dyno results - tyre effects
08-09-2011, 03:07 AM
#1
Three Wheelin'
Thread Starter
dyno results - tyre effects
I just did another dyno run with my car to baseline it before the ECU gets re-mapped this week. Since I have done a few dyno pulls in different configurations this particular run has highlighted the effect that tyres can make to a dyno reading. In this case 13Hp less recorded with my new PS2s vs with my old/worn Contis.
Details here ---> http://www.oz951.com/public/emmy.htm...%202011%20Dyno
I ended up doing a bit more research into the subject and have included a link to an interesting article.
There is also some information on spark plugs since I was doing some digging on that subject as well.
Details here ---> http://www.oz951.com/public/emmy.htm...%202011%20Dyno
I ended up doing a bit more research into the subject and have included a link to an interesting article.
There is also some information on spark plugs since I was doing some digging on that subject as well.
08-09-2011, 08:31 AM
#3
Rennlist Member
Even engine oil and transmission fluid can have an impact. It's even possible that there is a problem with the dyno's weather station - which is supposed to help correct for temp/humidity/pressure variations.
08-09-2011, 09:25 AM
#4
Three Wheelin'
Thread Starter
The weather station had fresh batteries, was reading as expected etc so I'm not doubting the setup of the dyno itself. (This is the same dyno I have been to the last 3 or 4 times and I am confident the operator knows what he is doing).
08-09-2011, 03:49 PM
#6
Three Wheelin'
Thread Starter
Trending Topics
08-09-2011, 06:31 PM
#9
Three Wheelin'
Thread Starter
The dyno has been run in the same configuration for my last 30 runs so SAE correction isn't a significant factor. If you look at the climatic conditions on the day of the last and previous run, they are not that much different anyway, a few of the conditions were slightly better and a few were slightly worse. The shootout mode is designed to account for those variations as it measures & calculates the result.
08-10-2011, 02:47 PM
#13
The difference in diameter between a worn tire and a new tire is ~12% (25.3" vs 25.0"). That yields a smaller moment arm at the contact patch of the tire and a reduced torque value of ~12%. This could easily account for your difference in measured torque values.
-Shawn
-Shawn
Last edited by Ubermensch; 08-10-2011 at 03:18 PM.
08-11-2011, 05:00 AM
#14
Three Wheelin'
Thread Starter
No worries, hopefully some info there will be of help at some point.
Going to a differennt dyno in 1/2 hr to get the car re-mapped, so this will be interesting to note the differences between the initial run and my last run and then the differences before and after tuning as measured on the same dyno.
Wish me luck as we try and eek a few more ponies out of her.
08-11-2011, 03:08 PM
#15
Drifting
Join Date: Jul 2005
Location: Prince George's County, MD
Posts: 2,481
Likes: 0
Received 1 Like
on
1 Post
I noticed no one mentioned how tightness of straps affect the dyno results.
No worries, hopefully some info there will be of help at some point.
Going to a differennt dyno in 1/2 hr to get the car re-mapped, so this will be interesting to note the differences between the initial run and my last run and then the differences before and after tuning as measured on the same dyno.
Wish me luck as we try and eek a few more ponies out of her.
Going to a differennt dyno in 1/2 hr to get the car re-mapped, so this will be interesting to note the differences between the initial run and my last run and then the differences before and after tuning as measured on the same dyno.
Wish me luck as we try and eek a few more ponies out of her.