lambodara

Can you put an s5 afm in a s4 car without modification?
thanks
steve

wozzoom

Define "without modification".

Is it plug and play? No.
Can it be done? Yes.

The S4 AFM pins can be mapped to the S5 pins. All you need is a soldering iron, some wire, and the wiring diagrams for the S4 and S5 AFM.

crasher2

ok here is another qusetion to go with that i think. I am going to be doing the 89 TB swap to my 87. would i need the TPS and MAP for that year or could I use my old one and have it work fine.

biorotary

i would really recommend you do a tb swap from a s5 to an s4 because the tpses are different...the s5 has 2 sensors and the s4 has one...plus on the tb itself, the screw holes don't line up...

there is a work-around if you really-really must do the swap...
1- find the tps wiring diagrams for both the s4 and s5
2- hard wire the s5 tps to the s4 harness..

again, i don't recommend it...

lambodara

so, does anyone know what has to be wired where?
thanks
steve

crasher2

what you dont recommend doint the TB swap or doing the hard wireing

RETed

My question is..."why???"&nbsp There hasn't been proof that the sliding-cone AFM makes "more power" than the flapper door type AFM; if it does make more power, I would bet it would be real minimal.&nbsp There is nothing wrong with the flapper door AFM unless you pushing real big power?&nbsp I just don't get it, John D. has pushed over 400hp with a big turbo on his 10AE with the stock ECU and stock AFM - I doubt you guys are getting even close to this...


-Ted

NZConvertible

Two probs:

1) The S5 AFM may have less internal resistance than the S4 one, but it's inlet is actually a bit smaller (60mm dia. vs 60x50mm), so I really doubt there'd be much difference in flow. As for power, you'd need a really good dyno to pick it.

2) You can't just "map the S5 pins to the S4 pins". The flow characteristics of a sliding cone AFM are totally different to a trapdoor type. You'd be sending completely wrong signals to the ECU.

Despite the number of times this comes up, and the number of times someone just says "it can be done", AFAIK nobdy's put their hand up and said "I did it, here's how I did it and here's the results". After 14 years, if it hasn't been done, it probably can't; and if it has, it ain't worth the trouble.

peacekeeper

Word to yo mother NZ.

crasher2

I found it on a web siter and someone has put the 89 throttle body on an 87 motor, my question was can I use the same intake tube and equpiment or would i need to use the one from the 89 motor

NZConvertible

According to the FSM's, both TB's are the same size (3 x 45mm), so why bother?

crasher2

from what I am reading, the 89 - 92 throttle body assembly give another 10 HP to the 86 - 88 N/A

Roy James

um, i think you are talkinga bout the VDI manifold swap there Crasher2, not just the TB.

XimbueX

A guy in my club did it pretty easily here's the email he sent me about it...

The first thing I needed was the wiring schematic of the two different MAF's. I found it from some website, I can provide it for anyone who needs it. The connectors are different but the wires do the same thing. The only difference is the 89+ cars do not have a fuel pump shut-off relay in the MAF.(It must be somewhere else in the car).

I got a bunch of very small spade connectors with both the male and female sides and used them to make a make shift patch cable. The fuel pump relay terminals in the wiring harness coming from the car need to be jumpered together, a short wire with a space connector at each end works fine. This results in the fuel pump running whenever the ignition is on.

The rest of the wiring is just matching up the car harness side terminals to the 89+ MAF terminals which is pretty easy when you have the wiring diagrams. The 89+ MAF has a wider range temperature sensor but that doesn't seem to effect the computer.

I wrapped everything in electrical tape, it isn't too pretty but it seems to work well. I haven't had any problems since it was installed.(knock on wood)

I forgot to mention that I unbolted the MAF from the plastic stock box, because a have a K&N style air filter it fit right over the smaller inlet end of the MAF. The other outlet end is larger in diameter and fits into the stock intake pipe. The bracket to hold the MAF had to be custom made, but it was just a matter of some bent metal with a few drilled holes. If I get some digital pictures I will try to forward them to you. If their is enough interest I can try to make a detailed instruction page that perhaps we can post on the website.

here's some more related stuff from him:
The MAF is very possible to swap, when you are into the wires it opens up a few more options. Such as my fuel pump relay is not wired into a toggle switch so I can shut off my fuel pump at will. I also wired in a 10 turn 10K potentiometer into the temperature sending wire, this allows me to adjust how cold the computer thinks the incoming air is which changes the fuel mixture. I have the 10 turn pot hooked to a micro switch which "actives" the increased resistance at about 3/4 throttle so I don't mess with the partial throttle mixture.


Doesn't sound too difficult to me NZConvertible...

Matt Ford
XimbueX

NZConvertible

Why am I so often misquoted?

I never said it was difficult. I know it would be very easy. Anyone who can read a schematic and solder could do it in under an hour. Since you missed it the first time around:

Two probs:

1) The S5 AFM may have less internal resistance than the S4 one, but it's inlet is actually a bit smaller (60mm dia. vs 60x50mm), so I really doubt there'd be much difference in flow. As for power, you'd need a really good dyno to pick it.

2) You can't just "map the S5 pins to the S4 pins". The flow characteristics of a sliding cone AFM are totally different to a trapdoor type. You'd be sending wrong signals to the ECU.

XimbueX

I'm not saying its worth the trouble, but it has been done.

I'm curious why you say mapping the pins together sends the wrong signal to the ECU, it seemed to work for my friend, so where's the problem? I'm not tyrin to be critical, just curious.

-Matt Ford
XimbueX

NZConvertible

It's the relationship between airflow and output voltage that's different. This is because the flapper type AFM has an output that's close to logarithmic. It only takes a little airflow to move through the first part of the flap's sweep, but because less and less of the flap is in the airstream as it swings open, a lot more airflow is required to move it through the last part of its sweep. The sliding cone type AFM has a much more linear movement of the cone as airflow increases, and hence its output is also close to linear.
Because of this, I'd be really surprised if the open-loop mixtures in your friends car weren't altered by the change of AFM. If they were right before, they won't be now. The difference may not be huge (not enough to see on a gauge on the stock O2 sensor), but do you really want to be making changes that have an unknown effect on mixtures?
Airflow is the other issue. Was the car dyno'd before and after? I doubt you'd see any difference because even if the S5 AFM can outflow the S4 one by 10% (on a flowbench, which I doubt), the difference it'll make to the whole engine's flow would be tiny.
I've never said it can't be done, just that there's no good reason to do it, not one backed up with any hard data anyway. Anyone care to prove me wrong? If I am, I'll buy one and swap them the next day!