This has been bothering me for months and I need some other peoples opinions. I had my car put on the dyno at Nationals last year and it read really low. It came out at 235whp (on a dynojet of course). I had the car put on a dynojet in April before the first race and it put down 260whp.

After the dyno pull at Nats, I immediately thought something was wrong with my car. Embarrassingly enough, I hadn't changed my plugs or air filter for a couple years. I pulled the plugs and they looked worse than I thought and definitely needed changed. The air filter. Again, I am embarrassed to say, it was black. It was pretty bad. I changed all the plugs and the air filter and the car felt better, but I don't think 25hp better. I did however, go out and run almost 1 second faster than earlier in the event. So...who knows? I did improve my driving, but I didn't think that much.

Anyway, after Nats, I did a compression check on the engine and everything checked out good.

Later on, I found that many people were complaining that the dyno at Nats was reading lower on their cars too. Not as low as mine though. I didn't think ambient temperature outside and current weather conditions effected dyno numbers because of SAE corrections factors. Or am I incorrect? It was much colder in April when I put the car on the dyno.

Thoughts and input welcome. Thanks!

 

SAE Correction can only correct things so much, but there are other factors too.

1) Did they do the National Dyno's while the cars were still heat soaked?
2) was your Air Filter wet from all the rain?

 

1) It sat for about 30-40 minutes after the session before it went on the dyno.
2) Air filter was dry.

 

Sorry to change the subject but can anyone comment on the altitude change for someone like me who lives at 6' ASLl? I think Mid-Ohio is 1300' ASL, any idea how this will affect my power? I guess I should tune it higher than my max so that the thinner air will bring it done to my limit.

 

No idea, but you're pretty accurate with the altitude at MO.