At what point does MAF size become restrictive?

Reply Subscribe

Thread Tools

Search this Thread

Jan 28, 2019 | 07:59 PM

98RedBird

Thread Starter

TECH Addict

iTrader: (77)

Joined: May 2005

Posts: 2,773

Likes: 3

From: Peoria, IL

At what point does MAF size become restrictive?

78, vs 85, vs 100, etc...

This isn't meant to be a MAF vs SD debate.

Building a 408, larger cam, TFS 245's, FAST 102/102, etc...

I am considering SD vs MAF still, but what I'm asking is at what point would the diameter of the MAF become a restriction on this motor? I imagine there'd be a difference between 78 and 85, but would 100 gain anything over the 85?

Jan 28, 2019 | 09:21 PM

Darth_V8r

Moderator

iTrader: (4)

Joined: Jul 2014

Posts: 10,450

Likes: 1,873

From: My own internal universe

Best way to tell experimentally is look at map key on engine off vs map under load. More it drops, more of a restriction the maf is.

Yes a 100 gains over a 85

Jan 28, 2019 | 09:46 PM

LilJayV10

TECH Senior Member

iTrader: (39)

Joined: Apr 2007

Posts: 9,711

Likes: 999

From: Evansville,IN

Quote:

Originally Posted by Darth_V8r

Best way to tell experimentally is look at map key on engine off vs map under load. More it drops, more of a restriction the maf is.

Yes a 100 gains over a 85

So at what point do you know when the MAF is the restriction and the intake isn't?

Multiple MAPs?

Jan 28, 2019 | 10:42 PM

Darth_V8r

Moderator

iTrader: (4)

Joined: Jul 2014

Posts: 10,450

Likes: 1,873

From: My own internal universe

You know ambient based on key on /engine off. Say your ambient is 98 kpa and under wot you get 94 kpa. The intake is a restriction. You pull the maf and you get 98 kpa under load? The maf is the restriction.

All there is to it really.

Jan 29, 2019 | 10:51 AM

G Atsma

TECH Senior Member

Joined: Jun 2016

Posts: 22,295

Likes: 3,617

From: Central Cal.

Easier yet, put a vacuum/pressure gauge between the MAF and TB. If at WOT you see vacuum, MAF is restricting. Kinda what Darth said only done differently

Feb 4, 2019 | 08:19 AM

danny_6725

Staging Lane

iTrader: (10)

Joined: Nov 2014

Posts: 73

Likes: 0

I asked my tuner the same question. He recommended I go maf instead of SD unless I'm going forced induction. I went with the 85mm maf. He's a very reputable tuner in the east coast

Feb 4, 2019 | 02:01 PM

Darth_V8r

Moderator

iTrader: (4)

Joined: Jul 2014

Posts: 10,450

Likes: 1,873

From: My own internal universe

for a basic cam only or bolt ons package on a 5.7, he'd be right. but for the OP's 408 with 245 heads, no way I'd run a 85mm maf.

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Verdad Gallardo

6 Common C5 Corvette Failures and What's Involved In Repairing Them

Pouria Savadkouei

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Verdad Gallardo

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Pouria Savadkouei

Top 10 Most Powerful Chevy Trucks Ever Made!

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Verdad Gallardo

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Verdad Gallardo

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Verdad Gallardo

10 Camaros You Should Never Buy

10 LS Engine Myths That Refuse to Die

Verdad Gallardo

Feb 4, 2019 | 03:09 PM

ddnspider

10 Second Club

iTrader: (26)

Joined: Aug 2004

Posts: 14,628

Likes: 1,778

From: FL

https://ls1tech.com/forums/pcm-diagn...er-setups.html
MAF's can make just as much power as SD if sized correctly. Darth outlined how to measure the restriction.