what are the free mods for ls1?
10-24-2007 | 02:37 AM
#16
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Joined: Jul 1998
Posts: 6,249
From: Charlotte,MI USA
The screen on a MAF is there to striaghten out the air flow so that it can be accurately measured. Removal of the screen can increase air flow but it can also cause calibration problems. It's a crap shoot and I'm not a gambler.
10-24-2007 | 02:39 AM
#17
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Joined: Jul 1998
Posts: 6,249
From: Charlotte,MI USA
10-24-2007 | 06:03 AM
#18
Registered User
Joined: Oct 2003
Posts: 2,140
From: DOVER DE
I actually doubt there was a dramatic increase in power. Any power increase from removing the screen does not come from removing the screen, it comes from the change in A/F ratio because the PCM no longer has a correct airflow reading. Even with the screen the stock MAF will flow more than enough for most modified cars.
Re'
10-24-2007 | 12:11 PM
#19
Registered User
Joined: Jan 2005
Posts: 2,594
From: N Falmouth MA
Check the stickey up top.. You'd be supprised what's in one of them..
https://www.camaroz28.com/forums/sho...6&postcount=12
FREE MOD SECTION
I'm tired of seeing threads about free mods... I'll throw them in here too...
Here's a couple sites containing full color photos about the freemods.
http://www.gmhightechperformance.com...ls1/index.html
http://www.installuniversity.com/ins...sity/index.htm
http://www.ls1howto.com
There are basically 5 free mods, all worth about 10 RWHP. I got all ths info from GM High Tech Performance Magazine, my own experience, and some info from this board.
You can also port your own TB. I don't feel like explaining that one so, Visit the website and read their instructions.
FreeRamAir Mod...or the FRA mod
To get more airflow on the cheap, loosen the factory airlid base by unscrewing the four 10mm bolts. Unsnap the airlid and remove it with the MAF still attached. The radiator support and the air dam both need to be removed both from the car. On the airdam, more flow will be seen by removing an area as wide as the slot down to the ridge. Use your choice of weapons--a jigsaw blade or a sharp utility knife will do the job, but a die grinder with a cutoff wheel works best--to cut a rectangular chunk out of the plastic. (see website for photo)
For the radiator support, leave the filter tray installed as a loose guide and mark around the insides of each square. Pull the tray out and grind away the two squares in the center area of the support.
-GMHTP Magazine Web Link above...
MAF Screen
You CAN remove the MAF screen by gently poking it out from the intake side to the filter side. If you dammage any of the three sensing units in the center of the MAF, you will have serious drivability problems and in turn will need a replacement.
This subject has been one of debate here at CZ28.com. There is no actuall proven power to be had here. The screen is used to evenly distribute the incomming air across the surface of the sensing ellement in the MAF. When you remove the screen, tuning it now can be troublesome. (LS1 Edited) Pluss, you can run the risk of sucking in forgotten tools/ parts (hose clamps) that have been mistakenly left on your air filter douring mod install...
IMO, leave the screen on your MAF. The stock MAF sensor is also good up to a conciderable HP level, so a HP replacement is not exactly necessary. Unless you are running some impressive #'s.
TB Bypass Mod
http://www.gmhightechperformance.com...ls1/index.html
http://www.installuniversity.com/ins...sity/index.htm
http://www.ls1howto.com
EGR Mod -Non LS6 intake
If you manually open the throttle, look inside. Where the EGR tube enters the manifold, in back of the throttle body, there will be a portion of the EGR tube protruding into the path of the incoming air. That needs to be chopped. Begin by removing the 10mm bolt that holds the EGR tube into the manifold. (from the top) Be sure to grab the O-ring seal, don't let it get loose int he engine. Pull the EGR tube up and chop the tube below the hat mount ridge. You can use a die-grinder or a dremel, what ever gets the job done. DON'T CUT THE MOUNT! There willl be no way to remount the EGR tube if you do!
Once cut, remove the burs and shavings w/ a file or what ever works. Re-install and snug the mounting bolt back. It doesn't have to be insanley tight!
Drill Mod -For Master cyl clutch line.
The slave is buried under the power brake booster. You'll have to snake your hand and arm underneath to get it out (have patience, it CAN be done). Once you get it out, take a roll pin punch and remove the roll pin that retains the braided line to the master. The disconnect the fluid reservoir from the unit. Drain, but do not clean with water! Brake fluid absorbs moisture. You can use brakeclean if you want, but it could stain the plastic.
-DRILL MOD-
-THE ENTIRE MASTER, RESERVOIR AND LINES MUST BE REMOVED TO PERFORM THIS MOD-
Wrap the master end of the line in an old hose piece to gently hold the master end of the braided line in the vice (looks like a brake bleeder valve. sorry no pic) If you insert the drill bit into the line with your hand you can feel an obstruction in the line. That's what will be drilled out. Use a 7/64" drill bit. The website, www.InstallUniversity.com, says to use an 1/8" drill bit, but I felt it was too big. Gently drill out the obstruction, lifting the drill frequently to remove shavings. Keep the line and drill bit as straight as possible as to not drill through the side of the braided line!
Voi La! You're done. I bled the line about a dozen times to be sure I removed all the metal shavings. Now bolt everything back up.
https://www.camaroz28.com/forums/sho...6&postcount=12
FREE MOD SECTION
I'm tired of seeing threads about free mods... I'll throw them in here too...
Here's a couple sites containing full color photos about the freemods.
http://www.gmhightechperformance.com...ls1/index.html
http://www.installuniversity.com/ins...sity/index.htm
http://www.ls1howto.com
There are basically 5 free mods, all worth about 10 RWHP. I got all ths info from GM High Tech Performance Magazine, my own experience, and some info from this board.
You can also port your own TB. I don't feel like explaining that one so, Visit the website and read their instructions.
FreeRamAir Mod...or the FRA mod
To get more airflow on the cheap, loosen the factory airlid base by unscrewing the four 10mm bolts. Unsnap the airlid and remove it with the MAF still attached. The radiator support and the air dam both need to be removed both from the car. On the airdam, more flow will be seen by removing an area as wide as the slot down to the ridge. Use your choice of weapons--a jigsaw blade or a sharp utility knife will do the job, but a die grinder with a cutoff wheel works best--to cut a rectangular chunk out of the plastic. (see website for photo)
For the radiator support, leave the filter tray installed as a loose guide and mark around the insides of each square. Pull the tray out and grind away the two squares in the center area of the support.
-GMHTP Magazine Web Link above...
MAF Screen
You CAN remove the MAF screen by gently poking it out from the intake side to the filter side. If you dammage any of the three sensing units in the center of the MAF, you will have serious drivability problems and in turn will need a replacement.
This subject has been one of debate here at CZ28.com. There is no actuall proven power to be had here. The screen is used to evenly distribute the incomming air across the surface of the sensing ellement in the MAF. When you remove the screen, tuning it now can be troublesome. (LS1 Edited) Pluss, you can run the risk of sucking in forgotten tools/ parts (hose clamps) that have been mistakenly left on your air filter douring mod install...
IMO, leave the screen on your MAF. The stock MAF sensor is also good up to a conciderable HP level, so a HP replacement is not exactly necessary. Unless you are running some impressive #'s.
TB Bypass Mod
http://www.gmhightechperformance.com...ls1/index.html
http://www.installuniversity.com/ins...sity/index.htm
http://www.ls1howto.com
EGR Mod -Non LS6 intake
If you manually open the throttle, look inside. Where the EGR tube enters the manifold, in back of the throttle body, there will be a portion of the EGR tube protruding into the path of the incoming air. That needs to be chopped. Begin by removing the 10mm bolt that holds the EGR tube into the manifold. (from the top) Be sure to grab the O-ring seal, don't let it get loose int he engine. Pull the EGR tube up and chop the tube below the hat mount ridge. You can use a die-grinder or a dremel, what ever gets the job done. DON'T CUT THE MOUNT! There willl be no way to remount the EGR tube if you do!
Once cut, remove the burs and shavings w/ a file or what ever works. Re-install and snug the mounting bolt back. It doesn't have to be insanley tight!
Drill Mod -For Master cyl clutch line.
The slave is buried under the power brake booster. You'll have to snake your hand and arm underneath to get it out (have patience, it CAN be done). Once you get it out, take a roll pin punch and remove the roll pin that retains the braided line to the master. The disconnect the fluid reservoir from the unit. Drain, but do not clean with water! Brake fluid absorbs moisture. You can use brakeclean if you want, but it could stain the plastic.
-DRILL MOD-
-THE ENTIRE MASTER, RESERVOIR AND LINES MUST BE REMOVED TO PERFORM THIS MOD-
Wrap the master end of the line in an old hose piece to gently hold the master end of the braided line in the vice (looks like a brake bleeder valve. sorry no pic) If you insert the drill bit into the line with your hand you can feel an obstruction in the line. That's what will be drilled out. Use a 7/64" drill bit. The website, www.InstallUniversity.com, says to use an 1/8" drill bit, but I felt it was too big. Gently drill out the obstruction, lifting the drill frequently to remove shavings. Keep the line and drill bit as straight as possible as to not drill through the side of the braided line!
Voi La! You're done. I bled the line about a dozen times to be sure I removed all the metal shavings. Now bolt everything back up.
10-24-2007 | 03:40 PM
#21
Registered User
Joined: Jan 2005
Posts: 2,594
From: N Falmouth MA
^ You're actually not supposed to modify the MAF opening, but polishing is fine. It's calibrated to meter air through that certain opening size. Although the O2's will catch what ever is on the opposite end. When/if you get a larger MAF, it's supposed to be properly calibrated.
10-25-2007 | 07:55 AM
#23
Registered User
Joined: May 2003
Posts: 1,747
From: Farmington, MI
If you replace your maf with a different unit, the table in the PCM needs to be updated with the correct values. The MAF table in the PCM simply translates the MAF frequency (in Hz) into an airflow value (in grams/second). You screw with the nature of the airflow and you're screwing with your fueling. Mods like an aftermarket lid can alter this airflow. But, it's not usually enough of a change to cause a problem because the stock O2 sensors and the fuel trims controlled by the PCM can compensate. Bore/descreen your MAF and you end up with two issues - 1) you now need to determine what your new MAF table looks like through a trial and error process using a WBO2 and 2) your fueling may not be consistently accurate without the screen.
Last edited by SSpdDmon; 10-25-2007 at 07:58 AM.
10-25-2007 | 09:32 AM
#24
Registered User
Joined: Jan 2005
Posts: 2,594
From: N Falmouth MA
^ correctamundo! THe Screen also helps evenly distribute the air flow over the sensors. It's only descreened for use of Dry nitrous system where it can actually freeze up. Like said above me..
THe Screen flows fine, I think people just think it's a restriction because it has the honey comb look.
2) your fueling may not be consistently accurate without the screen.
10-25-2007 | 10:09 AM
#25
Registered User
Joined: Sep 1998
Posts: 8,321
From: US 1 Mile Marker 52 in the Florida Keys
another near-free mod would be the skip shift eliminator.
all you need is a small resistor from Radio Shack...less than a $1....
you'd have to look up the specific size....i've fogotten.
maybe check my website in the sig...i think i posted a pic
all you need is a small resistor from Radio Shack...less than a $1....
you'd have to look up the specific size....i've fogotten.
maybe check my website in the sig...i think i posted a pic
10-27-2007 | 08:23 AM
#27
Moderator
Joined: Jul 1998
Posts: 6,249
From: Charlotte,MI USA
10-27-2007 | 10:03 AM
#28
Registered User
Joined: Jul 2000
Posts: 7
From: NOMAD...
I have descreened MAF and poly ported ends MAF. My MAF tables did get calibrated via EFI Live tune. No problems.
10-30-2007 | 08:16 AM
#30
Registered User
Joined: Jan 2005
Posts: 2,594
From: N Falmouth MA
EFI Live is a tuning software you can use to tune your car yourself. It's a LOT more indepth than the hand held tuners. It also requires the use of a Wide Band O2 sensor, which SHOULD be used to maximise results and for the program to properly read the exh gasses. They have a nice auto tune feature, my buddy anad I have been playing around w/ it on his 02 SS..
http://www.efilive.com/
http://www.efilive.com/
Last edited by Bayer-Z28; 10-30-2007 at 08:26 AM.