DMBfan

A friend of mine is planning on going to the dyno to actually tune his car and I am going to tag along and throw the 8 on just for fun.

I been told that typically you want to run the dyno in your 1:1 gear and for a 6sp that would be 5th. Ive seen that other people have spun the dyno in 3rd and 4th gear.

I want to make it some what worth my money so my question is....What gear have people used and any other things people have found that might be useful?

Thanks

dmp

use the gear closest to 1:1. every time.



Disconnecting the rear abs sensors is thought to help, as well.

RX3+5

The idea of testing in third gear is so you don't put so much stress on the engine.
Winding the car up in fourth or (much worse) sixth puts unbelievable stress on the cars cooling system. At eighty plus MPH allot of air is going through the radiators.
Do yourself a favor and limit how much dyno work you do and let the car cool down between runs.

Vince

Gord96BRG

Do a search on dyno testing - there are a bunch of threads that discuss what you need to do. Basically, the RX-8 ECU senses that the car is running on a dyno (rear wheels turning, fronts stationary), and goes into a safe mode that reduces power output - net result is that you can't get a real reading of your rear wheel horsepower. Disabling the DSC/TCS helps somewhat, but the sensors are still providing input to the ECU. Some suggest that the only way to get a close-to-actual dyno result is to unbolt the rear wheel ABS/speed sensors and tie them back away from the rear wheels, so that the car can't tell that the rear wheels are turning (just unplugging them doesn't work, because then the missing sensor triggers a problem mode). Even then, the ECU gets suspicious when the car is running at full throttle for more than 10 seconds when the wheels aren't turning and will go into a reduced power safe mode anyway.

In other words - unless you really know what you're doing, you're wasting your money because you will not get valid results. 90% of the dyno runs people have discussed here are useless because of invalid procedures.

Regards,
Gordon

dmp

Do the sensors work by visual means, or magnetic? other?

zoom44

i agree with everything gord said except the part about valid results. the results are only faulty because too many people wat to look at the peak number and only the peak number. if your doing it just for fun then go ahead get it strapped down and floor the sucker (turn off the dsc/tcs first) get your printouts and take a good look at them. if in the future you want to tune it and do some more runs then go back to the same place and run it again. compare the graphs you get. if your tuning has made a difference then you will be able to see it on the graphs before the car goes wonky on you. if you run it this time and you get 170hp reading before the car starts backing off and the next time you get 190hp before it starts backing off you can see that you got an actual gain. but remember that it matters where you made that power in the curve so comparing the graphs is better than just looking at the peak number.