LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

honeycomb?

Thread Tools
 
Search this Thread
 
Old Aug 19, 2003 | 09:44 PM
  #16  
SinisterSS's Avatar
Registered User
 
Joined: Jun 2003
Posts: 40
From: Illinois
96's have a snap ring retainer holding the screen in. Popped mine out 10,000 miles ago, noticed a little rougher idle, but otherwise, no problems (probably no gains either).
Old Aug 20, 2003 | 02:32 PM
  #17  
Z28SORR's Avatar
Registered User
 
Joined: Jul 2002
Posts: 3,768
From: Friendswood, TX, USA
Very interesting! I have a 97 and it didn't have a snap ring. I descreened mine and have had NO problems. I think those who have had problem are either, 1) unlucky, or 2) abused the MAF while descreening it.
Old Aug 20, 2003 | 02:46 PM
  #18  
LeftoverChinese's Avatar
Registered User
 
Joined: Aug 2003
Posts: 286
From: Florida
I fail to see a point in descreening the MAF. It flows more air than your car needs, why do it?
Old Aug 27, 2003 | 07:12 PM
  #19  
94formulabz's Avatar
Registered User
 
Joined: Apr 2003
Posts: 1,591
From: PA
Originally posted by LeftoverChinese


I have been wrong before, ask him and see what he says. Be sure to find out what kind of gain will there be and if there is a possible problem that could occur due to the lack of a screen. I would be interested in knowing what he says.
Verdict, ditch it. He said there have been a few rare cases where people thought they had a rougher idle. Maybe they didn't tighten the back of the maf down enough, or maybe theirs does idle rougher, who knows. No problems though once the airflow increases.

I ditched mine when i cleaned it. I think it will make a very cool beer coaster
Old Aug 27, 2003 | 07:43 PM
  #20  
shoebox's Avatar
Registered User
 
Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
It's not logical to compare screened factory MAFs to unscreened because the difference is in the design. One designed to work with and the other without. If you alter the design, you change the calibration. If you change the calibration, be prepared to make programming changes to properly compensate.
Old Aug 27, 2003 | 08:42 PM
  #21  
Scotts94z28's Avatar
Registered User
 
Joined: Jun 2001
Posts: 128
From: Houston Tx
I took my screen out about 175k back, first mod I did I think. Never had any problems.
Old Aug 27, 2003 | 09:23 PM
  #22  
1996 | Z28 SS's Avatar
Registered User
 
Joined: Jan 2003
Posts: 449
From: Toronto, Ontario
Descreen my MAF (96 SS) in 5 min... didn't notice any difference what so ever... no rough idle.. no better throttle response.. and no exhaust tone difference. Mine had a snap ring as well btw.. very easy to take out. And I agree... I think people who have had problems with doing this damaged the sensor.. I say go for it.. probably wont gain anything (you might.. even if it's in you're head I guess that counts ) but in my opion.. it wont hurt either.

Trevor
Old Aug 27, 2003 | 10:22 PM
  #23  
94formulabz's Avatar
Registered User
 
Joined: Apr 2003
Posts: 1,591
From: PA
Originally posted by shoebox
It's not logical to compare screened factory MAFs to unscreened because the difference is in the design. One designed to work with and the other without. If you alter the design, you change the calibration. If you change the calibration, be prepared to make programming changes to properly compensate.
I can kinda agree with that but on the other hand i don't.
Think about the throttle body being closed, very little flow through the MAF, then you open it up and you get more flow. Put on a larger tb and you get more flow still, the calibration just has to do with the diameter of the MAF. PORTING it will definitly screw up the calibration. The screen could be moved upstream and downstream and make no difference right? It's just like adding or removing any other restriction or modification. The MAF will recognize the MINUTE amount of additional airflow and say yeah theres more air there.

The straightening effect of the MAF has to be minimal anyways because even if there is turbulence the eddys will be static if you change your frame of reference to be the velocity of the flow through. In other words even if there is a swirling it's not like the air is going to loop around and pass the maf twice, it'll be through and sucked into the intake before it completes its swirl because the swirling is relative to the stream velocity not the maf. We are soo used to looking at fixed frames of reference.

BTW, bryan didn't think it was worth any HP, it was more of a it's free so why not deal.
Old Aug 28, 2003 | 03:52 AM
  #24  
anaik's Avatar
Registered User
 
Joined: Feb 2000
Posts: 1,335
From: Cleveland,OH
I think, like others, that it is a restriction. Brent had one flowed on a Superflow 300, and the results were, w/screen it flowed 759cfm and wo/screen 979cfm. Also I go by what my Scanmaster tells me. With screen, my MAF sensor shows 29X grams per second at WOT at 6K rpm. Without, it reads 30X under the same conditions. These are consistent readings. My car has no erratic idle, nor is my mileage affected. I am not trying to encourage anyone to remove their screen, that is just how it works for me.
Old Aug 28, 2003 | 07:49 AM
  #25  
LeftoverChinese's Avatar
Registered User
 
Joined: Aug 2003
Posts: 286
From: Florida
http://www.ws6zxr.com/showthread.php?s=&threadid=23392

just thought I would share
Old Aug 28, 2003 | 08:14 AM
  #26  
bad1LEz's Avatar
Registered User
 
Joined: Sep 2002
Posts: 245
From: Central Pennsylvania
I've replaced my stock MAF with a Granatelli aftermarket MAF. If I'm reading this right what you guys are saying is that I should get my PCM re-scanned and re-programmed? Even with LT1Edit? The guy I had reprogram my PCM in the first place already has the VIN lock license for LT1Edit for my vin #. He said he'll do any future stuff for free. Do I really have to get it done since going to the aftermarket MAF?
Thanks.
Old Aug 28, 2003 | 09:07 AM
  #27  
ZDriver96's Avatar
Registered User
 
Joined: Oct 1999
Posts: 1,490
From: Tampa Florida
I descreened my MAF and put in 65mm Tbryne MAF ends.
Tuning was originally designed for just descreened MAF and Short tubes. Not my larger MAF ends and long tube headers.
MAF ends are effectively a ported MAF.

I noticed no gains or losses with descreened and 65mm maf ends. Car runs fine.
By "port" are u guys refering to hand porting? In my opinion that wouldnt be smart.
bad1LEz- I'd at least have your guy check out your Air fuel and other info to make sure your not running too lean.

If descreening flows 900+ cfms then it doesnt matter a whole lot since the stock throttle body flows what.. 650cfms?? or about that.
What are everyones thoughts on MAF ends?
Old Aug 28, 2003 | 09:26 AM
  #28  
Brent94Z's Avatar
Super Moderator
 
Joined: May 1999
Posts: 4,060
From: Inverness, FL
Originally posted by bad1LEz
I've replaced my stock MAF with a Granatelli aftermarket MAF. If I'm reading this right what you guys are saying is that I should get my PCM re-scanned and re-programmed? Even with LT1Edit? The guy I had reprogram my PCM in the first place already has the VIN lock license for LT1Edit for my vin #. He said he'll do any future stuff for free. Do I really have to get it done since going to the aftermarket MAF?
Thanks.
The Granatelli MAF has a re-calibrated sensor in it. So, you do NOT need to have your PCM re-programmed when adding a Granatelli MAF.

IMO, the only time you should need reprogramming is when porting the stock MAF ends as this changes the cross sectional area where the actual MAF sensor is located. Removing the screen doesn't mess with the calibration of the sensor because the cross sectional area doesn't change at the sensor... all that is being done is an intake restriction is being removed. Think of it in similar terms as a CAI. You put on a CAI and this increases overall flow in a stock LT1 by around ~30 gps. No recalibration of the PCM is needed in this case because the MAF sensor can accurately see the increase in air flow. A similar thinking can be used when removing the screen... it just doesn't make anywhere near the difference as a CAI kit Sure, you could argue that the screen "helps" the MAF sensor to "see" the flow more accurately but in the crude testing I've done, I've seen absolutely no difference in gps flow or sensor behavior with and without the screen. So, in my case, removing the screen didn't appear to do anything for me but since it didn't hurt either and it IS A RESTRICTION (there is no arguing with fluid flow principles ) I just left it out.
Old Aug 28, 2003 | 10:13 AM
  #29  
94formulabz's Avatar
Registered User
 
Joined: Apr 2003
Posts: 1,591
From: PA
Removing the screen doesn't mess with the calibration of the sensor because the cross sectional area doesn't change at the sensor... all that is being done is an intake restriction is being removed. Think of it in similar terms as a CAI. You put on a CAI and this increases overall flow in a stock LT1 by around ~30 gps. [/B]
Thats exactly how i looked at it. Does my turbulence and frame of reference reasoning make any sense to you? just curious since noone commented on that.

I'll add this as well regurgetated from what bryan told me. Most of the aftermarket MAFs have less precise calibrations than the GM ones. They are much better than a hand ported stock one.
Old Aug 28, 2003 | 10:28 AM
  #30  
magius231's Avatar
Registered User
 
Joined: Mar 2001
Posts: 956
From: Winston Salem, NC
I descreened my 96 when I had it, and I had to destroy the screen to get it out. I noticed 0 difference. I haven't touched the MAF on my 95 nor do I intend to. The .5 HP increase isn't worth the possibility of problems to me.



All times are GMT -5. The time now is 07:06 PM.