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Have you seen my CAI Cowl Induction Air Cleaner setup.. Check my sig for pictures of it.
I have it fully working, both Vacuum and Electrical, with the throttle pedal switch . I tried both the (using LS1/LS6 intakes) port on the back of the intake near the MAP and it was too much vacuum, the flapper would hardly open. It was tee' into the Vacuum controls for the dash. I tried disconnecting the Vacuum can. But it still didn't open up qiuck enough or until the vacuum dropped really low.
I then tried using the EVAP port since I was not using the purge valve. I connected the Vacuum flapper and the Charcoal Canister to it. I found this combination worked the best.
The 70-72 Cowl Induction worked well with the 70's SBC/BBC that didn't really did produce a strong vacuum source. Using it with a newer engine that produces a strong +16" of vacuum is really too strong and doesn't allow it to open until the vacuum drops.
If you find a way to lower the Vacuum source and drop quicker. let me know.. I thought about using some more check valves or other items.. but never got around to it.
i guess ill have to rethink mine. any more info on solenoids you used or anything? you said you had it working w the vacuum on the evap port and an electrical setup?
The Factory setup had the outer flapper vacuum controled, you can see the setup in the 1st picture. There is also a inner flapper that is electrical controlled by a switch that is attached to the Throttle pedal inside. My setup is just a Repo of a OEM setup. I used the Rubber seal on my air box. I was able to get the box to seal against the hood. So it is just drawing cold air from the cowl area and not hot air from the engine bay.
The setup will flow enough air with both flaps closed.. but at 1/2 Throttle (i set it there), the inner flapper will open. The air flow will flow from the cowl just in front of the Windshield... the outter flapper is just for show (IMO).. and looks cool when you mash the pedal.
You cannot use a source that has any vacuum reservoir, cause that will store vacuum and not allow the flapper to drop vacuum source.
It seem that the vacuum is less at the EVAP as compared to the rear source(Near MAP).
Can't say that it would. I have tried the two different locations.. the rear which seem to have a stronger vacuum, with and without a can/reservior tee'd in. The Can would almost make it to the point it would not open due to the Reserve Vacuum.
The EVAP with this the Cowl Flapper and tee'd with the Charcoal Canister. Either way, by itself or shared with something else. the amount of Vacuum didn't really change the timing of the Flap.
I used the standard size hose that it would be OEM and I also tried using a smaller hose to restrict it some. not much differents.
Can't say that it would. I have tried the two different locations.. the rear which seem to have a stronger vacuum, with and without a can/reservior tee'd in. The Can would almost make it to the point it would not open due to the Reserve Vacuum.
The EVAP with this the Cowl Flapper and tee'd with the Charcoal Canister. Either way, by itself or shared with something else. the amount of Vacuum didn't really change the timing of the Flap.
I used the standard size hose that it would be OEM and I also tried using a smaller hose to restrict it some. not much differents.
can you show exactly how you teed it into the canister..did you tee it from the vacumn line into the canister and ran it back again? Theres two lines in the canister that say carb and tank..thanks a bunch
Wouldn't you want cold air all the time? I'm usually confused....
I have an ls1/4l60e swap in my 71 chevelle...it has a cowl induction hood.The vacumn in the ls1 is too strong from the throttle body or the rear port.I just want a functioning cowl flapper so when I hit the gas it lifts up....as of right now the flapper will come down and be seated when I start the car.When I hit the gas the vacumn should drop and the flapper should pop up but it stays in the down position because of the strong vacumm... I just need to filter it like bz...did with the charcoal canister...I just want to know how he teed it and with what hoses
Yeah. I have not been too active lately, I do check in from time to time.
I used the EVAP port off of the Throttle Body. Here is a photo of it. My set up is 99 LS1 from a F-Body. Your 5.3 truck aet up might be different.
Hose coming off of the port is then tee'd. The Hose going under the FRC goes to the Flapper.
FYI, if you engine produces a high vacuum, the flapper may not open as soon as you may want. The throttle may have to be fully floored for the flapper to open. I put a restrictor inline to the flapper to lower the vacuum.
Yeah. I have not been too active lately, I do check in from time to time.
I used the EVAP port off of the Throttle Body. Here is a photo of it. My set up is 99 LS1 from a F-Body. Your 5.3 truck aet up might be different.
Hose coming off of the port is then tee'd. The Hose going under the FRC goes to the Flapper.
FYI, if you engine produces a high vacuum, the flapper may not open as soon as you may want. The throttle may have to be fully floored for the flapper to open. I put a restrictor inline to the flapper to lower the vacuum.
Good luck with you project.
BC
what restrictor valve did you use?
The pressure or vacuum from my motor was so strong that it actually broke my flapper door...
03-07-2011, 10:30 PM
