Hey guys,
Over the last few days I've slowly managed to wrestle the plenum out of my z32 and I'm brainstorming everything I can think of short of the valvetrain to make future pulls unnecessary or at least easier. I'm replacing all of the pcv hoses and clamps, valve cover gaskets, all injectors to new style, new style injector connections, fuel rail to plenum seals, egr gaskets, plenum gasket, and other things above and around the plenum including either powder coating or polishing it along with my balance tube.
What I'm having trouble pulling the trigger on right now is the coolant bypass of the plenum. I was hoping to hear from some people who have done the procedure and can tell me the potential downsides of the bypass if there are any. I haven't been able to find any negative information relating to it yet other than it does involve modifying the EGR system. I live in California and although I'd love to remove every bit of emissions equipment I can rip out, I'm not willing to get refereed.
Also I'd love any suggestions as I am not looking forward to removing this thing again. My harness is immensely in the way on both sides and every single hose fought me bitterly. Fairly certain I was the first to remove this plenum since it was installed in 89 or 90.
Thanks for any input.
VG30DETT TB Coolant Bypass
-
DCaff300ZX
- Posts: 4202
- Joined: Sun Jun 14, 2009 8:18 am
- Car: .
1993 CRP TT- Modified - Location: Tacoma, Washington
Re: VG30DETT TB Coolant Bypass
Welcome!
First off congrats on the moxie to take this on yourself, and second for your choices of work, parts selection and the thought of doing it all right and at once.
That leads to part of my answer, which is actually to simply refresh everything and leave things as stock but to do some re-organizing and rethinking of a few things as you re-assemble and you should, as I have, get a better ability to get to everything you've worked on in the event a return is necessary. Probably less work than the coolant bypass and other relocates associated with that work. My Z guy has convinced me that time is in my favor, about 20 years worth (how long the car ran great with the original parts) and to keep that in mind when determining a course of action with the Z32- a notoriously over-engineered car from the standpoint of parts quality and performance in most cases.
So realize that
A) doing the right work with the right parts as you are and all at once, you may NOT need to return that deep in which case extra work may be wasted, and
B) anything that is modified has to be considered a failure potential, so really it's hard to see the mod being more than a removal/install aid rather than a good idea, or safer from the standpoint of a problem, and
C) plus that nasty emissions issue.
So I'd look at just doing some re-routes and maybe sensible replants as I have done to my TT, in an aid to repairs plus a cleaner looking bay but not a real tuck and no deletes.
I moved my PTU into the front of the car which helped in front of engine, and have removed the "looms" if you will that make such a mess on the sides of the plenum, redid that stupid IACV hose mess and the looping hose to the brake booster for WAY better DS access, and found easy ways to route those "loom" hoses and wires and more (rotated the turbo coupler bands, made a custom vacuum "tree" from the loom mess to bolt to a lower area and get those out of the way on PS, more small things like that) to better and out of the way places- I honestly now feel like it's looking into an NA bay until seeing the turbos and all of the intake piping end to end, MUCH unlike when I got her, and so often working on things isn't NEARLY the hassle of the first pass plus of course the practice of the past.
Not a lot of $ invested in the relocates and tidying, often adjusting OEM stuff and other misc parts, but I will admit to being a dressup junky though so I did go a lot further but just in that area with cost with a few dressups like throttle covers, SS bolts and Zspec washers, etc.
It's also pretty fun to do and plan, and not very fab intensive unless you want it to be, and everything looks better to boot!
First off congrats on the moxie to take this on yourself, and second for your choices of work, parts selection and the thought of doing it all right and at once.
That leads to part of my answer, which is actually to simply refresh everything and leave things as stock but to do some re-organizing and rethinking of a few things as you re-assemble and you should, as I have, get a better ability to get to everything you've worked on in the event a return is necessary. Probably less work than the coolant bypass and other relocates associated with that work. My Z guy has convinced me that time is in my favor, about 20 years worth (how long the car ran great with the original parts) and to keep that in mind when determining a course of action with the Z32- a notoriously over-engineered car from the standpoint of parts quality and performance in most cases.
So realize that
A) doing the right work with the right parts as you are and all at once, you may NOT need to return that deep in which case extra work may be wasted, and
B) anything that is modified has to be considered a failure potential, so really it's hard to see the mod being more than a removal/install aid rather than a good idea, or safer from the standpoint of a problem, and
C) plus that nasty emissions issue.
So I'd look at just doing some re-routes and maybe sensible replants as I have done to my TT, in an aid to repairs plus a cleaner looking bay but not a real tuck and no deletes.
I moved my PTU into the front of the car which helped in front of engine, and have removed the "looms" if you will that make such a mess on the sides of the plenum, redid that stupid IACV hose mess and the looping hose to the brake booster for WAY better DS access, and found easy ways to route those "loom" hoses and wires and more (rotated the turbo coupler bands, made a custom vacuum "tree" from the loom mess to bolt to a lower area and get those out of the way on PS, more small things like that) to better and out of the way places- I honestly now feel like it's looking into an NA bay until seeing the turbos and all of the intake piping end to end, MUCH unlike when I got her, and so often working on things isn't NEARLY the hassle of the first pass plus of course the practice of the past.
Not a lot of $ invested in the relocates and tidying, often adjusting OEM stuff and other misc parts, but I will admit to being a dressup junky though so I did go a lot further but just in that area with cost with a few dressups like throttle covers, SS bolts and Zspec washers, etc.
It's also pretty fun to do and plan, and not very fab intensive unless you want it to be, and everything looks better to boot!
Re: VG30DETT TB Coolant Bypass
Thanks for the reply!
Yeah I eventually decided against the bypass but Nissan actually stopped making almost half of the hoses. I can't seem to find a better solution at the moment and given that the hoses on it are not in bad shape, I'm going to look into replacing them on the next pull if and when that happens. I'm a little bummed but like I said, the hoses are not in bad shape. Seems like they were actually/possibly replaced at some point.
Next stop, repairing leaky power steering and a new front rack along with a hicas lockout!
Then there's the noisy snails.
Yeah I eventually decided against the bypass but Nissan actually stopped making almost half of the hoses. I can't seem to find a better solution at the moment and given that the hoses on it are not in bad shape, I'm going to look into replacing them on the next pull if and when that happens. I'm a little bummed but like I said, the hoses are not in bad shape. Seems like they were actually/possibly replaced at some point.
Next stop, repairing leaky power steering and a new front rack along with a hicas lockout!
Then there's the noisy snails.
Re: VG30DETT TB Coolant Bypass
I just completed the coolant bypass on my 90 TT and it's probably the simplest mod ive ever done. I dont see any potential downsides to the coolant bypass as its complete overkill to be cooling the intake. The biggest pro in my mind, is it makes removing the plenum much easier, simplifies the cooling system which leads to less points of failure.