this happened a few months ago on the dyno but since then i havent had a chance to spray the car but when i dynoed my car with the same bottle pressue and around the same temps as the last time i dynoed i was down about 40 hp and 40 tq, nothing had changed with the car between the times i dynoed, i have my car up and running again with the new full exhaust and clutch and alum flywheel and will dyno the car when i break the clutch in, but does anyone know what might of caused that ?

 

Did you have 2 heat the bottle, and was the a/f the exact same as before??

 

yes bottle was heated, also the af went off the chart rich vs 11.5 12.0 the last time it was dynoed but nothing changed tune wise. so i know the a/f probly did effect it but i wanna know why it would change so much and cause 40 hp 40 tq lose

 

When you went to the dyno the first time had your bottle just been toped off? How about this last time at the dyno, was you bottle not as full (but still good psi wise)?

 

both times the bottles where topped off, both times 1000 psi

 

This is an odd question, but did you happen to notice battery voltage/condition? A nitrous valve by nature is closed under pressure and opens againist the pressure by the coil. "If" the battery was not doing well, the 40amps to pull the solenoid totally open may not have happened, making you run rich (way more fuel then nitrous) and would show a large drop in HP. The only thing that can do what you are saying IS a lack of nitrous, and this may be an answer. The other answer is a bad nitrous solenoid doing the same (sticking closed) as mentioned above.

 

Do a compression check and a leak down check, almost sounds like you've got some blow by.