Who's actually got this running on a 5 port???
Turbo Mini Forums

I wouldn't get too excited Colin,

If you look the patent up, it is as shown in the article - the complete system, throttle body, manifold, ECU - which none of us have copied (we may have used some genuine Rover parts but not copies).

And the patent ceased in 1999 - due to "Non-Payment of Renewal Fee" :)

So I guess BMW didn't think it was worth bothering with.

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

Edited by Sprocket on 7th Sep, 2012.

Ahhh ...... memories.

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."

Sprox, it's sad to see someone so full of frustration and resentment about past events.

http://www.jbperf.com/

Well as we are so far off topic now.....

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

One small point. As you talk about the need to time pulses.. when using smaller injectors due to not having to time them for a small window in a sequential setup forcing the use of huge ones, you can to an extent "right size" them meaning you get much longer pulses and a less patchy mixture as a result. I've found using injectors just big enough to cope (up around the 80% of capacity) have given the best results in wet manifold setups.

That makes sense that using small injectors would help. And one way to get an even better result would be to use 2 or 4 injectors in some sort of staged configuration to keep duty cycle as high as possible over the entire range. Megasquirt will automatically do a form of staging when the pulses become longer and you get overlapping pulses. I don't know if other ECUs do the same.

But even then it might be interesting to vary the timing of the injection pulses in the low load/low RPM regions where duty cycle will be lower. There might be some improvements to find there. Of course timing becomes irrelevant as you approach 100% duty cycle.

Jean

http://www.jbperf.com/

I have 4 injectors and run them staged 2-2. Made the idle and very small throttle openings maybe slightly better but made less difference than I thought it would. I think I need smaller injectors for the first bank and larger ones in the second. At the moment they are the same size. I have a few around and am planning to experiment a bit.

Dazed and Confused....

Tried messing with fuel pressure down to 35psi and up to 60psi, all ran fine and just had to vary the overall fuel required number in tunerstudio. Settled on 45psi which is the spec for the injectors. Problem is if i drop the pressure to get the first bank opening longer then the second bank run out of puff. So I'd still need to change one set or the other. At the moment they are all 360cc, I'm going to try 200cc bank 1 and 500cc bank 2 as I happen to have them around.

Jamie, what exactly is your setup?

Jamie, I was thinking of something similar, have you got any photos of your setup?

I was going to go for a 45mm single tb, with a pair of small injectors as close to the tb as possible, after around 30% throttle change to bank of 2nd injectors (or one large single injector) which would be about 100mm up stream of the tb. I only need fueling for around 125bhp so nothing massive. Are using an Su manifold? I was tempted to try and make a long manifold to replicate the 45's manifold I'm currently using.

Team www.sheepspeed.com Racing

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=422621

http://photobucket.com/jamiesminibuild

If something is worth doing, it's worth doing half of.

cheers John x

Team www.sheepspeed.com Racing

Jamie, what your reason for the long runner between the injectors and the TB?

Team www.sheepspeed.com Racing

Convenience mainly. There is no need to have it crammed at the back.. so I didn't.

The tb is a 58mm one off a volvo 850, nice easy shape and for f.a. off ebay. I can't remember how much but less than £20. I made the inlet and exhaust manifolds and injector rails / boss myself.

Looks good,,have you taken any afr readings for inner and outer cylinders?

Team www.sheepspeed.com Racing

Not since I changed the design, and according to those in the know my test (done on another mini before I built this one) didn't tell much as the lamda's were in the manifold directly making the readings unreliable. To be honest apart from a quick glance at the readings, which I recall being close (or I would have taken more notice) the point was mainly to test if my original whacky manifold design would even run. I now wish I'd taken more notice but it was before I even joined the forum.

Is there an optimal distance to have the wide bands along the manifold?

Team www.sheepspeed.com Racing

I am guessing that Jamie is talking about putting the widebands pre-turbo Jim? If he didn't have sample tubes/chambers like Paul/Rod/Graham then the readings would be skewed.

With you being N/A I guess you could just put them the manufacturer prescribed distance down the manifold branch, that way you should get a reliable reading.

If something is worth doing, it's worth doing half of.

i think it its between head and turbo they should be at the end of a take off pipe. Something to do with pressure affecting the readings. After the turbo, mine is in the elbow and works fine. Other run them further away, but I read the bosch specs and they said to run it as hot as possible under max design temp is best.

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

Colin,

I start from the position of accepting the basic principles of the Bosch datasheet. They have their reputation to protect and I can't see that they would have published such detailed information if it wasn't basically correct.

The datasheet is fairly old (but just happens to refer to two of the LSUs I'm using).

If the datasheet is right in principle, the readings are skewed a lot by pressure and there will be large pressure changes in a turbo install.

So if the datasheet is correct (ish), of course you can calculate the actual AFRs but only if you measure the actual pressures at the LSU.

That would just be another way of doing it but installing pressure transmitters (that could stand the heat) would be just as complicated (IMO) as the sample tube method and would require some cute software added to do the calculation if you wanted the results in real time.

Although the point I've made is about the pressure dependency, I also think it would be very hard to keep the LSUs within their gas and body temperature limits if installed BEFORE a turbo. Again, only a couple of us have actually installed thermocouples so have some real measurements to look at.

But, yet again, way off topic, Jimsters question was about a N/A engine, not a turbo.

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