[E92Fan]

Originally Posted by ss134

Hi,
Just finished running in the car and took it out last night on the A7 Autobahn for a top speed run. The road was clear as it was late evening and made it to 160mph (stock car), thought it would stop at 155 but it went off the clock!
I noticed that the car started to feel less planted, with noticeable front end lift after 140mph- almost like it was 'floating' on the road rather than on it(i have M Sport Aero and suspension). Im wondering if this is to be expected at these speeds or if it could be helped by lowering tyre pressure.

Any thoughts?

Anyway, an AMG mercedes pulled behind me whilst i was at 160mph, i moved to the centre lane and he passed me easily! Theres always a bigger fish out there!!!

The front-end lift is normal even with the M-sport aerodyamics. What you will find helps the stability is the little M3 rear lip spoiler. Don't lower the tyre pressures as that will unstabilise the car as you're slowing down from the high speeds.

[ss134]

Originally Posted by E92Fan

The front-end lift is normal even with the M-sport aerodyamics. What you will find helps the stability is the little M3 rear lip spoiler. Don't lower the tyre pressures as that will unstabilise the car as you're slowing down from the high speeds.

Thanks for the reply- do you really think the M3 spoiler will make that much difference?

[edo]

Originally Posted by ss134

I noticed that the car started to feel less planted, with noticeable front end lift after 140mph- almost like it was 'floating' on the road rather than on it(i have M Sport Aero and suspension). Im wondering if this is to be expected at these speeds or if it could be helped by lowering tyre pressure.

Strange. I do 160+ every weekend and I don't feel any floating after 140. I mean, it's obvious that the cat won't behave the same as at 60 mph, but if the car floated at 140, then how would it run at 180+?

[ss134]

Originally Posted by edo

Strange. I do 160+ every weekend and I don't feel any floating after 140. I mean, it's obvious that the cat won't behave the same as at 60 mph, but if the car floated at 140, then how would it run at 180+?

I don't know-different roads, different tyres, tyre pressures, cross wind, all play a part. Do you notice a noticeable difference in the car from 140mph to 160+ ?

[edo]

Originally Posted by ss134

Do you notice a noticeable difference in the car from 140mph to 160+ ?

Nope, just wind noise is more pronounced.

[dxb335d]

Mine reads off the clock 160+

[ss134]

Originally Posted by edo

Nope, just wind noise is more pronounced.

What tyres/rims do you run? Run flats or regular tyres? do you lower/raise your tyre pressures for high speed runs?? Just checked , E92 has a Drag (cD) of 0.30 and the E90 has a Drag (cD) of 0.32, maybe at these high speeds this makes a difference

[dxb335d]

160 it will go a little light, thats some speed to Be travelling, deffo more noticaBle lift at 160+ than 140.

[ss134]

Originally Posted by dxb335d

160 it will go a little light, thats some speed to Be travelling, deffo more noticaBle lift at 160+ than 140.

Thanks for the reply mate

[jonm42]

(I hope everyone is speaking in mph .)

[edo]

Originally Posted by ss134

What tyres/rims do you run? Run flats or regular tyres? do you lower/raise your tyre pressures for high speed runs?? Just checked , E92 has a Drag (cD) of 0.30 and the E90 has a Drag (cD) of 0.32, maybe at these high speeds this makes a difference

235/35 R19 front and 275/30 R19 rear. Regular tyres, not runflats. I don't do anything with tyre pressure before my high speed runs.

Originally Posted by jonm42

(I hope everyone is speaking in mph .)

160km/h (100 mph) ir my lowest cruising speed on highway, so yes, I was speaking in mph

[dxb335d]

Yes all talking mph


Mine in standard trim easily pulled off the clock.

[Spike]

i also drive somtimes faster than 160mph. i have no problems with the aerodynamic of the e92. i have no m package. only the m-chassis.
i use the standard bridgestone 19" run flat tyres.