ttodhunter Posted December 21, 2011 Share Posted December 21, 2011 (edited) Probably every 280z out there has either had its AFM boot replaced at some point, has a leak in it, or has a ghetto fix like I did. Well, I finally decided to upgrade (mainly because I thought I had a vacuum leak) and hit the local parts store. I picked up: 1x 3-3" or 3-2.5" Silicone Coupler. It comes with a black insert. This is important. ~$7.99 1x 3" > 2.5" silicone reducer. ~$6.99 1x 45 degree 3" mandrel bent tube. ~$10.99 1x Crankcase Breather filter. ~$15 The stock boot is really small/short, and the two couplings alone are about the same size if set end to end. But, you need the 45 degree tube to make that bend and to mate the two couplings. So, you will need to do a bit of cutting on the tube. This is when you'll realize that its probably some cheap plastic with chrome covering and get mad that it cost $11... I cut it until the couplings touched each other on the inside of the bend. Took it over for a trial fit and found that it was gonna be close. I unbolted the AFM so I could wedge it in there. Throttle body end slipped right on and fit like a glove! The AFM end, on the other hand, was really loose. This is where the black insert from the 3-3" coupler comes in. I had to take a razor blade to the inside of the insert and try to remove about 1/10th of an inch, just enough to let it slip over the AFM outlet. Once that was fit, the 3" coupler can be slid over it and everything tightened up. This setup is still a little longer than the original AFM boot. I was unable to get the AFM mounted back to its original mounting point, it's off by about an inch. I assume you could trim a little more off of the tube, and angle off portions of the couplers, but it feels like it's on there pretty good. Don't forget to reconnect the ground to the AFM mount. This setup doesn't have a breather tube for the crankcase. I decided to put a K&N style crankcase breather filter on (it looks cool and the honda guys told me it's at least 10hp). The filter from the store was some kind of plug, so I cut a portion of the existing breather hose to mate to the crankcase. The plug of the filter wouldn't fit in the hose, so I trimmed material from the plug (rubber) and a little from the inside of the hose. Make sure all shavings are cleaned out and jam it in there. Clamp both sides and, voila. Soo, for $40-45, you too can have a setup like this! It's cheaper than buying a new boot online, it's stronger, will last longer, looks better, who knows, might even flow a wee bit better without the accordian. Edited December 21, 2011 by ttodhunter Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted December 21, 2011 Share Posted December 21, 2011 (edited) Dear baby jesus please use smaller sized pics. Also a K&N Valve cover breather can be bought for like $10 from MSA. It will fit a lot better then the trashy spectre filter. I did have the specter thing on mine for a while and got fed up with it popping off becasue I didn't trim enough, and when I trimmed enough it actually cracked Edited December 21, 2011 by BluDestiny Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 21, 2011 Share Posted December 21, 2011 I decided to put a K&N style crankcase breather filter on (it looks cool and the honda guys told me it's at least 10hp). You didn't put a winky face after this statement to show you were joking. That's hilarious. Have you started the engine since you modified it? Quote Link to comment Share on other sites More sharing options...
ttodhunter Posted December 21, 2011 Author Share Posted December 21, 2011 Ok, pic size has been reduced. I had no idea they would hold resolution on a big screen TV! Blu, I love your sig. NewZed, I've been driving it for a few days and it's probably more like 20hp. Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 21, 2011 Share Posted December 21, 2011 Groovy, even better. You do know that you'll have unmetered air (bypassing the AFM) in the intake manifold now, through the PCV valve and hose, with that breather on the rocker cover? Through the breather, down through the oil drain holes and through the PCV port in to the manifold. Should create a leaner mixture, idle quality would be the first thing noticed. Maybe you've blocked the PCV port, or it was already blocked, or "tuned" your AFM to offset it? Nothing wrong with modifying, but the EFI system and PCV system were designed for a sealed crankcase. Quote Link to comment Share on other sites More sharing options...
ttodhunter Posted December 21, 2011 Author Share Posted December 21, 2011 Well, crap. Thanks for pointing that out, now I've got some thinking to do... The idle was crappy which is why I thought there was an intake leak before. When I replaced this, the problem didn't go away so I assumed it was something else. Now, knowing that there's still a vacuum leak makes sense... Quote Link to comment Share on other sites More sharing options...
ModernS30 Posted December 21, 2011 Share Posted December 21, 2011 Groovy, even better. You do know that you'll have unmetered air (bypassing the AFM) in the intake manifold now, through the PCV valve and hose, with that breather on the rocker cover? Through the breather, down through the oil drain holes and through the PCV port in to the manifold. Should create a leaner mixture, idle quality would be the first thing noticed. Maybe you've blocked the PCV port, or it was already blocked, or "tuned" your AFM to offset it? Nothing wrong with modifying, but the EFI system and PCV system were designed for a sealed crankcase. wait, you are saying that the breather on the valve cover, makes a vacuum leak through the PCV valve on the intake manifold? I have never heard this. My PCV is blocked off though, running stock EFI. I just just put a plug in your PCV and a breather on the crank case. Problem solved. Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 21, 2011 Share Posted December 21, 2011 What you want to find (depending on the condition of motor mounts and how much torque you are making) is what is called a "Hump Hose" to replace that straight piece. I've see straight conversions like this pull out on torqueover. They DO make silicone hump hoses, and they perform the exact same function as the accordion pleats in the original boot. You still need a tapered transition, and a coupler pipe, but then the engine can move (and uh...even hit the hood when the engine mount fails...) and the boots just flex and stay attached. With poly captive mounts, or solid mounts of course this is not a factor. As for the "I just just put a plug in your PCV and a breather on the crank case. Problem solved." I would say except for the oil mist mess you create, as well as not really evacuating the crankcase of moisture on short trips, etc etc etc... Retention of some sort of POSITIVE crankcase ventilation is beneficial from many standpoints. The days of the Road Draft Tube are long gone! Unless you like oil haze blowing around your engine bay that is... Quote Link to comment Share on other sites More sharing options...
ModernS30 Posted December 21, 2011 Share Posted December 21, 2011 As for the "I just just put a plug in your PCV and a breather on the crank case. Problem solved." I would say except for the oil mist mess you create, as well as not really evacuating the crankcase of moisture on short trips, etc etc etc... Retention of some sort of POSITIVE crankcase ventilation is beneficial from many standpoints. The days of the Road Draft Tube are long gone! Unless you like oil haze blowing around your engine bay that is... I can understand this, How about running a catch can to prevent the oil from misting around in the engine bay? I just don't feel like spitting an oily mess like that into your intake system is a very good thing either. I don't see it being positive for the performance of an engine, spraying nasty engine oil and gunk mix into your cylinders combustion chambers. Also wouldn't this weaken the air/fuel mix and make it less pure, resulting in less of a burn. Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 21, 2011 Share Posted December 21, 2011 No. If you have that much oil, your separation system is inadequate, or your engine is shot and you need to rebuild it. Don't assume things on full-race engines are applicable to daily or even semi-used street cars. Even Top Fuel Dragsters run Vac-U-Pans (which is a way to ventilate it and not get any oil mist into the intake, BTW...) Some run small vacuum pumps to insure negative pressure in the crankcase. For them, it's quantifiable horsepower they can see running such a system. Don't be in such a rush to discard or dismiss it's benefits. The biggest being the great reduction for possible leaks from a marginally sealed engine, and contaminant removal from the crankcase. Quote Link to comment Share on other sites More sharing options...
ttodhunter Posted December 24, 2011 Author Share Posted December 24, 2011 I got around to getting the PCV system hooked back up properly. I went back to the parts store and bought a pcv elbow for $2 or $3 and trimmed the bottom off. Took a drill to the tube and got a hole that the elbow just barely fit in. It was almost snug enough that I felt it didn't need glue. But, I glued it in anyway just to be safe. I removed the crankcase breather filter and put the tube back on and everything back together. So, now I have a functional PCV system and a 3" mandrel AFM boot. The shopping list now looks like: 1x 3-3" or 3-2.5" Silicone Coupler. It comes with a black insert. This is important. ~$7.99 1x 3" > 2.5" silicone reducer. ~$6.99 1x 45 degree 3" mandrel bent tube. ~$10.99 1x PCV elbow ~$3 Total: ~$30 Quote Link to comment Share on other sites More sharing options...
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