calongo_SS

iTrader: (7)

I tried this in the dyno section without any luck, here goes again...

My question relates to how the car runs with different loads on the tires.
My car was tuned on a mustang dyno and the a/f was about 12.6:1. Put it on a dynojet (different shop) a few days later and it was lean @ 14:1 . Put a wideband on the car on the street and it was 12.7:1.

If this is normal, how are people really dialing in a car on a dynojet? Does every car that is tuned on a dynojet run richer on the street than it did on the dyno? Or do professional tuners have a way of correcting for this?

I tried asking the dynojet operator about this but he didn't really know what I was talking about w/ different dynos. He said he could change the load w/ his and nascar uses dyojets so that's good enough for him, lol.




Craig

slow

iTrader: (7)

What kind of wideband was used for each setup?

on a properly setup vehicle, with a correct maf transfer function, the fueling should be the same, (provided it was commanding the same air fuel, were you able to log that?)

A nascar dynojet is a heavier rollset than a normal dynojet, but not a huge difference.

Ryan

calongo_SS

iTrader: (7)

The mustang dyno had what I would call a digital set up. The dynojet had the copper tube with a pump hooked to it. I know what you're thinking, it didn't read right. I sprayed the car and checked a plug, it was definatley lean. On top of that, the owner said the whole wideband unit just came back from the manufacturer to get calibrated. The one on the street was a handheld digital one like the one dynotune sells.

I didn't do any logging, didn't have anyway to.

My tuner (mustang dyno) said he bought the mustang because they were having trouble really nailing the tune on the dynojet for their shop cars.