Modifiying AFM for more power???

[veedubin]

So I got bored tonight. The rain kept me inside my "shop" and I was looking at a spare AFM housing I had laying around. It dawned on me, I'm broke, and I want more power. I can't afford a LEX afm but i do know that you can modify the stock afm to raise fuel cut. Simply turn out screw to allow more air to go around the AFM. Simple philosophy, but on a prior engine I was running I had the screw backed out the whole way and still hit fuel cut around 12psi. So long story short, I got crazy; I am making my own ghetto lex afm housing. I have decided to "port and polish" the stock AFM. I am also greatly enlarging the lower chamber to aid in raising fuel cut even more. No unfortunately, my car is still not running and winter is fast approaching here, so I'm not going to try for any power gains till spring ( Supra's SUCK in snow and it's all I have to drive) So yea, I'll do the work on it, then get some dyno numbers and stats when weather breaks again. Or knowing me, I'll do it when there is a week of good weather. see pics for what I'm talking about. I'm very tired right now, so what I just typed may or may not make sense, sorry.

Also, if there is a flaw in my thinking, please speak up so I can alter my ideas.

 

[Poodles]

If you understand how it works you'd know this is a bad idea...

 

[RazoE]

you can get a Lexus AFM for like, $50-60, I recently sold two at those prices, and last time I checked, there were a few for sale on here...

I wouldn't run that thing, you might just blow your engine..

 

[gaboonviper85]

Not a bad idea aslong as he has a piggyback ecu and a wideband....no matter how much porting he does it will never be as big as a lex housing so fuel cut will still be lower....I really don't see a problem aslong as he has supporting mods. (although if he is too broke for a lex afm housing then he probably doesn't have any other required mods)<----bad idea

 

[veedubin]

Not a bad idea aslong as he has a piggyback ecu and a wideband....no matter how much porting he does it will never be as big as a lex housing so fuel cut will still be lower....I really don't see a problem aslong as he has supporting mods. (although if he is too broke for a lex afm housing then he probably doesn't have any other required mods)<----bad idea

Forgot to mention the reason I'm broke; the "supporting mods" 550's, AEM WB, walbro, Aeromotive AFPR. Yea, I've got the fuel side taken care of. I'm also waiting to see if my friend is going to be nice and sell me his AFC NEO. Now I know with the NEO I can raise fuel cut and all, but I don't have that right now. So I'm doing what I can with what I have. And besides when tax time comes around, I'll be going stand alone; either MOTEC or Mega squirt (still undecided).
My car has not run in about 3 years due to lack of an engine, so I came into some money, and my wife agreed I should get the car running again. I spent all the money I had, and this is why I'm broke. I wish I would have been able to purchase a few more items, but like I said, I'm doing what I can with what I've got. Most of you out there can relate.
I guess you could classify me as a typical MKIII owner, broke, but by no means am I illiterate when it comes to cars. I'm an ASE certified master tech with close 10 years experience. I've worked on everything from Neons to Bentley's ( Worked many years at the world's largest wholesale auto auction)

I do apreciate everyone's concern and ideas on this subject. I would not have posted if I did not want feedback, so seriously, thanks. I like how this forum shows a general concern for it's member's well being and their cars safety. Sides I get a little tired of BHG and rod knock threads myself :biglaugh:

So to wrap up, I still need to do some work on this and it's a project that i'm just messing around with during rainy times. I'll see how it does in the spring time. if it works cool, if not, cool.

again, thank you to all that replied

 

[RazoE]

in that case, carry on..

I personally sold the Lexus AFM's because I don't have money for supporting mods, so the temptation isn't there..

 

[veedubin]

in that case, carry on..

I personally sold the Lexus AFM's because I don't have money for supporting mods, so the temptation isn't there..

LOL Temptation is a veryfunny thing, It can get a person into a ton of trouble very quickly.

 

[radiod]

Temptation either turns in to a real fast car or a real broken car. Both ways result in a very broken bank account

 

[92nsx]

And besides when tax time comes around, I'll be going stand alone; either MOTEC or Mega squirt (still undecided).

:rofl::rofl::rofl: Those 2 are on two, totally different ends of the spectrum when it comes to stand alone. If your are broke now, you will NEVER afford the MoTeC. Lets see here megasuck is maybe $600-800 (maybe less) to put together. And MoTeC on the other hand is $5,000++ and goes up from there is you want any options on that there MoTeC. And this is just for the hardware/software. It like comparing a Kia to a Cadillac and saying there the same.

 

[GrimJack]

If you understand how it works you'd know this is a bad idea...

QFT. Where is the screen in there? This isn't a MAF, the screen *is* required on AFMs.

 

[IwantMKIII]

^that it is. Also, be sure all your surfaces are SMOOTH. There are two parts to a port'n'polish, porting and then polishing.

edit: that honeycomb is very delicate from what i understand so becareful.

 

[veedubin]

^that it is. Also, be sure all your surfaces are SMOOTH. There are two parts to a port'n'polish, porting and then polishing.

edit: that honeycomb is very delicate from what i understand so becareful.

Yes i took the honeycomb out for porting reasons, it is by no means finished. Also yes I know MOTEC is ungodly expensive, but It's an option I'm considering.

 

[mkIIIman089]

With an SAFC there is no benefit to doing this aside from a minor improvement in airflow... if it is any restriction to begin with.

I know it's been said before, but just to reiterate, Motec and Squirt are not even in anyone's wildest dreams comparable systems.

 

[veedubin]

Ok, I need to get this out there, and I apologize if I seem out of line.

It seems like everytime I or some one else has an "idea" there are numerous people to come in and degrade that person in one way or another. Now with this being an internet forum, I'm not sure if these people mean to be degrading or not. To me it seems that a lot of people on this forum are quick to pull the " you know nothing, I know everything" attitude. I've been on this forum now for almost 3 years now. I originally joined when I was purchasing my supra. The knowledge, and ideas that this forum has to offer is endless, that is why I kept returning. I do not, by any means, know everything about the toyota supra. I am, however, well versed in the automotive field. It is this knowledge that I apply to repairs or modifications to my vehicle. Yes there is a lot of little technical tricks that are specific to the 1986.5 through 1992 supra, but there are many that are "universal." That is what made me think of undergoing this little project of porting and polishing the AFM. And to all that had something positive to say, a sincere thank you goes out to you. To those that seemed to come in to this thread with a " you dumbass" attitude, I don't feel it's necessary.

I know it's been said before, but just to reiterate, Motec and Squirt are not even in anyone's wildest dreams comparable systems.

Onto the subject of my statment of stand alone systems.
Yes, we all know that MOTEC is exponentially above MS. But to say they are not comparable is just ridiculous. When making the decision to go to a full stand alone engine management system, you need to look at all the options available. At least I do. I am currently compiling a list of all known EMS systems available. when I am confident I have found all available options, I will then begin to look at what each one is capable of doing, and what it is not. Yes this list includes both MOTEC and MS, as well as many others; I've also included some piggy back systems into my list. Once I have a list of what each system has to offer, I can sit back and think of what I need that system to do, and how driveable will this system be. Yes some are expensive, but if they are going to work the way I want it to, I will spend what is needed. I do not believe in doing something "half-assed" Yea I know, modifiying AFM = 0.5 x ASS :nono: I am considerinng this a trial, if it works.... sweet, if not it goes to the scrap pile and all I've wasted was a few rainy days with some files and sand paper. No big deal.


Long story short, I absolutely love this forum. The knowledge is plentiful, the people are more than happy to help with any problem. I just seem to be seeing a lot of members on here trying to bust someone's chops whenever possible. There are a lot of young guys on here with very little knowledge of how these cars work. They have found this site in order to learn about thier supra(s). And eventually, these same "newbs" will be able to contribute thier new found knowledge with the rest of us. When someone replies to a thread in a demeaning manner or anything like that, it tends to make people hesitant to even post. If no one posts, then all that is left is a little circle of the "elite few" to talk about...... nothing.

I know I've probably left a sour taste in a few people's mouths. I'm not sure if I am sorry for this or not. But this is something I needed to say.

Once again, thank you to everyone (yes everyone) that has given me, or any other member usefull advice. I know that I will continue to give useful advice when I can.

 

[Poodles]

Truthfully that's the ideal way to go about selecting an engine management system. If a cheaper system has the features you need that a more expensive one doesn't, it's an obvious choice.

To clarify why modifying the AFM is a bad idea (and messing with the screw is a bad idea), they're set at the factory for idle and just messing with the screw can throw it out of wack (the karmen vortex AFM is very sensative and accurate). I know jetjock made a post about this around somewhere.

It's much like the questions we get about just sticking the sensor in a 3" pipe, it won't work correctly.

 

[veedubin]

Truthfully that's the ideal way to go about selecting an engine management system. If a cheaper system has the features you need that a more expensive one doesn't, it's an obvious choice.

To clarify why modifying the AFM is a bad idea (and messing with the screw is a bad idea), they're set at the factory for idle and just messing with the screw can throw it out of wack (the karmen vortex AFM is very sensative and accurate). I know jetjock made a post about this around somewhere.

It's much like the questions we get about just sticking the sensor in a 3" pipe, it won't work correctly.

Yes, the factory AFM is an extremely precise insturment. I'm more or less just screwing around. As stated before, killing time on rainy days. I think I read that post by JJ. as with most of the info on here, it was very enlitening and usefull. I've actually halted this little AFM project so that I can attempt to get this running. It
s got some wierd things going on right now.

 

[IJ.]

AFM mod = are you at a point with modifications that your engine requires additional airflow?

Keeping in mind it's a forced induction engine so you're not relying on atmospheric pressure for cylinder filling.

I'm not bagging your idea just that it's possibly a lot of time faffing around for no real measurable benefit.

As for MoTeC Vs others I've done the "others" and while on paper the others had comparable features at 1/4 the cost the reality is when it came time to utilise those features the software was lacking to the point that they were useless.

I had numerable meltdowns/explosions that at the time I put down to the experimental fuel system I was using or my own ineptitude but since going MoTeC not a single case of "Unexplained 7M death".

Where MoTeC is PRICELESS is after sale support and rock solid software, if you have an issues you call they sort it fullstop no BS no fucking you around for days,weeks,months.....

 

[veedubin]

AFM mod = are you at a point with modifications that your engine requires additional airflow?

Keeping in mind it's a forced induction engine so you're not relying on atmospheric pressure for cylinder filling.

I'm not bagging your idea just that it's possibly a lot of time faffing around for no real measurable benefit.

As for MoTeC Vs others I've done the "others" and while on paper the others had comparable features at 1/4 the cost the reality is when it came time to utilise those features the software was lacking to the point that they were useless.

I had numerable meltdowns/explosions that at the time I put down to the experimental fuel system I was using or my own ineptitude but since going MoTeC not a single case of "Unexplained 7M death".

Where MoTeC is PRICELESS is after sale support and rock solid software, if you have an issues you call they sort it fullstop no BS no fucking you around for days,weeks,months.....

At the point my car is now, no i do not need more airflow. I'm still on a stock CT. But, this is something I decided to do as a rainy day project. My car is currently not running yet, and it is sitting outside, not in a garage. While it was raining one day, I could not do any real work on my car to get it running. I have a small garage on the bottom level of my townhouse, that is not large enough for Jetta, and is filled with my wife's stuff. All my tools are in my service truck (former Snap On truck) So I was in my truck waiting out the rain a little bit, and saw the AFM sitting there. So this little project is not really wasting too much of my time. Although, I could have spent that time wiping down my wrenches and sockets, mabey even try to clean a little bit.... :biglaugh:

I keep hearing good about Motec, and with your statement about thier customer service, I'll add that to the "pro" list. For the software, I'm trying to get as many programs for as many standalone's as I can. I've already got MS software, and Although I have nothing hooked up to the software, I allows me to see the interface. I'll try to get Motecs software sometime soon, just to check it out. Thanks again IJ.

 

[jetjock]

People should come to this forum to learn about these cars. After all that's what it's for. The problem is many who come seemingly know almost nothing about cars at all. Any car. In other words they're lacking in even the fundamentals, something they should be learning on their own. Not saying you fall into this category, just making a point.

As for the turbo AFM, adjusting the screw will cause little to no change in idle mixture. This is because, unlike the N/A AFM, the screw wasn't put there for setting mixture. Adjusting the screw on an N/A results in a change in idle mixture for a simple reason: it causes the vane to be displaced. The displacement occurs because the vane, at idle, presents a significant restriction to air flow, a restriction that doesn't exist in the Karman and greatly diminishes at higher air flow even in the N/A.

It's one reason a custom longer screw was marketed for the LEX mod back in the day. It's also why the factory position of the screw on a Karman AFM isn't coded and stamped into the housing the way it is on a vane AFM. Bottom line: the screws have different purposes...

 

[IJ.]

Grab the MoTeC V3 software and have a play around with it, a lot of the old school guys swear by the v2 software but I find the v3 stuff 100x more flexiable and easier to make do what I want

While a few of the "others" may say their "features" are supported in the software the reality is they're not actually functional in the real world...

I find 99% of the MoTeC stuff just works, no fuss no bother and the other 1% has been bugs I've identified and had corrected in days by the guys at MoTeC.

MoTeC is a mid range product compared to some of the gear available but does get pricy when you start adding options/expanders, their new range of ECU's "should" address the expander issue as the 100 series hardware is getting quite dated and has had so many features added as after thoughts it's a bit of a compromise.