No more Unreliable side feed injectors. Z31 plenum install
#1
No more Unreliable side feed injectors. Z31 plenum install
I have been running sidefeed z32 370cc injectors for quite some time. I maxed them out on 14-16psi. So planned on upgrading just decided go top feed dsm 450cc (drop resistors wired in) Didn't feel up to making a custom plenum. Also wanted to get away from the tiny dual throttle body and my restrictive 2" inlet off the throttle body. I can take as many pictures as needed if someone wants to do the swap also. The z31 NA injectors are 180CC same as the Maxima. The turbo z31 are 260CC. Parts needed are z31 lower plenum and upper. 84-86 topfeed injectors with rail. Sensors and bolts for upper to lower plenum. Its pretty much straight bolt on. Use Maxima water neck on front and z31 coolant line on back. For me it wasn't a major issue since I elimanate dang near every sensor. For someone keeping all sensors etc will have to modify vaccum hardlines on bottom of plenum and front and some wiring possiblt. Also I am using a 240sx throttle body which will work but you can't use the coolant lines unless flip thorttle body upside down. This way will allow you to use stock throttle cables and can keep Cruise control. z31 throttle body is 54mm 240sx is 60mm. If anyone wants more pics im more than happy to take some. Hood closes no problems.
Last edited by akurtzer57; 03-14-2013 at 04:10 PM.
#4
#7
Very nice. I had originally planned to go top feed on my turbo but decided to go side feed as in you original setup with the z32 370cc's.
I've still got all six drop resisters brand new inthe packs if anyone wants/needs them.
I've still got all six drop resisters brand new inthe packs if anyone wants/needs them.
#11
#14
Been a while, but I was around when intake flows were being discussed when I was initially putting my turbo together. There was only a hand full of us boosting then. But, I recall that the z31 intake flowed less than the stock plenum. I actually came back into this thread to ask why you used the z31 intake for this very reason. That is also the reason I stuck with the stock manifold.
However, I have an idea about achieving increased volume and making better use of the flow on the stock Maxima VG intake. I have a brand new, unused/uninstalled NWP spacer kit for the VG. Now, it only installs at the throttle body and IACV. I believe if phenolic spacers could be developed for between the lower intake manifold and bottom plate of the plenum AND a spacer for between the bottom plate and upper intake plenum, then you would 1. extend the lower intake = increased volume and velocity and 2. would increase the volume within the upper plenum.
This is actually the modification I intend to make on my intake in the next year or two on my turbo to see what gains I can achieve. I also plan to cut out the center section inside the upper plenum, again increasing volume and flow. I recall hearing that cutting the center section out actually didn't help things on the stock setup. However, I think with the phenolic spacers and when considering a boosted application....things will be significantly approved.....that's my theory anyway.
I have approached Cory about developing a "kit" (if only for me) to include the two above mentioned spacers. Things got as far as dimensions and such being set in CAD. I provided him with the intake components to make the spacers a perfect fit. However, due to expected lack of interest in the 3rd gen forums and exhorbent cost for just my set, they were never put into production. I still plan on making my own. They won't look as clean, but they will be functional....at least enough to see if they make a difference.
However, I have an idea about achieving increased volume and making better use of the flow on the stock Maxima VG intake. I have a brand new, unused/uninstalled NWP spacer kit for the VG. Now, it only installs at the throttle body and IACV. I believe if phenolic spacers could be developed for between the lower intake manifold and bottom plate of the plenum AND a spacer for between the bottom plate and upper intake plenum, then you would 1. extend the lower intake = increased volume and velocity and 2. would increase the volume within the upper plenum.
This is actually the modification I intend to make on my intake in the next year or two on my turbo to see what gains I can achieve. I also plan to cut out the center section inside the upper plenum, again increasing volume and flow. I recall hearing that cutting the center section out actually didn't help things on the stock setup. However, I think with the phenolic spacers and when considering a boosted application....things will be significantly approved.....that's my theory anyway.
I have approached Cory about developing a "kit" (if only for me) to include the two above mentioned spacers. Things got as far as dimensions and such being set in CAD. I provided him with the intake components to make the spacers a perfect fit. However, due to expected lack of interest in the 3rd gen forums and exhorbent cost for just my set, they were never put into production. I still plan on making my own. They won't look as clean, but they will be functional....at least enough to see if they make a difference.
#15
Maybe irrelevant, but some good info from mtcookson regarding intakes. Just to add something more to the conversation...
http://forums.maxima.org/3rd-generat...-thoughts.html
http://forums.maxima.org/3rd-generat...-thoughts.html
#16
I understand this isn't the best flowing intake for the vg. But its easy install. Cheap top feed injectors. Can go to gutted plenum. Piping routing better for my setup. There are alot of benefits for me. Lots of ppl have made good power with z31 plenums.
#17
Absolutely and agreed.
#18
Finally got some more time to work on the swap. Pictures before I was just mocking all up. Got the z31 lower plenum ported and on.(Must use Maxima water neck for radiator hoses. As for the fuel lines it to some new custom lines. Pretty easy to do. For the return I made a hardline which yet to make mount to hold down. I didn't want a 4 foot rubber line running across the engine bay why I made a hardline. The new line you can see right above the fuel rails. Eventually I will get the brass Y to run my aftermarket FPR.
Went to local yard grabbed a z31 IACV. The z31 IACV is 4 wire Maxima is 6 wire will look into the fsm and figure that part out. All I have left is wire in drop resistors for injectors and mock up new charge pipe to throttle body. Cruise control cable does not work with stock bracket BTW.
Went to local yard grabbed a z31 IACV. The z31 IACV is 4 wire Maxima is 6 wire will look into the fsm and figure that part out. All I have left is wire in drop resistors for injectors and mock up new charge pipe to throttle body. Cruise control cable does not work with stock bracket BTW.
#20
Finally got some more time to work on the swap. Pictures before I was just mocking all up. Got the z31 lower plenum ported and on.(Must use Maxima water neck for radiator hoses. As for the fuel lines it to some new custom lines. Pretty easy to do. For the return I made a hardline which yet to make mount to hold down. I didn't want a 4 foot rubber line running across the engine bay why I made a hardline. The new line you can see right above the fuel rails. Eventually I will get the brass Y to run my aftermarket FPR.
Went to local yard grabbed a z31 IACV. The z31 IACV is 4 wire Maxima is 6 wire will look into the fsm and figure that part out. All I have left is wire in drop resistors for injectors and mock up new charge pipe to throttle body. Cruise control cable does not work with stock bracket BTW.
Went to local yard grabbed a z31 IACV. The z31 IACV is 4 wire Maxima is 6 wire will look into the fsm and figure that part out. All I have left is wire in drop resistors for injectors and mock up new charge pipe to throttle body. Cruise control cable does not work with stock bracket BTW.
#21
I did away with cruise on my build. A/C is a keeper......cruise control, not so much. Yank that waste of space out of there! Besides, if you climb a hill in cruise and begin to build boost, will it even still operate properly? I didn't care enough to find out, but I'm definately curious should you opt for it staying.
#22
I did away with cruise on my build. A/C is a keeper......cruise control, not so much. Yank that waste of space out of there! Besides, if you climb a hill in cruise and begin to build boost, will it even still operate properly? I didn't care enough to find out, but I'm definately curious should you opt for it staying.
On a turbo Z31, there is a vacuum tank with a check-valve'd connection to the plenum, and inside it there is a pressure switch so if the vacuum dimishes, an auxiliary vacuum pump nested below the passenger-side headlight kicks in and restores the vacuum. When doing an NA2T swap on one of those, i'm not sure if people actually factor that in (the tanks are different between NA and turbo, and the NA doesn't even have a vacuum pump)
#24
Good to know. Still not going to re-install it. Kinda replaced the steering wheel for a better aftermarket one. So, either way I'm out.
On a side note, I have an electric vacuum pump installed. But, it's purpose was really to pull vacuum from the crank case at over about 15% throttle. Originally thought i needed it to reduce blowby, but found that to be unnecessary. I'm doing some renovations to the turbo, the vacuum pump is going away as well.
On a side note, I have an electric vacuum pump installed. But, it's purpose was really to pull vacuum from the crank case at over about 15% throttle. Originally thought i needed it to reduce blowby, but found that to be unnecessary. I'm doing some renovations to the turbo, the vacuum pump is going away as well.
Last edited by Chris Gregg; 03-25-2013 at 05:52 AM.
#26
Havn't really got anywhere till today. I ended up running the Maxima iacv. In order do to this I made an adapter plate. Counter sunk 3 allen bolts that fit on the z31 plenum and bolted maxima Iacv to the plate. I had do to a little modification to the Iacv for it to clear the throttle body. I still have some things to remove/clean up in engine bay such as my adapter plate, misc lines, wires and throttle cable bracket. I did score and find some brand new z31 ngk wires at u pull it for $10 I will be using these once put on a z31 distributor they don't work with the Maxima Dizzy.
about 95% done can drive around. Still need to retune.
about 95% done can drive around. Still need to retune.
Last edited by akurtzer57; 04-28-2013 at 04:24 PM.
#28
Sweet man I bet you put down some big power. I'm still trying to tie up loose ends on mine. Everything takes forever when you're only able to work on it a few hours at a time on weekends
Your video won't play it says private?
I'm still
Your video won't play it says private?
I'm still
#29
Just fixed the video. Ya I have 8 month old son. Plus was working an opposite shift as wife for over a year made it tough to get anything done. I hope your right and put down good numbers.
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