# 1.8T Intake Manifold design and construction.

**URL:** https://forums.speedlife.net/t/1-8t-intake-manifold-design-and-construction/256373
**Category:** Shift518 Automotive
**Created:** [January 11, 2011, 9:12am UTC](https://forums.speedlife.net/t/1-8t-intake-manifold-design-and-construction/256373 "2011-01-11T09:12:22Z")
**Posts on this page:** 1
**Showing post:** 36

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### Author: ![1stgen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/1stgen/32/6288_2.png) [@1stgen](https://forums.speedlife.net/u/1stgen)
#### Post date: [January 14, 2011, 8:50am UTC](https://forums.speedlife.net/t/1-8t-intake-manifold-design-and-construction/256373/36 "2011-01-14T08:50:19Z")

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> [@ECW, Bringing back memories (vid)](https://forums.speedlife.net/t/ecw-bringing-back-memories-vid/38588/30):
>
> that says the plenum is 211.2 in^3 or 3.46L! stroke the shit  
> Is it that bad to have a larger plenum than displacement? I also head 1.5X the displacement is recommended. Annnd I also hear that a larger plenum might slow down initial spool, but act like a capacitor to hold boost/volume more on tap when its needed.
> 
> what do you think?

Very much so…depending on how fast you can fill the intake mani with new air will be the problem, turn the boost to 40 P.S.I basically. The bigger the plenum the steeper the drop in tourque, and it’s a motorcycle motor, you will never make huge power from it. I have 3 of these motors, each one makes decent power in three different trims.  
What is this going to be used for? a class built drag car? Or roadcourse car? Cuz more than 250 wheel in a FWD car on track is useless and you’ll get smoked off corners all the time. Less over all power, good tourque and all the grip you can get. If it’s a drag car then you should probably just put an LS6 in it and make it RWD.

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