Seven America on the Rolling Road at Lotus Engineering at Ann Arbor, Michigan

Six: Rolling, Rolling, Rolling...


While going up through the gears, I could feel a bit of a 'bump' as if the rollers were off center... of course the rollers were fine -- it was my wheels or rather tires that were a bit out of round. I was reassured by the operators that this was common even with more exotic machines, particularly as the tires were cold as the rest of the car. Eventually the tires warmed and the 'ride' smoothed, but I noticed a grin and some pointing at my rear wheels by a bystander. Sure enough, leaning over and peering out the passenger side, I could see that the wheel had a bit of 'wobble' as well. So much for those original Triumph Herald rims -- at least I have a spare! Didn't look like a problem serious enough to sweat over, so I went ahead and held my speed at 3500 RPM until I was given the sign to step it on up 500 revs. I held the revs at 4,000 and 4,500 until I was given the sign that the reference reading had been taken, then let the car slow down again and put it back into neutral and idle for a few minutes.

Now, when I'm out on the road, I've seen a bit over 5,000 in spirited acceleration, but I never felt that there was much more power up there. I was also still acutely aware that the car had spent the night before in sub zero (Fahrenheit) and was just a bit nervous about pushing it too hard. generally I figure if I'm gonna break the car, I'd prefer to do it on a race course (though I suppose it would be safer on the dyno, they'd probably bill me for the clean up!!) So for our first dyno outing, I kept a 4,500 rpm limit.

Now the real fun begins... I'm told that the operator will spin up the dyno so that the rollers drive my wheels at the speed which corresponded to the reference RPM we captured earlier. At 3,500 RPM that translates to 49mph though my speedo tells me I'm at 60mph ! I've always heard that a Seven feels faster than you're really going, but I didn't realize my speedo was THAT far off! Anyway, so here I am at idle with the road speed at about 49 mph. Now the trick is to bring the revs up to the predetermined 3,500 RPM, push the clutch, select 4th gear, and let the clutch up slowly while while throttling the engine up precisely to the RPM matching the road speed. Sort of the opposite of those TR7 "Shape of things that win" commercials back in the 80's -- you remember, where the TR7 cruises up to the back of the semi trailer with its ramp down and drives on up, the wheels skidding somewhat as they go from road speed to crawling up the ramp... never mind.


back to:

simplesevens home

Cars 1000 - 1500