what are the free mods for ls1?

i recenlty bought my second camaro z28.my first z28 was a '94 lt1 a4, and i did so free mods on it, tb collant bypass, descreen maf sensors etc.
now i have a '01 z28 ls1 m6, what free mods can i do to it, besides for the descreening of the mass air flow? let me know thanks

Don't fool with the MAF.

i know thats why i put anything besides descreening the maf

TB coolant bypass, TB bump stop mod, free ram air.

TB coolant bypass, TB bump stop mod, free ram air.
You forgot the free mod that one kid was talking about last year:

Hack off the back half of your exhaust just before the muffler. :lol: Then, you have a home-made loudmouth with the appearance of dumped true duals (no tips).

is the tb bypass the same as on the lt1

is the tb bypass the same as on the lt1

Yes... you're just connecting two hoses that you take off the TB.

Earlier cars also have the EGR mod (grind off the protrusion into the intake path).

Use a scan tool to do the TB stop mod or you may end up with a SES light.

ok, what is the ses? is it a bad sensor light?

S.E.S. - Service Engine Soon

http://www.gmhightechperformance.com/tech/0311htp_ls1_fbody_10_free_modifications/index.html

why shouldnt you remove the screen on the maf sensor?

why shouldnt you remove the screen on the maf sensor?

Because it gets more airflow and changes the readings on the MAF and completely throws off your PCM's fuel and timing

i removed my screen and it increase power dramitically with no problums??

you can also cut out the plastic panels under your air filter!!

what is the bump stop mod???

why shouldnt you remove the screen on the maf sensor?


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.

what is the bump stop mod???

You grind the WOT stop on the TB to get the throttle blades to open to 90°. But you have to be careful and use a multi meter or scan tool when diong this mod because grinding it too much will cause an SES light.

i removed my screen and it increase power dramitically with no problums??


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'

Check the stickey up top.. You'd be supprised what's in one of them..

http://www.camaroz28.com/forums/showpost.php?p=3927346&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/tech/0311htp_projls1/index.html
http://www.installuniversity.com/install_university/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/tech/0311htp_projls1/index.html
http://www.installuniversity.com/install_university/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.

that was the site where i heard about removing the m.a.f screen from i even went a step futher and bored my m.a.f to allow more air into the motor. Worked for me with no problems.

^ 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.

your supposed to reprogram your e.c.m if you bore your m.a.f sensor and remove the screen??

your supposed to reprogram your e.c.m if you bore your m.a.f sensor and remove the screen??
Correction. You're not supposed to bore/descreen your maf.

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.

^ 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..
2) your fueling may not be consistently accurate without the screen.

THe Screen flows fine, I think people just think it's a restriction because it has the honey comb look.

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.

:think: maybe check my website in the sig...i think i posted a pic

if your p.c.m is supposed to be reprgramed after you modify your m.a.f sensor then why haven't i had any problums with removing the screen and boring the m.a.f sensor bigger?? Or will i perhaps in the future?

if your p.c.m is supposed to be reprgramed after you modify your m.a.f sensor then why haven't i had any problums with removing the screen and boring the m.a.f sensor bigger?? Or will i perhaps in the future?

as I stated before it's a crap shoot. You got lucky, maybe.

if your p.c.m is supposed to be reprgramed after you modify your m.a.f sensor then why haven't i had any problums with removing the screen and boring the m.a.f sensor bigger?? Or will i perhaps in the future?

I have descreened MAF and poly ported ends MAF. My MAF tables did get calibrated via EFI Live tune. No problems.

I have descreened MAF and poly ported ends MAF. My MAF tables did get calibrated via EFI Live tune. No problems.


What is efi live tune??

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/

What is efi live tune??

Some screen shots from one of my older tunes...

HIGH OCTANE TIMING MAP
http://memimage.cardomain.net/member_images/8/web/392000-392999/392531_158_full.jpg

BASE TIMING IN GEAR
http://memimage.cardomain.net/member_images/8/web/392000-392999/392531_159_full.jpg

STOCK '01-'02 INJECTOR FLOW RATE
http://memimage.cardomain.net/member_images/8/web/392000-392999/392531_166_full.jpg

Is there a walk thru vid somewhere to teach you how to use that stuff?? My buddy does all the tuning, but it's WAYYYY to confusing for me. Too many numbers.. :cry:

Is there a walk thru vid somewhere to teach you how to use that stuff?? My buddy does all the tuning, but it's WAYYYY to confusing for me. Too many numbers.. :cry:
There's a few 'walk-thru' type instructions on how to use the software/scanner on EFI's website in the downloads section IIRC. That's just half of the battle though. Knowing what you want the car to do is the other half of the battle. In other words, knowing things like a typical cam'd LS1 likes ~27 degrees of timing and a ~12.7:1 AFR from 2400RPM on up at WOT is not going to be something listed in the walk-thru. EFI's training is more focused on enabling you to make the changes with their tool - not to give you the info for running an optimum tune. :)

As far as there being too many numbers, I like to keep two things in mind when tuning:
1) What you see in EFI Live is only ~10% of the calibrations in our PCMs. So, they did a good job narrowing the list down to keep it from being too overwhelming.
2) K.I.S.S. - Keep it simple, stupid. If you're going through long, round-about ways of trying to achieve results, you should really start to question whether or not it's the right way to do things. Remember, tuning a car is like skinning the proverbial cat. There's more than one way to do it and there's not necessarily a 100% right way that's better than all of the rest.

^ I don't think I can handle it then.. I'm REALLY not good w/ numbers. I'm not really up to spark advance stuff or fuel trims either.. I'll just put the parts in and have someone tune it for me.

^ I don't think I can handle it then.. I'm REALLY not good w/ numbers. I'm not really up to spark advance stuff or fuel trims either.. I'll just put the parts in and have someone tune it for me.

Its alot of reading, learning, asking questions from the EFI Live experts. Knowledge on engine schematics and how they work is a PLUS.:)