ITBS + plenum + turbo = worthwhile gain?
#1
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ITBS + plenum + turbo = worthwhile gain?
alright, I've got another thread that might potentially fire up the flamethrowers, but here goes. The facts are, I'm putting together a forged internals bottom end, but I haven't got pistons yet. Got carillo A rods though.
Basically, I've been studying plenum design and building one, and if I decide to go 9:1 CR or something, in the humble opinions of knowledgable people on this forum, will a plenumed ITB turbo setup show the benefits that it's worth? I could sell the whole setup for probably 1k, but I figure it'll at least be as good as a custom intake manifold, which would have a similar cost I figure.
the setup has 45mm throttle bodies, and a plenum would be attached to my 50mm air horns. If I wanted to dial in more torque, I figure I could add velocity stacks into the runners, but I doubt I'll need to worry about it with a turbo.
I would love to know the diameter of the runners on braineack's setup, for reference. Anyway, happy flaming!
Basically, I've been studying plenum design and building one, and if I decide to go 9:1 CR or something, in the humble opinions of knowledgable people on this forum, will a plenumed ITB turbo setup show the benefits that it's worth? I could sell the whole setup for probably 1k, but I figure it'll at least be as good as a custom intake manifold, which would have a similar cost I figure.
the setup has 45mm throttle bodies, and a plenum would be attached to my 50mm air horns. If I wanted to dial in more torque, I figure I could add velocity stacks into the runners, but I doubt I'll need to worry about it with a turbo.
I would love to know the diameter of the runners on braineack's setup, for reference. Anyway, happy flaming!
#6
Depends. If you want top end, it's probably worth it. Stock intake manifold suckssssss. Building custom **** like that always ends up being a bitch though. But if you did it, it would be badass. Most here don't like IRRRRRRRTBS because people with them think they're gonna runs 12's in the 1/4 with their throttle response.
#10
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I'm gonna take my time with this setup, probably run regular ol' itbs while i'm breaking in the motor for a while, while I try to figure out how to do this in the baddest *** way possible, investigate runner sizing, ideal literage of plenum, etc.
#11
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awesome. 1.75" = 44.5mm, so it seems like ~45mm is the ideal torque/horsepower tradeoff range. What kind of gains did you see after switching out that manifold from stock?
I'm gonna take my time with this setup, probably run regular ol' itbs while i'm breaking in the motor for a while, while I try to figure out how to do this in the baddest *** way possible, investigate runner sizing, ideal literage of plenum, etc.
I'm gonna take my time with this setup, probably run regular ol' itbs while i'm breaking in the motor for a while, while I try to figure out how to do this in the baddest *** way possible, investigate runner sizing, ideal literage of plenum, etc.
#14
The only difficulty I know of is tuning on vac side. The four tb plates will confuse the vacuum signal to the ecu's map sensor. Instead of a single tb vac of about 20 inches, you are going to find about 10 to 12 inches. Combining the four signals into a damper can might raise that to 13/14.
The consequence is that you must tune the entire span of vac side operation over 12 to 14 inches instead of 20, thus making the incremental changes more coarse and clearly needing a finer calibration.
This is tough on the guys that must have a magic system run perfectly right out of the box.
You are on the right track, it is worth doing.
The consequence is that you must tune the entire span of vac side operation over 12 to 14 inches instead of 20, thus making the incremental changes more coarse and clearly needing a finer calibration.
This is tough on the guys that must have a magic system run perfectly right out of the box.
You are on the right track, it is worth doing.
#16
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Join Date: May 2008
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The only difficulty I know of is tuning on vac side. The four tb plates will confuse the vacuum signal to the ecu's map sensor. Instead of a single tb vac of about 20 inches, you are going to find about 10 to 12 inches. Combining the four signals into a damper can might raise that to 13/14.
The consequence is that you must tune the entire span of vac side operation over 12 to 14 inches instead of 20, thus making the incremental changes more coarse and clearly needing a finer calibration.
This is tough on the guys that must have a magic system run perfectly right out of the box.
You are on the right track, it is worth doing.
The consequence is that you must tune the entire span of vac side operation over 12 to 14 inches instead of 20, thus making the incremental changes more coarse and clearly needing a finer calibration.
This is tough on the guys that must have a magic system run perfectly right out of the box.
You are on the right track, it is worth doing.
#18
Can be done successfully, search JeremyS on the pointy board.
His homepage
His top speed run, I don't know what he was running at the time though.
MX-5 Miata Forum - View Single Post - Fastest Miata?
ITB's are on my long term projects list.
Chris
His homepage
His top speed run, I don't know what he was running at the time though.
MX-5 Miata Forum - View Single Post - Fastest Miata?
ITB's are on my long term projects list.
Chris
#20
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4 tiny turbos would take just as long as one turbo 4 times as big ... well actually i think it would be worse due to the way the exhaust pulses would be hitting the turbines. Think about it, instead of 1800cc to power a turbo, now for each you have 450cc.
whatever, you were just joking anyway, and i ruined it lol.
whatever, you were just joking anyway, and i ruined it lol.