dang... i'm still waiting to get all my parts so i can install (but i haven't started yet)... it must be tough knowing you're 90%+ done and can't drive it yet. any updates?

 

Pullthrough or blowthrough, the amount of air passing through the MAF is the same.. If your engine is pulling too much air and pegging the MAF you can always use a bigger tube and rescale it (i'm sure the AP is capable of that..). No reason to go to a MAP setup and start getting at VE values...

 

I've got a track day a week from saturday. So its going to be operational then or I'll be a monkey's uncle.

I did sign up for the slowest class though, I'll be happy just taking a cruise and using the straight-aways for test and tune.

 

Yeah, but I've always wanted BOV sound, and with a MAF setup you have to recirculate it.

 

+1 For the BOV sound :D

 

While I'm still in the design/construction stage, would it work if I put the MAF right before the throttle body?

Why meter air, then vent it out the BOV?

The MAF would also give real inlet temps instead of pre-turbo/intercooler temp....

....or am I out to lunch?


S

 

You don't have to, but MAF based systems act funky when you vent the BOV though.

I would be in your shoes too, but having had 3 different BOVs and having run them for over a year, I'm OK with no noise in exchange for a OEM-like turbo setup.

 

with a blowthrough MAF setup you might get away with venting to atmosphere

 

We get away with it...

 

The mass is the same, but its flow qualities are vastly different and the MAF doesn't respond correctly.

Yes, as long as the BOV is before the MAF.

However, you will not get predictable results with the RX-8's MAF in a blow-through arrangement.
With a LOT of judicious tuning, you can get it to work, but it will behave as if significantly more air is passing through it than reality, thus limiting its range.
Scaling the tube to accommodate for this will remove a significant amount of sensitivity, thus adversely affecting the idle.

 

Gotcha, leave it where it is.....

S

 

I'm trying to understand this point from a theoretical perspective..

The MAF is supposed to be able to compensate for changes in density of the air passing through it (at least, within the limited range of varying altitude / weather conditions).

If a blow through setup will result in higher readings than a draw through setup for the same amount of air, does that mean that the readings are also affected by pressure? Higher pressure (boost) packs the air molecules closer together, so they take away more heat from the wire than the same amount of molecules spread further apart but moving faster?

 

MM: Sounds like tuning this turbo with an AP is going to be a bit on the challenging side...

 

It seems that it is just a quirk of the MAF itself, not a science thing.

Challenging, yes.
Impossible, no.

It just means more work and the "standard" tunes wont do.
Since I don't, as yet, have direct experience with this kit, anyone using the AccessPORT on this system will require special attention.

 

blowing thru the MAF tube creates turbulence in the air stream that does not occur in the draw thru systems the MAF is designed for. That turbulence creates inconsistent and generally higher readings than is reality.

read thru this thread https://www.rx8club.com/series-i-engine-tuning-forum-63/fi-maf-sensor-130428/ and the links i have posted there. ill dig out more if you need them.

EDIT: i should note that many people have done blow thru systems for years and had good luck with them. it does allow you to vent the BOV to atmosphere. it s just not the way I consider to be ideal

 

danke

 

damn, your gonna have one badass car.

 

as i mentioned elsewhere

D"OH we dont need to be chained to the factory MAF any longer!! why was i not thinking about this ?!!

replace it with a MAF that was designed with blow through in mind and then get a good tune on it with a FLASH.


http://www.vmptuning.com/store/index...=234&parent=29



with the ability to flash we can ditch the OEM MAF if we want

 

That doesn't sound like a bad idea but do you think it will actually work like the OEM unit?

 

yes thats the point actually

 

im confused the option they gave us for plumbing to the exhaust was for the wastegate right? so then is this BOV vent to atmosphere or plumbed in? I guess i would have to get it all together to see lol

EDIT: I tried to use that Mac Tool Fuel Pump Removal Tool and it didn't work at all I will be returning it, theres not that much room to get the tool in. Also the slots in the tool where the fins on the ring would fit in are too big if you put any kind of torque on it the tool slips off.

 

The BOV vents to atmosphere...yes you will hear it :D

 

Excellent...... My girlfriend told me that she would kill me if I spent that much money on a kit and it didn't make the cool PSST sound

 

Marry that girl!

 

Pics or it didn't happen.