dyno

[tom t]

my m8s just had his car dynoed. what gear is best to do the WOT runs? as the bloke was doing this in 3rd and thought most people on here say to do it in 4th? cheers

[Scoff]

its down to the operator and rollers really but depends alot on how much torque the engine wants to make. the more torque it makes the more likely it is to spin up in the rollers and so you use a higher gear. as long as it doesn't spin it doesn't matter much. I think operators also tend to use 4th because it's the closes to 1:1 ratio, how that matters I'm not sure.

[tom t]

cheers for that m8. havent been to one before so wasnt really quite sure what was going on etc lol

he got the fueling set up. and when he changes gear now there seems to be a flat spot so not sure how to solve this i think it goes really rich on gear change some how does that sound right? as i think thats what the graph was doing.

[Big Jim]

It's just about being in the highest gear possible, to limit the torque at the wheels, without overspeeding the rollers at the top end.

[Coops]

4th is usually favourite,last time i had mine done the guy tried 3rd, badger climbed out the rollers:rolleyes:

[rhys]

New poster! (less than 10 posts)

i think that if u want to measure ur bhp an torque u do that in 4th as its more or less straight thru the box but i suppose to set up fueling u cud do it any or all gears

[tom t]

kool cheers guys. also how accurate can the rolling road be? and do they all use temp probes? as later on in the runs the bloke moved the temp probe and the bhp went up. something about compensating for the temperature :eek:

[Rob1980]

kool cheers guys. also how accurate can the rolling road be? and do they all use temp probes? as later on in the runs the bloke moved the temp probe and the bhp went up. something about compensating for the temperature :eek:

The jury is out on how accurate a RR is. The general agreed theory is that trap speeds for a ¼ miles are the more accurate...