Quote:
Originally Posted by Myxalplyx
I just left the dyno shop. My intention was to show the difference a Level 10 Hydrosystem (Valve Body) has between shifts versus a stock shift setup. Also, I was going to compare a cold air intake setup with the ToMyx intake vs the engine bay setup I previously tested. I don't expect anything hp related to heat going through the air filter since it was tested in the engine bay with the hood open. I wanted to see if the extra length of tubing going into the fenderwell showed any difference than a short tube in the engine with length and/or sound resonance from the throttle bodies. Main purpose though was to look at shifting changes in between gears though.
Anyway, the dyno operator (Andy) was having trouble with the AWD system. The front wheels were moving much faster thant he rear wheels on the rollers. This did not happen with the previous dyno runs I did. With this happening, a dyno run could not be performed. I called TomsSVX inquiring about this while the car was on the dyno. He suggested adjusting the throttle position sensor. It needs to be at .48 - .5 (Help me out here Tom if you read this..  ) while the car is at idle. This sensor reads info to the TCU to tell it the load on the wheels. I did not do a voltage check there though. Time is money on the dyno. So....we stopped and called it a day.
I will be checking this out this weekend (My voltage). Meanwhile, has anyone else had a problem similar to this? If so, how did you resolve it? I was tempted to put a FWD fuse in and test on the dyno. I have done this on my Outback Sport and XT6 with no problems. Tom highly recommended against it so instead of being stubborn, I had to fight the urge off and let it be.
Anyone else experience rotating wheels at different speed issue? I have only once on one of my XT6s and the tranny was failing. The SVX tranny shifts and operates great right now, even in the pouring down rain (It has been raining hard all day). |
The TCU has nothing to do with the distribution of torque front to rear. The TCU varies the split on the basis of sensed wheel speed front/rear.
This whole scenario demonstrates just how unreliable are dyno readings. I gather than in this instance power was being read from only one axle, with the other running free, and it was going too be a matter of judgement when deciding if both axles were turning at the same speed. If this was the method used in respect of previous testing of the intake, the figures are certainly very suspect, as is the dyno operator.
It has been stated that, the US cars were equipped with a centre clutch as a means of enabling two wheel dyno systems to be used in respect of anticipated smog laws. Any dyno which simply provides a means of allowing the one set of wheels to freely rotate, can not in any shape or form provide reliable measurements, but can be used for simple smog testing.
Unless a dyno is highly sophisticated and measures total power delivered by both axles, measurements must be taken with the front drive fuse in place, so that all power is delivered by the front wheels. This fact can not be disputed.