Ign Table options: TPS/RPM vs MAP/RPM
Turbo Mini Forums

The latest wastegate control code from emerald is pretty good. Suppose I ought to do a bit on why Alpha-N plus boost isn't all bad...

ah right, well my ecu is about 6 months or so old.

i'll have to get round to giving it a go!

You will need a reflash then

ah, is it the latest ecu that has it? cant remember its name.

But i will be getting upgraded to that when i go to injection as its an ignition only ecu at the moment.

I like boost controllers...

They are useful when they can run different boost in different gears.

Whether you do that with a separate unit or with your ECU has pros and cons each way.

Some boost controllers, such as Eboost, are very very good and use proper solenoids, unlike others.

Alex

AlexF

iain, there have been a few major changes since your ECU. You can now have 3 maps running at the same time, and switch between them, and closed loop wide lambda and egt is now working.

Team www.sheepspeed.com Racing

yeah i know, i got a quote to update to this latest version and it was £40ish.

As i say i was getting this done at the point when i sort injection (i.e. my 16v head)

you can switch maps, boost levels all at the flick of a switch which sounds superb.

so Iain, are you now mapping your ecu mainly of MAP or TPS?

Team www.sheepspeed.com Racing

As we are onto to emerald, Alpha-N plus boost. Now, I am not a fan of alpha-N in general but it is very useful in some contexts.

Quick recap on alpha-N. TPS tells you nothing about the air going into the engine, merely the throttle angle, so the fuel map is litterally that, rather than an intermediate stage as it is with SD. The good things about it are
1. the code is simple
2. More RR operators understand this than anything else

The bad things are that it really can't cope with any changes (say air leaks) that SD will take in its stride (although of course MAF gets messed up by leaks as well).

In a boosted context, the alpha-n sets the base fuelling and the MAP adds extra fuel according to our good old friend the ideal gas law. As boost is just upping P in the equation and (within limits) completely linear this works rather well, if seeming a little antiquated.

I used to be very very anti Alpha-N for anything but sorting out lumpy idle, but as I get older I am happy to live and let live on this, mainly becuase it works, and the number of very high power cars out there running superbly shows that it can be done. I still wouldn't on one of mine though...

Well i havent decided to run only MAP or run TPS with MAP compensation.

I dont know yet how to sort the load sites for MAP only on the Emerald, i need to talk with Carl at Emerald again. I can only see it in % of full range but cant see anywhere to set that hence on the RR we're only seeing load site 15 on boost.

You Jim?

I'm still running mine on TPS with Map, not put much thought into it before this thread to be 100% honest.

Let me know what Karl and Dave say at Emerald Iain, no point us both asking the same question. Mention that I have the same question when you chat.

Team www.sheepspeed.com Racing

youv'e lost me unfortunatly.!!!.

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Its ok Karl - we are talking one engine and no noz!

:p

Alex

AlexF

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will