16V to quad throttle manifolds- in aluminium / carbon fiber

[axalotyl]

Long story, but I will try and keep it short Way back I saw a lot of T3 adapter installs where people had problems with stacks hitting the brake booster, and having to put the TPS at the back to keep it away from the water neck. I also saw that the CNC round to oval transition was pretty crude, and needed porting to smooth it out a bit.

I decided that I wanted something better, and since RS Chita wouldn't sell outside of Japan, I made my own. I went for more length to allow for a smooth taper, and curved the runners up to try and clear the brake booster (forgot about the clutch master). End result did allow the TPS to clear at the front, and having longer runners meant I could get away with shorter stacks.

One of the aims with this particular build was to see if it was possible to fit quads to a 16V without the loss of bottom end that was said to occur. That meant that a longer runner and a smooth transition were basic design features. And in that respect, the build has been a complete success, with the engine pulling strongly from low rpm even with 272 deg cams.



However, as you can see, there is not a lot of room at the back, and the filter mounting plate finished up exactly level with that little nub on the clutch master. Even after I shaved a few mm off the nub I still only have about 1mm clearance. But the filter fits and keeps bugs and leaves out, so I can live with that.

Cheers... axalotyl (jondee86 everywhere else)

[slide86]

This is a total day dream, but how awesome would it be if a variable length trumpet system could be designed.

[axalotyl]

[axalotyl]

Yamaha have actually implemented a variable stack length system on the R1
along the same lines as this ^^^ video. But interestingly enough, despite all
the technology they have at their disposal, they opted for a simple two length
system. The stacks are either short or long, as decided by the ECU according
the its analysis of several inputs.

I can only guess that the number of variables involved makes it impractical to
have a sliding "trombone" style stack modulated continuously like a VVTi system.
So, a pretty straightforward DIY if you are that way inclined

Cheers... jondee86

[slide86]

Yeah i actually looked at a heap of other videos that displayed only a two stage setup. Long trumpets for low RPM and then going to a short runner higher up in the RPM range.

This wouldnt actually be too hard to do, and any aftermarket ecu would be able to control it these days.

Hmmmmmm maybe I should have a go!

[Sam-Q]

axalotyl: yeah that's neat, good on you for doing your own. I am surprised you managed to get a ITG filter to fit.

slide86: that's a much better version of what I have seen before. Too bad the longest intake we can fit is still too short.

[Sam-Q]

Update: The level of oscillations on a 16V have been measured and I have decided on just a straight 80mm long manifold. Flanges will likely be 13mm each with three small 12mm thick trusses between the plates. I shall make a new model soon.

I decided to go with a straight manifold because it allows for a longer intake than tilted upright. I found out that those guys at T3 only tilted theirs up so that their vacuum fittings would clear the metal water line. My manifold won't have such a limitation and hence I don't need to down-grade my design as such.

I am also tempted to just make my own version of a 16V RWD outlet and that way I can keep my throttles the right way up. Mine wouldn't be cast but rather a machined base with a shrink fit steel pipe in the side angled forward.