Cheap Tb's?

[Rob Turbo 3]

Been looking at s16 inlet manifolds, the ones with the big plastic bit, if you take the plastic bit off you are left with this:

 

 

(Stole the picture from a google search!)

 

Now is it just me or would it be well easy to turn that into throttle bodies? My idea goes something like this:

 

Remove vaccum pot things

 

remove the butterflies and spindles, drill a hole in the middle divider

 

join the two spindles together (weld, brase, drill and tap etc)

 

put it back together, put throttle linkage on one side, TPS on the other, block the top set of holes off (i was thinking of making a plate that covers the whole manifold but only cut the bottom 4 holes, this will block the top holes and you could connect a filter to it, or in my case, a box thing connected to the cold side of my intercoler)

 

I dont think it would be too hard TBH, if ive missed something let me know, as soon as i get chance im gonna pull one apart!

 

Thanks

Rob

[M3Evo 0]

Surely you could just connect your throttle cable to the bit the vacuum actuator attaches to, and then blank off the redundant holes?

 

Alternatively just use the whole lot including the manifold (no idea what activates the system but no doubt you could rig something up with an aftermarket ECU)

[Rob Turbo 3]

Thats basically what I'm thinking, but theres 2 vaccum pots, one each side, and each one controls 2 butterflies, so to have a throttle cable and tps they would need joining together so one end controlls it and the other end has the tps

[M3Evo 0]

Aah cunning.

 

Could just run a thick rod (ooh er) along the top or bottom of the assembly which actuates each pair of butterflies, that way, you can adjust for any difference between them which I guess you couldn't if they were brazed together.

 

Less likely to twist that way too

[Sandy 191]

No balancing facility though, unlikely they'd all flow the same.

[boombang 2]

If that was an issue wouldn't it affect the cars running with standard system? (or you saying when the S16 runs both open it would balance out?)

 

Wouldn't the main issue be the rest of the construction - it having two inlet paths which would require a lot of filling to sort? (Not got a piccy or an inlet here otherwise would post)

[jochem 0]

I would think using just the bottom ones will result in too little air flow. Not sure on the diameter of the ports but why else would they open all eight on higher rev range?

Also you would need to fit large trumpets to comply with the required runner length.

 

Would make for an interesting project if you decide to give it a go though!

[DrSeuss 0]

I believe the throttle butterfly's in the lower runners are 45mm dia. they actually close during the midrange to accelerate flow.

[Guest andy309goodwood]

as above i belive they run a short in let tract at highr revs then at lower revs ie when there is vacume the butter flys close and the manifold uses the longer tract to increase the flow rate and rase the tourque produced

so some were behind those butterflys the two tracts meet dont know what kind of effect that would have on the inlet charge

how ever for the amount of work req im sure it would be just as much work and prob more benificial to make a manifold using some basic butterflys ( ie lotus ones ) from scratch

[boombang 2]

IIRC they are should be open on idle, they then close off idle until around 4k rpm when they open again.

 

When they are open at high revs I would assume the vast majority of the flow goes through them - unsure if they are best angled for use as throttle bodies or if flow is affected. The system doesn't give particularily good power on the s16 anyhow.

[Rob Turbo 3]

Does the length of the runner matter that much on a turbo? (thats what I'd be using it on) The runners on the standard 2.0 8v turbo are very short and that manifold is simlar to the t16

[Bonzai 2]

ive got one of these manifolds, miles said it was a pretty much pointless modification from what i remember http://forum.205gtidrivers.com/index.php?s...50&hl=s16+inlet

 

if you want any pics or measurements from one then let me know and i can do so when im down the garage next

[Rob Turbo 3]

I dont want to use the whole inlet manifold, I want to turn the metal bit into throttle bodies, like this (bad drawings in MS paint, but you get the idea!)

 

 

 

Thanks

Rob

[M3Evo 0]

If it were me, I'd definaltey actuate each pair individually. I'm reasonably sure it'd be pretty much impossible to weld the spindles together accurately enough.

[Rob Turbo 3]

I think that would be better TBH, like you originaly said, have a bar that connects the two running under the manifold

[Edd-XS 0]

I dont know an awful lot when it comes to this kind of business, but could the top 4 ports be used to house another set of injectors? Just an idea!

Edd

[Rob Turbo 3]

They could be I suppose, instead of making a blanking plate you could have injector holes and an extra fuel rail