A guide to driving the e30 gr.a / dtm properly

Hi guys !!

First of all please excuse my English as it's not the best, I hope you understand everything I have to say
Please feel free to move this thread if it's in the wrong section (it's my 1st post here.) I'll post it in chit-chat and in the physics bugs/issues tabs.

It has come to my attention that a lot of people (me included....) are having some problems with the

----BMW M3 E30 GRUPPE A ---- as well as the ---- BMW M3 E30 DTM----- versions.

That would be some severe braking problems (lock-ups) as well as massive oversteer on corner entry. That's why I would like to write a small guide, after winning (again) on Imola by almost a minute on a full grid and a 10 lap race. In the hope that you have much more fun driving the car, and getting better at it, for the sake of competition.
Because winning by a lot is only fun once, but racing closely with others is muuuch better....anyways.

I am using a Logitech G27 wheels and shifter, with no assists, manual shift. I replaced the steering wheel with a 320mm OMP one, but that's not that important.

What is important is that the racing E30 M3, maybe my favourite car in the world, scared the CRAP out of me while braking, in Assetto Corsa, every time on every course.
I can downshift, heel and toe, and modulate my braking, so where's the problem? Well, it's 75% with the car, and 25% with the driver (ME !!!).

Let's start with the easy stuff, the car and the setup. Even though I could understand some modifications I've done to the car, nothing erased that stupid corner entry oversteer.

I tried setting the brake balance all the way forward.....making the rear suspension softer, anti rollbar softer, more or less camber, fiddled with the differential and made it a bit better, but then the car would only lock up the front bakes and go straight on...
So what did I do? Annoyed I read all the descriptions of the setup adjustments till I found : "TOE", I never adjusted this on a car before.....before now !!!
After setting it a couple of clicks to the right (more toe in) on the rear suspention, the oversteer problem was largely improved. With the biggest hit out of the way, you may want to move the brake balance a bit back (say from over 80-82, to under 79), so that the front doesn't plough forward whlie braking. A couple of psi lower tire pressure in the rear, as well as the slightly softer suspension setup, solved the problem of the initial oversteer and brake lock-up problems.

The next problem I was having was the lockup of the differential even while heel-and-toeing with correct rev-matching. Here we come to the elephant in the corner, driver skill, or driver behaviour, to put it correctly. What I was doing was banging them downshifts in a quite rapid succesion, and even if the rev matching was OK (I thought), the diff kept locking up, because I wanted to get the downshifting over fast, to concentrate on braking.....BIG MISTAKE.

The hardest part is coordinating your 3 pedal imputs separately while braking. What I did before was modulating the brake pressure, and pressing the gas and clutch every time for the exact same time (both pedals) and with the same speed.... The key is that you have to separate them.

For example, while rev-matching from 5th to 4th, I would blip the throttle for 0.5 seconds, and let the clutch out in say 0.75 seconds.
For a much lower speed shift, say coming to the hairpin in Imola with the DTM shifting from 2nd to 1st, I would blip the throttle for 1 second, and let the clutch out only in about 2 seconds !!!! So a slower clutch release after having completed the rev-match is key to keeping the differential from locking while doing that.

There is much more to it than this, doing heel-and-toe and rev-matching is mandatory to being able to drive the racing E30 fast with no assists.
Of course, practice makes perfect, and after some fiddling with the setup, many will be able to run a 10 lap race at Imola with 2.02 - 2.03 times in the Gr.A car all day without crashing.


To keep it short..... give it more toe-in, softer suspension and tires on the rear, separate the 3 pedals while braking and take some time with that clutch release.

In hoping that this will help many guys while driving my favourite car in AC, the racing E30.
Have fun while practicing and feel free to ask anything !

Best regards
Vladiiiii

 

Sorry, but is it toe-in or toe-out? You seem to contradict yourself.

 

My mistake, was a typing error.....TOE IN corrected it.

Edit : Another sidenote I'd like to add, is trying to keep the braking in a straight line (hard on some corners in Imola, also because of some elevation changes, but easier at Monza for example)

 

What's your best around Imola?

 

As I'm not a particularly fast driver, the tips are aimed more to get more people to enjoy the car and have a friendlier/safer handling of the car.
High 1.57 with the DTM and a high 2.01 with the Gruppe A. Race times add 1,5 seconds for example. (Because of tires and fuel and.....driver fatigue )

 

Nice writup of the greatest original AC car by far (imho) , the E30 M3 DTM.

And you're right it's 75% the driver who's to blame.







Cheers
Robin

 

It`s here https://www.assettocorsa.net/forum/i...e-to-driving-the-e30-gr-a-dtm-properly.21154/

 

My mistake for posting it 2 times, didn't know where it fits better....I'm a rookie

@robin : For me, it worked the other way around, as written in the original post. To be able to improve the driving, I first had to make the adjustments. Then the driving. And maybe only then, further adjustments.

 

http://www.radiators-champ.com/RSRL...controller_type=all&community=all&friends=all

 

Good tips, with some exceptions

As Nao said in the other thread, brake bias in the 80´s is too much, you should set it to be at the edge of locking the front wheels at the hardest braking points (usually in the high 60´s or low 70´s).

You shoudn´t be coasting on the clutch for 2 seconds, you´re just losing time. The best way to help entry oversteer is to pay a lot of attention on how you release the brakes on entry, it needs to bee smooth so when you finally release it the rear of the car has some weight in it, when you release it too soon and too abruptly the balance ****s very fast and the rear is usually too light to cope.

 

Default setup is OK for hot lapping but not for 10+ laps race, at least not for me.
My "recipe" is to lower rear end and rebound on rear set to 0.

Avoiding quick shifting down is another story ... somehow it feels the best if you hit around 7000 rpm when shifting down ...

 

Unfortunately, I have to do some work till later today, but I can't wait to try out as you said, a better brake bias. I didn't change it that much after the toe change, I will definately do that.

Rodrigo, I maybe wrote it a bit wrong, I'm not coasting (keeping the clutch pressed in) for 2 seconds, it was just an example that letting it out slower (as in, taking 2 seconds for releasing it) worked better for me.And 2 seconds was only an example to emphasise the longer time I take to release it to help stability, I don't do it that slow (2 seconds is a lot.....).

Another thing, do you guys recommend running the long 1st gear? I think it's faster while racing, but being used to street ratios (shorter 1st) I am able to make up 2-4 positions at the start. I guess it depends on preference, right? For example I run the Gr.A with normal 1st gear but the DTM with long 1st gear.

Setting the rear rebound to 0 makes the weight transfer to the front while braking a bit less, right?

Many thanks to all for the useful tips !
Vlad

 

Even if you are releasing the clutch for about 2 seconds you´re still coasting, plus the fact that when you´re doing that you can focus 100% on the brakes. If the car is unsettled at lower speed then a harder blip to raise the rpm should help. Coasting is always bad, you should be either acelerating or braking.

The gear ratio depends on the track. I don´t mind having a slower start if it means a better pace through the whole race, but i never do quick 10 lap races. maybe in those very short it pays off.

 

That would mean braking right to the apex of a corner, and then accelerating out again in one smooth motion.....every time. I don't know about you, but I am not that precise. I consider myself to be a reasonably good driver, but I'm not Lewis Hamilton!!

 

Here is what I mean about my slower clutch release, please excuse the use of MS Paint.
Between the 2 different diagrams, there is no extra time difference or delay between braking and accelerating (that's what I understand by coasting), maybe I'm seeing it wrong

 

No, just allows rear shock absorbers to stretch faster. Lowering rear end does that ...

 

When i downshift the clutch stays depressed only in the time to change gears, certainly a lot less then 0,7. When the clutch is engaged you dont have engine brake, so in a way you are coasting and wasting braking power.

 

But why ignore engine braking? You are justing throwing away braking power. Brakes look simple to be tuned, but there is a LOT to be gained on them, most "brake tricks" i learned came from fixed setups championships where the only changes available were brakes and steering, and it did make a huge difference. Over the years i saw a lot of people with too much front brake bias wasting time and not realizing it.

If the wheels are locking, it doesnt meant that you are getting the most of the brakes, it only means you reach the limit of the tires. But changing brake bias, pressure (as it had on rfactor/gtr), and how hard/soft you blip the engine, can change a car from undrivable to perfect.

The key to tune brakes are the rear, not the front (on rwd cars), most people will run away from too much rearward bias, but there is were you can get most of it, because the brakes and the engine do the work, and you can modulate both. The "threshold" is still the front, but first you have to maximize the rear.