Wow, very good of Scott to get on the phone with you and help out even though most of the parts have nothing to do with him. Did you promise to send him a check, J/K

 

It was nice of Scott to help.

 

Its true, Scott rocks! He even helped me with a few INTX issues!

 

OK, after researching for about 8 hours I think I am going to need switch to Speed Density (MAP) using the Interceptor-X. At least for the time being. The reason for this is mainly my intake setup. The transition from the 3" CAI tube to 3.5" MAF tube and the 90 degree transition from the MAF tube to the turbo inlet are really screwing with my MAF sensor readings.



Things I could try:
1. I could possibly install a velocity stack before the MAF tube. However, I can't really find one that is 3.5" and I would have to loose the CAI.
2. I could install an air straightener before the MAF tube. There are multiple types but I can't find anywhere to buy many of them. The easiest to install would be a mesh screen. I already tried nylon door screen and it didn't work. I have some Stainless Wire Mesh but I don't think this is going to straighten out the airflow enuff to promote laminar flow at all load points. I really need some sort of a honeycomb air straightener but don't know where to buy one.
3. I could install an air straightener after the MAF tube. See #2.
4. I could lengthen the MAF tube to be 8" instead of 6". I plan to try this regardless.

Maybe Cobb will release a short ram intake that is 3.5" for the RX8 similar to THIS one for the Mazdaspeed 3. (hint, hint)

Anyway, I think I am going to switch to the Interceptor for now while I try to get the MAF situation worked out. I have too much time and money wrapped up in the car to just let it sit while I try to work out these issues.

Thanks for everyones suggestions!

 

It would probably work if you put the MAF on the other side of the engine bay in the CAI. Would require that you cut the maf harness to extend it though.

Most of the turbulence is coming from swirl from behind the MAF so you should use more screens 2-3 behind the MAF setup. One fine one directly on the turbo opening and a slightly larger one on the end of the MAF tube.

 

My suggestion would be just to move the MAFS away from the 90* bend and the compressor.

 

So you are saying to move it a couple inches forward?

 

I think ideally I would probably put it on the other side of the front bulkhead directly between the bend that comes out of the IC and the bend that goes into the engine bay.

If this is completely out of the question I would put it as far forward from it's current location as possible.

 

I don't really want to cut the MAF sensor off to extend it. Does anybody know if there is a plug that will fit it?

 

Should I develop, and patent, an extension harness to relocate the MAF sensor?

 

I would test the prototype for ya!

 

So would my DMM!
Shifty bastard, ya!

 

In the works

 

Have at it, Sir!

Which classification are you thinking of issuing it under?

 

Did you ever try swapping the MAF sensor with a known good yet?

 

The sensor is fine. I can see the readings on my CANScan. The readings are just way too eratic.

 

what are you describing as erratic?

cause the afrs will bounce around as you drive. In boost it changes and goes to a specific AFR based on load.

 

Airflow readings that go from 3.4g/s to 8.5g/s withing the RPM range of 850-900 is eratic.

 

I would get the 8" long MAF tube and position the maf 1/3 of the way along it to stay as far away from the turbo as you can . I think the turbo is more likely to cause swirl than the transition ...

looks to me like you could move the maf 3-4 inches further away from turbo without taking it or the transition outside the engine bay ...

 

I agree that the "airwaves" coming off the compressor blades are the biggest concern. And moving the MAF sensor farther away from the compressor inlet is the best place to start. Installing metal screens at the inlet and outlet of the MAF tube should also help.

 

Looking at your engine bay - if you were willing to cut down some of the IC piping (I guess) you can extend your MAF pipe another few inches; and then move the MAF. I think that may help a lot.

 

I used to see normal MAF readings when I worked at the dealership even though a MAF was bad. And they tend to make the engine run either full rich or lean. On the cars I worked on the MAF would make the STFT go lean most of the time but once in a while they would rich. I never worked on Mazdas on a daily basis so I wouldn't be able to say which way they tend to go. Maybe you should try and ask a tech at the dealer. It would be way easier and faster to do a quick sensor swap than anything else.

 

Rather than screens -you could try welding a piece of stainless sheet about 1mm thick by maybe 25mm long across the opening in line with the air flow to the inside of the tube . Then another at 90deg to make an x .

 

Actully the best thing would be to do the "x" thing with screens also.

 

Its full rich on the RX8. If you want to test it just unplug your MAF and start your car. It will run but it will be really rich.