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View Full Version : what mass air to use with a mpx?



TwoToneThunder
11-20-2007, 07:51 PM
i just bought a 76mm mass air flow sensor for my car and i plan on running a mpx blower with 60lb injectors


which mass air flow sensor would be the best? with a 76mm work or is it going to be to small?

fast Ed
11-20-2007, 08:16 PM
Stock longblock, or do you have heads and cam going on as well? I'm running a 76 C&L with the MPIII, stock engine. You would probably want to go with the larger version if you're doing heads and / or cam too.


cheers
Ed N.

TwoToneThunder
11-20-2007, 08:26 PM
dave dalke heads package
mpx blower 25% od
mp front mount ic
griffen radiator
60lb injectors

90scman
11-20-2007, 08:48 PM
there is a guy down in houston with a similar set up and he is running with a 80 or 85 mass air.

90blkbrd
11-20-2007, 08:53 PM
I'm running a 73 mm with an MPx and 50 lbs injectors.

It really all depends on your application.

pablon2
11-20-2007, 09:53 PM
My built block with 60lb injectors and an MPx was tuned with an 80mm C&L and was not close to pegging it.

CurtisPaulfrey
11-20-2007, 10:06 PM
I have an 80mm....thats what Dave said would work..........on a side note post pics of all these new parts

TwoToneThunder
11-20-2007, 10:07 PM
My built block with 60lb injectors and an MPx was tuned with an 80mm C&L and was not close to pegging it.

what kind of power numbers did it put down?


what are your other mods

CurtisPaulfrey
11-20-2007, 10:09 PM
what kind of power numbers did it put down?



http://www.sccoa.com/forums/attachment.php?attachmentid=29354&d=1195156689

fturner
11-20-2007, 10:50 PM
To put it this way, the 76 mm C&L MAF with the purple sample tube for 42 lb injectors can flow up to 2000 Kg/h of measurable air based on the stock electronics. In other words, the electronics will be sending a 5 volt signal once you are sucking in 2000 Kg/h of air through that MAF with that sample tube. (This is theory, because alot of things including how the CAI setup is done can alter those limits, and that can go either way.)

There's an electronic limit as well as a physical limit you need to consider. Alot of folks are surprised how soon they can peg a lightening MAF using its electronics.

So how much air in Kg/hr can an MPX overdriven at 25% move if the motor can use all that air going into it?

pablon2
11-21-2007, 12:00 AM
what kind of power numbers did it put down?


what are your other mods

Hmmm, let's see. It jumped off the dyno, then the XXIC split the top weld, and then we ran out of tuning time, AND THEN the thrust bearing went out, so I never got any numbers. Dam, I'm mad all over again. :mad: :) :o

Randy N Connie
11-21-2007, 12:38 PM
I don't know for sure ,but I am under the impression. That there
is no sample tube for the C&L 76MM MAF that go's with #60 injectors.

I thought that C&L had sample tubes to fit up to #50 injectors
for the 76mm MAF.

Randy

XxSlowpokexX
11-21-2007, 12:41 PM
Alot of folks are surprised how soon they can peg a lightening MAF using its electronics.

Didnt come near pegging it with 318rwhp..We shall see what happens once the AR is thrown on

XxSlowpokexX
11-21-2007, 12:43 PM
Hmmm, let's see. It jumped off the dyno, then the XXIC split the top weld, and then we ran out of tuning time, AND THEN the thrust bearing went out, so I never got any numbers. Dam, I'm mad all over again. :mad: :) :o


You blew your motor or is it just that the thrust bearing is kinda shot..Ive noticed the thrust bearing being shot on alot of high mile SC motors that are still running

Mike8675309
11-21-2007, 02:06 PM
dave dalke heads package
mpx blower 25% od
mp front mount ic
griffen radiator
60lb injectors

Just get one that fits in your budget. Start with asking your head provider his recommendation.

Since you are getting a chip, that will adjust the fuel mapping to MAF voltages. you just want to make sure that your MAF is sized such that it provides a smooth proportional increase of voltage to air flow without hitting 5v before you take the foot off the pedal.

I believe as far as value is today, the 80mm seems to be the no brainer, unless you are looking used.

kenewagner
11-21-2007, 03:20 PM
I don't know for sure ,but I am under the impression. That there
is no sample tube for the C&L 76MM MAF that go's with #60 injectors.

I thought that C&L had sample tubes to fit up to #50 injectors
for the 76mm MAF.

Randy

Randy is correct. I have 60lb injectors and the sample tube is for 50Lb injectors. The tuner has to be aware of that to make adjustment to the chip. I beleive the 50lb tube is a green one.

Ken

CurtisPaulfrey
11-21-2007, 05:30 PM
50lb tube is bright red

Greg Coleman
11-22-2007, 08:40 AM
I cant remember for sure but I got a sample tube from Dave for the 50's and he said it will do for the 60's aswell and I thought it was purple:confused::D Now I'm going to try and run at least 35% or more on the mpx on both cars so I'm thinking the 76mm might not be enough:rolleyes:

fturner
11-22-2007, 09:49 AM
For the 89 to 93 cars the purple sample tube on a 76mm supports the 42's, where the 94-95 cars I beleive that would be the one to use for the 50's if I understand how those things work?

XR7 Dave
11-22-2007, 11:52 AM
Damon, the Lmaf is typically good for somewhere around 400hp. However, Ira's car did repeatedly peg the 90MM MAF at about 345rwhp. We even changed meters and it still did the same thing. With an 80MM C&L it is not even close to pegging at 475rwhp. Another consideration is that the early EEC's do not support 60lb injectors and have a 1400kg/hr air mass limit which makes using the LMAF a little more challenging. I have used it with some success but a calibrated MAF always works better and tunes more easily than the LMAF does in those cases.

The 76MM MAF flows about the same amount of air as the 85MM TB. You can get a 60lb calibration for the 76. It is the green tube. But keep in mind that it doesn't match size for size with the 3.5" intake kit. Neither does the 90MM LMAF. The 80MM MAF fits nicely and flows way more air than you need but requires a 4" filter. For 60lb injectors in an early model car use a green sample tube. In a 94 use red.

Miller
11-22-2007, 11:59 AM
Dave/Damon, I have a 80mm collecting dust on the shelf. When we tune the car, I will be bringing it with me, so if we DO run into problems, we can change it out and re-tune it. Jason says the same as you, that they are generally good for slightly over 400whp, and anything after is stretching it. We'll see what happens tho :)

PS- Dave, what color tube does the 80mm need for the 60's in my 94? I just remembered it came off an earlier car, so it is going to be different im guessing.
PPS- Dave can you clear your PM's please