Well I have two runs here.. neither are that great.

What gear do Auto's dyno in? Both of these were in 2nd which isn't the closest 1:1 ratio gear (3rd is)

1st Run - stock, pod, no mevi activating
2nd Run - Y, pod, no mevi activating

 

Yes it needs to be down in 3rd gear.

 

This is on a rolling road dyno (as opposed to hub dyno) the guy running dyno reckons if they dyno in 3rd it will just kick down? So US Auto guys are dynoing in 3rd? If so I'll insist the guy does it in 3rd next time

 

Get it up to about 70mph(115khm?) and floor it. Make sure it is in 3rd/overdrive

 

just for curiosity, will the hp and trq be higher or lower in 3rd gear

 

You mean o/d off?

Will be higher


Anyone else with actual experience dynoing a Auto? I'm trying to gauge if any other tuning shops dyno in 2nd or if they all use 3rd like I want my place too

 

ive used 3rd gear for comparion sakes to other maxima dynos since its closest to 1:1. i use 2nd gear for tuning so it doesnt take as long for a run. i run mine to 65mph on my speedo with o/d off and floor it and mine stays in 3rd.

 

this is good to know. when you guys mean overdrive on , does that mean when the od light is on or off.

 

overdrive is on when the light is off. the indicator light only comes when overdrive is disengaged.

 

ok, so we dyno with the od light off after 70?

 

I've dynoed in 2nd and 3rd. IMO 2nd > 3rd.

No difference in HP. Smoother line, More RPM's (A33B), less stress on the engine.

 

65 works for me but 4th may have slight different gear ratios. that i am not sure of but at 65 according to my speedo which is supposedly only off by 1.5%, it will not downshift into second.

 

I did back-to-back dyno runs on a Dynojet...one in 2nd, one in 3rd. They were virtually identical.

 

Why no VI activation?


I asked a local dyno about autos, he said you can unplug a solenoid so it wont kick down. Is that true?

 

what will happen if it kicked down while on the dyno?

 

You will get a spike in the graph

 

No VI as I was trying to activate via switch and fried it (awaiting Summit RPM switch)

You could disconnect the revolution sensor on the trans that'll stop the kickdown happened to my friend when had the VBmod done and they didn't plug his sensor in - no kick down.

 

Oh i thought your car had the VI stock, my B

 

He does. It just wasn't activating.

 

Could someone help with interpreting the results? Is the red line stock and blue line with y-pipe? It looks like the y-pipe has less power up to about 5400 RPM, then the y-pipe has much more power all the way to red line. Am I missing something? I like to add a y-pipe to my automatic car, but based on the above result I don't think I will benefit.

 

nope its the other one - my bad for not labelling properly

Blue was stock, Red is with the Y pipe

Following the Red line I get more torque and more power earlier in the curve - it looks like a 10kw gain across curve (3400rpm to 5000rpm).. when my VI (when fixed) kicks in at 5100rpm the curve will look even better.

FAVOUR PLEASE Can some convert my torque figure to the torque figure you guys use so I can compare.. my maths is bad

 

after dynoing hundred of automatic cars, one learns where the kickdown is. Once that is known then the test starts from there. There arent many auto trannies that will not kickdown. as for dynoing a car in 1st or 2nd gear... that creates a lot of distortion and movement on the cars on the rollers. Also its very stressful to the straps.

We perform our tests on 3-4 on 5 speed cars and 4-5 6 speed cars. When doing steady state tuning we like to work on 4th gear.