[brainycheddar]

I dynoed my car on Saturday, and I noticed two dips in the torque curve. one at 4500 and another at 5500. ambient air temp was about 100 F and the IAT's according to my scangauge were close to 135 F. I have a pulley and an airbox installed. I'm just wondering what would cause these dips. my guess is that since I'm on the stock plugs, the hot air got the better of me and the timing retarded to prevent knock. either that or the injectors are singing their dying song. I've got new plugs that I'll install soon, but any insight would be helpful, I'm trying to figure out my scanner, but once I get it to work, I'll post the dyno sheet.

[MINIMANIAUK]

Did you also get a read out of the boost pressure? was it constant?

[MINI-Morgan]

Whats that in degrees C?? Log the timing.... I bet if you got hot it pulled the timing right back.

[Jaw_F430]

Quote: Originally Posted by MINI-Morgan (original)

Whats that in degrees C?? Log the timing.... I bet if you got hot it pulled the timing right back.

What he ^ said. You generally see a dip on the dyno graph if the IAT get above about 52 degreesC

[NeuroBeaker]

Quote: Originally Posted by brainycheddar (original)

Ambient air temp was about 100 F and the IAT's according to my scangauge were close to 135 F.

Quote: Originally Posted by MINI-Morgan (original)

What's that in degrees C??

100 degree Fahrenheit = 37.8 degree Celsius

135 degree Fahrenheit = 57.2 degree Celsius

Source: Online Conversion - Temperature Conversion

[brainycheddar]

ok, I figured that the timing was pulled, but I wasn't sure if maybe there was a flow restriction somewhere, or if some oil from the intercooler dripped into cylinders, tripping the anti-knock

[Paul Webster]

Was it dyno'd in 3rd?

[MINIMANIAUK]

2 things will dip the torque ,both controlled by the ECU --1 ignition retard,2 throttle closing
The igniton is a faster response than throttle and the primary used method as it is safer for the engine ,the throttle closing is a slower reaction and coupled with a boost drop (hence first question)
The tmap sensor signal used with temp to establish limits and onset of timing change(also compares with map sensor pre charger to give air volume
coolant sensor is also used to alter the timing for faster warm up of the engine ,so allow the temp to raise to normal pre dyno .
nb wheel spin can also close the throttle but a warning light would be flagged up .
Hope of some use to you
A

[brainycheddar]

It was dynoed in 4th on a dynapack chassis dyno, with the DSC turned off, at the nevada city MiniMania MINI meet. based on the temperature outside, and IAT's, I'm almost certain it was the car pulling the timing, oh well. hopefullly by next time I'll have installed a larger intercooler and an oil catch can to prevent it from happening again... o_O !!! Problem is that nevada city is about a 4 hr round trip so next time probably won't be for a while.