User Tag List

+ Reply to Thread
Results 1 to 25 of 25

Thread: Engine dyno vs in car figures

  1. #1
    Bodger

    Join Date
    Jul 2012
    Location
    Essex
    Age
    28
    Posts
    157
    Thanks
    0
    Thanked 6 Times in 6 Posts

    Engine dyno vs in car figures

    Hi All,

    Looking for some experiances here. Iíve got a friend who runs a full modern spec rally escort. He recently received a 2.4 duratec from and VERY reputable builder. The engine produced 320bhp and 225ft/lb in the dyno cell. With the engine is in the car, itís been in for remapping by again, a VERY reputable mapper.

    Now the engine is in the car itís making 284bhp and 197ft/lbs, I think we all understand that an engine dyno is the absolute perfect condition for making power, and in car there are realities like an inner wing and full exhaust that with affect power.

    My question/comments to him are, would you expect to lose as much as 35bhp and 30ft/lb? It seems a large amount for the sake of getting it into the car. Or is there something in the setup that damaging a great engine? Exhaust manifold (Simpson) or something similar?

    thanks guys

  2. The Following User Says Thank You to Shaunster For This Useful Post:


  3. #2
    TURBOSPORT SPONSOR Turbosport Subscriber
    Turbosport Moderator
    Turbosport Administrator
    Graham's Avatar
    My Race Car
    My 1st Project
    Join Date
    Feb 2006
    Location
    Ely, Cambs
    Age
    51
    Posts
    23,180
    Thanks
    226
    Thanked 1,835 Times in 1,719 Posts

    Re: Engine dyno vs in car figures

    if the engine wasnt dyno'd and rolling roaded on the same exhaust manifold and system, that could easily be a large chunk of the difference

  4. #3
    Racer Decade Plus User wildo105e's Avatar

    My 1st Project
    My 2nd Project
    Join Date
    Oct 2006
    Location
    Manchester
    Age
    48
    Posts
    2,602
    Thanks
    82
    Thanked 148 Times in 146 Posts

    Re: Engine dyno vs in car figures

    Are we talking flywheel or at the wheels figures ?

  5. #4
    I support TS Turbosport Subscriber rallyrob's Avatar

    Join Date
    Apr 2010
    Location
    Middlesex
    Age
    50
    Posts
    1,649
    Thanks
    54
    Thanked 106 Times in 100 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by wildo105e View Post
    Are we talking flywheel or at the wheels figures?
    My understanding is this is both sets of figures.

    This is the engine on the dyno

    Quote Originally Posted by Shaunster View Post
    The engine produced 320bhp and 225ft/lb in the dyno cell.
    And this is the figure at the wheels with the engine in the car.

    Quote Originally Posted by Shaunster View Post
    Now the engine is in the car it’s making 284bhp and 197ft/lbs
    I'm not sure I understand how it works down from flywheel figures anyway. But I know you can lose a sizeable amount down through the drive train.
    Last edited by rallyrob; 16-01-2019 at 11:48.

  6. #5
    Racer Decade Plus User wildo105e's Avatar

    My 1st Project
    My 2nd Project
    Join Date
    Oct 2006
    Location
    Manchester
    Age
    48
    Posts
    2,602
    Thanks
    82
    Thanked 148 Times in 146 Posts

    Engine dyno vs in car figures

    Quote Originally Posted by rallyrob View Post
    My understanding is this is both sets of figures.

    This is the engine on the dyno



    And this is the figure at the wheels with the engine in the car.



    I'm not sure I understand how it works down from flywheel figures anyway. But I know you can lose a sizeable amount down through the drive train.
    Exactly at the wheels must include losses. Dyno will have none. Unless they have calculated the losses and are still missing loads of power ?


    Sent from my iPhone using Tapatalk

  7. #6
    Pit Crew

    Join Date
    May 2012
    Location
    Camberley, Surrey
    Posts
    1,995
    Thanks
    2
    Thanked 178 Times in 178 Posts

    Re: Engine dyno vs in car figures

    Different dynos (completely different in this case), different days, different atmospherics = different results. Only way to be sure is use the same dyno everytime for everything and even then you'll still get % variances. Most chassis dynos will use the rollers to drive the wheels on the down run to get an idea of transmission losses - 30 - 40hp doesn't sound outrageous bearing in mind to two figures could be high / low in comparison!

  8. #7
    Bodger

    Join Date
    Jul 2012
    Location
    Essex
    Age
    28
    Posts
    157
    Thanks
    0
    Thanked 6 Times in 6 Posts

    Engine dyno vs in car figures

    All flywheel figures, and drivetrain loses properly measured on run down, not calculated.

    Iím sure the builder would have had a dyno manifold, and the engine now has a Simpson 4-2-1 on. Maybe something there?

  9. #8
    TURBOSPORT SPONSOR Turbosport Subscriber
    Turbosport Moderator
    Turbosport Administrator
    Graham's Avatar
    My Race Car
    My 1st Project
    Join Date
    Feb 2006
    Location
    Ely, Cambs
    Age
    51
    Posts
    23,180
    Thanks
    226
    Thanked 1,835 Times in 1,719 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by Shaunster View Post
    I’m sure the builder would have had a dyno manifold, and the engine now has a Simpson 4-2-1 on. Maybe something there?
    absolutely, even more so because in the dyno the exhaust will be totally different, if not non existant

  10. #9
    Bodger

    Join Date
    Jul 2012
    Location
    Essex
    Age
    28
    Posts
    157
    Thanks
    0
    Thanked 6 Times in 6 Posts

    Engine dyno vs in car figures

    Has anyone got first hand experience of something like a millington before and after? Iíd had a 20bhp loss in my head, just surprised itís as much as that.

  11. #10
    Bodger

    Join Date
    Apr 2013
    Location
    S Wales
    Posts
    74
    Thanks
    54
    Thanked 7 Times in 7 Posts

    Re: Engine dyno vs in car figures

    I've recently had a 2.1 Pinto dynoed at 153bhp at the flywheel, with 96bhp at the wheels. However, that then prompted me to look at the excessive drivetain losses seen. Turns out my left hand rear caliper was binding on.
    Although the RR session was worthwhile in balancing my carbs out and sorting my fuel mixture out, I had no idea my brake was binding before this. Click image for larger version Name:	2nd run~01~01.jpg Views:	215 Size:	56.3 KB ID:	83500

  12. #11
    Pit Crew

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    51
    Posts
    1,723
    Thanks
    5
    Thanked 149 Times in 129 Posts

    Re: Engine dyno vs in car figures

    I can hardly believe these engines can make 320 Bhp and 225 Nm from 2,4 Ltr. At what kind of RPM is this engine making 320 Bhp? Specially the torque sounds very high. That's 308 Nm without a turbo !!!!

  13. #12
    TURBOSPORT SPONSOR Turbosport Subscriber
    Turbosport Moderator
    Turbosport Administrator
    Graham's Avatar
    My Race Car
    My 1st Project
    Join Date
    Feb 2006
    Location
    Ely, Cambs
    Age
    51
    Posts
    23,180
    Thanks
    226
    Thanked 1,835 Times in 1,719 Posts

    Re: Engine dyno vs in car figures

    Ive seen a few duratecs make 300 bhp or over at dave walkers, but they all needed around 10,000 rpm to do it

  14. #13
    Pit Crew

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    51
    Posts
    1,723
    Thanks
    5
    Thanked 149 Times in 129 Posts

    Re: Engine dyno vs in car figures

    These are about the numbers I had in mind. Fortunately, once you want to upgrade from 300 to 320 you really need something more as extra 2įadvance. It's still miles away.

    I bet they where not making 225 ft/lbs.

  15. #14
    Mechanic lowscorts's Avatar

    Join Date
    Feb 2003
    Location
    Bucks
    Age
    43
    Posts
    600
    Thanks
    0
    Thanked 4 Times in 4 Posts

    Re: Engine dyno vs in car figures

    Get it all the time at work on both car and bike dyno, the car world is obsessed with crank figures and bikes are more wheel hp.
    see alot of bike engine cars and its dodgy doing coast down runs as the clutch release doesn't always survive so we dont offer it, all our figures are wheel figures and are generally iro 10% below crank figures

  16. #15
    Pit Crew

    Join Date
    May 2012
    Location
    Camberley, Surrey
    Posts
    1,995
    Thanks
    2
    Thanked 178 Times in 178 Posts

    Re: Engine dyno vs in car figures

    That's what drives the car along so should be the only pertinent measure............as long as no one changes the diff, the tyre (size / aspect / pressure) etc!

  17. #16
    Mechanic Matt75's Avatar

    My 1st Project
    Join Date
    Mar 2011
    Location
    Melbourne
    Posts
    756
    Thanks
    39
    Thanked 57 Times in 57 Posts

    Re: Engine dyno vs in car figures

    Had my Pinto dyno'd at 189hp at the flywheel and then 132hp at the wheels

    57hp seems like a lot but i was told 30% loss is normal

    Different operator though

  18. #17
    Pit Crew

    Join Date
    May 2012
    Location
    Camberley, Surrey
    Posts
    1,995
    Thanks
    2
    Thanked 178 Times in 178 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by Matt75 View Post
    Had my Pinto dyno'd at 189hp at the flywheel and then 132hp at the wheels

    57hp seems like a lot but i was told 30% loss is normal

    Different operator though
    Back in the day I chassis dyno'd my std RS2 which Ford quoted 110 crank hp and the rollers said 90hp so about 18-20% loss - 30% is NOT normal IMO!

  19. #18
    Pit Crew Forest_rallying's Avatar

    Join Date
    Feb 2013
    Location
    Derbyshire
    Posts
    1,224
    Thanks
    3
    Thanked 150 Times in 142 Posts

    Re: Engine dyno vs in car figures

    Back in the 80's the average Road Rally Pinto had approx 125 to 130 bhp at the wheels which we estimated to be between 150 and 155 bhp at the flywheel.

    A few years ago I witnessed a Pinto on 45's and a Burton 40/41 cam on an accurate calibrated static dyno and that made 160 bhp. The operator said that power was typical of an engine with a period cam in of the time.

    I certainly believe Katana's 18 to 20% loss is not too far off.

  20. #19
    Pit Crew

    Join Date
    May 2012
    Location
    Camberley, Surrey
    Posts
    1,995
    Thanks
    2
    Thanked 178 Times in 178 Posts

    Re: Engine dyno vs in car figures

    One thing to bear in mind is that transmission losses shouldn't vary much ie. if an engine dyno says you have 150hp and a chassis dyno says 120hp is hitting the tarmac then the loss is 30hp or 20%. But if you up the engine to 200hp you should still only suffer a 30hp loss and this only now equates to 15% ! !
    So IMO, % losses can be a bit misleading - probably why we bikers like rear wheel hp figures - level playing field (btw my bike has 370hp @ rear wheel)

  21. #20
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    43
    Posts
    18
    Thanks
    1
    Thanked 4 Times in 4 Posts

    Re: Engine dyno vs in car figures

    Its impossible to make comparisons because so many dyno's read differently, the important thing is to have accurate data logging, a good dyno operator and a dyno that reads consistently to measure even the slightest change, and use the same dyno when carrying out development work. It's a tuning tool, people get hung up on chasing figures instead of using it properly.

    Warren
    https://www.facebook.com/Warren-Heath-Performance-135194779879292/

  22. #21
    Pit Crew

    Join Date
    May 2012
    Location
    Camberley, Surrey
    Posts
    1,995
    Thanks
    2
    Thanked 178 Times in 178 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by katana View Post
    (btw my bike has 370hp @ rear wheel)
    I think i'll add a % transmission lose - chains are really inefficient LOL! - say 20% ........ WOW 445hp - I like that number!

  23. #22
    I support TS Turbosport Subscriber rallyrob's Avatar

    Join Date
    Apr 2010
    Location
    Middlesex
    Age
    50
    Posts
    1,649
    Thanks
    54
    Thanked 106 Times in 100 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by katana View Post
    I think i'll add a % transmission lose - chains are really inefficient LOL! - say 20% ........ WOW 445hp - I like that number!
    Now you're just showing off...

  24. #23
    I support TS Turbosport Subscriber rallyrob's Avatar

    Join Date
    Apr 2010
    Location
    Middlesex
    Age
    50
    Posts
    1,649
    Thanks
    54
    Thanked 106 Times in 100 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by Forest_rallying View Post
    Back in the 80's the average Road Rally Pinto had approx 125 to 130 bhp at the wheels which we estimated to be between 150 and 155 bhp at the flywheel.

    A few years ago I witnessed a Pinto on 45's and a Burton 40/41 cam on an accurate calibrated static dyno and that made 160 bhp. The operator said that power was typical of an engine with a period cam in of the time.

    Sorry for a daft question, but is a static dyno an engine Dyno then?

  25. #24
    Pit Crew

    Join Date
    May 2012
    Location
    Camberley, Surrey
    Posts
    1,995
    Thanks
    2
    Thanked 178 Times in 178 Posts

    Re: Engine dyno vs in car figures

    Spot on - same by a different name. Just like Rolling Road dyno's can be termed Chassis dyno's.

  26. The Following User Says Thank You to katana For This Useful Post:


  27. #25
    Pit Crew Forest_rallying's Avatar

    Join Date
    Feb 2013
    Location
    Derbyshire
    Posts
    1,224
    Thanks
    3
    Thanked 150 Times in 142 Posts

    Re: Engine dyno vs in car figures

    Quote Originally Posted by rallyrob View Post
    Sorry for a daft question, but is a static dyno an engine Dyno then?
    Yes.

  28. The Following User Says Thank You to Forest_rallying For This Useful Post:


+ Reply to Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts