View Full Version : Some might find this interestingl.....Is the MAF a Restriction??
Black02SS
November 10th, 2006, 10:47 AM
I was tuning a car today and we tried a test to see how much of a restriction the MAF was on a car. I am not talking SD/Non-SD as the car is in SD. I know several are runing SD, but still have the MAF in place, just disabled. On this car, we did a run with it in place, and then another with a 4" tubing and 100mm MAF in its place. Now the MAF's isn't used at all, but the customer didn't have a piece of tubing big enough to use, so he improvised and found this setup. When his new 4" tubing arrives, he will be removing the MAF and just runing the tube. Very good choice on his part. ;)
The car is basically cam only, full bolt on with a 90/90. There is NO change at all in the tune from one run to the other.
Run #5 - Stock 78mm Screened MAF
Run #14 - New 100mm De-Screened MAF and tubing (Bigger) +16hp/15tq
Run #12 - Same as 14 with cutout open +23hp/22tq
http://www.greenlightmotorsports.com/download/MAFRESTRICTION.jpg
ScarabEpic22
November 10th, 2006, 11:02 AM
Interesting, nice results. If I had a MAF I would remove it, but the I6 engine (until late 05 when they got MAFs) operates in SD mode from the factory!
Bruce Melton
November 10th, 2006, 12:10 PM
Not what I wanted to see, but thanks.
MCG
November 10th, 2006, 12:24 PM
Here is another example, same conclusion. This is Tim Tosto's N/A M6 422 cid HOSS Camaro. Main changes were dumping the MAF and going with a nice large air exchanger tube to connect to the lid. The car picked up from a 9.87@139 to 9.71@141 with just this change and reseting the A/F (it changed slightly when the MAF restriction was removed).
http://www.mccordcg.com/pcm/dynocharts/tosto_422.jpg
TAQuickness
November 10th, 2006, 12:48 PM
I don't feel so bad for selling my 85mm MAF for $20 bucks now (apples to oranges, but I got paid for my RWHP this time).
Thanks Chad - You made my night
Tordne
November 10th, 2006, 05:29 PM
Someone tell Mr. Diggler :)
Garry
November 10th, 2006, 06:46 PM
Wow! So, everybody going out to dump their MAF now?
TAQuickness
November 10th, 2006, 06:57 PM
Wow! So, everybody going out to dump their MAF now?
Nah. Chad just proved what we already knew.
bink
November 10th, 2006, 07:04 PM
I have an LPE 100mm MAF sitting in the garage. I guess I should get a 4" coupler and hook it up. Thanks !!
:cheers:
joel
Delco
November 10th, 2006, 07:17 PM
Did all these tests a few years ago on Project Monaro and found speed density to be a advantage even on a stock motor
http://chipmaster.com.au/page2.html
Tordne
November 10th, 2006, 07:32 PM
Nice looking new site Delco!!
Garry
November 10th, 2006, 08:09 PM
So I guess my MAF is going when I do the mods this winter :)
Black02SS
November 11th, 2006, 02:02 AM
Guys. I think some of you are missing the point of this. The car was done in SD, never with a MAF. The only difference is the physical opening of the intake track into the TB/Manifold. We used a 100mm MAF to compensate for a 4" piece of hose. The MAF was never activated. It just shows that if you have a smaller opening in the front of a bigger intake, then you could be leaving some power on the table.
Bruce Melton
November 11th, 2006, 02:12 AM
No, actually I just love what the MAF does and assumed that it was a insignificant obstruction. Now I guess I need a MAF with a bigger hole.
Wanna sell that 100mm?
Black02SS
November 11th, 2006, 02:38 AM
It is a LPE 100mm MAF. It was the customers unfortunately. I'll say this, man was it huge. :lol:
bink
November 11th, 2006, 03:31 AM
It is a LPE 100mm MAF. It was the customers unfortunately. I'll say this, man was it huge. :lol:
Here's a link to a related discussion. It's intertesting what Louis G has to say about the LPE 100 mm MAF and Big Cam Overlap/Reversion. FWIW
http://www.ls1tech.com/forums/showthread.php?p=5860076#post5860076
Rumour has it that Nick Williams is working on a 100 mm TB. With a 100mm MAF the bellows and CAI should be the next bottle neck for the C5/6 guys (as Jason says in the linked thread).
:cheers:
joel
Bruce Melton
November 12th, 2006, 06:13 AM
Having read all related links this is a somewhat confusing topic.
No one really seems to gain from changing from 75>85 mm maf.
As Bink and Katech point out what next if you just change to the 100mm MAF?
ie. what intake , filter?
SS, when you dynoed what was on the free end of the 4" MAF tube? filter?
Intrigued (http://www.tfd.com/intrigued)-
bink
November 12th, 2006, 02:09 PM
Having read all related links this is a somewhat confusing topic.
No one really seems to gain from changing from 75>85 mm maf.
As Bink and Katech point out what next if you just change to the 100mm MAF?
ie. what intake , filter?
SS, when you dynoed what was on the free end of the 4" MAF tube? filter?
Intrigued (http://www.tfd.com/intrigued)-
I'm think I'll try a C6 Callaway Honker on my C5. Looking at pics I should be able to use some 4" couplers and modify it to work - we'll see. Hopefully a 100 mm TB will be available soon. Winter project. :D
Redline Motorsports
November 12th, 2006, 02:14 PM
Chad,
Look at the KPA values over 4700 and see if the readings changed after taking the restriction out. I would be surprises with that kind of gain that the difference is 2-3 KPA!
Howard
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