We are working with DAHLBÄCK RACING AB on some of their higher end products and new technology. I am trying to get an idea of what you guys are looking for in new products, ideas etc... D. Racing will be looking at this thread so your help is greatly appreciated.<ul><li><a href="http://www.speedtechnik.com">Speed Technik</a></li></ul>

higher flowing MAFs, Injectors larger than 440cc/m and self-programmable ECUs.

Oh yeah, it should be affordable too :)

Or there are a lot of different MAFS that can be used if you know how to mod the SW like some of you guys do;-)
Rod

500 wheel hp

also some custom 3 and 3.25 exhaust turbo back and oxygen simulators sos you can dump the cats

and they can install on my car free of charge and ill test it out lol

you'd rather go with estimated air mass.

I have the flow chart for my MAF meter, and it shows the pressure drop in inches of water.

It's around 6" of H2O at max flow, or something like that, which is ~0.2 psi

It was flowed with a cone filter, and I bet a straight tube with a cone filter probably accounts for a good portion of the pressure drop.

I'm not losing any sleep over it either way.

BTDT and spent lots of money to find out the hard way, a 3" MAF is an impossibility for over 420hp crank HP. Sorry to disagree, but like I said I know this for sure.
Rod

My Ford MAF will flow 60 lb/min at 5V It's basically a 3" tube with the sensor hanging in the middle (and it's much smaller than the stock element)

the stock meter element in a 3" tube would only flow ~28 lb/min at 5V I would peg it by 5500RPM on my car at ~18psi

These aren't the flow limits of the tube, but of the element itself. The Ford elements can be recurved, so you could allow it to meter more air if you wanted. These meters are used on supercharged mustangs making alot more than 420HP.

The point is at a specific flow the speed of the air raises to a point where the wire rips out of the MAF. This is the only reason people use bigger tubes, and remember the MAF is a draw tru affair where the real air is moved when the turbo sucks hard and boost is building, so the velocity of a small tube isnt needed. I tore 2 wires out of an rs2 MAF before I figured out that I had maxed the velocity the wire would take. This is what had been written about these engines and the limit was about 420-430 hp. I then looked in the s-car archives and someone had found a paper that showed the velocity of air at around 650cfm or enough to make 420hp the air velocity was well up in the hundreds of MPH. Thus a wire breaks, and that is why I had to do a 4.? " MAF from a Porsche/sport quattro, etc, etc blah blah. But that is the reason, not any other, so in a way you are right.

So yeah, the flow velocity gets way up there for making big Hp.

like I said, they are used on some pretty high HP supercharged V8s, not to mention plenty of NA applications over 450HP+

IIRC, the stock Bosch meter from my car isn't a hot-wire type, it actually has a circuit board of sorts that sticks in the air stream, but these MAFs are known for burning out, so I won't even bother trying to mess with them.

I'm running mine in a blow-through configuration, so I'm curious if that has any affect on the air velocity.

for it. The duct velocity is: V = mdot / (Rho * A) where mdot is mass flow, Rho is air density of the air flowing in the duct and A is the cross sectional area at the point of interest.

mdot is in Slugs/sec so take your g/sec reading and divide it by 14593.9029 to get slugs /sec.

Rho = P static / R*T, where P is in PSF (or psi*144), R=1716 ft-lb/slug-R &amp; T = F+460 Rankine

A = 3.1416 / 4 * ID^2, where ID is in ft

The velocity comes out in ft/sec. To convert it to mph multiply it by 5280 and divide it 3600.

so it's pressurized from the turbo.

I was thinking that the pressurized air of the same mass would move slower. If I did the calcs right, then the calcs prove that assumption.

I used:
g/s: 250
ID: 2.875
Temp = 110
P static = 31.7 (14.7 + 17)

One of the main reasons I went blow-through was because, theoretically, the MAF in front of the TB should provide better Throttle response since the readings are more instantaneous to what the motor is doing. Plus it's a lot easier to plumb in :)

I guess another benefit is lower air velocity.

sirwills@yahoo.com

CAMS is a big one though across the board