DIY plenum porting
#321
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Originally Posted by Skrilla
https://my350z.com/forum/attachment....7&d=1147876681
After reading these two posts below I was observing that runners 1, 2, 5, 6 are all longer than runners 3 and 4. Maybe the angle cutting isn't a bad idea on those fours longer runners to make them the same length as runners 3 and 4. I now have an extra manifold (the 3 pieces) and are ready to go to work...what's your input?
After reading these two posts below I was observing that runners 1, 2, 5, 6 are all longer than runners 3 and 4. Maybe the angle cutting isn't a bad idea on those fours longer runners to make them the same length as runners 3 and 4. I now have an extra manifold (the 3 pieces) and are ready to go to work...what's your input?
Keep us informed with your results. If you can do a before and after dyno, since you have two plenums.
Later
Todd
#322
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Originally Posted by aceman
I was able to gain around 5 HP and 5 TQ on a stock 350z with the little i did. I believe the biggest factor to the gain is the front two runners. But making them all equal length should help aswell.
Keep us informed with your results. If you can do a before and after dyno, since you have two plenums.
Later
Todd
Keep us informed with your results. If you can do a before and after dyno, since you have two plenums.
Later
Todd
#323
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Originally Posted by Skrilla
I'll go for it...I was also thinking it will help to increase plenum size as well, maybe not by much but it could be a good improvement even if it only shows 1HP - it would be an almost free mod. I'll post results in a few days
*be carefull of where you're removing material...some areas don't have that much thickness from the interior to exterior.
can't wait for your results - try to get some good photos of the process.
#324
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Back in the day, we used to heat-up small block chevy heads in a furnace and then braze the backside of the intake walls so that we could widen them without breaking through.
You could do something similar.
You could heli-arc the backside of the area you want to grind on. Then, when you open up that area, you'd grind through into the weld, not open air. Much easier to do the welding first. Very hard to weld up a hole on thin metal.
You could do something similar.
You could heli-arc the backside of the area you want to grind on. Then, when you open up that area, you'd grind through into the weld, not open air. Much easier to do the welding first. Very hard to weld up a hole on thin metal.
#325
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thought I'd share my progress on my modified upper plenum...haven't had enough time as I'd like, but am almost done; just a few more spots to smooth out and a few more coats of paint:
filling in the 6 bolt holes W/ JB weld - I roughed/drilled the area so it's a very strong interface
filling in other areas so that it's level
paint process
latest pic - after lots of sand paper an coats of paint
the internal side of the plenum has the bolts hole areas entruding about 1/2"...I didn't want to make it 100% flush b/c it'd probably be too week.
Once I finish everything, I'll make another post w/ a complete write-up and photos.
-Peter
filling in the 6 bolt holes W/ JB weld - I roughed/drilled the area so it's a very strong interface
filling in other areas so that it's level
paint process
latest pic - after lots of sand paper an coats of paint
the internal side of the plenum has the bolts hole areas entruding about 1/2"...I didn't want to make it 100% flush b/c it'd probably be too week.
Once I finish everything, I'll make another post w/ a complete write-up and photos.
-Peter
#326
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Originally Posted by first350
thought I'd share my progress on my modified upper plenum...haven't had enough time as I'd like, but am almost done; just a few more spots to smooth out and a few more coats of paint:
filling in the 6 bolt holes W/ JB weld - I roughed/drilled the area so it's a very strong interface
filling in other areas so that it's level
paint process
latest pic - after lots of sand paper an coats of paint
the internal side of the plenum has the bolts hole areas entruding about 1/2"...I didn't want to make it 100% flush b/c it'd probably be too week.
Once I finish everything, I'll make another post w/ a complete write-up and photos.
-Peter
filling in the 6 bolt holes W/ JB weld - I roughed/drilled the area so it's a very strong interface
filling in other areas so that it's level
paint process
latest pic - after lots of sand paper an coats of paint
the internal side of the plenum has the bolts hole areas entruding about 1/2"...I didn't want to make it 100% flush b/c it'd probably be too week.
Once I finish everything, I'll make another post w/ a complete write-up and photos.
-Peter
#327
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just installed it - work perfectly, no sealing problems.
**after driving more than an hour, i can pop the hood, and place my hand on the plenum - before, the plenum would be too hot to leave my hand there! Cooler plenum, cooler air,...maybe I got 1/5 HP gain from it!
here's the pic of it installed...I wasn't able to make it look perfect b/c of time issues (first AutoX is this Satruday!)
**after driving more than an hour, i can pop the hood, and place my hand on the plenum - before, the plenum would be too hot to leave my hand there! Cooler plenum, cooler air,...maybe I got 1/5 HP gain from it!
here's the pic of it installed...I wasn't able to make it look perfect b/c of time issues (first AutoX is this Satruday!)
#328
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Great job on the custom work!
OTOH One significant thing I noticed in the pics. ...Your intake is sitting naked in the engine compartment.
Get that intake shrouded! It will make a real and tangible difference. 120-160 'F Vs 80'F (depending on weather)
40+'F will make a significant difference on ecu's timing curve/power results.
OTOH One significant thing I noticed in the pics. ...Your intake is sitting naked in the engine compartment.
Get that intake shrouded! It will make a real and tangible difference. 120-160 'F Vs 80'F (depending on weather)
40+'F will make a significant difference on ecu's timing curve/power results.
#329
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Originally Posted by Hydrazine
Great job on the custom work!
OTOH One significant thing I noticed in the pics. ...Your intake is sitting naked in the engine compartment.
Get that intake shrouded! It will make a real and tangible difference. 120-160 'F Vs 80'F (depending on weather)
40+'F will make a significant difference on ecu's timing curve/power results.
OTOH One significant thing I noticed in the pics. ...Your intake is sitting naked in the engine compartment.
Get that intake shrouded! It will make a real and tangible difference. 120-160 'F Vs 80'F (depending on weather)
40+'F will make a significant difference on ecu's timing curve/power results.
I've been tinkering around with ideas of how to do this...I've thought of FG'ing a box, or modifying the OE box, or getting some thin sheet-metal...I like how the ARC box looks, but am planning to DIY. Any other ideas?
thanks,
Peter
#330
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Originally Posted by first350
I've been tinkering around with ideas of how to do this...I've thought of FG'ing a box, or modifying the OE box, or getting some thin sheet-metal...I like how the ARC box looks, but am planning to DIY. Any other ideas?
thanks,
Peter
thanks,
Peter
you could just get the JWT popcharger, or at least use that design if your going to make one
#331
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Originally Posted by cturnbull802
you could just get the JWT popcharger, or at least use that design if your going to make one
I'm fairly set on the idea that I'll be making it myself, just haven't figured out how I'll be doing it.
-Peter
#333
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Originally Posted by Hydrazine
Other than stock, Stillen has the best heat shroud by far.
Could you fit it over your current filter?
Could you fit it over your current filter?
-peter
#334
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Zquicksilver used a tupperware container to take advantage of plastics natural heat resistance...Looked pretty funny but also functional:
Thread:
https://my350z.com/forum/showthread....ght=tupperware
Thread:
https://my350z.com/forum/showthread....ght=tupperware
#336
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Originally Posted by 350Zenophile
Zquicksilver used a tupperware container to take advantage of plastics natural heat resistance...Looked pretty funny but also functional:
Thread:
https://my350z.com/forum/showthread....ght=tupperware
Thread:
https://my350z.com/forum/showthread....ght=tupperware
wow - looks like the kinda of stuff I had done to my old '90 Geo...I'm hoping to make something that would resemble a higher quality peice - either way, it'll be a fun process. (I've been reading up on welding units...looks like a decent MIG welder costs near $800)
-Peter
#337
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Originally Posted by first350
wow - looks like the kinda of stuff I had done to my old '90 Geo...I'm hoping to make something that would resemble a higher quality peice - either way, it'll be a fun process. (I've been reading up on welding units...looks like a decent MIG welder costs near $800)
-Peter
-Peter
#338
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Curious as to what you guys think...
Okay I know for sure that I will be milling down the front two runners of my lower plenum. How much should I mill them down? I do have a manual Bridgeport and a CNC Mitsui Seki so I can be accurate within the ten thousandth if need be.
Also, would you guys reccommend an aftermarket plenum (Crawford, Kinetix SSV, or APS) or a plenum spacer (Motordyne or AAM), I will be running FI.
In addition I read this entire thread and Im so glad some people have finally took a step in the right direction and started doing things themselves. Thanks you fellas for being pioneers so the rest of us have something a lil more tried and true when we begin.
Also, would you guys reccommend an aftermarket plenum (Crawford, Kinetix SSV, or APS) or a plenum spacer (Motordyne or AAM), I will be running FI.
In addition I read this entire thread and Im so glad some people have finally took a step in the right direction and started doing things themselves. Thanks you fellas for being pioneers so the rest of us have something a lil more tried and true when we begin.
#339
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That looks great!!
I am havings some chunks of metal welded into the holes so that I can completely grind them smooth inside and then if there is visible lines of the welded in material I will weld it from the inside and grind smooth.
I am also going to be milling the front to runners slighly shorter soon and smoothing out some of the lines.
I am havings some chunks of metal welded into the holes so that I can completely grind them smooth inside and then if there is visible lines of the welded in material I will weld it from the inside and grind smooth.
I am also going to be milling the front to runners slighly shorter soon and smoothing out some of the lines.
#340
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I didn't do a before/after measurement of the how much material I took off...I just made sure it was equal amounts for the passenger/driver side. There's a good amount that you can take off, just watch out in some areas b/c the lower plenum isn't too thick on some spots.
great to see some guys with w/ good tools getting into this - keep us posted!
(I just bought a simple welding unit...doubt I'll get a chance to redo the plenum for awhile, but it's on my list!)
-Peter
great to see some guys with w/ good tools getting into this - keep us posted!
(I just bought a simple welding unit...doubt I'll get a chance to redo the plenum for awhile, but it's on my list!)
-Peter