Turbo build tune questions
10-12-2015, 02:24 PM
#11
This tuning stuff is crazy. I just thinks it's crazy you add a bigger fuel pump, bigger injectors and the damn thing runs lean...lol. how much boost/power can I make with stock MAF. All the stuff I find talks about scaling it. The way I understand is it maxes out at (x) and you can go off the numbers up to that point and just scale it to go further? I'm really wanting quite a bit of boost. I may need to go speed density. If so I need an IAT and a MAP? I'm thinkING 15-16 psi so what MAP? and what do I have to do in terms of OS? I try to find conversion threads and it's always threads where everyone all ready knows what the hell they are talking about and I'm just reading scratching my head.
I've heard grumblings about the stock MAF being good for somewhere in the 500whp range. Most setups I've tuned who expect to push the limit of the stock MAF swap it out before needing to. But no, if you want to scale the MAF, you have to scale it over the entire flow range. Basically you divide the flow numbers on the MAF calibration table by two...this tells the PCM that half of the actual amount of air flowing through the MAF is reaching the engine. Now since it reads half the air, it will inject half the fuel...so you'd need to divide the stoichiometric ratio by two as well to get injector pulse width back where it needs to be. Just remember to account for stoich dependencies elsewhere in the tune.
Most people just ditch the MAF and go SD though. Because of the blowoff valve location and air that isn't of uniform density across all of the cross sectional area of the intake pipes, turbo setups generally aren't MAF friendly. That said, I have a turbo setup in the works that retains the MAF sensor...so we'll see how it goes lol.
As for the MAP sensor, if you don't retain the MAF, you will need a different one to account for boost. A 2 bar would handle 16psi, at my elevation anyway. Its only good for 14.7psi at sea level though, so it will depend on your elevation. If you don't want to worry about it you can always wire in the bulky 3 bar MAP sensor.
10-13-2015, 10:40 PM
#12
Staging Lane
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Ok so I talked to my tuner...a highly recommended tuner, I don't want to name drop out here. I'll pm you if you need info. He recommended to just put the MAF pre turbo, and he does know I'm wanting to push around 14-17 psi. I believe I would have to get a different blow off valve because mine isn't flanged for a pipe to recurculate. And I haven't found a lot of info on people doing this in the trucks. I did seem to find a decent thread on ls1 tech.
1. Is my MAF also IAT? I read that somewhere
2. If it is, and Im going to be using meth injection, doesnt the IAT need to be between meth and throttle body or in the I take manifold? I honestly don't know where my IAT is right now.
3. Does making in draw through like this sound like a good idea? The tuner seems extremely confident about doing so and stated it makes it easier on me also because the stock MAF location is right were my filter and intake pipe to my compressor will be.
I was planning on putting the stock MAF after the intercooler between blow off valve and throttle body and I guess the meth nozzles would be closest to the intake? So the same question comes up there about the IAT being apart of the MAF, that may be a camaros thing as I read that on ls1 tech and the thread was a boosted camaro
1. Is my MAF also IAT? I read that somewhere
2. If it is, and Im going to be using meth injection, doesnt the IAT need to be between meth and throttle body or in the I take manifold? I honestly don't know where my IAT is right now.
3. Does making in draw through like this sound like a good idea? The tuner seems extremely confident about doing so and stated it makes it easier on me also because the stock MAF location is right were my filter and intake pipe to my compressor will be.
I was planning on putting the stock MAF after the intercooler between blow off valve and throttle body and I guess the meth nozzles would be closest to the intake? So the same question comes up there about the IAT being apart of the MAF, that may be a camaros thing as I read that on ls1 tech and the thread was a boosted camaro
10-13-2015, 10:46 PM
#14
Runs lean, meaning you have started it like that? Running lean untuned for bigger injectors is a very bad thing. It is providing additional fuel, but enough that its too much to combust, slowing the burn down and leaving unburned oxygen coming out of the exhaust pipe. O2 sensors will pick up on this and it will appear lean. That's basically the definition of a misfire and how you diagnose a miss using the narrowband O2 sensors.
I've heard grumblings about the stock MAF being good for somewhere in the 500whp range. Most setups I've tuned who expect to push the limit of the stock MAF swap it out before needing to. But no, if you want to scale the MAF, you have to scale it over the entire flow range. Basically you divide the flow numbers on the MAF calibration table by two...this tells the PCM that half of the actual amount of air flowing through the MAF is reaching the engine. Now since it reads half the air, it will inject half the fuel...so you'd need to divide the stoichiometric ratio by two as well to get injector pulse width back where it needs to be. Just remember to account for stoich dependencies elsewhere in the tune.
Most people just ditch the MAF and go SD though. Because of the blowoff valve location and air that isn't of uniform density across all of the cross sectional area of the intake pipes, turbo setups generally aren't MAF friendly. That said, I have a turbo setup in the works that retains the MAF sensor...so we'll see how it goes lol.
As for the MAP sensor, if you don't retain the MAF, you will need a different one to account for boost. A 2 bar would handle 16psi, at my elevation anyway. Its only good for 14.7psi at sea level though, so it will depend on your elevation. If you don't want to worry about it you can always wire in the bulky 3 bar MAP sensor.
I've heard grumblings about the stock MAF being good for somewhere in the 500whp range. Most setups I've tuned who expect to push the limit of the stock MAF swap it out before needing to. But no, if you want to scale the MAF, you have to scale it over the entire flow range. Basically you divide the flow numbers on the MAF calibration table by two...this tells the PCM that half of the actual amount of air flowing through the MAF is reaching the engine. Now since it reads half the air, it will inject half the fuel...so you'd need to divide the stoichiometric ratio by two as well to get injector pulse width back where it needs to be. Just remember to account for stoich dependencies elsewhere in the tune.
Most people just ditch the MAF and go SD though. Because of the blowoff valve location and air that isn't of uniform density across all of the cross sectional area of the intake pipes, turbo setups generally aren't MAF friendly. That said, I have a turbo setup in the works that retains the MAF sensor...so we'll see how it goes lol.
As for the MAP sensor, if you don't retain the MAF, you will need a different one to account for boost. A 2 bar would handle 16psi, at my elevation anyway. Its only good for 14.7psi at sea level though, so it will depend on your elevation. If you don't want to worry about it you can always wire in the bulky 3 bar MAP sensor.
10-13-2015, 11:06 PM
#15
Staging Lane
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That's what's crazy from research I've done I see the same thing. But from OTHER research this guy is super good and tons of boosted ls people use him. I'm in TX.
I can still use stock ecm and convert to SD? Can anyone send me a GOOD link to converting to SD. I've tried and tried to look stuff up and I get way mixed results from to many mouths.
I want to know everything it entails in detail. Where they mount sensor, what sensor they used (more specific than 2 bar like part number, model number ect.) I'm definitley new to this stuff. I understand a little more than the basics but not enough on the tuning side and what sensors need to go where or what ecm or OS
10-13-2015, 11:12 PM
#16
Staging Lane
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Also I have not started the vehicle. Injectors should be here tomorrow. I'm just trying to get all my ducks in a row. Honestly trying to get all the hardware in all the right places and hoping that's it's right so a tuner can make it all magically work....all that and a prayer. That's how little I know about tuning. As I've said before I have been doing A LOT OF research though, it's just hard to take it all in. I feel like the only way I'll learn is by getting hpt and I don't want to drop the money on it right now.
10-13-2015, 11:13 PM
#17
blah blah blah. We've all heard that rhetoric about tuners for years around here.
Tuning a turbo setup is not hard, but it needs to be done right. The stock PCM is very powerful with a custom EFI live or HP tuners tune.
The 2 bar MAP sensor comes from a Cobalt SS. A high quality wideband oxygen sensor is required.
Tuning a turbo setup is not hard, but it needs to be done right. The stock PCM is very powerful with a custom EFI live or HP tuners tune.
The 2 bar MAP sensor comes from a Cobalt SS. A high quality wideband oxygen sensor is required.
10-13-2015, 11:18 PM
#18
Staging Lane
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blah blah blah. We've all heard that rhetoric about tuners for years around here.
Tuning a turbo setup is not hard, but it needs to be done right. The stock PCM is very powerful with a custom EFI live or HP tuners tune.
The 2 bar MAP sensor comes from a Cobalt SS. A high quality wideband oxygen sensor is required.
Tuning a turbo setup is not hard, but it needs to be done right. The stock PCM is very powerful with a custom EFI live or HP tuners tune.
The 2 bar MAP sensor comes from a Cobalt SS. A high quality wideband oxygen sensor is required.
I have a wideband installed...granted I don't know where the "in", "out" or analog stuff needs to go. And also not sure on high quality. Innovate brand. Thanks for the info on the 2 bar. Where should I install it? I have a MAP on my manifold right now don't I? I thought I saw it cleaning my intake up today. Can I put it in place of that one, if not do i just not use that one?
10-13-2015, 11:20 PM
#19
Staging Lane
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Best question of the night...how else do you suggest I find a good tuner in my area? I can't do much better than Google and see what I get. And this guy's named gets dropped all over the place.