Join Today
Page 1 of 2 12 LastLast
Results 1 to 20 of 23
  1. #1
    Senior Member
    This user has no status
    volvotuning's Avatar
    Join Date
    Oct 2004
    Posts
    1,894
    Thanks
    0
    Thanked 1 Time in 1 Post

    Lightbulb The Science of Dyno Testing

    I have written an article about dyno testing. For anyone who wonders why people argue about accuracy of figures etc, have a read of this. It's quite long, and a bit complex in places but I've tried to keep it as simple as possible.

    Here is the link -

    www.dyno-tuning.com\dyno-tuning\dynoscience.pdf

    Adam.

  2. #2
    Lawnmower Boy
    Now known as WAPAHO!!!
    JUDGENINJA's Avatar
    Join Date
    Nov 2004
    Location
    Guildford, Surrey
    Posts
    6,707
    Thanks
    1,058
    Thanked 1,733 Times in 1,162 Posts
    Nice ...not overly complicated article...now it's late so go to bed...!!!!


    Current Garage:
    1997 960 3.0L 24v - Polestar...(Honest guv..!!)
    1997 855 T5 S - stripped to 1300kgs gross weight - 14.2sec qtr(rank 17*)
    2001 V40 T4 SE - 14.199@100.15MPH - Hybrid Turbo/VXR injectors and DeCat(Rank 15*)
    *Data Sept 2013
    Any Stuff For Sale - check out my Ebay link

  3. #3
    Andrew
    Guest
    This user has no status
    and the correct URL is:

    http://www.dyno-tuning.com/dyno-tuning/dynoscience.pdf

    Well done Adam.

  4. #4
    Senior Member
    This user has no status
    Vikingxl's Avatar
    Join Date
    Mar 2005
    Location
    Reykjavic
    Posts
    7,766
    Thanks
    656
    Thanked 670 Times in 487 Posts
    Cheers Adam!

  5. #5
    Senior Member
    This user has no status
    volvotuning's Avatar
    Join Date
    Oct 2004
    Posts
    1,894
    Thanks
    0
    Thanked 1 Time in 1 Post
    If anyone does read it (without falling asleep) and would like any clarification about any point discussed, please let me know so I can include it in the document.

    Adam.
    Last edited by volvotuning; Friday 3rd February 2006 at 10:45.

  6. #6
    Member
    This user has no status

    Join Date
    Aug 2004
    Posts
    8,250
    Thanks
    73
    Thanked 229 Times in 169 Posts
    Blimey - beauty and brains LMSO!!

    Useful info, makes for interesting reading (and i am still awake!!)

    Thanks

    x

  7. #7
    Senior Member
    This user has no status
    Engineer's Avatar
    Join Date
    Aug 2005
    Location
    London
    Posts
    2,024
    Thanks
    5
    Thanked 45 Times in 24 Posts

    Cool

    Should make it a sticky as it would help new and old members alike who may miss it this time.

  8. #8
    Suspended
    This user has no status

    Join Date
    Oct 2005
    Posts
    332
    Thanks
    0
    Thanked 1 Time in 1 Post
    interesting - thanks.

  9. #9
    Senior Member
    This user has no status
    siamblue's Avatar
    Join Date
    Nov 2004
    Location
    Ilford,Essex.
    Posts
    6,154
    Thanks
    747
    Thanked 403 Times in 349 Posts
    Cracking read Adam, very interesting

    Gary
    V40 2.0T Sport Lux Titanium grey,(03) 133k,standard
    Yamaha R1 5VY,(06) 180bhp/165whp,100nm

  10. #10
    Senior Member
    This user has no status
    volvotuning's Avatar
    Join Date
    Oct 2004
    Posts
    1,894
    Thanks
    0
    Thanked 1 Time in 1 Post
    I've made a a few ammendments, thanks to feedback from Chris Kay!

    1. Spelling mistakes removed (due to writing at 4am LOL).
    2. Chassis Dyno description paragraph ammended.
    3. Explanation why measuring drag loss on coast down will never give 100% accurate engine power.

    Thanks!

    Adam.

  11. #11
    Senior Member
    This user has no status
    aeroresh's Avatar
    Join Date
    Aug 2005
    Location
    Mold, North Wales
    Posts
    600
    Thanks
    29
    Thanked 24 Times in 22 Posts
    Very interesting and I didnt fall asleep.

    Who dares to post up the link on VOC then?
    '96 855 T5 auto ...GT30 and everything uprated!

  12. #12
    Suspended
    This user has no status

    Join Date
    Nov 2005
    Posts
    260
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Found this info on the scooby forum, very interesting reading!

    http://www.dentistmapped.com/roadtuning.htm

  13. #13
    Senior Member
    This user has no status
    volvotuning's Avatar
    Join Date
    Oct 2004
    Posts
    1,894
    Thanks
    0
    Thanked 1 Time in 1 Post
    I do agree with most of the stuff said on there, but there is one point which does need to be addressed - ROAD MAPPING!!!!

    Road Mapping is for race cars and NOT for road cars. As it states, the track mapping is the final testing stage, which I also agree with.

    Mapping on the road from scratch is generally a bad idea, and anyone who says it's a good idea will normally say so because they don't have a dyno. Mapping on the road is very danegrous for a start, and requires speed of 40-130 mph on a T5, which is quite obviously impossble to do legally in the UK on the public roads. Also, on the road it's not possible to hold a fixed rpm if you need to do static load mapping. I've mapped on the road before and it's not something I'm comfortable with, mainly from the safety aspect.

    In summary, you should always map on a dyno and test on the road. Not the other way round.

    Adam.
    Last edited by volvotuning; Sunday 5th February 2006 at 11:57.

  14. #14
    Senior Member
    This user has no status

    Join Date
    Apr 2005
    Location
    stratford on avon
    Posts
    252
    Thanks
    3
    Thanked 0 Times in 0 Posts

    Wink

    Quote Originally Posted by volvotuning
    I have written an article about dyno testing. For anyone who wonders why people argue about accuracy of figures etc, have a read of this. It's quite long, and a bit complex in places but I've tried to keep it as simple as possible.

    Here is the link -

    www.dyno-tuning.com\dyno-tuning\dynoscience.pdf

    Adam.

    ya i no !!!!

  15. #15
    Senior Member
    This user has no status
    pault5's Avatar
    Join Date
    Sep 2004
    Posts
    412
    Thanks
    69
    Thanked 23 Times in 18 Posts

    Wink

    Quote Originally Posted by aeroresh
    Very interesting and I didnt fall asleep.

    Who dares to post up the link on VOC then?


    Go on I dare you

  16. #16
    Senior Member
    This user has no status
    volvotuning's Avatar
    Join Date
    Oct 2004
    Posts
    1,894
    Thanks
    0
    Thanked 1 Time in 1 Post
    If anyone is interested in what sort of fan you need to give a turbo car half a chance on the dyno, here is the one we use -



    And before the clever ones comment, yes it's parked outsided to show you a comparison of size against a Pug 106.

    Even this thing struggles in the peak of summer to keep intake charge temps down.

    Anyone who has been to us knows that we have two fans - a very small one, and the large one shown above. We use the small one when doing some diagnostics work where we are not looking for best performance figures. But when we are trying to get the maximum performance out of the car, we always use the large one.

    Adam.

  17. #17
    Senior Member
    This user has no status
    GuyD5's Avatar
    Join Date
    Aug 2004
    Location
    Halesowen, West Midlands
    Posts
    525
    Thanks
    2
    Thanked 3 Times in 1 Post
    Missed this the first time round, thanks for putting the picture up and bumping the thread Adam ... makes interesting reading and explains a lot of what goes on with the dyno testing ... thanks again mate
    Wise men talk because they have something to say; fools, because they have to say something - Plato

  18. #18
    Member
    This user has no status

    Join Date
    Mar 2005
    Location
    New Zealand
    Posts
    33
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Excellent read…thanks for that Adam.

    Not having ever seen a Dyno in action, your article was well worth the time taken to read and no I didn’t fall asleep.

    I have a couple of questions however.

    With regard to “Operator Issues” and more specifically “Incorrect Coast Down”, you mention that during coast down on a manual car, the operator must dip the clutch at the end of the run to disengage the clutch from the engine to allow the Dyno to measure the power back to the clutch or the flywheel. Some operators put the car into neutral, which has the effect of lowering drag losses, thereby reducing power figures when convenient.

    Question: What is the procedure when you have a car equipped with an Automatic transmission on the Dyno? The same as above? What is the nett. effect of what happens?

    Question: We have all seen Dyno charts that have all these squiggly lines all over the place, but how do you read them, and how can you tell if they have been “fudged”?

    Can you please write an article on this as well at some stage?
    Geezer

    Eargasm: A 2.3 Litre 225HP 5 Cylinder 20 Valve At Full Howl!!

  19. #19
    Senior Member
    This user has no status
    volvotuning's Avatar
    Join Date
    Oct 2004
    Posts
    1,894
    Thanks
    0
    Thanked 1 Time in 1 Post
    Quote Originally Posted by Geezer
    Excellent read…thanks for that Adam.

    Not having ever seen a Dyno in action, your article was well worth the time taken to read and no I didn’t fall asleep.

    I have a couple of questions however.

    With regard to “Operator Issues” and more specifically “Incorrect Coast Down”, you mention that during coast down on a manual car, the operator must dip the clutch at the end of the run to disengage the clutch from the engine to allow the Dyno to measure the power back to the clutch or the flywheel. Some operators put the car into neutral, which has the effect of lowering drag losses, thereby reducing power figures when convenient.

    Question: What is the procedure when you have a car equipped with an Automatic transmission on the Dyno? The same as above? What is the nett. effect of what happens?

    Question: We have all seen Dyno charts that have all these squiggly lines all over the place, but how do you read them, and how can you tell if they have been “fudged”?

    Can you please write an article on this as well at some stage?
    Good questions!

    I will add the answers asap to the document. Interpreting a dyno chart is sometimes quite tricky, especially since many dyno systems present the info in different ways. Auto testing is a little more complex, and does sometimes present the dyno operator with some problems, so I will explain this in detail too. Give me a few days

    Adam.

  20. #20
    Member
    This user has no status

    Join Date
    Mar 2006
    Posts
    98
    Thanks
    0
    Thanked 0 Times in 0 Posts
    interesting read Adam, one point i must have missed in the text(which i feel is the most important) is dyno calibration, how and how often do you calibrate?, ive seen some muppets put there mums saxo on rollers before and calibrate from the factory specs :-), how do you do yours?
    surely none of the text is valid if the calibration is incorrect


 

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

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
  •  
This website uses cookies
We use cookies to store session information to facilitate remembering your login information, to allow you to save website preferences, to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.
     
ipv6 ready