Siemens Injectors
Turbo Mini Forums

Finally got my 60lb injectors from Aus.



I'm thinking of putting them side by side at 16mm centres above the inlet tract as close as possible to the head.

Any thoughts?

EDIT: Just to add that they will be staged. Idle and part load on a single injector then bringing in the second at higher load.

I might also wish to swap out the second injector for an EV14 once we get into higher hps.

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...%3AIT&viewitem=

Edited by Paul S on 8th Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

With that slender body 16mm apart and parallel to each other looks feasible.

When I mocked up the "side by side" configuration for my twin (staged) injector runners, I had to put a large angle between them because of the large solenoid body on the older style injectors, thus potentially favouring either the inner or outer valve before staging comes in.

It doesn't look like you will have much of an issue like that.

My only thought would be that with them being off centre to the tract, you might increase wall wetting slightly.

Schrödinger's cat - so which one am I ???

It should be fine side by side even if it may slightly favour one cylinder over the other when staging is off. As long as you have the outer injectors as primary and the inner as secondary (or vice versa) to have things symmetrical on both intakes and not pair them left for primary and right for secondary.

Jean

http://www.jbperf.com/

What cc's are these equivalent to Paul?

Look very similar to some we have for the DON.

630cc/min according to the blurb.

Not really big enough for 200+hp on a 1293 Turbo but a good starting point. 5 port that is.

I'm thinking now about getting a couple of blocks of ali to make a combined flange and injector boss. This will minimise the welding and potential distortion.

Edited by Paul S on 8th Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Sounds like they are the same as we have, apparently from what I've gathered a very good injector.

i was going to suggest making injector bosses with two holes, but it sounds like youv'e thought of that.

I'm now trying to find out if the EV14s are the same length, but struggling.

Not a real problem as Siemens do a 80 lb/hr version of this injector. That should be big enough with four in total.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Back into proper units..... how many cc/min are you looking at in total for (say) 200bhp and at what duty cycle ???

The duty cycle is the killer with the requirement to keep the pulses seperate, or are you going to try for a single pulse at high loads along the lines Jean has spoken about ???

I'm doing all my estimates on the basis of 20% duty cycle so far but, until I get the engine running again (tomorrow hopefully) and see what the actual pulse widths are at the correct AFRs, I really can't figure out (mathematically) what I need in the end.

Schrödinger's cat - so which one am I ???

On the basis that I got equal AFRs on my 998 up to 6000rpm and, say, 60hp with 375cc/min injectors on a single pulse, then by my calcs, 240hp would be possible with 1500cc/min per port.

Allowing for 7000rpm, then a lttle bit more from two 840cc/min injectors per port should do the job. Single pulse.

I'm not convinced you can work it out from a theoretical duty cycle in this instance, but you could work back from the above numbers. I did a quick mental calc and I thought it was around 15%, but don't quote me.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Siemens Injector..........

Hmmm there is a joke there somewhere...

Edited by Paul S on 9th Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Working your figures the other way around (I've used tables off the internet to see what size injector(s) I require) and using 0.47 BSFC (more commonly quoted for intercooled engines) I get pretty much the same....

For 240hp at 20% duty per cylinder requires just over 1500 cc injectors (ie, 1500cc/min per port injected twice, once for each cylinder) the way I've calculated it.

So good correlation.

The reason I've been working the other way around is that (at the moment) I'm determined to keep duty cycle low enough to still run individual pulses so wanted to know what injector size I needed to achieve that and I'm working on the basis that 20% will keep the pulses far enough apart even with moving the timing around to balance AFRs.

Schrödinger's cat - so which one am I ???

Edited by Paul S on 9th Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yes, that's why I said "at the moment"......

I've just been running my actual settings on the JimStim and watching on the scope (I wanted to make sure the IACV was actually doing everything right before re-assembling it to the engine) and, despite my calculations, I get the pulses merging at less than 5k RPM WOT..... with the loss of every other second pulse as we've seen before.

I'll post the scope plots up later.

Schrödinger's cat - so which one am I ???

So my problems may have been due to the loss of pulse, rather than injector size?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Possibly - without a scope you can calculate the maximum pulse width before merge becomes close with basic 90/90 timing, but once you start moving the injector timings, and especially if you are moving them in tables with different differences at different RPMs, it all becomes a lot harder to try to visualise.

There is no doubt that when the pulses begin to merge, you lose half of every other one.

Jean has explained why, and the solution is either to keep them well apart, or go for the single pulse solution that you and Jean have been discussing.

I was just hoping to keep with two pulses.... It's just strange that the injectors I chose to use should have been OK at 90/90, but today, JimStim says no....

In fairness though, I've changed a few things to get the IACV right so until I run it for real later, therer may be some other settings pushing me outside my intended limit.

Schrödinger's cat - so which one am I ???