Blimey! Racing a BMW X5!

[Dino IV]

*/Humbly approaches the grid of racers.../*

Just a bit of roadracer and with some tracktime under my belt in saloons and FF, I want to ask for some tips for an offer I had, to race the most monstrous car I could imagine driving on a track: a BMW X5! I will have a go in this 4WD 'truck' at the track of Assen in the Netherlands in four days preceeding the MotoGP. Now this thing will probably have lots of roll and pitch, all kinds of electronic gizmo's like ESP, ABS etc, weighs in at 2.000+ kilos and a 38%F\62%R 4WD and probably have the Steptronic automatic gearbox. On the positive side it has wide tyres, large brakes and a good V8.

Can any of you guys provide me with some good tips for racing this car? Like how to drive with this automatic gearbox (left foot braking?), what to do with i.e. the tire pressures, how to handle the 4WD (never driven one), how to handle the lots of roll and pitch and what effects to expect from the electronic controls and if possible to switch them off.

[DAVID PATERSON]

BIZARRE!!!!!!!

Are you kidding? Are you going to RACE this thing or drive it on a race trck? If you are going to race it, what against? Will it be stock standard or substantially modified. Remember it is based on the 5 series touring, so it mightn't be all that bad. Let us know as much as you can find out and we'll try to offer something helpful.

[Dino IV]

Yeah, really bizarre! No not racing against others (or maybe another one of these cars I don't know the programme) but taking press and sponsor people for a few laps around the track. But from wednesday till sunday that will be a lot of tracktime and it needs to be at speed, not cruising ... like they had to actually tell me that.

At first I thought they said an 'M5' and I thought 'ok, ah supertanker, but not bad' but when he mentioned 'you know the 4WD BMW' I knew they were talking about the 'X5'. So it's stock standard, really standard, even the tires, that's why especially the tire pressures and turning off the electronic gizmo's interest me as these are the only modifications I can think off to get the handling together. I now have the funny idea that it will drive so bad it will flip over at every corner. So if you have any idea of how to get the most speed out of this and what to watch out for please let me know.

[DAVID PATERSON]

Check the manufacturer's handbook for the recommended tyre prssure and add about 10psi to that. They probably want you to leave all the gizmos connected so you can show your passengers how well they work. If they're just ordinary people off the street, not competitive drivers, they'll be very easy to impress anyway. I love giving newbies their first taste of a race track, I've had them screaming out in fear, when I was just warming the car up on a sighting lap.

[Morris 1100]

If it is stock you will need to up the tyre pressures, on an M5 (yeah I know it is different!) it needs about 40 psi in the tyres (Most road cars need around 40 psi on the track)
The M5 with all the gizmos is too good for the track, sometimes you need to get the rear sliding to get around but the electronics won't let you!
Does the X5 have the sport mode on the auto (push the stick sideways from drive into another slot)
It shouldn't fall over but build up to speed and don't throw it around on the first lap!

[Dino IV]

OK, I will get the tyre pressures up to 40psi (or Stock+10psi whatever comes first). I am wondering how does it work when i.e. the car is only pushing on in corners, understeering badly. What do you do then? Lower the front pressures a bit? By how much?

And how do you check\change pressures on track? You get on with cold tyres and come in again checking warm tyres? Sunny day, cold day etc? Is there some basic rule of correcting this?

Morris > It has this sport mode I believe. Shifting 'sequentially' by pushing forward or back. Don't know how good this is. I've had a go in a few Renaults where the sport mode resulted in red hot trannies. Electronics went totally bezerk stuck in some sort of 'security mode' = blocked.

David > I guess soem will be first-timers but most will know the drill. Should be fun taking the boys from 'Fast Bikes'-mag around ..

[Morris 1100]

The BMW sport mode is very good, you push the stick into sport and change manualy or leave the stick alone and just let it do it for you! The sport mode changes the point at which it changes gears, on the upchange it runs right up to max revs and changes.
My choice is to let it do most of the changes but on some corners it might be in third when you want second!

If you go normal pressures plus ten it should be in the ball park!
Check what the maximum pressure written on the sidewall is and it should be about 45-50psi so you could go that high if you need to.
Adding more air gives you more grip (to a point)

I drive medical cars and pace cars, they give you a fast road car and standard tyres, the tyres roll during cornering (tucking under the rim) and if you look at the sidewalls they are wearing about half way down the sidewall!
So about 10 extra psi gets it about right for starters, they may meed more or less from there for maximum grip but then it would need more camber as well!
Don't worry to much about hot/cold unless you are doing lots of laps it won't change much.

[Dino IV]

OK, great tips, Morris! My sidewalls are wearing like that on my road car and I take those tires up to 40 till 43 psi as well.

Especially with the wide plus high sidewall tires on the X5 - which has 235\65 17" inch ones stock - sidewall roll must be enormous.

[Lee Janotta]

Personally, I'd mount some tires with a lot less lateral grip than stock. Will allow the truck to slide rather than roll, so you can drift thru the turns and _really_ scare the **** out of the passengers! Won't have to worry about rollover either.

[Dino IV]

After the first day I guess tires will be worn well beyond stock approval.

[DAVID PATERSON]

I've seen a couple of videos by the FAST BIKES mag guys, they'll be fast asleep in the back of your bimmer when you're going round flat out.

[Dino IV]

I know, David.
I was a subscriber when I was young. When you're used to blast Turbo'ed Fireblades through the soundbarrier a leaning over SUV probably won't make your heart beat any faster.

But it's going to be fun to get some speed out of it, get some laptimes recorded and have a little race between the fellow drivers.

That's why I want some advice, is it i.e. wise to get going with leftfoot braking in order to brake right to the apex and have the power on early and maybe even a little while braking to smooth out the pitch of this thing? How would you do it?

[Stacy]

Excellent stuff!

I have absolutely no idea on what to do with an X5 on track, except a snippet of info which I recall from the publicity stuff on launch.

Basically this involved BMW demonstrating this car around the Nurburgring with an ex-F1 driver. From this I deduce that it won't quite be the understeering lurching barge you think it will be. In fact I think he spun it..

Aside tyres which has been covered, I'd be more worried about cooking brakes on a road car - especially on an X5 which is carrying some weight. So might be worth braking earlier, but less and looking after them for a lap before you come in.

Anyway, have fun!

Stacy

[mattray]

If I was you I would turn into all the corners really really hard on the brakes maybe even introducing Mr Bar to the roof of the car every now and then. Definitly pump up the tyres maybe 60 rear 40 front just to make sure it wont understeer and then get the passengers to hurl themselves at the oposite window to the corner just to make sure!
this should all be done while exlaiming you are still being trained under YTS and will be neding them to sign your sheet to prove you turned up!

[djeffries]

Drove this car on the road and found it handled really well..Particularly for the size and type. You need to put it into sport mode on the box and take off the traction control..no track maps on the satnav but dont worry most tracks are mainly all left handers anyway..some sneaky keeps putting in the odd right hander just to confuse you

[Dino IV]

Thanks for the tips guys. I'll do my best to scare the living daylights out of them .. ahum .. I mean, take the thing around the track with sufficient pace.

Couldn't find a thing on the introduction on the Ring, but have found a pic of an X5 on the Ring:


The X5 Le Mans with the race-Le Mans V12 in it delevering 700+ bhp. They clocked a time of 7.49,92 minutes!

[RickP:Clio51]

Note the tyres on that and the height of the suspension, check and see if you persuade the thing to lower itself a bit Dino...
Have you driven Assen before? A lot of the corners are quite banked so that'll help the rolling over feeling, tough track to be taking something soft around though as there are lots of camber changes that are going to upset the truck significantly...
Good luck

RickP

[Dino IV]

Tnx, Rick. I must say the thing they asked me to do beforehand was not the same as they allowed my driver squad to do during the GP. The circus is one big stress-festival of three-day-ego's.

Anyway I had fun with the car. It's so rock stable it's pretty tough to get it out of shape. Switching the stability control off was the only thing I could find to get it beyond it's grandma-mode. It still left you with the ABS, some kind of TC and an auto-gearbox so slow (whether manually or on auto, the latter faster I reckon) you could have a cup of coffee while the thing was busy pursuading itself if and when to change gear.

On the enthusiastic mode the 4.4 liter V8 is a powerful thing which could be a great basis for a block in another (light) car with a decent gearbox. And the Assen track is absolutely awesome. The banked corners are fantastic, it's very fluent and the off-set braking zones are a nice challenge. I have driven Zandvoort and Spa before and although Spa is nice, Zandvoort is pretty mickey-mouse compared to Assen. Superb track.