All finished!

[_Nathan_]

Is it showing less torque at 8100 rpm though? Peak torque figure is meaningless, if you can make more torque higher up the rev range with cams for example you'll get more power without having to increase the peak torque figure in the lower rev range?

We know that:

power = (torque * rpm) / 5252

Therefore

(power * 5252) / torque = rpm

Looking at that graph at max power torque looks to be around 245 therefore

(380 * 5252) / 245 = rpm = 8145 which seems a sensible RPM - enough to suggest that the power figure is accurate for the measured torque and that the power figures on screen shot haven't been doctored (not saying that the torque has been accurately measured though, but the rolling road debate is one for another time :banghead: )

Having met CantFind1 I don't think he is the type to claim silly figures for a simple remap for example but I know this engine has had more work than that...

[The Gorilla]

Hi,

Quote-

'' if you can make more torque higher up the rev range....''



Nathan- that was my original point its making the 'same'
Torque as a std S54, so where does the
Power come from ?

Regards,

The Gorilla.

[_Nathan_]

My CSL doesn't make 245 lb/ft at 8150 rpm, if it did then it'd have 380 bhp :thumbs:

[The Gorilla]

Hi,

Quote-

''My CSL doesn't make 245 lb/ft at 8150 rpm, if it did then it'd have 380 bhp''

Exactly.

The Dyno is showing an Under square engine making
circa 250 lb Torque from 1800 rpm to 8150 rpm,
How ?

Attached is the S65 Torque Curve.

Short Stroke Oversquare V8 making 414 BHP @ 8400 RPM,
so how does the S54 engine almost match it ?

Regards,

The Gorilla.

[_Nathan_]

Maybe I'm missing something but the RPM scale isn't shown, it is missing off the bottom of the photo?

250lb ft at 1800 RPM would be 85 hp and that isn't shown on the graph below...

The point on the graph where there is 150bhp and 245lbft must be 3215 rpm, on the graph you posted the S65 is making 290lb at the same point.

[monkeycsl]

:119:

[The Gorilla]

Hi,

Nathan- I was trying to illustrate that at
6250 rpm the S65 Short Stroke motor,
running 12.0 CR with 4 Cams etc
has its Torque curve already in decline.

Another point is that the Duty
cycle of the std S54 Fuel Injectors is maxxed
out at circa 375/380 BHP.

Regards,

The Gorilla.

[mattCSLnut]

Popcorn time !

You're not wrong there dUnk :smt014

[_Nathan_]

Hi,

Nathan- I was trying to illustrate that at
6250 rpm the S65 Short Stroke motor,
running 12.0 CR with 4 Cams etc
has its Torque curve already in decline.

Another point is that the Duty
cycle of the std S54 Fuel Injectors is maxxed
out at circa 375/380 BHP.

Regards,

The Gorilla.

Number of cams is just a function of the number of heads surely?

Rest of if no idea, maybe the op can chime in with his engine spec...

Any more info on the injector duty cycle as I have customers running far more than that on oem injectors (maxed out admittedly, Motec giving 100% duty cycle warnings but still well above your figures).

[plug]

I wonder could he have fitted a lightened flywheel? Would that have an effect on reducing torque?

[cslsuperfan]

any spare popcorn dunc!!:119:

[alexk]

Seems a bit optimistic to me, if the engine only has airbox, cams and exhaust.

[The Gorilla]

Hi,

Quote-

''Any more info on the injector duty cycle as I have customers running far more than that on oem injectors (maxed out admittedly, Motec giving 100% duty cycle warnings but still well above your figures).


Nathan - I had an article here somewhere on it.
Will try and dig it out and send it on as it explained
why not to run fuel injectors at anything higher
than 80 % duty cycle at over 5 bar fuel pressure.
it was to do with the way spray patterns are optimised
at something like 75 psi.

Anything over and the fuel droplets can go to fine
which can cause hot spots etc.

There were a couple of exceptions, F430 springs to
mind with its 5 spray injector etc.

I think the std S54 is approx 0.52 BSFC [Brake Specific Fuel Consumption]

So if you do the figures on 380 BHP-

380 x 0.52 / 6 x 80
= 197.6 / 4.8
= 41.16 Lb [Req]

Stock Injectors, how ?

If you increase the Duty cycle to
99% then of course you fall back to 33lb
still not sure how this would work 100% on
stock injectors.

Of course you can Crank the Fuel Pressure
up to say 6 Bar, but it will be saturated
at idle, and the engine will be hunting like
a 'U' Boat Captain.

Not much use in a road Car but prehaps passable for
a Track Car.

I know of a certain CSL that idles just like that !!!!

Regards,

The Gorilla.

[Mark CSL]

[AlexGTT]

Hands looking slimmer Mark.