Once you force induct an engine the Brake Mean Effective Pressure (BMEP) changes and sometimes radically. The reason HP and torque drops off on a naturallyaspirated engine is the inability for the engine to suck enough fuel-air mixture. When forced induction relieves that handicap both torque and horsepower can increase all the way to a prior set rpm limit. However, if the rpm limit is extended eventually you will find torque and hp fall off in the same manner. Its just that in the case of the forced induction you didn't go far enough in rpm. And the limit is set by the engine limits on strength of parts. combustion pressures sure but also rpm forces.

 

It all depends on the power climb to peak in relation to the rate that the power tapers off.If the taper off rate is slower than the climb rate, as it is on my car, you will make up the slight loss in aacceleration rate and more when you hit your next gear at a higher RPM. The higher gears require more power to accelerate and you want to shift as close to the peak as you can.... I read about this in a 1966 BSA Lightning manual 35 years ago. and watched dyno runs on road race bikes to determine how far past peak they could rev to be higher up the power band in the taller gears on the race track. It isn't exactly rocket science, is it.?

 

What did you ingest before reading that? Maybe that's why that BSA is no longer with us.

 

Lets all have a meet at an airport strip and find out!

 

Go to You Tube and watch "Fit leads a lap at VIR" and see if you can hear any sign of a governor. But there is an interruption in rpm from redline out of Oak Tree.

 

I'm telling you guys, there is a limiter. It's at 118mph for the GE8.

I've tested it on some airstrip, then once again at Summit Point.

 

What rpm were you running at 118 mph?

 

5600 something.

I'll make video of it tomorrow if you want. I'm heading out to Summit Point tomorrow morning.

 

Just ran the calculations, and it should be 5500 rpm in 5th gear that will give you 118mph.

 

Good. thats what we calculated too and we can't get 5500 at VIR, which has longer straights, presuming you're using the old course. If memory serves, its uphill 10 to S/F and downhill to one from there. We have much video from several cars at SP as well and getting a Fit to 118 from S/F is a tall order.

 

Weather was crummy, and I didn't go.

I'll try to get out to the airstrip sometime this week and shoot some video.