well i haven't done any of the free mods on my car because i simply havent been really concerned with them. for those that have done free mods what do you think of them and is it worth it. Has anyone gotten negative results from doing free mods and if so what? i have been thinking about doing them(some) when i put my cam in since everthing will be apart, but i am not going to waste my time if it isnt worth it.

 

tb bypass, FRA, EGR mod, ported TB all worthwhile.They're free, why wouldn't you want to do them?Is 10 dyno proven hp (FRA/ported TB) worth it?

 

i didnt know what kind of numbers they had put up or any for that matter..i hear of people doing things for nothing more then knowing they did it..apparently these mods are MORE that worth it...looks like ill be free modding it up soon

 

!AIR - Removing the A.I.R. system removes weight and engine clutter and makes spark plug changes easier. This will throw an SES code if you don't have edit. You exhaust will also be "dirty" until your car warms up.

!EGR - Removing the EGR system removes weight and engine clutter and makes your engine run better, because you arn't filling your cylinders with exhaust gas. This will throw an SES code if you don't have edit. Your exhaust might not pass emissions.

EGR Mod - Shortening the EGR tube in the intake will allow for better air flow. Just make sure not to break anything.

TB Bypass - Running coolant so that it doesn't go through the Throttle Body helps cool it and your intake air off. You may encounter freezing TB problems in cold winters, but I don't know anyone who has.

Cold Air - Cutting a hole in the bottom of your air box will give you cooler air intake. If you eventually get a real cold air or aftermarket ram air system, you will do this anyway. If you have factory ram air, these two arn't compatible.

MAF descreening - Removing the screen from you MAF gives you better air flow. It may cause the MAF to not work right though. The later Z06 MAFs don't have a screen.

MAF Porting - Removing the fin inside the MAF tricks your PCM to change the Fuel\Air ratio. This change might be a good thing, if you air/fuel ratio was wrong to begin with. It might just push it further in the wrong direction. This one is a shot in the dark. It might help you in the same way that kicking your VCR just might make it spit the tape out. If you do this, custom PCM edits will never work right, and the stock setup probably won't work either.

TB Porting - Opening up the TB, Sharpening the blade, and adjusting the bump stop will all give you better air intake flow. You could also just spend $300 to let somebody else to the same thing for you. If you remove too much bump stop and the blade goes beyond 90 degrees, it will throw and SES code, so be careful and using edit to get it perfect is helpful.

 

I've heard there's a whistling sound from the FRA mod due to removing the air silencer on the air box. So there's a negative, but I haven't done the FRA myself so I don't know.

 

you remove the "silencers" if you put an aftermarket lid on anyhow, that big plastic black thing around the stock lid
ive heard some people say it was louder with a new lid, but that hasnt really been the case with me....

 

I know I can't hear the difference without the silencers. Some people say they can. Most like it. At any rate, the noise is so slight that, if it bothers you, you bought the wrong car.

 

"EVERY LITTLE BIT COUNTS!"

I have done many of the free mods, but only did them when I was doing some other mod at the time when it was convinient. I did the !EGR mod during my cam swap, and TB bypass during my lid install, and ported the MAF ends because I was bored

 

There is an article in a new magazine solely on ls1s that i got from walmart (can't remember the name right now) where they did fra, tb bypass, and shortened the egr and got 15 rwhp. The article was over getting 22 hp with 220 dollars. The 220 dollars were for underdrive pulleys, which freed up the additional 7 hp.

 

7 hp at the wheels from a new underdrive pulley?? how much would a whole new pulley system free up??

 

That is what he means, the crank pulley is the only one I have heard of being underdriven.

 

im to lazy to do any free mods? i'd rather pay the bucks for my mods.

 

If you can find it, please tell me the name of this magazine. I would be curious to read the article. I just cannot imagine those actually getting 15 rwhp, but if the test was done right, sweet!

 

GMHHP article

http://www.gmhightechperformance.com...11htp_projls1/

 

Shortening the EGR tube is just plain needed IMO, it really protrudes too much and if your in warm climates the TB bypass is worthwhile, but you'll notice the most gain from the FRA mod.