360 Challenge Stradale Dyno Run II

This might sound obvious, but did you try to "ram" air into the intakes with a large fan on the dyno?

Sounds hokey, but a leaf blower also works excellent for this

 

Most leaf blowers are over 100 mph!

Also, you are right about most fans as they are meant for volume and not velocity. The kind I was referring to are the "squirrel cage" type that move high velocity air over a smaller area. The dyno I go to has one like this and I use it to blast my intercooler. I dont think it simulates true 100+ mph blasts down the road, but its certainly better than stagnant air.

 

what is you altitude?

 

Here is a torque curve from a German Magazine Sprt auto, I don;t know if they actualy did the dyno but here are the results

 

Figure 400- 405 HP for a freshly stock rebuilt F355 C at the flywheel, on an engine dyno. Done it. Extrapolate using 18% driveline loss yeilds about 328 HP at the wheel.

Rob Schermerhorn

 

I don't know whay but it did't want to upload

 

As musch as I know there is a 5% up or down margin of error, I think basiscly the avrige of the cs built will be 425 hp, oh by the way what is the regular modenas drivetrain loss

 

Ram Air is a myth. COLD AIR provides most of the HP gain.

A couple of years ago, the motorcycle guys instrumented a Kawasaki with ram air. They added a pressure measureing equiptment to the front of the bike, and inside the air box. Result: at 170 MPH there was a 0.5 PSI gain in the air box, while there was a 3 PSI gain on the windshield. This corresponds to a 3% gain in HP at max velocity, and less than 1% gain at 100 MPH.

The big difference in the airbox, is that you have a hungry engine consuming all the pressure of the intake. This is an entirely different situation than the pressure on the front of the car. In the air box, the air never gets a chance to stop, where on the front of the car at the stagnation point, the air actually does stop and can convert all of its velocity difference into pressure.

Notice also that to gain pressure from the air inlet to the air box, the shape of the duct needs to expand like the second half of a carbuertor venturi.

 

Thomas,

Not sure I understand soft limiter, But I certainly hit the hard limiter today for the first time.

It's difficult to see the presise cut out point as the neddle bounces around quite a bit and I didn't want to hold it there for too long
but I would say 8500-8650 seemed about right for mine too.

The first thing that strikes you is that it does NOT automaticly change up a gear as in the 360M.
Then it sounds just like a pit lane limiter. It didn't seem to do the car any harm but I doubt if I will do it again intensionlly.

Wazza

 

i can't remember for sure, but i don't *think* that my modena would automatically upshift at the rev limit while in sport mode?? do you recall?

also, do you know if the stradale handles the rev limiter the same way regardless of being in sport or race mode?

 

In normal mode it will auto-upshift; in sport mode it will NOT... it'll let you bounce off the rev-limiter.

 

So, in a dyno run, such as you were doing, the torque/load should be exactly what its supposed to be up to 8500rpm, right?

So, what are they saying? That the 409/425hp is theoretical... that's where the curve would go if it weren't for the fact that the tranny can't handle it and so the soft-limiter cuts power?

Sorry, that answer demands more questions!!
Does soft limiter kicking in on a dyno run make sense to any of you??

 

Errr - that would be the engine I think

 

Could it be only at a standstill or on a dyno where this would occur? Maybe even with the ASR off, there is a non-defeatable portion that cuts back power if the front wheels are stationary or not rolling fast enough? I find it hard to believe that you would not notice that kind of drop in power on the road. It just falls off a cliff.

I could see the benefit of this from a standstill. If the rear tires break loose from too hard a launch the rpms will instantly hit the rev-limiter and stay there as long as you keep your foot to the floor. Maybe that is the kind of damage to the engine/transmission it is trying to prevent?

 

Hmmm... how long did it take your car to run up the RPMs on the dyno... was it really quick (lightly loaded)... or really slow (heavily loaded)... maybe it was really, really slow... as if you were climbing a huge incline, and as a result the ECU was trying to protect the tranny/driveline which perhaps can't handle that much torque applied for that long????

Just trying to put 2 and 2 together here...