Hey all, I am always seeing Mass Airflow sensors for other cars and was just wondering if anyone out there made less restrictive AFM/Mass Airfolwo sensors for our cars?

 

yeah you can use just about any aftermarket or stock AFM out there. as long as you get a computer (i.e. haltech) to run it. there arent any stock chages you can make as far as i know. the S5's are different and flow more than s4 but i dont think they are interchangeable at all

Justin

 

no

 

just talking out of my *** here, i dunno how or if its possible, but if you are good with electronics you *MIGHT* be able to wire in a less restrictive mass air unit from another car. like i said, im talking off the top of my head, i dont know if it could work.

 

I doubt it would work unless you had a programmable ecu.

 

you have to calibrate it to the old one,.. would be alot of work, im sure someone could pull it off though

 

well, you can do it with some kind of conversion circuit but who has the time or energy to design one? What would one of these be worth? I have all the brains and more resident electrical engineering people than you could wave a stick at (huge part of my school is EE) who would think this was a paultry test of designing circuits to make one for me. But if I were to produce them what would the market sustain as far as price? Granted I have my own reasons for making the swap, but for the cost of the S5 AFM I could build a megasquirt and be using a MAP sensor eliminating the entire unit from the airflow.... not to mention perfect fuel maps and ultimate tunability.

 

 

Wouldnt you toss the AFM into your neighbor's yard after you got a haltech?

 

You kidding? I'd send mine into orbit!

 

Aftermarket programmable ECU's don't use airflow meters at all. However with an S-AFC (or similar) you could run any AFM you wanted as long as it's of the same type. FC's use flapper or sliding cone AFM's so any of these could be used beacause they all basically work the same, but hot-wire AFM's cannot because they use completely different programming. Any AFM swap (including S5) would require the S-AFC to be dyno-tuned to make it work properly with the stock ECU's fuel maps.

 

Looking through the S-AFC's manual... it appears the only compatable AFM that could POSSIBLY be any bigger, is off of one of the cosmo motors...

 

The wolf 3d 4.0 can use MAF's.

 

the haltech can usa a maf too, i have no idea why you would want too....

mike

 

'cause then you don't have to retune every time you change the VE of the engine (such as adding intake/exhaust, etc)

Henrik
87TII

 

You'd want to re-tune every time you change anything on the engine. Are we not aware what programable ecu's are for? It's to get the MOST out of the engine. When you change something you can go back and maximize the programing for it.

As for using the S-Afc to run a different afm... I wouldn't do it. The resistance values are different so that the flow readings would be off under all driving conditions. You'd need a stand alone to make it work right, or else you could really only tune it for a set rpm and throttle position.

How much for a cosmo afm?

 

*note* the only AFM's that MIGHT be bigger, are the cosmos'.

I've never even SEEN a cosmo AFM (blocks don't come with AFM's) so it could be the exact same as a S5 TII's or whatnot.

 

i found this long time ago and saved it thinking i may need it in the future.

 

the S5 AFM might read across a larger range or a different mixture, but take one look at it and tell me that bullet isn't a huge airflow restriction. I believe the S4 AFM is superior bc of it's apparently better flow characteristics and the ability to play with them (crude tuning w/ the spring inside provided you have an EGT gauge). anyone notice any kind of performance increase w an S5 AFM on an S4 NA?? power? gas mileage?

 

I hit 61% on my s-afc today. That is completely maxing the flapper door on the afm. (because when you hold it wide open thats what she reads) If I had access to a S5 I'd throw it in to see if it changed anything.

The resistance differences are big enough to require correction, but could be small enough to still function.

 

What about a VPC??? DSM guys use those all the time. Gets rid of the AFM and uses speed density, I believe.

 

Speed density isnt all that great but it could work with alot of work that probally wouldnt be worth the while. -Gabe

 

That's true, but one of the big advantages of an AFM system is that changes that increases the engine's air flow (intake, exhaust, etc) are measured by the AFM and accounted for by the ECU up to a point. With speed density the change in airflow doesn't result in a change in manifold pressure, so the ECU has no idea it should be injecting more fuel to suit. Basically AFM systems are a lot more tolerant of changes, so you don't need to re-tune every time you change something. That's what the S-AFC is for! You simply tune the new AFM's readings to suit the ECU the same way you tune the stock AFM's readings to suit bigger injectors. It's no different.

 

Yep, it lets the stock ECU read a manifold pressure signal instead of airflow. Unfortunately they were only made for S5's, and they're very rare and very expensive (not much cheaper than an E6K).

 

All aftermarket ECU's and quite a few factory ones use speed-density, so it's not hard at all. It's not as accurate as an AFM, but it does work fine.