When we set the dyno to a steady state at 2000rpm it fluctuates.. And we are kind of thinking it is the cars ignition system that simpley interfere with the dyno. We have tried 3000 and 4000 rpm also.. We have come to the conclusion that it is not the car that makes the dyno unstable mecanicly.. It is the dyno that cant keep the car stable at a given rpm..

Have anyone had problems like this..

The car is a jdm crx sir with obd 0 distribuator and accell external coil. Magnacore sparkplug wires.

We have tried to go back to stock distribuator with stock coil, changed to msd plug wires. Disconected caralarm, disconected alternator. The sparkplugs are NGK comen r ones that worked 100ds of times before.. AFR is fine.
We tried mount a complete stock volvo on it and it keeps it stable.

We are lost?

The car works fine on the road when we road tune it up to 0,7 bar of boost. We stoped there and was thinking that we will do the rest at the scedual dynotime.
Only the innovative wideband lambda spiked some times to like 27 in afr for lika half a second if even that when we road tuned it. I guess that it is also effekted by the interferance of some sort..

But what the h*** are we going to do to fix this..?

The dyno has no electric incomen with the car.


Modified by The sweed at 11:11 AM 5/12/2008


Modified by The sweed at 2:12 PM 5/12/2008

 

Bump..

 

I see no one has replied.

Have you tried these people?

http://www.dynopack.co.nz/

 

I think Enzo on here is a dealer.

 

I have posted on evans tunings forum but Jeff has never had any problem like that..

The guys that owns the dynapack told me they would see if they can get any support from dynopack in new zeland.

I think the problem is in the dyno and it makes it sensitive to electrical enterference..

 

If you ever figure this problem out please post up your findings. Although we have never experienced this type of problem on our dyno we certainly have seen "oddball" electrical problems and would like to know what caused it in the event it happens for us.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SpeedDreamz.com &raquo;</TD></TR><TR><TD CLASS="quote">I think Enzo on here is a dealer.</TD></TR></TABLE>

not for dynapak..

Does this happen on other cars or just this one?

 

We have a Mustang dyno but the same should apply.

Do steady state via the MPH that correlates to the RPM that you want to hold. Usually the inductive pickup is a little bit choppy and makes it difficult for the dyno to hold it steady.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by david@didrace.com &raquo;</TD></TR><TR><TD CLASS="quote">Do steady state via the MPH that correlates to the RPM that you want to hold. Usually the inductive pickup is a little bit choppy and makes it difficult for the dyno to hold it steady.</TD></TR></TABLE>

dynapak's get rpm from the hub speed..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Enzo-Racing &raquo;</TD></TR><TR><TD CLASS="quote">

dynapak's get rpm from the hub speed..

</TD></TR></TABLE>

I'm not familiar with them at all but they don't have any way to pick up RPM besides that? I've diagnosed many bad torque converters by comparing engine RPM via inductive pickup to wheel speed and doing some math to get torque converter slip %.

 

David, which Mustang dyno do you have? Sorry, not trying to hijack the thread....

 

MD250-P



That's me under the hood.

 

Pic doesn't load but thanks for the info.
We have a Mustang IMP-SE. Opted for the Mustang over Dynojet but sure wish the Powerdyne software was more intuitive!

 

Whoa! pic loaded now! A beautiful Mopar! I have a 70 Plymouth GTX and that pic makes my heart pound!

 

440 or a Hemi? and what did it put down?

Sorry again for thread hijacking.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike@OSTdyno.com &raquo;</TD></TR><TR><TD CLASS="quote">440 or a Hemi? and what did it put down?

Sorry again for thread hijacking.....</TD></TR></TABLE>

It was a while ago, I remember that day though the highest hp was a Chevy Truck - Diesel/Dually w/ stock turbo pushing 400rwhp w/ over 750 ft/lbs torque.

Mustang software is pretty nice, it just gets old explaining why their hp is low compared to a DynoJet.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The sweed &raquo;</TD></TR><TR><TD CLASS="quote">When we set the dyno to a steady state at 2000rpm it fluctuates.. And we are kind of thinking it is the cars ignition system that simpley interfere with the dyno. We have tried 3000 and 4000 rpm also.. We have come to the conclusion that it is not the car that makes the dyno unstable mecanicly.. It is the dyno that cant keep the car stable at a given rpm..</TD></TR></TABLE>

Try grounding the car to the dyno and dyno computer and then grounding the dyno equipment to an earth ground. I've had electrical issues with some cars that was solved by doing that. Mind you it was a different brand dyno so do at your own risk.

 

I actualy thought of that as a last test before we scedual on an other dyno.. I will ask the dyno owners if we can test that sometime..

 

I highly doubt that there is any sort of electrical interference issue with your setup.. What happens at the higher rpm at WOT? I've never had this issue with my Dynapack either..

 

The guys that owns the dyno had the same issue ones before.

They couldnt get a stable reading of the widband lambda ether. When they roted the lambda wire avay from the sparkplugs it got better. So the changed the sparkplug wires MSD ones and the problem went away completly.. The bad sparkplug wires had a coper lead.

I have also discovered today that the dyno has no conection to ground erth..

I bet that is the problem.. We will try to get a day off from our daytime job ones again and see if that is the problem. Over here we have 240 volt 1 phase. The ground erth is standard on newer buildings in cellers and garages and workshop etc.. But the building that the dyno is in did not have ground erth for some reason.. We will rout power from a grounded power sorce and see if that cures the problem..

I´ll post when we find out..

The new zeland guys was sure it was a mecanical problem in the car but that is ruled out. We regreted that we did not video taped that dyno setion.. But we will do it next time.

Edit: We did not try any wot pulls at the dyno but at open roads the car works greate anyway.. The cars tune works acceptable on low boost so we can make wot pulls to 8k anyway.. Maybe we will try that if the ground thing dont solve the problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by david@didrace.com &raquo;</TD></TR><TR><TD CLASS="quote">
Mustang software is pretty nice, it just gets old explaining why their hp is low compared to a DynoJet.</TD></TR></TABLE>

No kidding! Someone asked if they could name our machine the "heartbreak dyno"

 

I talked to the wrong guy.. it turned out that the dyno was conected to ground erth.

Back to scuere one.. I think we will try a diffrent dyno but it is in the middle of the season so I hope to get my hans on a canceled sesion.