Using MAF when tuning SD to get proper cylinder Air mass basis?
08-17-2016, 06:34 PM
#1
Using MAF when tuning SD to get proper cylinder Air mass basis? Hey guys. Hope you're all doing well. Making a little progress on my tune to my 96 Z28 Turbo (PT7675) Camaro with it's purpose built 5.3. I have a 3 bar SD (Open Loop only) tune and it's slowly taking shape. I'd been entirely 2.24 version until last weekend when a tuner friend convinced me to try 3.2.55. I tried it and the bugs that I'd encountered before seem to be fixed. So as I'm getting more and more familiar with the interface, I keep seeing the cylinder air mass referenced and I was just wondering, have any of you SD guys thrown your MAF on there, just to capture the CylAirMass just so you'd have a solid reference point?
On another note, when I was acquiring parts for this project, I bought a pre-ported stock LS1 cable driven Throttle body. When I got it, it looked great. Clean, shiny, etc and already had a hole drilled in the throttle plate. Bought new IAC and TPS sensor too. But, when I was playing around with the tuning, my tuner friend said we needed to reset the TPS because it was showing something like .7x volts and 3.1% with Key On/Engine off(KOEOFF). So I got the volts down to .6x and went through the procedure (Key off, disconnect TPS sensor, Key on for 30 seconds, key off, reconnect TPS). So beauty, right? We're at .6x and 0% with KOEOFF. But as soon as I crank it, freakin' 7.x volts and 3.1% at reading in the scanner. WTH? So I go through the same process over and over and over. Same.freakin.thing.every.time. The tuner friend said "what the hell is going on?". He thought it might be harness. Nope. Brand new $800 plug n' play. Wiggle it while key on, no change. He thought it might be the sensor(old? Used?) Nope(more on this later), it was new. So, we decided to slot the TPS sensor holes and rotate it to get the right combo. No matter. Everytime I started it, it would shift the volts/percent. He then thought it might be electrical interference. So, leaving it connected to the harness, I took it off the TB and just laid on the manifold. They when the key on, of course it was zeros in both volts and percent but when I started it, it didn't bump up any, so I felt confident it wasn't interference. So I just stared at the TB and thought, "well, if it isn't electrical, it must be physical. Maybe the vacuum of the engine is pulling the shaft around when she starts". So I disconnected the TB and held the body of it with one hand and tried to move the butterfly shaft with my other. Now, I don't know how much play is supposed to be in these things but it felt sloppy to me.
I went and bought another TPS sensor since I was otherwise stuck running in circles. I put it on and it does seem to stay at .67 and 0% at KOEOFF and .67 .04% when running. At anyrate, I went ahead and ordered a new Edelbrock 80mm TB from Jegs just in case. I would've gone bigger but I only have a stock LS1 Camaro intake on the engine at the moment anyway. I won't get to work on it till 2 weekends from now, but I'll follow up with anything I find.
On another note, when I was acquiring parts for this project, I bought a pre-ported stock LS1 cable driven Throttle body. When I got it, it looked great. Clean, shiny, etc and already had a hole drilled in the throttle plate. Bought new IAC and TPS sensor too. But, when I was playing around with the tuning, my tuner friend said we needed to reset the TPS because it was showing something like .7x volts and 3.1% with Key On/Engine off(KOEOFF). So I got the volts down to .6x and went through the procedure (Key off, disconnect TPS sensor, Key on for 30 seconds, key off, reconnect TPS). So beauty, right? We're at .6x and 0% with KOEOFF. But as soon as I crank it, freakin' 7.x volts and 3.1% at reading in the scanner. WTH? So I go through the same process over and over and over. Same.freakin.thing.every.time. The tuner friend said "what the hell is going on?". He thought it might be harness. Nope. Brand new $800 plug n' play. Wiggle it while key on, no change. He thought it might be the sensor(old? Used?) Nope(more on this later), it was new. So, we decided to slot the TPS sensor holes and rotate it to get the right combo. No matter. Everytime I started it, it would shift the volts/percent. He then thought it might be electrical interference. So, leaving it connected to the harness, I took it off the TB and just laid on the manifold. They when the key on, of course it was zeros in both volts and percent but when I started it, it didn't bump up any, so I felt confident it wasn't interference. So I just stared at the TB and thought, "well, if it isn't electrical, it must be physical. Maybe the vacuum of the engine is pulling the shaft around when she starts". So I disconnected the TB and held the body of it with one hand and tried to move the butterfly shaft with my other. Now, I don't know how much play is supposed to be in these things but it felt sloppy to me.
I went and bought another TPS sensor since I was otherwise stuck running in circles. I put it on and it does seem to stay at .67 and 0% at KOEOFF and .67 .04% when running. At anyrate, I went ahead and ordered a new Edelbrock 80mm TB from Jegs just in case. I would've gone bigger but I only have a stock LS1 Camaro intake on the engine at the moment anyway. I won't get to work on it till 2 weekends from now, but I'll follow up with anything I find.
