1989 Mondial t Dyno run!

Well your average out put looks like 243 at the wheels. Taking in 17% that's 284hp at the crank. Even if it was an 18% drive train loss that still only puts you at 286hp at the crank. So you aren't making the published 300hp figure.

 

It is probably close enough for Ferrari's publishers

 

I did a "coast down" measurement on my 1989 Mondial T on a Dyno Jet dyno, and came to the conclusion that our driveline loss could be as little as 12 - 13%. Fifteen percent is a generally accepted driveline loss figure to use however. I think 18% may be excessive though. Of course you can feel free to use what suits you best.

However, with that said... If you take your 245 HP reading and DIVIDE that by .82 (.82 equaling 18%) that does work out to 298.78 @ the crank assuming that high 18% driveline loss estimate. So, your math is correct -assuming those numbers.

But... If you use an acceptable 15% (in other words divide 245 HP by .85) you reach a crank figure of 288.23 HP. That is probably closer to correct.

Your car just may be in need of a minor adjustment or could just be a tad down on power. Looking at my dyno sheet I see that my essentially stock 1989 3.4 Mondial T dynoed at 260.2 HP & 200.6 TQ. Doing the math (my 260.2 divided by .85) that equals 306.11 crank HP. That is pretty close to reality.

I eagerly wait your results with your soon to come upgrades. I hope you can see a nice stout 260 @ the wheels like mine gives. It makes for a pleasureable drive. Please keep us posted.

 

Yes it would be 245 subtracting 18.3% from 300. But I think an 18% drive train loss is a bit high. However if you added 18.3% to 245 that would put you at 289. When I add these things I take what the wheel power is and add the percentage to the number. So to me you would need to be showing 255 at the wheels to get 300 at the crank, with an 18% loss. But maybe I'm calculating it wrong?

 

18% from the number Ferrari quotes and 18% from the actual number he got are 2 different numbers. Which is actually the way to calculate? Who knows? His actual curves look great which is important. I would rather lose a few top hp numbers and have a nice smooth curve that shows no deficiencies or problems. Your motor looks like it is well tuned.

 

You work with engine HP - drivetrain loss to get power output...except that the dyno measures power output.

So reverse the above equation (engine HP - drivetrain loss = power output) to give yourself engine HP=drivetrain loss + power output.

Of course, you'll first have to calculate (guess, really) your drivetrain loss...say, 17% of engine HP...not 17% of the measured power output.


So, if you have 300 HP engine HP and 17% drivetrain loss then you'd expect to see the dyno report (300 * .83) 249 hp at the rear wheels.

This will slightly understate actual road horsepower, however, because most dynos have stale indoor air. Ram air cars such as Ferraris that have air intake ducts will push more air into the engine at road speeds than what the engine draws in by itself with a motionless car on a dyno.

So there is perhaps 3hp to 8hp that you'd have on the highway or track at speed that the dyno can't measure in the stale air of a garage.

 

Yes but here is the problem. We don't know exactly what the drive train loss is for his car. The only why to do that would be to pull the engine, put it on an engine dyno to get the true hp at the crank. Then put the engine back in run it on a wheel dyno and the calculate the percentage from there. Then you can more accurately get the hp from a wheel dyno.

So the real question is, what is the actual drive loss, and what does it truley make at the crank?

 

I agree. You're just getting a ballpark figure with a dyno run (but one that is useful for playing with your A/F ratio curve, ignition dwell, engine mods, etc).

The drivetrain loss is somewhere above 12% and below 19%, plus some small ram air amount at speed.

 

It's nice to see a beautifully flat torque curve over such a large rpm range. I'm not an expert but I believe that is the hallmark of Ferrari, not like some of these modern engines where you can feel the ECU switching between fueling curves or whatever.

just my .02...

 

10 years ago drive train losses were assumed to be 26-30% and dyno's were calibrated accordingly, as little two years ago it was deemed to be 18-22% and the software was re-written.
There is no point in trying to determine the crank horsepower from a RWHP reading based on "actual" drive train losses, as the dyno number is based on what the dyno software designer determined to be the average loss at the time of writing the software.

 

Hell with all this driveline loss talk- I about crapped myself when I saw the AFR chart. KNOW THIS, YOU ARE HURTING YOUR ENGINE RUNNING SO LEAN !!!! That is scary lean all the way to 6 grand. Besides getting those numbers closer to 13:1 all the way thru the rev range will increase your HP as well as give you better management efficiency(better mileage to).

SERIOUSLY, GET THAT FIXED BEFORE YOU DRIVE IT MUCH MORE. Your going to burn your engine up.

 

Yes, he's too lean early on...those 3 dyno runs appear to my eye to be at partial throttle up to almost 4,000 RPMs, then full throttle after that.

So his full throttle ECU fuel map looks pretty good (could still be a might bit richer, though).

But he's lean enough early on (pre-4k rpms) to warrant concern about burning valves.

More fuel, please!

 

Who said 300 hp?

For the Europeans ts Ferrari gave a figure of 300 hp w/o cats and 295 hp with cats. In Switzerland with its tighter emmission requirements and heavier cats horsepower was quoted with a mere 285 hp.

So if your car runs with cats it would be no surprise if the unmodified engine puts out a little less than 300 hp.

 

This is very interesting information - Was this also in DIN as opposed to SAE?
Many thanks

 

348 specs from manual, don't know if the T is different.
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Trying to use the same units of measure:

No Cat: 221kw @7200 / 323 Nm@4200
Eu Cat: 217kw @7200 / 317 Nm@4200

US Cat: 223.7 SAE kw @7000 / 310 Nm@4000

It is interesting to me that the US version develops the least amount of torque but quotes a higher power # at a lower rpm. I also thought a kilowatt was a kilowatt as a standard metric measure.

Also interestingly, the Non cat car and the cat car list the same specific output of 88.1 CV/liter. The non cat car inded does calculate out to 88.1 CV/liter, while the Cat car calculates to 86.6.

Thanks for posting the Factory specs - very interesting!

 

I think your numbers look pretty damn good if you ask me. I think you are a little lean down low as I am about 14:1 at 2k partial throttle and that then smooths out to around 13.5:1 at 5k and down to 12.4:1 at 7800 which is a little rich but still not to awful.

I had an issue at first with the car washing down the cylinders at idle up to 2k with a A/F of 10:1 due to the MAFs not being adjusted right with the screws on the top. I messed around there on the dyno and was able to fix it.

I also love the statistics lying game that always comes up with dynos. Someone said it right that you should calculate crankhp*0.83 as that gives you true loss. I forgot even trying to calculate CHP and just stuck with RWHP.

All this dyno fun just reminds me I need to get back and do it again before this track season.

 

Excellent!

I hope for the best for you. Cant wait for the results.

 

Two thoughts I would like to interject into the discussion. First of all, most of these dyno's everyone is running on simply work off enertia. The rollers are a particular weight, and they simply time along a curve how long it takes to accelerate them. This would be more like measuring the CARS power, not exactly the engine, as anything that is connected to the motor, from the flywheel back, would alter its enertia, or its ability to accelerate. In other words a lighter flywheel, or cam pulleys, lighter pistons, etc, would show up as a higher HP than what the engine is actually producing. A true calculation would "brake" the engine at a certain RPM and hold it there at wide open or part throttle and measure a static reading. In fact, the workshop manual discusses this very thing in the engine seaction.

The second thought is driveline loss. Its been years since I studied this stuff, and was amazing how much I forgot. I think using a percentage for drivetrain loss is unrealistic. From information I have read, the more probable is simply a fairly flat HP loss. For example, a article i was reading on the subject pertained to motorcycles. The author had seen that adding things like 50 HP nitrous kits would actually show a 50 HP increase on an enertia type dyno. If the transmission and final drive were a percentage of loss, there would have been a percentage of the 50HP lost as well. It is my feeling that with a car like the 308, the driveline losses are probably at about 30 HP, and probably dont go up perceptably with load. In a car like the Mondial, you have to make a 90 degree turn using a hypoid gear, you might be able to figure another 15-20HP loss. Additionally, if you figured a 17% loss, 300 HP would be about 50 HP of energy. Thats a lot of heat. I seriously do not think its that high.

 

I always wanted to "chip" my '89 T Cab as well but was reluctant to be a test pilot. Keep us up dated and let em know, I am right behind you if all goes well...my T is completely stock and was reluctant to even go with the K&N for fear of fouling the MAF's which I have learned from experience if they are off , your Ferrari life can become hell!

I was going to use Imported Cars of Stamford for the chip and dyno work...we will ahve to compare notes...