VAF Elimination/conversion?

[scorpion1]

Im aware that one of the biggest "issues" with the supras intake comes from the rather restrictive VAF system at the filter. Is there a way to convert this to MAF, MAP, or simply do away with it? If I remember correctly what I read it has something to do with controlling the fuel supply which is why Im asking. My buddies RX-7 had the same thing and he couldnt find any information on a conversion or elimination. Any help would be appreciated as I will be trading my truck this weekend for an 87 N/A 5SPD and I will be looking to make as much N/A HP as possible with what will probably end up being a pretty extensive build. I know turbocharging is popular with the Supras and so are swaps which is why Id like to do an N/A build as its somewhat unconventional.

[DarkSupra2.5]

I think there's a write up about using a lexus VAF/MAF for the supra. If not though, it shouldn't be to hard to get rid of it all together by mapping the pins for the sensor and then using a MAP sensor and IAT sensor in it's place. Since the Vaf is used to monitor air flow and air temp, those two sensors could take it's place and then you wouldn't have to worry about restrictive airflow.

I'm curious what you come up with though.

[cre]

The Lex AFM is a 7M-GTE specific mod... 7M-GTE uses a KVAFM (Karmann Vortex Air Flow Meter), 7M-GE uses a VAFM (Vane Air Flow Meter)... and not one Toyota Supra ever used a MAF (Mass Air Flow) sensor.

The only real options you have are: a) a full standalone EMS $$$$$$, b) MAFT Gen II and a GM MAF, or c) a MAFT Pro and whatever type of air flow measuring system you want. None is simple or cheap. The standalone will be the most expensive, then the MAFT Pro, then the Gen II. You're going to need to tune the new management system so either count on shelling out for dyno runs and tuning or add a wideband such as the LC-1 by Innovate Motorsports to the list as well... the wideband is recommended as all three of the systems I listed are capable of integrating with it and will help track the AFRs and it helps monitor for serious problems.


Don't bother trying to build a beastly N/A... it doesn't work out well... trust me. You'll never break 300RWHP and even getting there costs a fortune. The 7M is a crap N/A platform... if you want N/A drop in a 2JZ-GE or a V8.

[cre]

BTW, since we got it working on the 7M-GE the MAFT Pro can be used on RX-7s which use a VAFM... the Gen II now supports VAFMs as well. I haven't looked to see if Bob's added the scaling for their meter, but they can set it up as if using a 7M-GE's meter and then just tweak the settings.

[scorpion1]

Thanks for the info. I was planning on doing something along the lines of a tuneable MAF and IAT setup but I wasnt sure how to convert the signals into readable ECU language as Im sure theyd be quite different. Ive heard a bit about the GM MAFT setup on DSMs since my buddies planning on doing something along those lines to his AWD Talon. As far as the build goes (havent done a whole lot of research into the engines just yet so I could be way off base) but I was planning on porting and shaving the head and getting higher compression pistons for starters to raise the compression as much as safely possible then going from there. Possibly look into CO2 (cryo) setups to greatly reduce the air temp since its alot more stable than spray. Obviously I wouldnt be buying a box kit because theyre generally lacking. Something along the lines of copper tubing lining the inside or outside of the intake pipe to create a much larger supercooled surface as apposed to the tiny "bulbs" in the store kits which generally restrict airflow. Its been quite some time since I did my Supra research as I just figured Id never get one so I do have to redo alot of my homework. Theres always the LS1 :-)

[cre]

Go with the LS1... the 7M-GE will net you dick... even with high comp and NOS. The only CO2 systems I've seen are used to cool intercoolers in order to compensate for the extreme increase in air temps due to compression from turbo and s/c setups... it's not sprayed into the intake nor does a N/A have enough surface area in the intake tract to reduce air temps enough to make any real difference. Actually spraying inert gasses such as CO2 INTO the intake on a relatively low displacement and low compression (even with off the shelf higher compression pistons) engine like the 7M is more likely to cost you power than gain any.

I know a few people who've spent absolute fortunes on the GE only to abandon the project or settle with the fact that they'll never see the numbers a mildly modded GTE will get. I was like you... had BIG plans for the GE... now I run a turbo.

An IAT isn't really needed with a GM MAF... do you mean IAT and MAP sensors? It's referred to as Speed/Density. FYI, a MAF measures actual air flow whereas with s/d it's calculated.... s/d can be a bit tricky to get running smoothly but imposes no restrictions on the intake.

I ran high comp and s/d on a very well tuned 7M-GE... still didn't dyno past 200RWHP... Just reaching 200RWHP on the 7M-GE is quite difficult. If you want some more negative commentary on the lacking potential of the 7M-GE from those who have tried it head over to supramania and search the 7M-GE section for "potential" (might as well just search "irony"). Then look up build info from members including "Defiant7M" and "AJ's 88". For 1/10th the cost you can achieve more power with a forced induction setup. Sorry, but that's just the way it is. On the upside, at least you don't have a 1G-GE.