Rifling Of Manifolds, Dumps And Exhaust

[Hanaldo]

Rifling would be a waste if time and great expense, because you aren't realizing that it's for the projectile, not the gas.

Also, using boost pressure for water methanol is another waste of time. You need the wmi at low levels of boost when the car is under the most load. Without much pressure, you aren't going to atomise the the mix anywhere near enough, so it's not goin to work.

My system worked well at 150 psi, the mix was like steam. Anything under 50psi and it dribbled, like the shit your posting.

Common sense, there is a lack of it these days. People need to realize these ideas would be utilised by BMW, Ferrari, Nissan, etc if they were so great. Why? Because they have millions for R&D, and much smarter people than a few kids on a forum.

I don't see the need to be so harsh... You blindly discourage innovation. It was an idea, even if it doesn't work, it was someone trying to think of a method to improve.

Explain why it wouldn't work, pat him on the back for thinking. Don't shoot him down for both.

[The Mafia]

Nice post, made a lot of sense. Thanks.

[Johnny]

I don't see the need to be so harsh... You blindly discourage innovation. It was an idea, even if it doesn't work, it was someone trying to think of a method to improve.

Explain why it wouldn't work, pat him on the back for thinking. Don't shoot him down for both.

Thanks man, like i posted that im no engineer and dont understand gas dynamics. I just had an idea and wanted to learn from the pros.

I saw Mafias post and wondered how he treats people around him in everyday life who ask a question.

Now GTSboy, im impressed with but i wont pretend to understand everything he wrote but i got some of it. Thanks man

[_x_FiReStOrM_x_]

Slightly off topic. (sorry) I'm not sure if i'm just a bit slow lol, (actually i probably am), but something i didn't know up until a couple of years ago after seeing some engine dyno results, was that exhaust manifold and port sizes should not be port matched. I've seen alot of people taking to their exhaust ports and cast manifolds with die grinders trying to get a perfect port-gasket-runner diameter match, when infact there should be a 'slight' step in diameter with the exhaust port of the head being smaller than the runner diameter to help stop a bit of exhaust gas reversion back to the cylinder.

Edit. Not sure if this particularly applies to forced induction, as they were only atmo engines i saw results for. I guess with the pressure differential between inlet and exhaust on a turbo it wouldnt make a huge difference.

Edited August 7, 2011 by _x_FiReStOrM_x_

[GOD12A]

Heya GTSBoy!

Good to see someone who actually knows what the fark they are talking about.

Just to add, 'rifling' would be best designed for a small range in velocity. Low speed 'rifling' would disturb laminar flow at high velocity and high speed 'rifling' at lower velocities would be much less effective.

GTSBoy, what do you do?

I learnt most of my aero knowledge through a good mate who was an aerodynamicist at Williams F1 for a while.

PM me if you're keen for a chat about nerd stuff!

Mark

[bubba]

Ever seen the inside of an RB26 plenum?

There are spiral embossed grooves (for want of a better term) leading to each runner..

[GTSBoy]

And? Look inside most OEM plenums and you will find all sorts of interesting lumps and bumps and grooves designed to even the distribution to the cylinders. Ever wonder how the hell a conventional RB20 or 25 inlet manifold manages to get pretty eve distribution to all 6 even though the TB is directly opposite #s 3&4? Same reasons.

There is no way that a spiral groove on the inside of a plenum is going to get the whole mass of gas rotating in the <1 complete turn available from the TB to #6. But it may well be able to influence the shape of the flow to make it spread out a bit better (and not purely because it's spiralled.....that may just have been a crackbrained ida that some Nissan engineer tried and found out that it did what they wanted).

[bubba]

And?

I was just pointing out that Nissan HAS done something like that and they wouldn't have gone to the effort of it without good reason.

I'm just a designer, not an engineer but as a designer I have to take into account HOW things are made and you certainly wouldn't make your casting any more complicated that it needed to be.