OK, I have searched for info elsewhere, and haven't gotten anywhere. I am planning on using one of the aftermarket intakes that are available for the LT1 (probably Holley) and those don't even have the hookups for EVAP. Also, I'd like to clean up the engine bay as much as possible. I'm sure that some of you here in this forum have found a different way to vent the gas tank that using all the BS that goes along with the EVAP system. Could I just use a vented gas cap and plug the vent line? Or are there other alternatives?

 

Wellllll.... back in the good ol' days, before pollution controls, there was either a vented cap or a vent pipe provided on the tank. Might smell a little on a hot day, but nobody noticed it 40 years ago. The recirculaing fuel system and submerged pump does put heat into the fuel system, so there is probably more vapor coming out of the tank than there was back tthen.... .

If you think about it, you actually save a little on fuel if you collect the vapor and burn it.

 

Yea, it use to be that there was a simply vent line that ran parallel to the filler neck and exited right alongside of it.

You might want to look at the systems on some vehicles from the late-70s/early-80s - they might be significantly more simple than the modern systems. I thought that they just used a charcoal canister and a vent line to the manifold. Of course, one thing to keep in mind is that the LT1 PCM controls the EVAP function and adjusts the fueling accordingly, and deleting or altering this function may or may not cause an issue.

 

Thanks for the info guys. I'm going to check out the systems in place on my friends cars - '79 Trans Am and '68 Firebird. Is there anyone here who has sucessfully deleted the charcoal canister and EVAP system? Do you think I could get away with putting a resistor in the wire harness, or would I have to get it programmed out? Another reason I want the EVAP out of there, is I'm going to run stainless fuel lines up the back of the firewall, instead of the DS fenderwell, and I don't want that black EVAP vacuum line running in that spot.

 

DON'T DO IT!

If it's a 4th gen, then let me say that you are making a mistake by removing the EVAP system... I tried removing the system and using a vent before I knew any better- trust me when I say you will literally get sick in no time from the fumes. The big problem with removing the EVAP is the way the exhaust system is routed on a 4th gen - the muffler sits RIGHT under the tank. The tank gets pretty toasty, and without the EVAP hooked up, the vent will spew hot gas fumes like crazy. I capped the vent for a day until I could purchase a new EVAP solenoid/line, and found that the heated gas fumes built up so much pressure in the gas tank that the tank would actually 'moan' (akin to a submarine in a WW2 movie that is diving too deap). Needless to say it got parked until the parts came.

Besides, there isn't much to it - a vacuum line from the tank to the solenoid, then a vacuum line from the solenoid to the intake. All you need is a vacuum port on the intake or throttle body to hook it up, so "my aftermarket intake has no provisions for it" stuff is balony.

 

EddieP - when you had your EVAP system unhooked, did you notice a decrease in gas mileage, and did you get a SES light? Or did you put in a resistor or something?

I honestly don't mind the fuel smell, maybe I'm just used to older cars and trucks that run a little rich. I had the system unhooked for a few days by accident (I must have knocked the vacuum line off the solenoid working in the engine bay) and I definitely noticed the fuel smell, but it wasn't anything terrible. Plus, I'm about to get rid of the exhaust system under the tank and dump it before the axle, so the muffler location will no longer be an issue.

 

It's been awhile (close to 10 years)- I don't know if it set a code or not ('93 Trans Am), but I do remember setting a quad driver failure code when I took something off... I can't recall if it was due to the evap or EGR, though. I didn't have it unhooked long enough to find out how much of an impact it made on mileage. Knocking the line off the solenoid/intake side of it wouldn't be nearly as bad as an open tank to solenoid line... something to keep in mind. Anyway, it looks as if you've made up your mind about ditching it... have fun with that

 

Thanks for the info, EddieP. But no, I haven't made up my mind about ditching it. I don't have all the answers, and that's why I post on this board, so I can learn (and hopefully help others from my own experiences). Any other opinions would be welcome.

 

Look around and see what most of the guys that race the cars use. I'm kinda wondering what I'm going to do with it when I put the fuel cell in the car here in the next month or so. I don't think I can keep it with the cell, so I'm going to have to figuer out something. I'm pretty sure the World Challenge cars didn't have EVAP on them. For street use I would leave it on as well....be safer and it wouldn't stink all the time, not only that you wouldn't smell like gas everytime you got out of the car.