well. The Dinan S3 favors tight, technical tracks and NSXen like the faster ones. YMMV.

Originally posted by Number9
After having extensively driven the finest US market NSX (Limited Edition Zanardi) and the top finishing BMW in the 2K One-Lap, my OPINION (only) is this: the Zanardi has much better feel, in part due to its non-power assisted steering and its great suspension setup. The Dinan S3 M3, with similar boosted power, also handles great, but feels a bit numb in comparison. The M3 steering is overboosted (and don't get me started on the E46). The NSX has no boost and the other, lesser NSXen have electric boost that cut out at higher (track) speed. Handling is an unrigorous term and has lots of components, but both M3s and NSXen handle well. The Dinan S3 favors tight, technical tracks and NSXen like the faster ones. YMMV.

Of course Dinan does only sell street suspensions... maybe if the car had a better suspension it would have placedhigher in One lap?

Originally posted by melmyers12
Of course Dinan does only sell street suspensions... maybe if the car had a better suspension it would have placedhigher in One lap?

I'm sure you know it wasn't running a street suspension then, though it is now, after having been relegated to commuter car duty where it belongs. And both it and my wife's stock 95 M3 have been less reliable than the Honda car to boot...

Lots and lots of caster... (to a point of course)

caster makes your wheels want to flop over at initial turn in. Running zero toe with the most caster will get you quicker turn-in. Although I would not go so far as to put offset c/a bushings in a 96+, you might run into rubbing issues with that setup.

mike

Originally posted by yMike
Lots and lots of caster... (to a point of course)
... Although I would not go so far as to put offset c/a bushings in a 96+, you might run into rubbing issues with that setup.

mike

I do have a '96> suspension with offset bushings :) No rubbing yet...

RHL

Really... =) now I want to do that too!

Can you give me specifics as far as wheel width, offset, and whether or not you're running spacers, etc. I want the offset ones because they are solid. Thanks

Mike

Well, this goes back to the caster issue I was wondering about earlier...

Less caster = faster turn in

Right? Can anyone refute this with hard data? The vast majority of my experience with suspension geometry comes from 2 wheelers, but the same concept should be true...unless I'm missing something.

I thought the reason that M3's were given more caster was for better high-speed stability. The set of the suspension happens slower in this case, because the wheel is rotated more from the side than the top, i.e. less actual turning happens and more rolling over onto its edge. That can make things feel more in control I suppose, but it's got to be slower than less. :dunno

Originally posted by yMike
Lots and lots of caster... (to a point of course)

caster makes your wheels want to flop over at initial turn in. Running zero toe with the most caster will get you quicker turn-in. Although I would not go so far as to put offset c/a bushings in a 96+, you might run into rubbing issues with that setup.

mike

what would make something rub? 95 M3's came with eccentric Control Arm bushings... and if they work there, what would make them different on a 96+ car? I realize the upper strut mounts are different, but I wouldn't think that difference would lead to any rubbing issues...

both cars came with 7.5" front wheels, although I run 8.5" front wheels with 255 tires and 15mm spacers.

Originally posted by Kos-motate139
Well, this goes back to the caster issue I was wondering about earlier...

Less caster = faster turn in

Right? Can anyone refute this with hard data? The vast majority of my experience with suspension geometry comes from 2 wheelers, but the same concept should be true...unless I'm missing something.

I thought the reason that M3's were given more caster was for better high-speed stability. The set of the suspension happens slower in this case, because the wheel is rotated more from the side than the top, i.e. less actual turning happens and more rolling over onto its edge. That can make things feel more in control I suppose, but it's got to be slower than less. :dunno


I think I agree with you. I will check my veh dyn book at work, but I think it has something to do with the scrub. I think the changes wouldn't be that easy to notice though...

Originally posted by Number9
I'm sure you know it wasn't running a street suspension then, though it is now, after having been relegated to commuter car duty where it belongs. And both it and my wife's stock 95 M3 have been less reliable than the Honda car to boot...

I am guessing you never changed the bushings though, so you don't know what it feels like with poly or delrin bushings...

Originally posted by melmyers12
I think I agree with you. I will check my veh dyn book at work, but I think it has something to do with the scrub. I think the changes wouldn't be that easy to notice though...

Well, it's a good sign if I'm not completely nuts. :)

Driving my two cars back to back seems to be an obvious difference, but there are other differences as well. I've just put GC adj plates in the 318, perhaps some experimentation is in order. Thanks!

Originally posted by melmyers12
what would make something rub? 95 M3's came with eccentric Control Arm bushings... and if they work there, what would make them different on a 96+ car? I realize the upper strut mounts are different, but I wouldn't think that difference would lead to any rubbing issues...

both cars came with 7.5" front wheels, although I run 8.5" front wheels with 255 tires and 15mm spacers.

Hey Mel, 95's and 96+ cars use different control arms. Eccentric bushings, in the outboard position in a 96+ car, will push the wheel pretty far forward and increase caster beyond 95 specs.

IIRC, when you ran them outboard on your track car, you got rubbing even with the front fender rolled and the wheel liners removed. At least that what I remember, when we were coming back from catching that Latino band at the bar on Sixth street where the barmaid caught the freaking ceiling fan on fire from breathing fire with 151 rum. Very cool. :cool:

Anyway, I'm not sure I'd put too much stock in what Mel says. That sumbitch could drive a friggen yugo around a track on two wheels and embarass most of us. :stickoutt

Originally posted by melmyers12
I am guessing you never changed the bushings though, so you don't know what it feels like with poly or delrin bushings...

Well the limited edition Zanardi came stock with harder bushings (not to mention track ready shocks/springs/anti-sway bars) and I added the non-compliance rear beam/toe-links on top of that, so I know what an NSX feels like that way - kind of like a Skip Barber formula dodge with a slower steering ratio and way more power. But no, haven't setup the Dinan S3 M3 that way because its intended application is friggen grocery getter!!! :rolleyes: But obviously, most of us drive the commuter car more than the track car, so you can (correctly) infer that I love driving the M3.

Originally posted by frayed
Hey Mel, 95's and 96+ cars use different control arms. Eccentric bushings, in the outboard position in a 96+ car, will push the wheel pretty far forward and increase caster beyond 95 specs.

IIRC, when you ran them outboard on your track car, you got rubbing even with the front fender rolled and the wheel liners removed. At least that what I remember, when we were coming back from catching that Latino band at the bar on Sixth street where the barmaid caught the freaking ceiling fan on fire from breathing fire with 151 rum. Very cool. :cool:

Anyway, I'm not sure I'd put too much stock in what Mel says. That sumbitch could drive a friggen yugo around a track on two wheels and embarass most of us. :stickoutt


Geez dude, why are you always right??? I always said- if I go big I want you to be my engineer ;) You are always thinking about this kind of crap.

31 12 2 227 249, 250 for 95m3

31 12 2 228 461, 462 for 96+m3

Yah, I remember the rubbing on mine now. So I guess the answer is on a car with the 96+ control arms installed you are most likely required to run the eccentric bushings with the holes oriented inboard to get no rubbing. Less caster than stock, but more track width, and possibly better turn in because changes to both variables. That's probably why my turn in is insane with the delrin bushings and Hoosier 245 tires.

One other thing, lighter wheels and tires probably help with turn in, as you are reducing the gyroscopic effects associated with a rotating mass.

On another note, when you put Kumhos tires on my car, the turn in becomes soft and feels like you are floating on four big marshmallows. So yes, tires are everything.... no matter what suspension tricks you have, you still have to transmit the forces through four little pieces of rubber.

-Mel

Originally posted by melmyers12
That's probably why my turn in is insane with the delrin bushings and Hoosier 245 tires.....On another note, when you put Kumhos tires on my car, the turn in becomes soft and feels like you are floating on four big marshmallows. -Mel

Are you serious? I usually find it the other way around (assuming same size tires). The hoosiers usually roll / feel softer than the Kumhos. They grip like sumbitches... but don't feel near as stiff in the sidewall area.

Could it be the difference between 245 / 255 series tires?

Not doubting you... just not what I've seen/felt/encountered on the mustang with 275x40s with Hoosier, Victoracer V700s and Ecsta V700s.

Regardless of the set up, I feel that the location (in respect to the front axle) and weight of the engine might play some role turn in. The 911 is rear engined, while the NSX is mid, and the S2000 has a small 4 cylinder behind the front axle. The 6 cylinder engine in a BMW hangs out over the front axle, and most have a block made of cast iron. This weight in front of the front axle takes away from the turn in. This is why some feel that the E30 M3 has better turn in than its successor, because the E30 M3 has a small 4 cylinder that doesn't hang over the front axle. Just a thought :cool:

Originally posted by John in Houston
Are you serious? I usually find it the other way around (assuming same size tires). The hoosiers usually roll / feel softer than the Kumhos. They grip like sumbitches... but don't feel near as stiff in the sidewall area.

Could it be the difference between 245 / 255 series tires?

Not doubting you... just not what I've seen/felt/encountered on the mustang with 275x40s with Hoosier, Victoracer V700s and Ecsta V700s.

I am dead serious. The kumhos suck donkey nutz.

Originally posted by BimmerToad
Regardless of the set up, I feel that the location (in respect to the front axle) and weight of the engine might play some role turn in. The 911 is rear engined, while the NSX is mid, and the S2000 has a small 4 cylinder behind the front axle. The 6 cylinder engine in a BMW hangs out over the front axle, and most have a block made of cast iron. This weight in front of the front axle takes away from the turn in. This is why some feel that the E30 M3 has better turn in than its successor, because the E30 M3 has a small 4 cylinder that doesn't hang over the front axle. Just a thought :cool:

you have it backwards. More wieght on a given axle means more cornering force can be transmitted through that tire. hence, you should have better turn in with more weight (up to a point, as long as you are not overloading the tire's design limits) on a given axle.

I think what bimmertoad might have been going after, was not so much axle/tire loading, but noting that some cars with wicked turn-in have this characteristic b/c of a lower polar moment of inertia.

The S2000 has beautiful turn in, and, like many mid engined cars, has a low polar moment of inertia.

Low PMI is a double edged sword though. . . the car will get loose much faster and you've got to be quick to correct for it. (couple that with unwelcome bumpsteer, and you've got a handful at the limit, as in the case of the S2000)

Mel, I'll give you a ring today; my old work number is no longer good. :D

Mel, you mentioned that the E36 handles better when the front is "raised" over the rear. GC recommended ride heights also match that remark. The front is far from being slammed. I've seen a few people with their front end very low on Koni c/o's and would like to feel what kinda handling they are getting out of them.

Originally posted by frayed
I think what bimmertoad might have been going after, was not so much axle/tire loading, but noting that some cars with wicked turn-in have this characteristic b/c of a lower polar moment of inertia.


Is there any way to measure the PMI, perhaps with corner balancing information? I wish there was some way to predict what the effect of adding a few pounds here or there would be.

ti needs an I6...current engine ends right behind the front swaybar...and it's 80 lbs less. Hmm...

I've thought about putting in an I6 into my TI as well. :) I've heard that swapping out the 4 cylinder for an aluminum block 6 (found in the Z3 6 cylinder cars) keeps the weight about the same, but by putting in any I6 engine, aluminum or iron block, the weight of the 2 extra cylinders goes over the front axle, hurting the PMI. If only there was some way to shove the I6 farther back in the car.