DIY - Poor man's Z-tube
Joined: Mar 2009
Posts: 18,299
Likes: 1,488
From: By the sea, Tx
G35 sedan w/ too much money in mods

It'll be nice to put names with faces in Sept.
I would not recommend doing this at all. First a Z tube is cheap, I see them all the time on craiglist for $50-$75. Main reason I wouldn't do this is fear of sucking that cap over the hole into the engine. Look inside the factory airbox and you will se ALOT of ribbing and braces. Its there so the factory air box will not implode during WOT. The engine sucks alot of air, enough to cause flexing. If the cap isnt sealed down tight, it will suck into the engine...............then boom!
Joined: Jun 2003
Posts: 14,505
Likes: 451
From: NorCal
I didn't use a cap. I guess you are referring to the one DaveB did. The section I cut out goes over the hole completely and I used the thick plastic from the resonator. I can understand your warning but I just don't see it happening with how I did it.
definitely agree with the above author, check out mine that i have listed for sale classified - you either break the gtube or take pieces of the gtube with it if you wanna break loose the bondo and the covering on the resonator hole...
The reason I went with the cap was because I didn't want a shallow void where the lower resonator once was. The cap filled in the void. The cap I used was somewhat tapered plus I used marine-grade Goop sealant which is designed to live in much harsher environments than a 160 degree engine bay. I've used this stuff on other parts and previous modded intakes and I've never had it fail. It's too pliable and resilant. Plus, if in the off chance it were to fail, all the glue wouldn't fail all at once. I know there would be a problem because there would be one bad vacuum leak at a sealant break. In the one billion chance the cap where to actually make it into the pipe, past the throttle blade, and into the plenum, the farthest it could possibly go is an upper manifold runner. It get stuck there and I'd have to remove the upper manifold and pop out the cap.
With that said, Papa how do you like it? I love it. IMO, it's a deeper sound than the Z tube and I think the throttle response is better.
With that said, Papa how do you like it? I love it. IMO, it's a deeper sound than the Z tube and I think the throttle response is better.
Joined: Jun 2003
Posts: 14,505
Likes: 451
From: NorCal
I'm actually running a Ztube
I have a few aesthetic things going on under the hood and it just looks cleaner with the Ztube. My friend seems to be really enjoys it though 
If you plan to keep the engine bay fairly stock and not start blinging it out, this is a great mod IMO. No need to spend the money ($50 bucks is $50 bucks
) on a Ztube to get the same (or less?) results.
I have a few aesthetic things going on under the hood and it just looks cleaner with the Ztube. My friend seems to be really enjoys it though 
If you plan to keep the engine bay fairly stock and not start blinging it out, this is a great mod IMO. No need to spend the money ($50 bucks is $50 bucks
) on a Ztube to get the same (or less?) results.
Registered User
iTrader: (7)
I did this to both my G and wife's FX intakes I had laying around in the garage. We both have the Stillen Z-tube. If this holds up and still sounds cool, I might have 1 or 2 z-tubes for sale.




Thanks Tim (it is Tim right?
)