Has anyone with a turbo relocated the MAFS to the post intercooler side of the system (i.e. right in front of the throttle body or there abouts). It seems the MAFS would get a better reading of exactly what is going into the engine at that point. However, I searched and didn't see anything on this, so there must be a reason why nobody (or not many people) have done it. Ideas?

 

I remember on some other cars people tried this but the MAF sensors were too fragile and broke in the compressed air stream. I don't know how fragile the RX-8 MAF is, but at under 14 pounds for more people, that isn't a boat load of boost. I think the situation I remember was around 25 pounds of boost people were running that MAFs broke.

 

I second GTAW. I have mine mounted in about the same spot as his and it works marvelously.

You'll just have to adjust the fuel maps slightly because the car will be a little rich. So far it has worked great...

Chris.....Esmeril

 

this is all good feedback. The next question is, has anyone done it with the GReddy kit. I've not seen a kit where there is a MAFS bung on the pipe right before the throttle body. How did you guys do it? Custom pipe and bung?

 

you would need a MAF bung and weld it to the pipe before the TB. Then you would need to remove the section of pipe where the MAF used to be and seal it up with a new solid piece of piping

 

Both the PTP and SFR kits use the blow through configuration. I plan to use this setup also.

 

I was discussing this with tdiddy the last time we ran into one another at a meet. If I go the custom turbo route some day, I might just save myself the hassle and use the MS CAI as it already incorporates the MAF on a 3" tube in the very location everyone is discussing. Really, though, this will be dependent on Cobb's recommendation after they release the Accessport.

 

I'm sure you're correct and it is 3.5 not 3, I was just recalling off the top of my head.

 

Yes, the Mazdaspeed intake is 3.5". It could easily be modified to be used with the Pettit supercharger and using part of it could be possible for a custom turbo setup. I don't know if using the MAF mount piece would be easily done though. Notice in the pictures that the MAF mount piece has a slight bend in it. This could be a problem. Also, and probably more important, is the length of the MAF mount piece. It extends past the top cross member at the front of the engine bay. This could be a problem getting the piping from the intercooler to meet in with the MAF mounting piece. I'm sure it could be done but there might be easier ways.

 

Hmmm...what I'd had in mind from time to time was to run from the intercooler and attach to the MS/Maf mount like how Rotorocks did his rear mount turbo...probably relocate the battery to the trunk and place the intake filter there to lead down to the turbo. Though that location might be horrible for sucking in hot air from the engine bay, but no worse then the GReddy location.

One of his earlier pictures in the initial stages, but the idea is transparent:
https://www.rx8club.com/attachment.p...5&d=1160961612

For that matter, I'd still like to figure out some way to Vmount an intercooler. I'm just not comfortable with a FMIC on a rotary.

 

We relocate the MAF right before the TB on our SFR turbo system.We made a custom MAF housing with screens in it as we found out that running this MAF without screens, right before the TB, lead to some erratic idle issues.

 

I see what your thinking now. You would be able to use everything except the "turn piece" that the filter connects to for that setup.

 

I experimented with the MAF in both positions and I found no benefit to having it post-compressor.
In theory, it would eliminate vented volume errors, but since I didn't have those to begin with, this benefit did not outweigh the consequences.
Erratic idle was persistent. Adding screens may have improved this, but I wasn't particularly sanguine about having all of that obstruction post compressor.

Having the IAT post compressor is a good idea, however.

 

I'm guessing you have plans to move to the flash software, or at least experiment with it? Any thoughts on where you'll locate the MAF?

edit: seems many factory turbo cars, are locating the IAT pre turbo, never really got that logic myself as it would seem I'd want to favor reading the charge temps post intercooler...

 

Or through tuning.

You got an answer, stoopid beyotch!

 

Thanks for all the input. The solution Synaptic3 is going with is using the blue MAFS mounting tube that comes with the Racing Beat kit. We are going to cut the pipe that comes up to the throttle body and insert the Racing Beat tube with silocone couplers there. Now clearly it would add quite a bit of complexity to put one of the screens in there before the MAFS. Also, would the airflow through the MAFS be as erratic post turbo/intercooler as it would directly post air filter like in an N/A application?

And please excuse my ignorance, but what is IAT?

 

The idle could be considerably more erratic since the air is "chopped" by the turbo.
The pipe diameter is also not a minor consideration. It is very difficult to "recalibrate" for the incorrect sizing of the charge pipe.

IAT = Intake Air Temperature sensor.

 

Thanks MM. Would you suggest we go down a route of trying to get a screen in that racing beat tube before the MAFS? Thats a big restriction (as you mentioned) and I'm also worried about the screen coming loose in there.

The piping diameter for the racing beat MAFS pipe is 3.5" which makes it perfect for this, except the screen issue. I'll have to look into the racing beat setup to see how the screen is in there again.

Anyone else running this?

 

as MM put it - "chopper" air, probably would not be to big of an issue past intercooler. The air will have plenty of time to get "back together", however you may probably want to keep it away from the BOV somewhere.
Get a thiker mesh with larger cells, if you worry about it breaking.

 

you mean keep the MAFS away from the BOV correct?

 

Unless someone can show significant advantage over a properly installed and tuned setup with the MAF before the turbo, this doesn't sound like the relocation effort is worthwhile.

And besides air loss from a non-recirculated BOV, the MAF should read the same either way.

I'd rather have screens on the non compressed air stream too.