Bumpin' Yota

For those who might not remember, Cebby and I were both independatly working on a mod that logically has a LOT of promise for the 3vze...a 7mge VAFM in place of the 3vze's VAFM. (Cebby's 3vze got shot down and now he's putting in a toy v8, so wish him luck with that adventure! )



History:

Typical mods for this engine consist of free flowing exhaust, headers, intake, tb, etc. But they all missed on thing and it is my belief that that one thing is a HUGE hinderance.

If you were to look at the business end of a 3vze VAFM (Vane Air Flow Meter), you'd be confronted with a very small opening. As far as I can tell THE SMALLEST VAFM that toyota employed on any engine! (It's the same size as the one used on a 22r/re/ret! Even our sister engine, the 3vz-fe has a larger VAFM.)



Thoughts:

There are an ass-ton of other VAFMs out there that are bigger and should flow much more air. 7MGTE, 7MGE and quite a few others including some smaller v8s employed by toyota.

Here is the thread comparing the openings of a 3vze and a 7mge vafm's - the pics are gone (EDIT by Cebby: Pics are back!) but the measurements remain. Keep in mind that is about a 30% increase in flow size:
https://www.yotatech.com/forums/show...1&postcount=15

And here is the thread it came from:
https://www.yotatech.com/forums/f88/custom-fabricated-intake-tube-box-snorkel-37554/


At wide open throttle, OBD1, as far as I know, switches from open loop (sweeping O2 sensor) to closed loop at about 80% throttle. What this means is that at about 80% throttle the computer ignores the O2 sensor and delivers fuel according to a predetermined set of table specifically designed to run rich and produce more power.

Typically my 3vze runs idiot rich - sometimes it almost pegs out my AF gauge. This tells me that there is unburned fuel that needs to be used, and that my cat is getting one hell of a work out So leaning out shouldn't be an issue in open loop operation. (I have a 2.25" cat back with turbo muff, free flowing cat, FIPK currently, and a ported intake plenum. All of these mods should lean it out but they don't...)



What VAFM will work?

I believe that the 7mge's vafm will work. Keep in mind this is the non-turbo supra/cressida engine that is also a 3.0L (2995cc IIRC) When examining the Toyota Factory Repair Manuals for both engines, the output resistances are identicle. (If anything the specifications are more stringent for the 7mge.)

Here is the TFRM for a 93 3vze:
http://personal.utulsa.edu/~nathan-b...fsm/index.html

And more specifically the page for 3vze vafm:
http://personal.utulsa.edu/~nathan-b...92volumeai.pdf

Now here is the 7mge TFRM:
http://www.cygnusx1.net/supra/librar...fi/FI_094.html

Here is my determination of exactly what each and every wire is on the 3vze's vafm. At the end of the post, I state what each one is and what it reads out at:
https://www.yotatech.com/forums/f116/3vze-vafm-help-56281/

And here is a pic that I uploaded:



One thing worthy of note is that the 7mge may not be plug and play just yet...the airflow output's linear voltage output may not be as linear as a 3vze's and the slope could be off as well. If this is indeed the case, it should show up on my AF gauge and be quite noticable. And if this is indeed the case, there is a solution - gut the 7mge's vafm and insert the innards from a 3vze's VAFM. The idea has already been implimented here:
http://www.well.com/user/mosk/AFM1.htm#AnchorBigAFM

He also has pillar gauges for 1st and 2nd gen 4runners as well as pre-tacoma trucks on his site. (Of which I am ordering one.)



Current Mod:

If you will notice Cebby's thread states the outside diameter of the 7MGE VAFM is a hair over 3" OD and our TB (throttle body) is about 2.75" OD. So to keep thing simple based on rubber hose reducer selection, a 3" mandrel intake is best suited for plumbing.

Here is a pic of my intake after initial welding, it has since be cleaned up, rewelded and awaiting recleanup of the welds:


I still need to weld on 2 bungs for the valve cover port and the other hose, both seen here (you can also see my painted intake plenum):



Thus far, the parts ive needed are:

Used 7mge VAFM..................................50 bux
3" mandrel Upipe...................................20 bux
TB/intake reducer (3" to 2.75")................20 bux
3" to 3" hose for vafm/intake...................10 bux
3 3" clamps and 1 2.75" clamp.................25 bux
chop saw to cut pipe.................................free
buddies mig welder....................................free
24" Drillbit extension................................3 bux
2 die grinder stones (clean up inside)..........8 bux
Bench Grinder at work to clean up outside.....free
3 gauge Apillar......................................75 bux
AF guage............................................. 20 bux
Ractive Superflow Airfilter...........................free
3" Air filter adapter.................................12 bux

things im going to need:

1. NPT threaded hose barbs for the two vacuum hoses
2. Breather filter for thoe hose line that normally goes on top of the stock filter location.


Here are some background links to info pertaining to VAFM's:
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml

1. A HUGE thanks go to Nathan Buchanan of the University of Tulsa for putting online what most of us dont have - toyota factory repair manuals on the 3vze. THANKS NATE!!!

2. Cebby for doing the initial homework, idea, and his link

3. Special thanks to CygnusX1 for the 7mge/7mgte TFRM found online

4. Thanks to Jeff Mosk for his gutting the vafm idea that works.



I assume no responsibility directly or implied from damage to one's vehicle when performing this mod. Mod at your own risk.

Bumpin' Yota

PS - more pics to come of the intake!

futurerunner

If you need those npt by hose barb, we supply those from work.

PM if interested...

Ganoid

Im very curios about the out come of this mod.

Morphine

I'm also very curious as to your out come. Great post by the way on updating all of us of the progression of this mod.

-=Morphine=-

ChickenLover

I am also very interested in this mod. Hat's off to bumpin' for diving headfirst into such a complicated project. If there is anything I can do to help, let me know.

Silver_Truck

You could always put a breather on the valve cover hose and the other line to the intake like this:

Toysrme

Or instead of a breather filter, you can slip a square inch of nylon pantyhose across the breather, then put a small bit of hose on it to hold it in.

It doesn't melt, and I find it not to wear out over time like paper breather filters do. Works just as well, and is normally free. (If you're embarressed, let the hose hang an inch past the nylon so you can't see it)






Retune the AFM while you're at it! Cut the silicon seal that holds the plastic top on, then slip something thin against the back of the plastic top and pop it off.
(Taken from my 3vz-fe afm)




I've finally have been able to talk 3s-fe, 2vz-fe, and 3vz-fe owners into doing that. Between that and advancing the timing to 17*btdc with the distributor, you can get the fast majority of what a piggyback (al-la smt) can for free. Still shouldn't ping on 87.
AFM is good for 10 peak horsepower on all of them with enough playing. God love OBD-I, it doesn't argue!

Bumpin' Yota

if i advance my timing at all my engine pings like MAD (like 2 marbles in a paint can on a paint mixer) the same is true if i dont run 93 octane...

Currently Im restricted to one gas station's 93 and a maximum of 10* BTDC timing advance...

Toysrme

I swear I try to help you 3vz-e's out, but it's useless LoL!

Yall get the shaft compaired to the FE vz's badly. (no offince)
Dang you can bearly make most 3vz-fe's ping if they're taken care of. :\

Bumpin' Yota

I know!! But my engine has over 260,000 on it, so I'm guessing it wont ping when I rebuild it at 300,000. I could probably dump some octane booster and advance my timing to see what happens though....


Pics of the intake coming very soon!

Bumpin' Yota

Pics of the intake post secondary clean up, now Im using JB weld to fill minor imperfections on the weld joints to get a smoooth surface. I want this sucker to look like it was mandrel bent!



another angle

Bumpin' Yota

Thank you!! I appreciate the offer, but as this thing nears completion, I dont think they'd get here in time. But thank you for the offer!

ROMAD

Great info!! I am also in the process of doing this swap (bought the parts from Cebby)...I have everything gathered up but still need to make the mods to the tube for the hoses before I can test run this set up.

I'll try to take some pics of my current setup and get them posted in this thread.
Here is an older pic with the muffler shop tube...doesnt fit though, it hits the master cylinder



I now have a 3" aluminum tube with a 45 deg mandrel bend in it - looks like it will work better than the old one.

(edit) What is the correct sealer to use when re-sealing the VAFM after adjusting the mixture? I know it needs to be a sealer that doesn't give off fumes harmful to the electronics. Any idea on which sealers to use?

Bumpin' Yota

me 2!!

Are you past break in yet? How quick is it now compared to before?

Eric

why replace a bad design with a larger bad design?

get rid of the AFM and watch your power soar

ChickenLover

Care to elaborate?

Bumpin' Yota

He is talking about the split second MAF conversion kit. Basically allows us to use a MAF in place of the vafm. The ONLY draw back is that you end up dropping close to 600 for the total conversion. Im not ready to drop that kind of money just yet.... Now after the engine and tranny are rebuilt and I turbo the 3vze, you betcha ill get that MAF conversion!

Bumpin' Yota

Those kinks are specifically what I wanted to avoid - not even the largest, most well known muffler shop down here, Stacy's Muffler, had a 3" mandrel bending machine So summitracing got 20 of my bux! lol

Yikes, I dont know what the correct sealer would be to seal upthe lid of the vafm....time to go searching on the supra forums..

Toysrme

Any type of silicone will work fine.


AFM's in general are not as restrictive as an equivilant size MAF.
For the record. In most applications where you retain a stock ECU, the ECU runs out of programming on the signal it recieves before the AFM's are thrown into their maximum range.

That and you can tune with them semi-effectively (with planning, and understanding) even on a mild-medium FI setup is just icing on the cake.

I just said in general, keep that in mind before replying.