Just added a Roushcharger to my 06' F150 and took it to the shop to get it dynoed??. The shop guy did the runs in 3rd gear and kept hitting the speed limiter (around 4 grand) so never hit max hp. Plus, he never was never really able to go to WOT because it would downshift.

Should I go to another shop, or is there some trick to keeping the tuck in 3rd and not hitting the speed limiter??? I asked if there was a parameter to change the gearing and run it in 1st or 2nd. The answer was NO (he claimed it needed to be at 1:1 ratio). They didnt charge me so thats good I guess.

 

well he should have had it in 2ed and hit it. The truck should do about 90-95 in 2ed gear. what numbers did you make?

 

The pull should be done in 3rd gear and brought up slowly to 3Kish and then go WOT. If you are in 3rd and at 3Kish it wont downshift at WOT at 5300rpm my wheel speed was 120ish mph.

I would go to a different dyno/tuner if i were you.

Wayne

 

My max torque was 414 ft-lbs @ 3700 RPM (1st run). Max hp was 322.5 at 4500 RPM (3rd run) and that is where the speed limiter hit. Fuel/air ratio (exhaust) is around 16 until about 3600 RPM and then it starts dropping and works it way to around 10.

 

exactly what he said

 

You must have missed the part where he said the speed limiter kicked in...

I agree though, go to a different dyno. I've done a pull or 2 in second gear without any issues

- NCSU

 

Third gear in an auto is 1:1 which would be correct for the dyno. It does not sound as though the operator was very sharp.....move on.

 

You can do the dyno pull in 2nd gear and it will not down shift and will pull from 2k until rev limiter. It will however give you a little higher torque reading.

 

Your Dyno operator is a nut. Any competent dyno operator will know that a 3rd gear run on a stock PCM will always hit the speed limiter before the rpm limit is reached. What was the purpose of the run? Just to get a number? I would have at least gotten the Air Fuel ratios checked out. So if you ever have a other run done somewhere get the Air Fuel ratios too. If they are out of wack get a tune. It will keep your engine safe and unlock more of the potential of the blower.

.

 

^^^^^ Yep. And, a competant operator will set up the trans to not down shiift to 2nd...........

 

I wanted to compare my numbers to Roush numbers... plus my friends have told me stories of MAF problems with superchargers so I wanted to make sure everything was working like it was supposed to. The air/fuel ratio was 16/1 until around 3k or so where it dropped to around 12/1. Does that sound right?