HellaFab

Hey all,

I was wondering if there is a golden rule or maybe even a way to optimise injector placement in an intake manifold.

The intake in question is being built for a turbo conversion engine. I didn't know if there was a way to determine the best placement and if going forced induction made a difference on injector placement.

Matt

tepid1

Best bet is to have the injector spray hit the back side of the valve. Anything else will hit the intake walls and form into larger droplets which don't burn well.

that-guy

as close to the intake port as possible. or if there is the little provision in the intake port where the factory injector tip protrudes into (like in the B series heads) than use that

redboost10

exactly, right on top of the valve.

MidShipCivic

Best best is not do anything said as if it's definite way....

Grab some fluid mechanics books on the fluid you're working with, do bench test and simulations on CFD.... and find the optimized spot for your setup.

Back of the valve is only good for idle.

esteen2

Placement also has a lot to do with the type of injector used, and at what rpm the engine will be operating.

efHondefender

Probably on the back wall of the plenum with each facing the corresponding runner opening. LOL. That would be my guess for maximum power.

MidShipCivic

Placement has to do with EVERYTHING around the injector.

wantboost

iTrader: (2)

I've also wondered if there's some magic formula to figure out how to change the injector firing event timing(crank rotation in degrees, where it opens initially) when you move the injector away from the port

My primaries will probably be 2-3 inches further back than the stock location and my secondary shower injectors will be close to 6-8 inches from the port/valve (mounted to the plenum, inline with the port and centered to the runner opening

I just need to figure out how to properly time the opening of the secondary shower injectors so the fuel won't slow down and have time to cling to walls.

I'm also doing direct port water/meth injection with my itbs (meth injected post butterflies) need to figure out the best nozzle style and minimum distance from port/valve for complete atomization

sorry for the thread jack but I thought it a proper question given the topic

tepid1

A good ems will allow you to change the firing dynamics of the injector.

MidShipCivic

Even DIY EMS like Megasquirt have ''Injector timing'' function.

wantboost

iTrader: (2)

yea I know, it's just figuring out how much to change the injector timing for both primaries and secondaries.

I thought I saw some sort of math formula somewhere a while back but I cannot remember it for the life of me