Tuner Is Confusing Me. Need to be set straight.

[brandon_s0854]

So my tuner is having problems tuning my car. It's currently set up as a draw thru with a bypass valve. Car has a Procharger f1d on it.

He says there's two problems. First, the maf pipe size is different than the intake pipe size causing turbulence around the meter. Second, recirculating the air back in to the system is causing problems with the maf reading, because the new supercharger is blowing a lot more air at idle than my old p1. I could see this as a problem and agree that converting to blow off is the fix.

However, he is proposing to just turn the bypass to blow off without moving the maf, and changing intake so it's all the same size.

So he would be blowing out metered air. I specifically asked him if it would be a problem, and he said it would be fine since modern cars have some feature he called decel fuel something rather. Lol.

Anyway, am I crazy or what? Is this actually gonna work?

 

[EvilTwins]

What is the difference in size between your inlet piping and your MAF? It's a pretty common practice to have the MAF in larger piping to give the meter more range.

I can't see how venting metered air off would NOT cause problems... I think you might wanna try another tuner if you can...

 

[brandon_s0854]

I'm not sure exactly. I believe the intake is 4", and the maf is whatever the sct ba3000 comes in

 

[ugotbit03]

You could try something like this-

http://www.treadstoneperformance.co...yComb+MAF+Mass+Air+Meter+Airflow+Straightener

Either way, with erratic MAF counts it's like chasing a moving target. You definitely need to solve the problems to calm the flow over the sensor. For just a quick and dirty test you could put a piece of window screen in front if the MAF to settle it down.

I would definitely get a BOV and vent to atmosphere.

ETA- I wouldn't think you would want to dump metered air anywhere, but I don't have any real experience with a setup like yours.

 

[brandon_s0854]

You could try something like this-

http://www.treadstoneperformance.co...yComb+MAF+Mass+Air+Meter+Airflow+Straightener

Either way, with erratic MAF counts it's like chasing a moving target. You definitely need to solve the problems to calm the flow over the sensor. For just a quick and dirty test you could put a piece of window screen in front if the MAF to settle it down.

Yeah, I've seen those. Haven't heard how effective they are though

 

[ugotbit03]

Yeah, I've seen those. Haven't heard how effective they are though

I have tried the window screen trick and it calmed the airflow over the sensor by 20 counts.

 

[brandon_s0854]

I have tried the window screen trick and it calmed the airflow over the sensor by 20 counts.

Thanks. I'll definitely keep that in mind. I'm more concerned about venting metered air though. Has anyone done this successfully?

 

[svtshadow]

So you blow off valve is after the MAF. Change the blow off valve to be before the MAF, just like a turbo car and vent it into the atmosphere, at least thats the way I had my old
PSC1 setup.

 

[smashedheadcat]

Never vent metered air. Your car will run like dog-shit and be extremely rich under any condition other than wide open throttle.

 

[brandon_s0854]

Thanks guys for confirming my suspicions

 

[SlowSVT]

Never vent metered air. Your car will run like dog-shit and be extremely rich under any condition other than wide open throttle.

Agree

Venting air to atmosphere after it's been "metered" kinda defeats the purpose.

Just say "no" to turbulent air entering the MAS. Best to keep it in the middle of a straight section of the intake tube.