Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax aero8 and bad roads...

Some good advice from Mr Tony, remember its a racer for the road the quicker you go the more compliant it becomes(never over 70 though).


Em

Fixed that for you. How else would one see an indicated 160++mph in an Aero?

You'll never see an indicated 160 in a series 1 unless the speedo is broken my speedo topped out at bruntingthorpe around halfway along the runway at an indicated 149, actual terminal speed is around 140. Feels far more terrifying than the FF at 203 though...

The Aetomsx managed a true terminal velocity of around 155 indicating high 160s if I remember correctly.,,

I have to admit it is not a nice car to drive at 150mph - the mirrors look like they'll break free at any moment!! The old B3 was a far more soothing place. The B5s hasn't yet stretched its legs - although a B5 Touring was clocked at 198 on the Nardo. The Alpina bosses were only expecting low 190s based on the banking and touring body shape. There are videos on the interweb of the B5s going through the 320 (200mph) mark.

i just checked , as i had recently new tyres ( Michelin Super Sports) , to see that they are at 2.2 bar ,cold.
The time we hit those bad roads they must have been really warm

perhaps this is to much pressure for a "light" car ?

They should be at 1.7 bar or 25psi shouldn't they?

You're at 2.2 bar which is nearly 32psi.

Double check this in the manual as I could be wrong.

Checked on the Plus 8 Tyre pressure rating plate:
25psi front and rear, 18" or 19" wheels.

And there's me thinking you bought her because she has a boot for your kettle and biscuits and a picnic table on the front for the coffee cups,and electric sidescreens......

As Mr Tony says, and we're talking about the same car as I also owned it, maxed out at a correct 165 mph through the beam - different attempts using different manual and automatic changing patterns gave the same result. Likely to be an aerodynamic limit I think?

I also tried V-Max in my SuperSport, which according to the rolling road was giving more bhp than the AeroMax, but the SS would not do more than 155 mph - absolutely flat out. The first time I did this speed the car was extremely unstable under heavy braking, the end of the runway looks quite close.

MMC now have a CFD programme and whilst not as representative as the F1 Team's
programme, it does give some idea of what is happening aerodynamically with the different Aero model's.

The rear of the AeroMax falls away too quickly to the rear and the air does not stay attached, this creates a vortex and lift which is probably the limiting factor on top speed. In the case of the SS the culprit is the flat rear boot lid, which acts as a wing and again creates serious lift - this explains the lower by 10 mph top speed and the problem with the braking, the rear is partially flying and wants to overtake the front end.

I have not seen the CFD programme applied to the Series IV, but apparently the Aero 8 models do not perform aerodynamically as well as the AeroMax so the top speed is lower so it is very doubtful that the smaller BMW-engined (4.4L) cars will do 160 mph.

The new Series V has been designed using the CFD programme so possibly it may have the highest terminal speed of any Aero-chassised model so far.

@Brian - as mentioned before on here, I hit 165mph indicated (true 150mph) in Germany and except for the extreme mirror wobble the car felt pretty stable - and the brakes pulled the car up strongly without it feeling unstable. The car feels "ruffled" at those speeds though and far from the contented 100mph cruiser it can be with the roof on. (Which reminds me I need to get silicon spray for my roof rubbers as they were squealing like a piggy this morning.)

I have hit an indicated (terminal) 270kmh in an Alpina Roadster S and 270kmh (indicated) in the B3 Coupe - both felt far more attached to the road (Alpina body kits are specifically designed to remove lift) with the B3 still pulling - just not particularly hard.

Back to the original point - and my drive in this morning. The SS definitely prefers good tarmac - and imperfections at slow speeds can make it feel fidgety but not disconnected. As mentioned already, maybe a tweak to the suspension settings might dial back your GTN to a more acceptable level