Not good tymes. Sorry to hear this bro.

if there's one thing i've learned from all of these supercharger threads... it's **** SUPERCHARGERS! TT or go home.

why F SC's? seems like only the stillen ones are having major issues?

^^^^ that is not true. Mine is running great and I even track my car and have no problems. Maybe they need to find a better tuner.

just drove my car around and pushed it a little bit! it's bogging on the low end again.

Too much fuel, some needs to be taken out. Without looking at a wideband it's hard to see where your curves are, unless you're on a dyno. Are you sure your car was knocking, and not just bogging?

i'm sure i know what bogging is and knock. trying to set an appointment for a dyno session asap.

Good luck, hope all goes well.

I'd like to use the excuse about different elevation and fuel, but I can't. Christian on the 37 forums shipped his car from Maryland to California for his twin build and there hasn't been one issue with his tune.

It's the damn draw-through style MAF sensor. It's not able to properly account for the air that's going through the throttle-bodies, Weiboy said it best.

Do you think there is an alternative solution to those MAF weak spots? Is there the possibility of using a different style to solve the problem?

My mechanic is working on a 3rd MAF sensor (after the supercharger, before the throttle-bodies) that could be added, who knows how much of a pain in the *** that's going to be. At this point, even if you properly tune the car for summer driving, you'll have to tweak it during the colder months, otherwise you're more prone to knocking issues.

Ah, that stinks. Thanks for the information, it's a shame the stock MAFs are so finicky! What about converting to MAP sensors; I know it is not an apples to apples comparison, but I know that LS2 GTOs can be converted to run with MAP sensors only and that relieves the issues you talked about with finicky map sensors.

I don't understand why you would have to retune a MAF based on different temperatures. One of the reasons OEMs use MAFs is because that type of metering is not temperature sensitive i.e. MAFs take into account the temperature change inherently. The trouble with MAFs on aftermarket setups is typically related to turbulent airflow across the sensor which really f's up the readings.

Good point, but if the MAF is reading a certain temperature, lower then what's actually going to go into the motor... there lies a problem. I've heard UpRev has a calibration tool to allow you to compensate voltages to get a better reading after the supercharger. I'm going to contact UpRev in regard to that, along with another question that I have pertaining to my lightened flywheel and adjusting idle.

the MAF's reads IAT also so that can also be throwing it off a bit. got this off the net:

Air intake temperature is used to correct fuel quantity (pulse width) since air temperature effects air density. (colder air is much more dense) Approximately 70°F is generally used for 0 correction, temperatures above will result in less fuel to compensate for the lower air density, and conversely temperatures below 70° will result in steadily richer (by volume) mixtures. Bad readings will effect ECM attempts to keep the air to fuel ratio proportional.