442HP and 539TQ (uncorrected) whatever that means. I was happy w/ those considering I only have a K&N filter installed.Just kidding!

Ok now for the questions...

On the Dynojet the truck did not ping, but on the road i heard mild detonation The timing was @17.5 up top. Temp was 53 degrees and 42% humidity. The bottom line is timing had to be dropped to 14 so I did not get detonation. Why would a vehicle kick **** on the Dyno w/ no problems but under "load' ping slightly. I know that I have ran w/ 20 degrees and 18 degrees in the summer w/ no problems w/ Sunoco ultra 94. I now have a Diablo revolution and a new SCT chip w/ 4 tunes...HMMMMMMM Is it the cold weather specifically? Or are there other factors involved?

 

I made 447 RWHP (451 uncorrected) on a 50 degree night down here in Miami recently. This was with 18 degrees timing. No detonation on the dyno (all on 93 octane). Out on the road, got detonation at 18 degrees, backed it down to 17 degrees, still got detonation, then finally went to 16 degrees which seems the max I can run on 93 octane on the road and staying out of etonation.

The dyno does not load (labor) the vehicle as much as when the motor is actually pushing the 4800lb vehicle at 100 MPH through massive resistance, under a longer more sustained blast in high gear. Basically, the dyno is comprised of the drums that have a calculated weight/inertia and the dyno measures how fast a vehicle "spools" the rollers up. The more power you make, the easier/quicker your motor will spool up the rollers. That "quicker" spool up amounts to higher horsepower. There may be a small amount of drag on the rollers, but again, it can't compare to a high MPH run in 3rd gear.

By the way, 53 degrees and 42% humidity is pretty crisp weather for the way these trucks are usually tuned. There are several really experienced guys with these trucks recommending staying out of the gas on cold days (50's or colder) all together, rather than trying to tune to meet those weather conditions.

I am gradually getting on board the "don't dog it on cold days" bandwagon.

 

In my expirience with dyno's being though this is the 3rd car that I am seriously modding dyno numbers are just that, numbers. A tune made on a dyno is really really good, its ALMOST perfect. but a street tune can be better if you drive your car on the street mostly. A dyno tune is tuned to make the most power. From the eyes of the person tuning your vehicle, the more power they make, the happier you will be. Sure they throw a fan in front of your truck to help cool it down, But it just isnt the same as when you are on the road. Im getting my lightning tuned today, Im going to ask them not to advance the timing too far, or see if they can give me a street and a race gas tune. I rather have a more conservative street tune, one that gets me 85-95% of the power Im looking for, but remains safe for daily driving. A dyno queen is exactly that, a vehicle that was tuned on the dyno that made high numbers.



Its time for me to get rolling and put down some #'s

 

That's why I tune on a Mustang Dyno under a load, then when I want the big #'s I go and do some pulls on a DynoJet.

 

also you can do simulated full 1/4 mi passes on the mustang dyno with all factors for increased wind resistance Etc. , usually there times are within a tenth of real life runs. so you can get tuned very close to real world conditions.