Haltech E6K Or Nistune For A Rb20

[Rolls]

Therre was a ca/sr ecu that changed between sequential and batch, but considering the rb20 ecu only has 2 injector drivers it is batch only. No sure about ignition tho.

Pretty sure ignition is because you have 6 ignitors, if it was batch they would save money and use 2 or 3.

[Crans]

At best it would be wasted spark no way 1 coil could handle more that 1 spark plug they struggle as it is with the one

[Rolls]

I never understood why they did batch mode injection, FETs are like $3 each for high amp ones.

[Crans]

Not enough memory I guess the extra timing calculations would require alot more code CPU used has limited outputs

[Rolls]

Not enough memory I guess the extra timing calculations would require alot more code CPU used has limited outputs

Im actually a programmer and one of my job was writing software for old processors, namely the same cpu used in these early boards. The code for writing to 2 outputs vs 6 and doing sequential vs batch is basically identical, the cpu still runs fast enough to process that many events. I can't see the CPU being the limiting factor, would have been something else but f**ked if I know what.

[Crans]

Funny enough I'm a programmer aswell yeah there wouldn't be a heap of extra code there is a bit of room available then again I've never worked on these chips they are probably faster than I give them credit for

[W0rp3D]

You guys dont have a clue.

You realise in going to the haltech you will be batch firing injectors and coils! The std ECU is fully sequential on both. It will do everything about 100times better than the haltech ever will.

http://www.fueltech....pdfs/HalE6K.pdf

8 injector drivers as standard equipment

There is a reason haltech doesn't support the earlier ECU's anymore is beacuse they are shit.

You dont think it has something to do with the fact that the e6k is near on 10 yrs old now and used old technology, how many companies do you know of that keep producing things for 10yr old hardware when there goal is to always develop newer technology? Edited September 17, 2011 by W0rp3D

[Legionnaire]

A bunch of programmers here haha.

Not a lot of additional code would be required to implement fully sequential injection/ignition. You basically just need slightly more sophisticated CAS decoder subroutine and cylinder counter and assign calculated outputs to different output ports based on that counter (using it as either input variable or index on inj/ign subroutine call). It's just one more routine and a couple of additional RAM values.

Those old CPU's are not very fast, but fast enough to handle engine management (some of early factory ECU's have hardware cap of 8000 rpm - been tested by Nistune developers, don't remember if RB20 is one of them). The only reason for not using fully sequential management I can think of is CPU may not have enough output ports.

[Crans]

Not enough output ports is probably the correct answer.

[Rolls]

Even using multiplexing wouldn't be very expensive or difficult.

I'm still fairly baffled why they would do this.

[Legionnaire]

Multiplexing can be a bit tricky in real-time applications like engine management. Requires some cleverly arranged synchronization.

On the other hand, it depends on how exactly CAS/load-calc-output data flow is implemented.

By the way I'm pretty sure I've read somewhere that R32 RB26 uses fully sequential management.

[Rolls]

I've been told the neo motors also do.

[Legionnaire]

Neo motors use 16-bit processor, different family and higher performance. R34's use Mitsubishi 7700 processors, earlier Skyline ECUs use some kind of Motorola 8-bit clone manufactured by JECS, if I'm not mistaken.

EDIT: I mean I'm agreeing with you I'm just explaining why full seq. mode is easier for later ECUs

Edited September 19, 2011 by Legionnaire

[Rolls]

Neo motors use 16-bit processor, different family and higher performance. R34's use Mitsubishi 7700 processors, earlier Skyline ECUs use some kind of Motorola 8-bit clone manufactured by JECS, if I'm not mistaken.

Yep, much newer processor with more features.

[Crans]

Id like to know if the gtr is sequential as they are running an 8 bit cpu like the rb20(At least the r32gtr is)

[Rolls]

How many bit the CPU is doesn't mean anything, it is just the design.

[Crans]

What I meant was I'm pretty sure the chip used is the same between the gtst and gtr meaning the gtr will be batch fired aswell

[Rolls]

Oh right, yeah I get what you mean. Probably the case then!

[Legionnaire]

Not necessarily so. The CPU itself may be the same/similar, but its peripheral devices can be very different - it's an ECU architecture thing. E.g. RB26 ECU may incorporate multiplexing/decoding logic you were talking about.

Sure, it is all speculation only. The best way to do it is to open ECU case and take a look what's in there. And assembly code would be handy also.

But I seriously think they are all sequential, otherwise they would use crank sync trigger instead of CAS.

By the way 16-bit processors are seriously faster than 8-bit in this particular case because all AFM values and load calculations use 16-bit arithmetic.

[W0rp3D]

Hey I was wondering what ecu would be better for my setup mods are

Td06h-20g 8cm housing

550 injectors

3 inch exhaust

35 mm turbosmart external wastegate 17 psi

Stainless high mount

32 gtr cooler

I know nistune will be cheaper but lets put price aside on this one

so which one did you go with?