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Upgrading OEM Throttle Body


jnoz

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Hi all,

 

Has anyone tried this at all? I've got a machine shop to hand, was going to open up the throttle body and use a larger butterfly flap.

 

I'm going to dyno before vs after. Looking to do a range of little upgrades like this before the remap.

 

Feedback appreciated!

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Pics will be up when I have a plate, jnoz if the local place let's me down ill hit you up :)

 

And can test fit on my own Z ;)

 

basically I think the NWP kit, once you factor in postage, import duty etc, is overpriced so I'm copying their idea, not directly copying plate though as that means buying an NWP kit so designed from scratch :) will be as plug and play as NWP though :)

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Once I've done it I'll throw up a photo. Working on a few other products at the moment. Also be looking into the 370z setup as have one of those to hand also.

 

Hey, just seen this, throttle body spacer. What the hell?

 

4-6HP?

 

http://www.ebay.co.uk/itm/Nissan-Altima-Maxima-Pathfinder-350z-Infiniti-G35-Throttle-Body-Spacer-FIT-3-5-/131743080814?hash=item1eac7fe16e:g:UDIAAMXQzkZRmsYn

Edited by jnoz
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I thought / have read that the limiting factor was the plenum chamber? Increasing the TB or intake tube wouldn't increase performance if the bottleneck is the plenum?

 

I have no doubt that you know more about this than me, but all the articles and threads I have read where larger TB's have been installed, there has been little to no evidence of performance gains?

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Well i would take usa figures with reserve. That means that just with basic bolt on's and larger tb he is having around 330 on crank. For me bit optimistic.

Also on stock plenum after larger TB you are again coming on a smaller diameter of plenum "neck". Should this "neck" have to be bigger diameter to follow flow of larger tb

 

Sent from my SM-G850F using Tapatalk

 

 

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It's optimistic going by UK figures but very well documented state side. Right through all the mods we consider the max for bolt ons :) but as no one in the UK runs long tube headers, or bigger tb, or bigger maf and intake we have never seen it :)

 

NWP have dyno plots etc of the difference a larger tb makes, a tb has a butterfly etc inside which disturbs the flow don't forget :)

 

The key strangle points on a normally aspirated vq are the manifolds, tb and intake pipe/maf, then the plenum, then the cams etc

 

The tb, inlet pipe/maf were improved on the hr by doubling up, something nissan didn't just do with no reason to. The hr also had significantly improved manifolds but still compromised due to emission laws needing the cats close to the engine.

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I'm with Paddy on this, I don't see how boring out or replacing the TB with one 5mm bigger can make a difference if the plenum inlet is still 70mm. I assume it gets modified also?

 

Regarding HP claims by NWP, I'd ignore them, considering companies like Takeda claim up to +15hp increase with their induction kit for the 350 and K&N are the same, yet cone kits like these have actually been shown to lose power.

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As explained, an open tb isnt an empty hole, theres stuff in the middle that disrupts and restricts air flow :)

 

That 5mm diameter increase, increases the surface area by 13%, the diameter change doesn't sound much but its actually a big change :)

 

And nwp dyno'D the items back to back, its all online if you're willing to dig through Google :)

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I do agree with pretty much all the comment I'm seeing guys. Opening the entrance of a bottle neck indeed won't remove the restriction half way down the neck, the smallest point must indeed be increased.

 

I need to get my hands on a spare intake really, and review how much it can be adjusted. I have a spare 100mm throttle body that would really allow a comparison. Obviously this is all expensive R&D just for a single thread.

 

Does anyone have a spare throttle body for sale? Seem to be around 40 pounds on eBay.

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