Gti6 Inlet Manifold On An Mi16?

[eob 7]

I'm presuming they flow slightly better? Is there any plastic manifolds that fit without sacrificing power? (I'm all about the weight saving )

[petert 588]

GTi6 manifold has trumpets cast into the design, whereas Mi16 are squared off flat. No idea about plastic manifolds.

[Simes 248 2 Cars]

I'm presuming they flow slightly better? Is there any plastic manifolds that fit without sacrificing power? (I'm all about the weight saving )

 

Potential power gains with the mildly larger TB.

I'll be able to tell you in about a week, although I'm also changing over to an Emerald K3 at the same time.

[Miles 331 1 Cars]

It will be good having a sort of back to back, but the RR I'm having this done is known for giving lowish figures which isn;t a bad thing really, But the main reason's I say are

 

Single Large Buttlefly (T/:), Less moving parts to wear out like most Mi's are now

Use of a proper TPS saves brackets and Mounts

Slightly shorter manifold so fits in the engine bay without needing to move anything bar the oil filler tower

Slightly longer Inlet track's as said they bell mouth into the Plenium chamber

[eob 7]

Interesting stuff chaps. One of the things that always impressed me about the TU was the use of the plastic inlet manifold = much weight saving. I'm presuming the plastic XU inlet manifolds just don't flow as well as the GTi6/Mi16 alternative?

 

Will be fitting the GTi6 inlet manifold next time I'm in my engine bay.

[dee205 3]

I'm sure a properly made plastic inlet would flow better than a cast jobbie if done right. Cast metal isn't the smoothest whereas plastic sets smooth with little rough faces and edges. If you were doing it DIY I'd assume you have to do some research on plastics. You don't want to soft a plastic that flexes under induction or too brittle that ends up cracking with heat or vibration.

[DrSarty 90 1 Cars]

I'm sure a properly made plastic inlet would flow better than a cast jobbie if done right. Cast metal isn't the smoothest whereas plastic sets smooth with little rough faces and edges. If you were doing it DIY I'd assume you have to do some research on plastics. You don't want to soft a plastic that flexes under induction or too brittle that ends up cracking with heat or vibration.

 

I've thought of finding ways to join a plastic flange ( ) from an XU10J2 and bastardised plastic runners from that and any other plastic inlets to make Mi/S16 inlets, but for ITBs instead of a single ITB. Would need some serious plastic welding/adhesive research, and most likely be more effort than it's worth.

 

However he who dares....

 

But the points above about how fragile it may be means the cast/fabricated alloy inlets for either set up are probably the best option, regardless of the extra weight.

 

Plus, if I'm not mistaken, smooth isn't always best. The slight courseness of the surface of the entire inlet tract helps matters as I understand it, as it creates beneficial turbulence, which is why 'polished' inlet ports is not supposed to be super/mirror smooth, but 100-200 grit paper-smooth at best.

 

In summary, I don't think it's worth the effort to go plastic; it's too much hassle for not much gain.

 

But I've elected to use GTI6 inlets over anything else on my builds for all of the reasons stated by others above.

[DRTDVL 4 1 Cars]

Plastics aren't all that weak... It's a bit of a misconception....

 

Also one thing to remember with plastics is you can get some very very good application specific plastics in this case you would be looking for a plastic that would have low thermal expansion and also low thermal conductivity. Look at the uses of plastic in your cars at the moment... Your battery box is plastic, new cars engine covers, the s16 intake manifold, intake piping, drop-links,etc...

 

The hassle factor is a big thing...

 

DrSarty, you could look at the cost of getting a DCOE style runner injection molded which you could then bolt on a plastic box/chamber/ITB onto. use them inconjuction with a phenolic spacer against the head away you go...

[Anthony 1,003]

Interesting stuff chaps. One of the things that always impressed me about the TU was the use of the plastic inlet manifold = much weight saving. I'm presuming the plastic XU inlet manifolds just don't flow as well as the GTi6/Mi16 alternative?

I've got a couple of different XU 16v plastic inlet manifolds in the garage (one from a 1.8 16v XU7JP4 and one from a 2.0 16v XU10J4R engine), as well as an alloy GTi-6 one, so I can take some comparison pictures if you like?

[bobob 0]

I've had my S16 (306) rolling roaded, whcih may or may not help. The results are at the wheels. The only modifications to the standard S16 engine are: Magnex exhaust system, decat and gti6 inlet manifold.

 

http://i2.photobucket.com/albums/y29/bobob...wer120909-1.jpg

Edited December 16, 2009 by bobob

[McDude 33]

Plastics exist that will easily do the job of an inlet manifold. The most common used is PA66 (Poly-Amide) a glass filled nylon. In fact most inlet manifolds nowadays are plastic.

 

The reasons the OEMs have gone this way is cost and packaging - weight is a factor too, but not a huge one. Performance is no better or worse between a properly designed manifold of any material. Obviously you need to keep heat away from plastic but you'd be amazed at what this stuff will cope with, 200C constant and 400C peak. Only really an issue on Diesels running high EGR.

 

Boost isn't a problem either, most are tested to 6Bar for backfire tests.

 

The problem us punters have is making a plastic manifold. Most are 2 shells minimum, sometimes 3 or even 4, friction welded together. How the man in a garage could cost-effectively mould and weld a plastic manifold is beyond me.

[cybernck 402 1 Cars]

^ I'm sure M3Evo would find a way!

[pablo 0]

what about this?

 

get a gti6 manifold

cut the runners leaving a stump on each

silicon pipe on each one

into a carbon fibre plenum

throttle body installed onto plenum

 

There are generic airboxes available pipercross make one.

 

Edited December 16, 2009 by pablo

[welshpug 1,661]

don't see the point of that tbh, as it simply replicates the standard setup.

[pablo 0]

its lighter is my only contribution.

[eob 7]

If it's possible to make an Mi16 run 180bhp (my target) with a plastic S16 inlet manifold for low weight, then I will definitely sample the S16 manifold route. Would be tempted to go with GTi6 management while I'm at it to dump the heavy AFM and simplify the engine bay.

 

My worry would, perhaps, be that Peugeot clearly went the alloy inlet manifold route on the GTi6 for a reason..

[DrSarty 90 1 Cars]

then I will definitely sample the S16 manifold route.

 

I think you'll find you can't, as it's not as simple as that.

 

The plastic runners on an S16 is only part of the manifold. There is an alloy casting which bolts to the head, which siameses two inlet runners into one port where they join to match the single inlet port on the head (1 per cylinder naturally). This alloy casting is about 7-8" long and has a set of butterflies on a spindle on one set of the ports.

 

The plastic manifold bolts to this, and continues these double inlet runners so in effect you have 8, and it's the ECU-controlled, vacuum-operated actuators that close or open the aforementioned butterflies so that the engine is using either the long or short set of runners built into the plastic inlet.

 

It's a variable length inlet tract system, and is heavier than any other I've ever seen. Brilliant when it works though.

 

Basically it's a no go with that inlet as you'd be starting with 8 inlet ports.

 

I think you keep talking about saving weight (such as losing the 'heavy' AFM) and swapping management to make up for a poorly set-up engine. It's not mapped right and/or some of the sensors are shot IMO.

[eob 7]

Thanks Sarty Much appreciated

[welshpug 1,661]

also with the S16/2.0 Mi16 there's a vacuum solenoid controlled by the ecu at certain RPM, not a function found on any other XU ecu.