TB42 turbo mafless tune
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It's possible, just not with a standard ECU. The MAF sensor is best before the turbo so it's not under pressure.
Not even with a nistune, the MAF is the primary and only load sensor, in the 2D map for fuel and timing (Maf v RPM) the LS1 and 2 have both a MAP (Manifold Absolout Pressure) as well as a MAF allowing the MAF to be deleted and the ECU mapped in 3D on the throttle position (infinate between closed and WOT), RPM and MAP output.
The TB42 MAF is only good for about 155 rwkw before it will run out of output, You will be pulling the K constant (injection) up to allow enough fuel in the top (as the standard fuel map value wont go high enough) which will make the whole map too rich.
You can shoehorn the actual MAF sensor into a larger pipe and recalibrate your MAF translation table (Hotwire inhalation voltage quantifier) to suit the larger pipe diameter. or change out the MAF with a larger one (go to change MAF in the operations menu in nistune) that will bring the K constand back down making the map more tunable for larger power figures. The list in this menu gives you a rough power maximum for each MAF, however there may be wiring changes to consider between different MAF's. Ideally when putting in larger injectors (which i assume you did for turbo) you need to go to a bigger MAF also, the injectors pull the K constant down and the MAF brings it back up again to near standard giving you normal tuning resoloution.
Also ensure you have adjusted your Fuel and timing load scales to suit the higher loads your MAF will see with boost. Or you will have little or no tuning reloloution under high load. (i.e. you will hit the top load column in the tables at 3000 rpm with 2500 still to go where the computer is just interpolating and it will lean out.)
As for location of the MAF, it can be before or after and not make a great deal of difference except you can vent a BOV to atmosphere before it without it affecting mixtures, before the turbo you will need to put a plumb back BOV in the system to prevent compressor reversion on backoff enrichening the mixtures and causing stalling/rough initial idle after high load. They are not designed specifically to handle positive pressure however they are sealed and metal body so should have no issue handling moderate boost levels.
The TB42 MAF is only good for about 155 rwkw before it will run out of output, You will be pulling the K constant (injection) up to allow enough fuel in the top (as the standard fuel map value wont go high enough) which will make the whole map too rich.
You can shoehorn the actual MAF sensor into a larger pipe and recalibrate your MAF translation table (Hotwire inhalation voltage quantifier) to suit the larger pipe diameter. or change out the MAF with a larger one (go to change MAF in the operations menu in nistune) that will bring the K constand back down making the map more tunable for larger power figures. The list in this menu gives you a rough power maximum for each MAF, however there may be wiring changes to consider between different MAF's. Ideally when putting in larger injectors (which i assume you did for turbo) you need to go to a bigger MAF also, the injectors pull the K constant down and the MAF brings it back up again to near standard giving you normal tuning resoloution.
Also ensure you have adjusted your Fuel and timing load scales to suit the higher loads your MAF will see with boost. Or you will have little or no tuning reloloution under high load. (i.e. you will hit the top load column in the tables at 3000 rpm with 2500 still to go where the computer is just interpolating and it will lean out.)
As for location of the MAF, it can be before or after and not make a great deal of difference except you can vent a BOV to atmosphere before it without it affecting mixtures, before the turbo you will need to put a plumb back BOV in the system to prevent compressor reversion on backoff enrichening the mixtures and causing stalling/rough initial idle after high load. They are not designed specifically to handle positive pressure however they are sealed and metal body so should have no issue handling moderate boost levels.
The TB42E injectors are truely unique. They are not an 11mm O ring injector (more like 10.5) they are also slightly longer than a normal 0 ring denso injector. I have used series 4 RX7 (late model high impedance) injectors, with 3mm O rings and a drilled out rail, with an extra O ring over the pintle to space it up, they are 520-550cc or so.
MAF will support 155-160 rwkw, or so.. after that i dont know what would be a straight fit, perhaps a ford lightening (good for 400 hp or so) or drop the sensor in a larger pipe and recalibrate.
MAF will support 155-160 rwkw, or so.. after that i dont know what would be a straight fit, perhaps a ford lightening (good for 400 hp or so) or drop the sensor in a larger pipe and recalibrate.
Looking for some help with the gq where I'm at now is the ute is in Newcastle and the shop working on it are not having any luck. It has not got bigger injectors 550cc but ever since I put them in it will only run for 10 mins then it stalls from being way to rich. It is of the gauge on the afm. If anyone has any help they could offer it would be very appreciated.
So what injectors did you end up with? or are they just standard ones?
Who's tuning it? Is it a proper tuner shop or a backyard job?
Who's tuning it? Is it a proper tuner shop or a backyard job?
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