Charcoal canister

[240crawler]

I am installing a cold air intake on my 91. Can I remove the charcoal canister and simply hook the two lines together somewhere? I do not have emissions testing, or a cat for that matter.

I am looking for a good header that will not break the bank. All I require is equal length tubes (big ones--1 3/4" or more) and a 3-3.5in collector. What can I get?

[Chezedik]

I am selling my wrapped OBX header for 120 plus ship. It is a nice header, but I am going turbo. It has been installed, but never used. If you are interested, shoot me an email at [email protected] .

[240crawler]

Tell me about the OBX, what are the tube diameters? Is it a 3 inch outlet. If I take the wrap off, what color is the header? I still need an answer on the canister.

[Chezedik]

The header you are looking for will be hard to find. This one is 1 1/4 in tubes to a 2 1/4 in collector. I do not know of one like you are looking for and will likely have to be custom made. The header is stainless. On the charcoal canister, you crush the line underneath it and use caps to plug off the lines source. Or if you really go crazy with removing all of the emissions stuff, you get to where you have only one vac line.

[240crawler]

I removed the canister, and connected the two fuel lines together with a line splice. I also plugged off the vacuum line. Will this work?

With 1 1/4 tubes and a 2 1/4 collector, will it not be hard to use 3in piping? Are there any benefits to the smaller primaries? I would think that it would help keep low end power and smooth the entire powerband. Wrong? I do not know.

I will send an e-mail later today, so thank you for your quick reply. Is it an equal length header?

[Chezedik]

For your canister problem, I would say it is solved.

On the header, first thing you have to realize is that there can be a pretty severe disadvantage to having runners and collectors that are too big. While the KA24DE is known to be a motor that loves a release in back pressure, too much can be too much. When too much pressure is relieved, you suffer from a significant loss in low end torque, which is important to a good holeshot, particularly in NA form. While having smaller primaries (although upgraded from stock diameter) you tend to get better torque across the band. And so yes, as you pointed out the powerband will be smoother, and more bell shaped than what you might expect from a custom header like you are describing, which would be very peaky (and could put the peak out of use for you). Also, it is of the 4-2-1 design, which is supposed to make for a beefier mid than a 4-1 design. There also will be no problem going from a 2 1/4" to 3" as this is pretty much standard procedure for all N/A 240s running off the shelf gear.

[240crawler]

I sent an email back. I am not trying to make a high rpm screamer, I just wanted the best flow possible for everyday. If 1.25 is larger than stock, and the header is obviously designed with smoother, faster flow in mind, then I am sure that i will see an increase. I just want my engine to keep good bottom stump pulling power but breathe better on top.

I really want to use 2.5 piping, but I am afraid that Insanity will come kill me in bed tonight. Just Kidding but funny.

[Chezedik]

Well for your cat back, 3" will be great, but I think Insanity sometimes goes a little too far when it comes to his idea on back pressure. Unfortunately, there is such a thing as too little back pressure, no matter what his sig says.

[240crawler]

I was only kidding about your friend Insanity. For all I care, if I wanted a 2.5 he could suck an asspimple and keep whining. I know that a 3 inch was not to big on an Acura 1.8 of mine. 2.4 is even bigger. On a 5.0 V8, I use 3 inch on each side, why not compare it two two joined 2.5 4-cyl?

As far as backpressure, I will run 2 resonators before a Flowmaster 2-chamber 40 series. This gives the best sound to me on any large 4 or inline 6. I will not argue the point. It is what I want, and I have the flowmaster installed now, with no resonators. It gives a very deep sound, like a Trans-am/Camaro SS with factory piping. NEVER ricey.

I will e-mail later today about shipping.

[Chezedik]

Nah, Insanity is not my friend, I have just seen him on the boards, and I know how into the whole 'No Such Thing As Too Much Backpressure' thing that he can get. And I agree, I like the flowmaster sound, and I know exactly how important a resonator or two can be. I got your email, and you have mail back.

[TrueSlide]

WRONG, "backpressure" is a BAD THING. When you get a GOOD exhaust it will keep the exhaust velocity high while keeping the least "backpressure".

[240crawler]

WRONG, "backpressure" is a BAD THING. When you get a GOOD exhaust it will keep the exhaust velocity high while keeping the least "backpressure".

I know that alot of backpressure is a bad thing. I am going to have two resonators or two short glasspascks before a Flowmaster 40 series. I should have sufficient backpressure to keep from killing my low-end without strangling my top. The header, 3in. piping, intake, and timing reset should give me a good, strong, usable powerband. I am not trying to kill a Viper, just pull better.

This fall, I am going to have my motor completely overhauled. I am talking new hi-comp pistons, performance cams, new oil pump, and electric fans. I am considering going to a z32 MAF, a little larger injectors, and a JWT ECU. I also want to eliminate EGR and all emissions equipment, and clean up my vacuum line for a nice bay. I have removed my AC, and will remove my condenser when I pull the radiator for the build. It will also help the Silvia front fit better, as I have to use a new radiator support for the headlights.

[Chezedik]

Some backpressure is a necessary evil. Also, you will not likely need the TT Z32 MAFS for an NA setup, I have an N60 (non-turbo) if you are just looking for something to tune with the SAFC that has a larger diameter. I just bought the turbo MAFS since I am going to boost my KA.

[240crawler]

Check is in the mail. Also, I have noticed that pulling off the charcoal canister sucks. When you have a full tank of gas, the car will lose control of idle and stall unless the A/C button is on. I have taken off my compressor, so I use the button to boost my idle when playing stereo. When the level of fuel in the tank reaches 1/2, it will run great. I sent a new shipping address with the check.

[Chezedik]

That should be fine. Did you check to be sure all of your vacuum lines are plugged? Sounds like you are missing one.

[240crawler]

All vacuum lines are plugged. I do not understand, I just keep less than 1/2 tank and I am fine.

[Chezedik]

The only other thing I can think of is that it is causing vapor lock from increased tank pressure, you may think about a vented cap. Besides, if you haven't replaced it in a while, then it will help mileage. Also, the reason your idle gets better when the AC is on, is because the IACV is opened a little more by the computer when the AC is activated.

EDIT: Not really vapor lock, but some kind of other pressure related condition. Like maybe there isn't enough of a differential.

[sleepyRPS13]

yeah its definetly not vapor lock since he said he plugged everything. how are you venting vapors developing on the tank anyways?

well anyways, my guess at it is everytime the computer detect a more then 1/2 of fuel the computer tries to purge so fuel trim goes leaner on idle. the computer expecting the purge vapor so it wont run richer. a leaner idle then normal = bad idle.

just wondering if the bad idle also happen when warming up your car?

edit: i would also check the IAC, maybe clean it up or something. GL

[s13satch]

So why did you remove the charcoal canister? There is nothing mechanically good that could come from removing that piece.

[240crawler]

The only other thing I can think of is that it is causing vapor lock from increased tank pressure, you may think about a vented cap. Besides, if you haven't replaced it in a while, then it will help mileage. Also, the reason your idle gets better when the AC is on, is because the IACV is opened a little more by the computer when the AC is activated.

EDIT: Not really vapor lock, but some kind of other pressure related condition. Like maybe there isn't enough of a differential.

How will a vented cap help milage? I understand that it may cause the missing, but how will can it screw mileage? Noob question for sure.

just wondering if the bad idle also happen when warming up your car?edit: i would also check the IAC, maybe clean it up or something. GL

Idle is perfect when cold, only goes to missing when car is completely warm. Another noob question, but wtf is a IAC? I have removed some of the emissions stuff, like the black box between intake and exhaust manifold, and the cat. I am interested in blocking off the EGR if it will benefit in any way when I install the new header.

So why did you remove the charcoal canister? There is nothing mechanically good that could come from removing that piece.

Because it was ugly and in the way. I needed more room for my super rice filter when I get the new intake tube. I like a little show just for me, although no one ever gets to look under my hood. All these riceboys think that all 240's came with SR20, so wtf?! I just let them keep thinking, especially when I smoke their POS non-VTEC single cam h0m0 dx. Going from 2nd to 5th in town is a blessing. They really look funny when I go from a 5 mph in 2nd all the way to 55. They think my first gear is hella-long.

[Chezedik]

1. The cap being vented is not what helps mileage, what helps is having a new cap, for the seal around the outside. But now that I think about it, that probably would not be the case, since it will be vented to atmosphere anyway.

2. IAC = IACV = Idle Air Control Valve. It is the valve on the bottom of the intake plenum towards the back. It's function is to regulate a certain amount of air at idle into the motor past the throttle plate, to keep the engine running. When they fail or get dirty they can cause a very erratic idle, or worse, a hard start condition. They can be cleaned though.