EOI Custom intake manifold

mrb1 · Post by **mrb1** » Wed Aug 30, 2006 4:50 pm

toysrus wrote:Tuned runner lengths are not necessary with Forced Induction.

Wrong, they work exactly the same as they do in N/A

Cordzboy · Post by **Cordzboy** » Wed Aug 30, 2006 5:51 pm

mrb1 wrote:
toysrus wrote:Tuned runner lengths are not necessary with Forced Induction.
Wrong, they work exactly the same as they do in N/A

My understanding of the theory was that tuned length is less important for F/I, but still plays a part. And after playing with a turbo engine on a dyno with nothing changed but runner length and fuel/ign trimming for the different lengths, the power and torque curves definitely change.

turbo_onion · Post by **turbo_onion** » Mon Sep 11, 2006 9:00 pm

Quick update. Am getting a former CNC'd at a low cost of NZ$350. This is for *hopefully* a perfect sweep from a trumpet to the odd inlet port shape. The former is just an experiment to see if the metal can be streched as much as i need, so i really hope it works. I had a personal meeting with a director of the company doing the machining to discuss what exactly I wanted and he rekons it is gunna be f**kn tricky to make. But hey, im paying goodmoney so he should damn well try. That was monday last week and I havnt heard anything back yet.
If it doesnt work i wont pass the cost of it onto the price, ill just take it and cry :D

Plenum volume is pretty much finalised.

Still havnt found that much info about the runner lengths that will optimise the power, but from what info i can get, it is possible to get slight power and torque increase across a very narrow rev range by wave tuning on a turbo car. I think im going to run with a shorter runner so theoretical better throttle response, which is what im after. Hopefully this doesnt hinder top end power.

Cordzboy · Post by **Cordzboy** » Mon Sep 11, 2006 11:39 pm

Again, not trying to be too picky but you didn't really anwer all of the questions in there

If we ignore tuned lengths (which I'm happy to for a F/I engine), there's still more involved than just plenum volume. The shape of the whole manifold will have an effect on flow and thus power made by the engine.
But really, the big one I'm curious about is how you're planning on mounting injectors and fuel rail onto the manifold (because it's something we have yet to do well

).

Cheers,
Adrian

Starion VR4 · Post by **Starion VR4** » Tue Sep 12, 2006 7:03 am

Ummm, sorter lenght runners make more power up top, not more torque, longer length runners make torque, remember the std VR4 inlet, only 1 runner works at low RPM via butterfly & the lenght of the std inlet track is long, as RPM increases the vacuum is lost/switched so both tracks work, because they R of different lenghts this creats different velociteys in the port/head resulting it swirl in the combustion chamber. If u work on the STD lenghts U will improve either top/bottom end. As it is a perforrmance orentated result U may want, then short runners is what is required. Do U need money to fund machining costs if so PM me i will payin advance. :beer

turbo_onion · Post by **turbo_onion** » Wed Sep 13, 2006 7:34 am

Starion VR4 wrote: Do U need money to fund machining costs if so PM me i will payin advance. :beer

I should be right at the moment but thanks anyway.

Cordzboy wrote:But really, the big one I'm curious about is how you're planning on mounting injectors and fuel rail onto the manifold (because it's something we have yet to do well ).

I havnt got around to that side of the design just yet. I dont actually have a vr4 mani to look at so im knid of going blind and using my eyecrometer whenever I see someone with a vr4 parked somewhere, I wander on over ask ask for a look. I was expecting to fit the fuel rail and injectors after the manifold has been fitted to the side of the head, so that I can just make some mount flanges and tack them onto the runners at the right points. I dont know of any problems with this so far? if you can think of any please let me know

As for the plenum shape, that will be a guess and check on the first prototype. If there is too much air turbulance then out comes the die grinder. Its all good drawing it in cad but that doesnt really give me a physical thing to play with. So like I say im going at this entire thing kind of blind

It seems runner length may need more research. If anyone can volunteer for this that would be great, Google seems to be too vast for my patience, but I have been through a lot of shit. I was wondering if anybody knows of a design book or something, rather than just going off peoples comments and guesses!

Also, I need all the criticism I can get so dont worry about being too picky or whatever :D

Cordzboy · Post by **Cordzboy** » Wed Sep 13, 2006 12:32 pm

turbo_onion wrote: I havnt got around to that side of the design just yet. I dont actually have a vr4 mani to look at so im knid of going blind and using my eyecrometer whenever I see someone with a vr4 parked somewhere, I wander on over ask ask for a look. I was expecting to fit the fuel rail and injectors after the manifold has been fitted to the side of the head, so that I can just make some mount flanges and tack them onto the runners at the right points. I dont know of any problems with this so far? if you can think of any please let me know

Nope, I just realised that the vr4's have the injectors and fuel rail going onto the head, not the intake manifold like the SOHC multipoint setup

turbo_onion wrote: As for the plenum shape, that will be a guess and check on the first prototype. If there is too much air turbulance then out comes the die grinder. Its all good drawing it in cad but that doesnt really give me a physical thing to play with. So like I say im going at this entire thing kind of blind

The big problem I see here is that if you're making it from sheet metal you won't have anything to die grind - it'll make a very unhelpful hole in your manifold.

turbo_onion wrote: It seems runner length may need more research. If anyone can volunteer for this that would be great, Google seems to be too vast for my patience, but I have been through a lot of shit. I was wondering if anybody knows of a design book or something, rather than just going off peoples comments and guesses!

Also, I need all the criticism I can get so dont worry about being too picky or whatever :D

Take a look at some of the aftermarket manifolds available already for a good start on runner lengths. There's plenty of good books out there on wave and acoustic tuning of manifolds - take a quick trip to your library and you'll find some. But, to narrow it down for you, try searching for info on helmholtz resonance - it should lead into intake design.

turbo_onion · Post by **turbo_onion** » Wed Sep 13, 2006 5:30 pm

Cordzboy wrote:
The big problem I see here is that if you're making it from sheet metal you won't have anything to die grind - it'll make a very unhelpful hole in your manifold.

Yea i was thinking of just getting one prototype and then changing it if its all wrong. Are you looking at the "step" as such on the back end of the manifold by chance?

Cordzboy wrote:
Take a look at some of the aftermarket manifolds available already for a good start on runner lengths. There's plenty of good books out there on wave and acoustic tuning of manifolds - take a quick trip to your library and you'll find some. But, to narrow it down for you, try searching for info on helmholtz resonance - it should lead into intake design.

Cheers, ill do some research into the Helmholtz as soon as I get an opportunity

redzone · Post by **redzone** » Thu Sep 14, 2006 6:24 pm

i actually saw an article in an american import tuning mag a while back on this exact thing, for a 4G63 dohc, they actually made 3 different manifolds and dyno tested them, they were more concerned with the taper of the runner going into the port than runner length (i think they optimised that beforehand on paper) so if u could find out what mag it was and what the content was in the article then that would be a big help..

sorry i cant remember what the mag was, i`m kicking myself for not buying it!! :glare:

turbo_onion · Post by **turbo_onion** » Thu Sep 14, 2006 8:46 pm

redzone wrote:i actually saw an article in an american import tuning mag a while back on this exact thing, for a 4G63 dohc, they actually made 3 different manifolds and dyno tested them, they were more concerned with the taper of the runner going into the port than runner length (i think they optimised that beforehand on paper) so if u could find out what mag it was and what the content was in the article then that would be a big help..

sorry i cant remember what the mag was, i`m kicking myself for not buying it!! :glare:

Cheers redzone, ill try finding that one on my travels through the vast wilderness that is google

turbo_onion · Post by **turbo_onion** » Sun Oct 15, 2006 9:21 am

almost finished cad paper and had to do a bit of photoworks for the manifold:

thoughts?

redzone · Post by **redzone** » Sun Oct 15, 2006 9:42 am

i just saw that hi octane has now got available exactly what we`re making here! it is meant for transverse or rear wheel drive applications, the plenum unbolts so u can reverse it....

your one looks nice though, i`ll find out what the hi octane one is worth anyways. could be ridiculously expensive!

turbo_onion · Post by **turbo_onion** » Sun Oct 15, 2006 1:33 pm

that would be cool redzone, i still havnt got a clue as to how much its guna cost to make! and what is Hi Octane? is it a aftermarket shop?

Starion VR4 · Post by **Starion VR4** » Sun Oct 15, 2006 4:44 pm

Hey man, I am in need of a manifold in the next 2months, I can get it made here is it's not going ahead. Could U send the cad data to me if it's not happening.
:beer

turbo_onion · Post by **turbo_onion** » Mon Oct 16, 2006 6:54 pm

wow the pressures really on now! I have the mould for the the funnel getting case hardened as we speak, i have done two prototypes with different size aluminium and it works beautifully. They have been welded up so now all i have to do is get hold of some proper pipe that i will use and then send the drawings off to be lasercut and CNC folded. Uni will have finished after the 8th of Nov so the production will be full on.

As for sending the cad drawing, no offence intended, but that would be cutting my own lunch! I will sort something out. still dont know prices

Austarion

EOI Custom intake manifold

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