Scott Posted October 11, 2015 Share Posted October 11, 2015 I've asked this question before but I didn't really get a solid answer. I've removed the charcoal canister from my car and so I have been left with the fuel tank breather pipe in the engine bay. Should I block this off or leave it open to the atmosphere? I'm just worried of the fumes igniting or something dangerous like that. At the moment I have a wee silicone cap over it. Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted October 11, 2015 Share Posted October 11, 2015 Extend it, and route it through the hole in the inner wing (where the cc was), and into the passenger wheel arch bud Quote Link to comment Share on other sites More sharing options...
Scott Posted October 11, 2015 Author Share Posted October 11, 2015 Extend it, and route it through the hole in the inner wing (where the cc was), and into the passenger wheel arch bud So there's absolutely NO chance of fuel coming out of it, and there's no way it'll be expelling precious fuel out there? I understand that the charcoal canister was kind of air tight? Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted October 11, 2015 Share Posted October 11, 2015 The fuel tank needs to vent, otherwise it can implode. It's only fuel vapour that comes out of the line. The charcoal cannister basically filters the fumes, and vents them back into the inlet manifold. Fuel will definitely not come out of the line mate. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 11, 2015 Author Share Posted October 11, 2015 Ok, I'm suing you if you're wrong Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted October 11, 2015 Share Posted October 11, 2015 :rlol: Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 12, 2015 Share Posted October 12, 2015 It will smell of fuel no matter what you mate, my brother's Aristo had its canister removed. As the man said the tank has to vent somewhere, I personally would run a pipe under the car Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted October 12, 2015 Share Posted October 12, 2015 Just fascinated, why would you want to remove the filter ? what is the benefit ? Quote Link to comment Share on other sites More sharing options...
mwilkinson Posted October 12, 2015 Share Posted October 12, 2015 Mine has been removed. I think I'm going to reinstall it. The fume smell is noticeable. I don't see any reason to remove it other than to have a cleaner engine bay. Are there any modern smaller alternatives to the charcoal canister? Quote Link to comment Share on other sites More sharing options...
Ric Posted October 12, 2015 Share Posted October 12, 2015 Refit it and get some of SRD's engine bay boxes to cover the corners up? Quote Link to comment Share on other sites More sharing options...
David P Posted October 12, 2015 Share Posted October 12, 2015 Charcoal Canister removal mod I have looked into the charcoal canister removal mod, and it appears that no one has thought the job through properly! The Supra fuel tank and pump are designed to operate at a positive pressure of 2psi. The fuel filler cap, is a 2psi relief valve, maintaining pressure on charcoal filter up to 2psi and gently venting excess. Without the pressure gurgling out through the charcoal filter, the cap has a little more relieving to do. 3 pipes on charcoal canister, listed below with direction of flow. 1 goes to induction vacuum. 1 comes from fuel tank. 1 goes to drain. Remove vacuum pipe from inlet manifold and cap it off. Pipe to fuel tank can be capped, or removed completely and blanked off on tank. Drainpipe can be left open, or removed completely. Simples ! A tidier job and minor weight reduction is made by removing pipes and blanking at source. (An even simpler explanation is; remove it and blank off the pipes.) Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted October 15, 2015 Share Posted October 15, 2015 Good technical answer David, but seems a lot of pain and little gain to me. Quote Link to comment Share on other sites More sharing options...
berg Posted October 15, 2015 Share Posted October 15, 2015 Mine is vented into the wing and i never smell fuel unless im stood over it with the engine running Quote Link to comment Share on other sites More sharing options...
David P Posted October 15, 2015 Share Posted October 15, 2015 Good technical answer David, but seems a lot of pain and little gain to me. No gain at all unless the space it used was required for an after market Gizmo. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 16, 2015 Share Posted October 16, 2015 Please show me where it says the fuel tank should see positive pressure!!! If that were the case, and you had a full tank, removing the filler cap would vent fuel over someone. I have NEVER seen a fuel tank on a production car that SHOULD or DOES run pressurised, but most have some vacuum, and you can hear air rush INTO the tank when you remove the filler cap. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 16, 2015 Author Share Posted October 16, 2015 Yeah it's a vacuum, I'm guessing that's what he meant Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted October 16, 2015 Share Posted October 16, 2015 The Supra is the only car i have, and still own, that do not pull a noiticeable vac when you remove the filler cap, not really sure what the difference is in design charachteristics to most other cars and what the advantage if any, there is ? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 16, 2015 Share Posted October 16, 2015 No, he's said it before and is of the opinion it's pressurised. Quote Link to comment Share on other sites More sharing options...
David P Posted October 16, 2015 Share Posted October 16, 2015 Rattling petrol about in a sealed tank creates vapour which creates pressure faster than a fuel pump can reduce it, not vacuum. It is this positive pressure that the charcoal filter system is all about, which without pressure to push these vapours through it, would be merely an ornament and the pressure relief valve is a one way, out only valve. Suck and blow makes a similar noise, but suck would stick the cap to the tank, which it doesn't. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 16, 2015 Author Share Posted October 16, 2015 They all stick the cap to the tank, it's the fact that it's a screw cap that brakes the seal. Must admit, I'm with Chris here. Supra and every other tank I know creates a vacuum in my experience. Quote Link to comment Share on other sites More sharing options...
David P Posted October 16, 2015 Share Posted October 16, 2015 If it was a vacuum, Mr T. would not have wasted profit fitting a charcoal filtration system to filter fuel vapours from the positive pressure. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 16, 2015 Author Share Posted October 16, 2015 If it was a vacuum, Mr T. would not have wasted profit fitting a charcoal filtration system to filter fuel vapours from the positive pressure. They could still fit a charcoal filtration system vacuum controlled via the intake to filter fuel vapour though. With a 2psi vacuum relief on the cap and a constant vacuum pull from the intake/fuel drop there would be no chance of any leaks around the system. Vacuum prevents leaks, positive pressure causes them. Quote Link to comment Share on other sites More sharing options...
David P Posted October 16, 2015 Share Posted October 16, 2015 The charcoal filter relieves petrol vapours from positive pressure. That's what it is for! The fuel cap is a 2psi positive pressure relief valve. Please research this instead of blindly following an old wives tale. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 16, 2015 Share Posted October 16, 2015 If a fuel tank is not vented it would gradually reduce the fuel available to the injectors because the vacuum created by the fuel displacement would make it harder for the pump to produce positive pressure to the fuel system. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 16, 2015 Author Share Posted October 16, 2015 The charcoal filter relieves petrol vapours from positive pressure. That's what it is for! The fuel cap is a 2psi positive pressure relief valve. Please research this instead of blindly following an old wives tale. Please point out any links to back up your claims and I will gladly read them. - - - Updated - - - If a fuel tank is not vented it would gradually reduce the fuel available to the injectors because the vacuum created by the fuel displacement would make it harder for the pump to produce positive pressure to the fuel system. It'll be vented regardless due to the relief on the fuel cap Quote Link to comment Share on other sites More sharing options...
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