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El Verdugo · Joined: 15 Feb 2005 Posts: 502 Location: New Orleans

Since these CVT transmissions are being more and more used in the auto industry. I had a client called me asking me if my dyno could test cars with a CVT? He sent me to a thread on a Sentra forum and there there was a comment about how hard it is to test these cars on dynos due to the finicky way the CVT transmission behaves.

So I ask the forum if some one has tested and what thing to look out for when trying these vehicles out.

Thanks,
Alberto
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Alberto I Correa, Jr.
EFI 101 Graduate 7-16-05
AEM EMS factory trained
www.corrperformance.com

Gadgeroonie · Joined: 24 Aug 2004 Posts: 1723 Location: UK

yes you can run them fine

but

they do not represent a fixed drive from the engine to the wheels

so make the customer aware you are measuring wheel power only

getting an rpm signal from the engine itself may be beneficial and plot any graphs with time along the x axis and rpm up the side for simplicity
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Dyno Developments
2WD and 4WD Chassis Dynamometers

www.DynoDevelopments.co.uk

El Verdugo · Joined: 15 Feb 2005 Posts: 502 Location: New Orleans

Thanks man for the tips on testing these cars. I really appreciate it!

Have a good weekend.
_________________
Alberto I Correa, Jr.
EFI 101 Graduate 7-16-05
AEM EMS factory trained
www.corrperformance.com

awddynotodd · Joined: 21 Oct 2006 Posts: 249 Location: Sydney, Australia

I've driven a few different cars with CVT, but I recall testing a Mitsubishi Lancer renter with a CVT and on it you just moved the gear lever to the manual slot and you could test it just like any normal transmission.

El Verdugo · Joined: 15 Feb 2005 Posts: 502 Location: New Orleans

Thanks Todd.
_________________
Alberto I Correa, Jr.
EFI 101 Graduate 7-16-05
AEM EMS factory trained
www.corrperformance.com

sohc_mshue · Joined: 04 Mar 2006 Posts: 366

Like others said you will not be able to get engine torque by using roller speed as an engine speed estimate. An engine speed signal will be needed. The CVT should do fine though on the dyno. I test these on the dyno on a regular basis.
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www.shuetuning.net
efi101/102 graduate

PanteraTurbo · Joined: 28 Jul 2007 Posts: 128 Location: Victoria, BC

Gadgeroonie, Thanks for the tip on running one axis as time. We were waiting for a customer this past weekend and decided to throw my 50cc scooter on the rollers. The plot was pretty useless. In case anyone is wondering it made 4hp and hardly registered any torque.
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Blaine Carmena
blaine@5252motorsports.com

stevemhudson · Joined: 13 Jul 2006 Posts: 10

Raising this thread from the dead.

Had a customer with a Polaris RZR with a CVT belt drive on my DD dyno yesterday and couldn't get a good sweep test. Put a load on the dyno and held a constant throttle position to keep RPM constant, then hit the Up switch and rolled into the throttle. At about 8,000 the RPM stopped climbing but MPH continued to increase making a vertical line on the graph. And it measured very low HP, 45HP. Any tips or thoughts on what I should do?
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Steve
www.powercurvedyno.com

baldur · Joined: 12 Oct 2007 Posts: 430

I'd recommend popping the clutch off and connecting the engine by a driveshaft to an engine dyno, if engine performance is what you want to assess.
You could also limit the shiftout of the transmission by making a spacer that goes where the spring is in the primary pulley, preventing it from upshifting beyond a certain point.

stevemhudson · Joined: 13 Jul 2006 Posts: 10

I don't have an engine dyno, so that's not an option. I need to research the spacer idea.
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Steve
www.powercurvedyno.com

boca juniors · Joined: 21 Nov 2003 Posts: 126 Location: NOLA