PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

MAF size for 408

Thread Tools
 
Search this Thread
 
Old Jul 9, 2011 | 02:08 PM
  #1  
331stroker's Avatar
Thread Starter
Teching In
iTrader: (5)
 
Joined: Nov 2005
Posts: 13
Likes: 0
Default MAF size for 408

Guys,
What size MAF is needed for a stroked LQ9 408?
I keep hearing the stock LS1 MAF is too small. I believe it is 78MM.
If it is, will a Z06 85MM MAF cure the problem?

Oh yeah??? The problem is, we seem to be running out of air at WOT.

Using HP tuner to tune with.
It's either the tune, the MAF or weak valve springs. The heads were reworked about 2,000 miles ago, although we did discover we were running too long of a pushrod. Changing the pushrods helped alot.
There is no missfire at WOT Pulls to 6,000 hard then falls off.

Running a LS6 intake,ported TB, custom EPS cam 604/607 lift, shorty headers, gutted cats, Magnaflow exhaust, 243 Patriot stg 2 heads (reworked) (valves were not seating correctly out of the box), 36# FAST Injectors, 255LPH fuel pump, K&N cold air intake setup.

Any answers appreciated...
Reply
Old Jul 9, 2011 | 02:38 PM
  #2  
SSpdDmon's Avatar
TECH Addict
iTrader: (10)
 
Joined: Jun 2004
Posts: 2,918
Likes: 0
From: Commerce Twp, MI
Default

Z06 MAF will help some. A FAST 90/90 or higher will help more...especially over 6K RPM.

I run a 85MM with a FAST setup on my stock shortblock. Pulls real nice up top.
Reply
Old Jul 9, 2011 | 03:45 PM
  #3  
99TransAmLS16Spd's Avatar
TECH Apprentice
iTrader: (8)
 
Joined: Dec 2005
Posts: 395
Likes: 0
From: Morris, IL
Default

Im not sure what the duration is on your cam - but for perspective my 416 has a 244/250 hyd roller in it with TFS 235s.

with the pacesetter lts, fast 92/92, and Z06 85mm MAF, hp pretty much flat lined at 5,700 rpm to 6,400rpm then started going down. Was 3 cells from maxing out the MAF.
Swapped out the pacesetters for some kooks stepped lt's, didn't put it back on the dyno but data logs indicated I was still choking my engine past 5,700 rpm. Swapped a supervic/4150 tb but haven't even driven it yet. Will be going SD tune though.

In your case, I do not think going with a bigger MAF alone will provide the gain you are looking for. If you upgrade the MAF, highly consider upgrading the intake and TB as well.
Reply
Old Jul 9, 2011 | 05:00 PM
  #4  
331stroker's Avatar
Thread Starter
Teching In
iTrader: (5)
 
Joined: Nov 2005
Posts: 13
Likes: 0
Default

Thanks guys for responding...

The cam duration is 238/246.
Sounds like this fire breathing dragon needs intake, throttle body, maf and long tube headers to reach 6,800.
Reply
Old Jul 9, 2011 | 08:14 PM
  #5  
WKMCD's Avatar
TECH Junkie
iTrader: (2)
 
Joined: Mar 2005
Posts: 3,416
Likes: 2
From: Northern VA
Default

I ran a 100mm PowerMax MAF in my 403 build and still run it in the 427.

Reply
Old Apr 10, 2020 | 08:43 PM
  #6  
812meland's Avatar
Teching In
 
Joined: Feb 2012
Posts: 1
Likes: 0
From: indiana
Default 408 shutting off at 5700 rpm

Originally Posted by 99TransAmLS16Spd
Im not sure what the duration is on your cam - but for perspective my 416 has a 244/250 hyd roller in it with TFS 235s.

with the pacesetter lts, fast 92/92, and Z06 85mm MAF, hp pretty much flat lined at 5,700 rpm to 6,400rpm then started going down. Was 3 cells from maxing out the MAF.
Swapped out the pacesetters for some kooks stepped lt's, didn't put it back on the dyno but data logs indicated I was still choking my engine past 5,700 rpm. Swapped a supervic/4150 tb but haven't even driven it yet. Will be going SD tune though.

In your case, I do not think going with a bigger MAF alone will provide the gain you are looking for. If you upgrade the MAF, highly consider upgrading the intake and TB as well.
did you ever figure out why your 408 was falling out at 5700? Mine is doing the same thing and I can't figurge it out for nothing..anyone pkease help?!?!
Reply
Old Apr 11, 2020 | 12:30 AM
  #7  
G Atsma's Avatar
TECH Senior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2016
Posts: 22,288
Likes: 3,615
From: Central Cal.
Default

Good question- Poster hasn't been here in about 8 years
Reply




All times are GMT -5. The time now is 01:03 AM.