Ferrari F355 Dyno's 313.8rwhp/225rwtq

Uh, so that 375 HP factory spec was at the flywheel? Isn't 313 a bit low?

 

I have been told Ferrari overrates its HP. This would be a pretty prime example of that. 313rwhp is not very good for a car that should have 375 at the crank. And this car isn't stock!

 

Isn't rule of thumb 15% loss for manual transmission cars (rwhp = 0.85 * chp)?

That would put the target/estimate @ 318 rwhp.

Also, what kind of dyno? And are the numbers corrected or uncorrected?

 

The rule of thumb you are talking about is the drivetrain loss for rwd cars. 10-15% is normal.

 

With the exception of a few models they have always been known for over estimating HP. This is especially true with US versions. The factory dyno sheet on my wall for a US spec 360 says 368 HP. 400 is the advertised #.

 

wait, who did that 360rwhp dyno??

 

That is crankshaft HP on the factory dyno in Maranello

 

I saw your thread on supraforums and it appears the "few other people" is only allanlambo....wtf is he doing on the rice forums anyway?

 

Hmmm. That is almost exactly what we got when we dyno'd my buddy Brian's box-stock F355 last year.

Bear this in mind: according to a recent article in Car & Driver on the subject, radiator cooling during a dyno run plays a huge effect on the RWHP produced.

They found that if the radiator heat isn't removed at the same rate as if the car were going down the road, the knock sensor will detect resultant early pinging from the extra heat, and the ECU then retard the spark, thereby producing a substantially lower reading than what would be obtained in normal road use.

In the article, Dinan (SoCal BMW tuner) is installing some super capacity fans in their shop to the tune of $60k, if memory serves, to combat this problem.

Finally, the guys running the dyno on Brian's dyno run placed the radiator fans at the front of the car for the test! Duh! It took some effort to convince them to place the fans at the door intakes. Otherwise, they were just cooling only the front brake rotors!

FWIW, Al

 

You know what proves that Ferrari isn't lying with their numbers? Speed and acceleration numbers! Simple.

incidentally, every Ferrari I've ever seen on a dyno (and that's a few now) has had almost EXACTLY what Ferraris claims. Either that, or every Porsche that has been on the same dyno is also overclaimed.

re 355. 0-100kph in 4.7 sec...how much HP do you reckon that would take? I remember seeing rule of thumb formulae for working that stuff out. You simply can't get those figures without the HP in a car of that weight. That goes for all models.

 

Have to agree with Peter here.
310+hp on a Dyno Dynamics dyno is the same as 330+hp on a Dynojet which reads approx 8% higher in my experience, which involves literally 100's of runs on different dynos. The Dyno Dynamics software is written assuming 20-22% transmission losses.
Do you know what mode/corrections were used for the dyno run?
As a comparison an M5 is hard pressed to show over 275hp on a Dyno Dynamics, yet commonly pull 325-335 on the Dynojet which is so popular in the US.

 

And just one more time for the record....(please, let it be the last time)

Chassis Dyno's are good for nothing other than wearing stuff out and doing comparitive testing.

Torque/Power Measurements need to be taken on an engine dyno.

As simple as that.

Really.

No. REALLY REALLY.

Ok??

Good.

 

I thought I had heard that hp lose is higher in the F355 because of the why the transmission is transverse which causes a higher lose of hp. 360 trans are set up differently.

 

That may be true where you are but we know as fact that US cars make less power.

 

Well, I must say I am pretty happy with these numbers for my car. It is a 95, with tubi exhaust and a pair of K&N airfilters. Apart from that it is totally stock.

Of course, if anyone in LA has access to another dyno, I'm happy to run my car on it to get a comparison also.

So, anyone else got first hand numbers to report?

Dave

 

But Phil, that's we we are doing.... COMPARATIVE testing, and wearing my car out

 

Could you post the dyno result and conditions...if I understand correctly dyno dynamic test results are extrapolated and not measured compared to dynojet. There was a posting at KTR for a 2000 Modena on a dynodynamics that showed peak rwhp at about 313, see attached...it's hard to say which is accurate, yours or the 360. Did you do a baseline with stock muffler/filters to compare the results?
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There were several posts in a thread a while back that discussed this and I think had to do with the extra gearing and loss associated with those...

 

A few 355 dyno graphs overlaid.
http://www.pless.com.au/355s.jpg

 

Peter, what sort of dyno (Dyno-Link or is that just the software)?

Those figures seem weird... even 190 kW at the rear wheels equates to about 241 hp. That's a different realm to 313....

Dave