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.

[scorpion1]

haha yeah. the more Ive thought about it Ill probably build a GTE motor for the car and keep the NA motor to tinker with after the swap. I love fabricating and coming up with new ideas. By the way the point wasnt to spray CO2 into the intake but rather through a coiled copper tube inside the intake pipe and vent it to the air so esentially the entire pipe would become a giant cooler. Also thought about forced enduction ideas like running the pipe into a chamber containing an AC block since Ive seen AC's freeze over already but quickly dismissed it since it would be such a hasstle and I doubt it would bring any real gains. just random ideas. I like to dream big lol. Ill probably look around for a reputable shop and pick up a 7mgte longblock and have it rebuilt from the ground up. i was trying to work on a new build list but this damn laptops too slow so Ill just have to wait. thanks again for the info on the conversion. Ill probably hold off on any real modification until I do the swap. whats the point in doing things twice.

[cre]

A refrigerated chamber would only add unwanted travel time and, depending on the design, add turbulence. Look in the FAQ for a fairly recent discussion on CAIs before you do anything dumb like throwing out the resonator.

I though about the coiled cooler before but wanted to use a refrigerated system... there's not enough surface area to cool the volume of air coming through at high loads to make an appreciable difference and the power requirements of the required compressor are detrimentally high.

Then, I thought about using a finned heat sink assembly with peltiers to cool them... again, power requirements create way too much of a load on the system.


There are plenty of things you can upgrade which will carry over after the swap: fuel pump, suspension, brakes, wheels, tires, cooling, adjustable fuel pressure regulator.... You could even go ahead and install a system such as the MAFT Pro and a wideband and learn how to operate the system and how to tune with it on an engine that's less likely to grenade when you make mistakes (and you will make mistakes).

[scorpion1]

Alright, so how does this list sound to you?
fuel pump
fuel rail
intake manifold
bigger tb
Spectre filter and adapter (cheap and functional)
car already has a header so Ill probably toss on a CherryBomb Extreme muffler.
short shifter
D2 Coilovers
Wilwood or Baer brakes
minor weight reduction
adj cam gears
air intake hard pipe.
Care to share on the resonator deal? Im assuming it smooths airflow.
MAFT PRO and MAF conversion

[cre]

Skip the fuel rail, the stocker is sufficient for around 500HP IIRC.

Skip the TB, the stock intake isn't large enough to support bigger and there aren't any aftermarket intakes available for the GE... besides, it won't carry over to the GTE and a larger intake = slower air velocities; You don't want that on a N/A.

Spectre is crap.... I thought you were trying to UPgrade? Read this: http://www.toyota-supra.info/forums/...-location.html There are more threads about the matter here as well, just don't have the time to dig them up. Two filters not covered in that review are AEM's DryFlow and Amsoil's EaO... The DryFlow is less expensive than both the Apex'i and Amsoil, uses newer tech than the Apex'i and supposedly filters close to as well as the Amsoil.

I wouldn't do anything to make a N/A louder... It's annoying and everyone with a decent build knows you're just over compensating.

Intake hard pipe? Depends on what you're using it to replace... The only things in the stock intake tract that can be improved are the accordion hoses could stand to be replaced with smooth couplers. Also, if you insist on installing metal, consider getting it ceramic coated or wrapping it with heat wrap to keep the intake cooler, aluminum lets more heat in faster than the stock plastic. As mentioned in the thread I linked to above, keep the air filter OUT OF THE ENGINE BAY!

The resonator (big plastic bulb in the middle of the intake) is a Helmholtz resonator. It removes oscillation from the in coming air; This causes two things: quieter intake and better and more consistent airflow. Despite the claims of the ignorant, it is NOT a restriction of any sort and has been shown in dyno testing to provide gains in HP... or rather its removal has been proven to cause losses.

I like the MAFT Pro. As far as piggy back controllers go, it's my favorite. It allows you to run s/d, has a built in boost controller, has timing control capabilities, integrates with a wideband (I run a LC-1 wideband with it) and it will work with GE and GTE electronics.... Oh, and there are only two people running it with 7M-GE electronics... so, there's bragging rights, I guess.

Wideband, don't forget the wideband.

Also, if you don't have a LSD, add it to the list.