Dual plenum pics

[Mark Halligan]

some sort of data logging facility would probably be best

[Mark Halligan]

If you are doing your own Mark, I would definitely get 5 EGT sensors mounted in your EM so you can see if you are getting equal amounts of air into each cylinder. I'll be doing that in my next EM just to be sure - don't want to melt a piston like Timucin.

I might well do that Doug, this is the reason why I am doing another inlet manifold. I am not too sure that the modified AAN manifold that we are using is giving particularly good flow distribution. Remember when I had that overboost situation and partially melted those sharp edges on two of the JE's? Could be that those two cylinders were running leaner?

Mark.

[Mark Halligan]

I haven't fully decided yet but I might use these velocity stacks as runners and have the top inch or so of the bell mouths protrude through into the plenum, like the picture at the top of this thread.
I got these from the U.S. and first saw them in this THREAD by Justin Olsen over on Motorgeek.com. The only thing is as Justin points out in his thread they are a little thin at ~1mm, but I have spoken to my Tig welding bloke and he reckons they will be no problem to weld.

[Mark Halligan]

another, even just sitting on the flange they look 'hungry' and ready to gulp down lots of air.

[Mark Halligan]

Compared to a sectioned piece of runner from a standard IM you can see they are a lot wider at the top end.

[Mark Halligan]

.....and slim down to the right size at the flange end. Any comments from engineers amongst us as to how these may affect the power band, would be appreciated

[Doug_RS2]

I have had my head off, running 2.15bar of boost on the inlet manifold, there are no visible signs of a piston being hotter than another (and I still have the sharp edges). But I know where you are coming from, much more power and I want to have the extra knowledge that they are all matched. It will also show up if an injector is not working or correclty balanced (or at least an injector or a flow problem - it won't tell you which unless you move injectors around to test that)

For the next power levels I think I am going to have 5 seperate gauges. It is easy enough to connect temp sensors to a AD converter card for a pc and you can setup warning levels etc - but the pc won't be connected all the time.

I might well do that Doug, this is the reason why I am doing another inlet manifold. I am not too sure that the modified AAN manifold that we are using is giving particularly good flow distribution. Remember when I had that overboost situation and partially melted those sharp edges on two of the JE's? Could be that those two cylinders were running leaner?

Mark.

[Mark Halligan]

For the next power levels I think I am going to have 5 seperate gauges.

yes thats easy enough, if they all have peak hold/warning built in (although five will get expensive ) it will be even more useful, as it will save trying to watch all of them and drive at the same time .

In the normal run of things in a well tuned engine like yours I doubt your pistons would show any signs of a flow distribution per cylinder imbalance, even if there are variances. It only showed up in mine due to a loss of boost control (loose hose to WGFV, my fault ) causing it to make crazy boost, albiet for only a few seconds.

Would it not be possible to make/build some sort of small pc type thingy to monitor five EGT's full time and data log them? I'd buy one.

Mark.

[meep]

Hmm well how about a In car PC. Like a 10" screen with a small real pc somewhere in the car. If you mont it niice then you would have a niice medi system to watch movies and so forth but also you would be able to run such applications and get them up on the screen.

[S2 Ant]

Meep, thats what im planning on doing... The PC is already in the car and running music, sat-nav, bluetooth, wireless network (and when i sort it out, TV, Radio and GPRS Internet)

Im gonna be speaking to some other friends about making some kind of interface that can be plugged in to measure gauges etc. hopefully they'll say its not too hard and i'll be able to do it.

Only thing from your list i have that is different is that my screen is 7" touch, in the S2 dash you might squeeze in an 8" if you took the screen apart etc otherwise 7 is as big as you can go without butchering the car

[S2 Ant]

Just read thru that US post, thats some impressive work going on over there!!!
Might have to see if a friend of mine can replicate those IM's too, along with making me an EM!

[Keeper of The Kitten]

.....and slim down to the right size at the flange end. Any comments from engineers amongst us as to how these may affect the power band, would be appreciated

Not going to pretend that I have the greatest knowledge here, but I'd say that the wider mouth and more aggressive taper would have a stronger venturi effect, when coupled with the fairly long runner length, would be good for the lower end (more torque). Is the runner longer or about the same as stock, or whatever you've been using prior to this?

I'm on holiday for the next couple of weeks but popping into work on Wednesdays, I think I might ask my "fountain of knowledge" former engine building colleague about this!

__MDC__

[Keeper of The Kitten]

Just a thought, if you get a flange welded around the five trumpets at a suitable place near to the mouth end, you can try different plenum shapes in an interchangeable fashion... Go CFRP and have moulded plenums for even greater flexibility!

__MDC__

[Mark Halligan]

but I'd say that the wider mouth and more aggressive taper would have a stronger venturi effect, when coupled with the fairly long runner length, would be good for the lower end (more torque). Is the runner longer or about the same as stock, or whatever you've been using prior to this?

Makes sense to me. The runners are a little longer but not by much.

I gave the first parts over to the fella that does my tig welding today, suppose I wont really know how well (or not) it works till I get it onto the motor. Its going to be a tight fit though with the smaller primary plenum as there is not a lot of room, time to move more stuff around.

Mark.

[RS2 Sedan]

does anyone drive the dahlbäck manifold?? whats the price??