Is there any problem with running the AFM right before the turbo? Also I remember there being a thread about running the AFM after the turbo and getting better response and acceleration. What is the reason for that?

 

No problem running the AFM right infront of the turbo, except that it has a 3.5(?) in outlet and the turbo has a 2.25in(?) inlet, there aren't THAT many silicone adaptors around that are like that.
But if you find a good quality adaptor, that wont colapse under high vacume then theres no problem.

 

The AFM already is right before the turbo... If you mean close-coupled, that's daft. Think heat man.

Did you read the thread about running the AFM after the turbo? Your answer's in there.

 

Thats what I first thought aswell, but im pretty sure he means removing the entire stock TID black plastic bit and just having a AFM<->Connector<->Turbo inlet.

thats what I made of it anyway........

 

Yes I meant TRUBO-COUPLER/ADAPTER-AFM no stock TID or any TID for that matter between the AFM and turbo.

 

I can't see why you'd want to do that, but I would think that AFM damage due to excessive heat would be very likely.

 

mine never got particularly hot when I had mine setup a bit like that.. (loong storey as to why, I wont go into that.. ) basically one main concern you should look out for is the the AFM + filter/adaptor/pipping whatever weighs a fair bit. Make sure you have a very good bracket holding the AFM rigidly in place vertically, or else you will run into big problems... or at least I did

 

Read my NA-turbo thread.

 

After doing the N/A-turbo conversion, I moved the AFM to after the turbo, and after the IC of course.

I have 2 reasons, as follows-
Before the turbo, the AFM represents more of an air restriction than after the turbo. This is because there is a much higher flow rate BEFORE the turbo than after- since all the air that is flowing into the turbo is compressed. It needs to take in regular, non-compressed air at a much faster rate to make the same volume of air compressed. Therefore, less restriction=more power!
I'm running the AFM right at the TB, after a big FMIC (2 stock cores), and the upper intake pipe is always ice cold, I'm not worried about heat in the slightest.

The second reason (the reason I actually did it) is that having the afm in front of the turbo, the piping, and the FMIC caused a little bit of initial stumble whenever I'd hit the gas. This was caused by a delay in the throttle plates opening, and the subsequent low pressure finally reaching the AFM, causing it to open.
This resulted in a temporary lean condition, that cause a split second hiccup that was annoying.
Moving the AFM instantly cured that problem.


Reasons NOT to do it?
Well, one could argue that the calibration of the AFM is thrown off, it's going to be reading less than if it was before the turbo, (while mass of air flowing through is the same, volume is DRASTICALLY decreased) causing lean running.
Now, the compressed air is more dense, that means more force per square inch will be exerted on the cone than with the non-compressed air flowing through- moving the cone more.. Now, while I don't know how to prove it mathematically, I still don't think that it will equal quite the same calibration.. I think there is some loss or something somehere in that equation.
Bottom line? Use an S-AFC to retune, and move the AFM to after the turbo (and IC). Everybody wins.

Oh, and don't put the AFM an inch before the turbo, that's just plain retarded. Heat is a factor, and you are also going to get turbulance like crazy hitting the turbine blades, that really decreases it's effeciency.. almost like caviation in hydo flow.

 

we did it on the yellow car, it the "race" tid