2 pulls for 75 bucks 2WD or AWD. No tuning during the dyno day…just pulls. We’ll see you here! :tup:
Please make sure the car runs safely and is safe to drive at wide open throttle and high speeds, because that’s what a dyno pull involves. If the car isn’t safe to race it may not be safe to run on dyno. That means it must track straight, can’t have dry rotted or chorded tires, leak fluids etc. If the car is deemed unsafe to run it will not be run.
Also, we had one car that could not be run on the dyno because the custom exhaust the owner made for their car hung too low. It was about 2" from the ground before we put it on the dyno and it wanted to sit on the dyno once the car was loaded up. If your car has less than 2-3 inches of ground clearance it may not fit on the dyno without scraping so keep that in mind. This is a very rare thing, but I mention it now to avoid any surprises. Most cars we put on the dyno are lowered and still have plenty of clearance so again…this is not a common problem.
I look forward to another day of hanging out with you guys.
I hope you guys re-calibrate your LM1 between cars this time, I don’t think you were last time and I know a few cars got rich readings when our cars do not run rich.
Lets hope for better weather and less flooding this time too!
My runs showed 12.0 A/F on the dyno day but I had my car tuned at a perfect 12.5 before I went on the dyno, I have been back to my tuner since and my car is still a 12.5. He uses Innovative LM1. I know there was a termi that was on the dyno before me and he was concerned that his A/F was rich but after he went and had it rechecked by his tuner that is was still ok and not rich.
Every dyno puts different load on the cars which will affect AFR readings.
Then the gear you use affects the AFR.
Then every single wideband will read differently. I’ve had 3 widebands in a single car with all of them reading different. Differences of around 0.5 AFR on gas are common between widebands despite proper calibration. Saying that one is more accurate than another is only a guess. The Innovate LM2 I use on the dyno has tested well in independent comparison tests where lab quality units were used for comparison so I feel the readings are as accurate as you’re going to get for non lab quality equipment.
You can’t say your car is tuned to 12.5 AFR and leave it at that. Changes in atmospheric conditions, load, RPM, location of the wideband sensor etc. will ALL affect what the wideband reads. I’ve never seen a car that hits the same AFR to the tenth in every gear and that’s without considering differences in other conditions…one right after the other.
There is no reason to free air calibrate a sensor every 30 minutes when cars are going on and off the dyno for 2 pulls. Once a session is ample.
I thought it was generally know that you will be a little more rich typically on a dyno. I remember hearing this back in 2002! when a tuner did not want to go over 12.7 AFR on my NA setup on the dyno as he said it would be about .5 higher on the street.
It depends on the dyno and on the car. On turbo cars on Dynojets where you often have far less load than on the street you often go rich when you put the car on the street on the top end of the RPM range. On mine I’ve had some cars run the same on the street as on the dyno and some run a bit richer or leaner (all same day with the same wideband). This is aside from the car running different AFRs in different gears. Most cars get richer in higher gears. I’m only talking about WOT here BTW…
I forgot one other thing. Going from 10% ethanol fuel like they have at most stations in NY state to 0% ethnol fuel and vice versa can change your AFR over 0.5 AFR (gas) from back to back testing I’ve done. Pay attention to what’s in your fuel.
