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360 Challenge Stradale Dyno Run II

Discussion in '360/430' started by thomas_b, Jan 23, 2004.

  1. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    User Manual (Flywheel):
    HP (EEC Dir. 97/21): 425 HP @ 8500 RPM
    Torque (EEC Dir. 97/21): 275 lb. ft. @ 4750 RPM

    Dyno Run (Rear Wheel):
    HP (SAE J1349): 329.4 HP @ 8000 RPM
    Torque (SAE J1349): 243.1 Ft-lbs @ 4750 RPM

    As you can see from the attached graph at 8000 RPM the engine would dramatically reduces power. This is consistent with the first run we did. I have run the car for >300 miles with 76 100 octane racing gas, i.e. it was also used during the dyno run; based on that I believe that the car does not runs into knock control as assumed for the first run

    The ECU throttles down the car above 8000 RPM in V gear. We did runs in III and IV gear to see if we can get results without the drop at the end. Although no drop occurs the HP & Torque numbers did not reach the V gear runs, i.e. the car run strong up to the rev limiter but results are significant lower.

    The most likely reason for this consistent behavior in V gear is that the ECU is programmed to protect the cats. Note that (to my knowledge) the Stradale is supposed to never up shift automatically, however it does that in normal mode and V gear on the dyno at the same RPM point! All my runs therefore have been done in race mode.

    I extrapolated the numbers and we should have seen:
    349.7 HP @ 8500 RPM

    Based on 350HP the drive train loss is reasonable. Now we need someone in the EU to dyno the car to see if the same behavior is displayed
     
  2. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,505
    The twilight zone
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    The Butcher
    It's a little hard to see, but it looks like a much cleaner graph than was posted before, very smooth just like it should be, the octane helped, al the dips are gone....right up to 8K anyway where the ECU is clearly cutting the power. Is there a place in your area that has a 4 wheel dyno? You may be able to get it to pull smooth to redline with the front wheels spinnning???
     
  3. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765

    the dyno I am using is actually a 4 wheel one - I did plan to try it but we run out of time - there are a limited number of runs you can do because of increasing heat (by the way - we had a fan pointing into the engine bay this time too)

    your theory was our third choice - impact of ASR failure on engine ECU (the light comes on) - second choice: missing air flow due to standing operation and related ECU reaction

    next step for me is to talk to the F folks and find out what they think
     
  4. 720

    720 F1 Rookie

    Jul 14, 2003
    2,623
    So. Cal and No. Utah
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    Rick
    i'm going to try to pass these results to a friend of mine who has a friend at ferrari. i'll let you know if i get any answers.

    thomas, did your butt-dyno (brian recently coined this term i believe) feel any difference between pump gas and 100 octane gas while driving those 300 miles (around town i presume)? i want to do everything within reason to optimize the performance of my stradale and if mixing some 100 octane race gas with pump gas registers well on the butt-dyno then i will do it :)
     
  5. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    driving the car is so cool that I don't trust my butt-dyno anymore at all - having said that the car feels much more smooth during acceleration

    I am using a gt2 timer and that shows an improvement - there was also some ringing sound from the engine during accelaration from below 3000 rpm which is gone

    without a consistent baseline on the dyno it is very hard to make any assessment
     
  6. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,505
    The twilight zone
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    All good ideas...speaking off the "butt dyno", if the engine is realy loosing 25% of it's power at 8k on the road, there is no doubt you'd feel it. If it pulls smoothly to redline, I think you can safely claim 350 rwhp and it's making what the factory says it should.
     
  7. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    It might be worth trying a calibrated butt-dyno... go get a G-Tech and see what an accelerometer gives you with and without the 100 octane gas. You can't judge Ferrari's numbers with it... but if you're consistent with your test conditions, you can measure deltas with it. And you can see what the shape of the actual in-motion curves are and compare to what you're seeing on the dyno to see if the stagnant conditions might be contributing negatively to the measurements.

    Just a thought. (Whenever mine arrives, I'll be doing both!)
     
  8. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765

    V gear & 8000RPM ~ 140 mph - what type of "road" you are talking about - yes I agree with 350hp for the US but that should mean close to 360hp in the EU without the pre-cat - this is what I am dreaming about
     
  9. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    on the track yes - but with the current weather and typically three big winged japans cars following me on public roads - easier said than done
     
  10. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,505
    The twilight zone
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    I was thinking maybe second gear. When I'm testing or rough tuning my car, I find a nice quiet, straight back road or and do a few second gear pulls or 3rd gear pulls on the highway, that keeps the speeds reasonable. With a g-tech, you could easily make a second gear hp curve, then do it in fith gear from idle up to say 80 mph. If they are the same (like they should be) then you know the second gear pull to redline is good. The only way I can think of that the hp can be signifiganly lower in the lower gears is if the EUC is pulling the power back. The only way I can think of that it would know to do that is info from the wheel sensors and that won't be a problem with the car in motion. The only other way would be if it's using the gear selection info, but I don't think it would make any sense to to cut the power all the time in gears 1-4. I really think it's the wheel sensors. They are making things so freakin complicated these days...now that is is finally easy to find a machine to measure hp, the car makers start building cars that can't be measured.....
     
  11. FLATOUTRACING

    FLATOUTRACING F1 Rookie

    Aug 20, 2001
    2,684
    East Coast
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    Jon K.
    I have dynoed my 355 C using everything from 93, 95 and up to 100 and at most we saw 2 hp gain. Keep in mind I have no emissions gear on the car.

    Where we saw the most improvement was when we jumped to 110 leaded race gas (which can't be used on a CS with emissions gear).

    We registered a 3.4 total hp gain.

    Bottom line is that you aren't going to notice the additional power through you seat of the pants. However you might notice better driveability with higher octane.

    Regards,

    Jon P. Kofod
    www.flatoutracing.net
     
  12. rketex7

    rketex7 Formula Junior

    Jan 8, 2004
    508
    Midwest
    Full Name:
    K.C.Y.
    Jon,

    For live of me, I can not find anywhere on the internet or this forum for the rwhp of anyF355. Of course, there are claims of my friend heard and had.... But can you share your dynoed result of your F355. I am looking to add just a Challange exhaust as mod. From the look of the exhaust, it will be very loud right...? T.I.A.

    Ken
     
  13. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765

    I did the 100 octane exercise because of an assumed knock problem with the 92 pump gas - in the absence of knock the higher octane is a waist of money - I tried to calibrate and find the best octane mixture but got impatient - my conclusion is to use 100 octane only for the track
     
  14. FLATOUTRACING

    FLATOUTRACING F1 Rookie

    Aug 20, 2001
    2,684
    East Coast
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    Jon K.
    Ken,

    I only ever dynoed my 355 in street form once and I seem to recall that it made 304 at the rear wheels. This was with a Tubi sport exhaust and the stock ECU's.

    Once it was converted to a Challenge car and we took off all the emissions gear and added the updated Challenge software it dynoed between 312 and 319 rear wheel horsepower over the past 3 years.

    Most of the 95 OBDI Challenge engines dynoed between 311 and a high of 321 at the rear wheels from what Ferrari of Washington and people like Rob S. have indicated here on Ferrarichat.

    There are two Challenge exhausts the muffled one and the one without mufflers.

    If your car is a street car the loud Challenge exhaust will not pass most noise ordinances. Mine registered 110 db's which will wake up the whole neighborhood.

    I had to pull my trailer into my driveway and winch the car into it. It was way too loud to start in the driveway or in the garage.

    Regards,

    Jon
     
  15. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    on the dyno you get higher parasitic losses if you use lower gears - a lot of the differences are created by the fact that the inertia mass simulated by the dyno does not match road conditions - the faster the car accelerates the more (inertia) loss in the drive train occurs

    validation on the road does not take different weather conditions into account

    comparing the P car and F car runs I have seen I am of the opinion that P takes special car of the dyno situation and F not – sort of similar to high-end audio gear which is optimized for the standard measurement patterns – P knows that a large percentage of cars is put on the dyno – a fool who would not take this into account – this is an opinion

    my dealer promised to try to hook me up with some F dyno folks – we simply have to get more know-how how to treat these cars on the dyno
     
  16. rketex7

    rketex7 Formula Junior

    Jan 8, 2004
    508
    Midwest
    Full Name:
    K.C.Y.
    Jon,

    Thanks for the great info. A friend of mine just replaced his F355 F1 for 360C. So he has a Challange exhaust from the F355 which looks to me like just straight pipes with 2 resonaters. Although I never heard it when he had it on the F355. According to him, it almost sounds like his 360 C. Well, it is loud...!

    Thanks!

    Ken
     
  17. tracknut

    tracknut Rookie

    Nov 1, 2003
    31
    Folsom, CA
    Full Name:
    Dave Mills
    Definitely. Boy I wish you'd done this dyno on a dynojet, so it would be comparable to the dyno results practically everyone else uses. As it stands, unless someone's also dyno'ed on a Mustang Dyno, with the same parameters, you have nothing to compare to. I can virtually guarantee you that Ferrari's factory numbers do not include predictions of "road conditions".

    Dave
     
  18. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    the different results from the dynos come to a large degree form the mass equivalents they are using (caused by the roller design) - Mustang 1088kg and Dynojet 1633kg - the closer the ME to the cars weight the better the results (and more realistic)

    the Mustang is the only 4 wheel dyno in my area that's the reason I am using it - but I might change since we have such a hard time to get at the raw data in the dyno software - one of the nice things of a dyno is that you can run stable patterns to analyze what the car is doing - I haven't even gotton there with all the stupid max. HP runs :-(
     
  19. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,505
    The twilight zone
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    "validation on the road does not take different weather conditions into account "

    I was really just talking about the 8000 rpm step, not the exact numbers and thinking you could do the street runs back to back....hopefully ferrari can answer the questions so you can concentrate on just enjoying it :)

    "on the dyno you get higher parasitic losses if you use lower gears - a lot of the differences are created by the fact that the inertia mass simulated by the dyno does not match road conditions - the faster the car accelerates the more (inertia) loss in the drive train occurs"

    When I had my car on the dyno (dynojet) a couple years ago, I did pulls is 2-5 and they were within a few hp, like 300-304. The drums inertia is pretty big compared to the drive train so I didn't see a big difference, although I guess it would be more pronounced on the mustang since it has a lighter drum. When the weather breaks, I need to get back on the dyno and see how the upgrades (intercooler and bigger supercharger) I finished in the fall are working out and get the fine tuning done.
     
  20. 4sfed4

    4sfed4 Karting

    Dec 22, 2003
    231
    The dyno I use tested what I believe was a stock F355. Ignore the lower run on that chart as that was a different car.

    [​IMG]
     
  21. 4sfed4

    4sfed4 Karting

    Dec 22, 2003
    231
    Those dynos also measure using different methods as well.
     
  22. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    6,988
    I took the liberty of drawing some lines on the dyno run. I must say, i like the shape of the dyno run right up to the point the engine runs south.

    It is easy to pick out the harmonics of the intake system. There is a low end operating range from idle to about 4000 RPMs. There is a region from about 4000 RPMs to 6400 RPMs where the torque curve is boosted by the longer path of the intake system. There is a region from 6400 to 8000 where the torque curve is boosted by the shorter path in the intake system. Then there is an indication that the ECU took out either fuel, advance, or throttle in the region over 8000 RPMs.

    I took the liberty of extending the current torque at the top end and found this line intercects the 8500 RPM point at 207 lb-ft. This corresponds to 335 HP.
     
  23. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    you are correct and I was wrong in my extrapolation - shh

    I have the raw data and

    RPM.......Torque.........HP
    7900......217.17.........328.70
    8000......215.17.........329.41
    8100......196.69.........303.89

    the previous 5 Torque value samples decreased on average by 2 per 100

    HP = (RPM * Torque) / K and K = 5225.6 based on dyno adjustment

    8500.....205.............333HP
     
  24. spyderman

    spyderman Formula 3

    Nov 4, 2003
    1,469
    Toronto - Canada
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    Spyderman

    What do you think you are losing in the ram air effect??
     
  25. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    I don't know - I tried to find some figures but most results seemed to be as good as randomly picking a number

    one assumption for the dyno run is that the ECU senses missing air flow compared to what is programmed into its map and goes into protective mode, i.e. reduces throttle as seen in the graph

    obviously the designers have included a protection mode - we need to figure out what they want to protect and based on what combination of sensor signals
     

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