OPL-20T
17th July 2004, 09:10 AM
Date: Tue, 06 Apr 1999
From: Jim Conforti <[email protected]>
Subject: Dyno's and proper SCIENTIFIC procedure
Guys,
Before you let some slick haired dyno-boy take your money please take
some time and learn about proper procedure.. Especially if you're
trying to actually get some USEABLE information.
If you're not testing mods in a BEFORE and AFTER method, don't waste
your time and money.. or mine.. having to read the drivel.
The *proper* and *only* way to test something sorta goes like this:
1) Load car on dyno at full operating temp. (i.e. run it around
the neighboorhood for 10 mins and get everyone a cold GatorAde
since it's hot in the dyno room!)
1a) On OBD-II cars disconnect all 4 sensors and clear adaption.
2) Start car and run it for at LEAST 3 mins to get it into
RUNNING conditions and not "Start", "ColdStart", or
"After Start Enrichment" conditions.
(Yes, kiddies.. if you just start it and run it you can get
all SORTS of wild numbers depending upon how many seconds
between start and run.. until the NS timer runs out)
[Thats NS = NachStart = After Start]
3) Make at least THREE closely (I'll skip the statistics)
comparable (called *significant*) runs pre-mod..
4) If you don't get 3 tight runs.. let the car run LONGER before
the runs.. sometimes it takes FIVE minutes :(
and do MORE runs until you have 3 close ones.. 1-2%
5) Once you have 3 runs, record what you did to get them
6) Average the runs and plot
7) Make the *mod* ..
8) Again, warmup the car to operating temp..
9) Repeat 2-6 using the exact same method recorded in 5..
10) Compare the results..
10a) On OBD-II cars.. reconnect the sensors and clear faults
NOW.. GEE.. you have REAL SCIENTIFIC NUMBERS..
And if you're not doing it this way, which takes conservatively
2 hours per car per mod.. then don't waste your time or money
at they dyno.. or our time reading it.
Jim C.
--------------------------------------------------------------------------------
Date: September 20, 2000
From: dpeete <[email protected]>
Subject: Re: So how does one DYNO an OBD2 Car?
Sorry to dog your post last week, I didn't scroll down and see it until just a minute ago when I was scanning the archives. I will be at Laguna Seca in Nov with the Miata group, but not the BMWCCA event. As you know, the Miata guys are more fun!
As for the dynoing. The dyno day we did two weeks ago had every BMW get stronger on each run. The runs were pretty consistent and always had the best run towards the end of the session. For a hardcore, true dyno, Jim C had some long process which involved removing O2 sensors, clearing the Check Engine lights, dynoing... blah blah blah. It is most definitely the proper way of doing it, but you are probably just fine with disconnecting your battery for a few minutes and then plugging it back in. This doesn't clear all of the adaptation, but it does clear the Long Term Fuel Trim (as verified with OBDTool by Shawn Fogg). You can then take the car for a few hard runs around the block before throwing your car on the dyno. Remember to have the card with your radio code before doing this because you will have to re-enter it.
Cheers,
Doug
Posted by Luxo M3 on September 20, 2000 :
> Is there an OBD2 method for dynoing as it seems you can't just strap the car onto the machine and run.
> And will this method prove reliable?
>
> Thanks!
> Luxo M3
From: Jim Conforti <[email protected]>
Subject: Dyno's and proper SCIENTIFIC procedure
Guys,
Before you let some slick haired dyno-boy take your money please take
some time and learn about proper procedure.. Especially if you're
trying to actually get some USEABLE information.
If you're not testing mods in a BEFORE and AFTER method, don't waste
your time and money.. or mine.. having to read the drivel.
The *proper* and *only* way to test something sorta goes like this:
1) Load car on dyno at full operating temp. (i.e. run it around
the neighboorhood for 10 mins and get everyone a cold GatorAde
since it's hot in the dyno room!)
1a) On OBD-II cars disconnect all 4 sensors and clear adaption.
2) Start car and run it for at LEAST 3 mins to get it into
RUNNING conditions and not "Start", "ColdStart", or
"After Start Enrichment" conditions.
(Yes, kiddies.. if you just start it and run it you can get
all SORTS of wild numbers depending upon how many seconds
between start and run.. until the NS timer runs out)
[Thats NS = NachStart = After Start]
3) Make at least THREE closely (I'll skip the statistics)
comparable (called *significant*) runs pre-mod..
4) If you don't get 3 tight runs.. let the car run LONGER before
the runs.. sometimes it takes FIVE minutes :(
and do MORE runs until you have 3 close ones.. 1-2%
5) Once you have 3 runs, record what you did to get them
6) Average the runs and plot
7) Make the *mod* ..
8) Again, warmup the car to operating temp..
9) Repeat 2-6 using the exact same method recorded in 5..
10) Compare the results..
10a) On OBD-II cars.. reconnect the sensors and clear faults
NOW.. GEE.. you have REAL SCIENTIFIC NUMBERS..
And if you're not doing it this way, which takes conservatively
2 hours per car per mod.. then don't waste your time or money
at they dyno.. or our time reading it.
Jim C.
--------------------------------------------------------------------------------
Date: September 20, 2000
From: dpeete <[email protected]>
Subject: Re: So how does one DYNO an OBD2 Car?
Sorry to dog your post last week, I didn't scroll down and see it until just a minute ago when I was scanning the archives. I will be at Laguna Seca in Nov with the Miata group, but not the BMWCCA event. As you know, the Miata guys are more fun!
As for the dynoing. The dyno day we did two weeks ago had every BMW get stronger on each run. The runs were pretty consistent and always had the best run towards the end of the session. For a hardcore, true dyno, Jim C had some long process which involved removing O2 sensors, clearing the Check Engine lights, dynoing... blah blah blah. It is most definitely the proper way of doing it, but you are probably just fine with disconnecting your battery for a few minutes and then plugging it back in. This doesn't clear all of the adaptation, but it does clear the Long Term Fuel Trim (as verified with OBDTool by Shawn Fogg). You can then take the car for a few hard runs around the block before throwing your car on the dyno. Remember to have the card with your radio code before doing this because you will have to re-enter it.
Cheers,
Doug
Posted by Luxo M3 on September 20, 2000 :
> Is there an OBD2 method for dynoing as it seems you can't just strap the car onto the machine and run.
> And will this method prove reliable?
>
> Thanks!
> Luxo M3