Batch Injection Vs Sequential

[zoomzoom]

Just curious what the difference would mean for tuning a daily driver.

How does a batch injection/spark ECU setup compare to a (much more expensive) full sequential system, all compared to stock tune in terms of:

Fuel economy for cruising between 2-3k rpm, or general fuel economy.

Idling, any driveability or practical issues etc.

Is any aftermarket ECU with a good tune going to beat the stock tune?

Thanks.

[Ben C34]

That depends on alot of things like injectors and engine mods etc.

[89CAL]

I don't think it is much of an issue running wasted spark. Not on mildly modded cars.

Any good tune will be more powerful than stock tune/ecu. They are conservative to prolong engine life

[KiwiRS4T]

There's a big difference between batch ignition and batch injection.

But batch ignition is not a big deal at most normal levels. My G4 Link is not sequential ...you need to go to the more expensive version to get that.

[GTSBoy]

Batch injection used to be the norm when suitabe electronics to fire solenoids were kinda expensive. These days there can hardly be much of an excuse not to have at least 8 injector drivers in any ECU. So if right at this moment the question has to do with choosing between an ECU that can only do batch injection and one that can do sequential, stop thinking about the old tech nasty that can only do batch and come kicking and screaming into the 21st century.

As to what the difference in operation is between the two......sequential injection fires the injectors at exactly the right time for each cylinder. This means that each cylinder is treated equally in respect of fuel delivery timing. In batch when they all get fired at the same time, once cylinder will likely be just at the right time to inhale the shot of fuel+air, another won't be far off, etc etc until you get to the last cylinder in the firing order that has only just finished breathing in and closed the inlet valve just BEFORE the injector fires. That means that the fuel mix has to sit around in the port, getting hot and wetting the walls and coalescing into larger droplets until the engine goesa reound twice more and the inlet valve opens up to let the mix in. That sucks. That means that one cylinder gets a nice clean shot, one gets a shitty shot, and all the others get something in between.

What that means for power delivery should be obvious. You can't tune an engine as thoroughly (ie pushing any native boundaries) because at least one of teh cylinders is not getting as good a treatment as at least one of the others. It also tends to kill the ability of the tuner or OEM to get decent emissions performance. This is why old EFI engines (80s and 90s perhaps) got away with batch firing, because it was better than carbies so was an improvement. But as time and legislative expectations marched on, OEMs had to abandon batch and go to full sequential.

Here's another interesting tidbit. Back in the day, many factory EFI setups didn't have enough injector capacity to run full sequential (you only get about 16 ms to open and shut the injector at ~7000rpm). So they'd run sequential at low loads and revs (especially cruise, to give good emissions performance) and then switch over to a sort of batch firing where they would double fire the inectors (one shot at the right time, one shot in between). Interestingly, this is still a possible way that anyone could try to eke a bit more power out of injectors that are not quite big enough - if their ECU would let them.

[zoomzoom]

I guess the main options will be a 4 driver ECU, so 3 would be used to provide spark and fuel for pairs of cylinders on the RB. It wouldn't fire all injectors at once. So in essence the fuel which goes into each cylinder would be 50% from the injection that occurred while while the intake valve was closed, 50% while on the intake stroke.

My mods are a hypergear r33 high flow turbo, and a 3 inch exhaust. I only intended to ever have light mods, though even that seems to be too much for the stock ecu.

I realise that technically going to paired batch injection is a "step down" from stock sequential, but can you achieve more efficiency with a tuneable batch injection system compared to stock? For example if I was to end up with worse cruising or highway economy, I wouldn't be too happy. Ideally I would like it to pay itself off a little....

[Ben C34]

What car do you have?

[nicksamaniac]

As an example of what gtsboy says, older RB30 vl (eccs) used 2 types of batch fire, 2 lots of 3 injectors would fire at low load, then at high load it would fire all 6.

This is due to the ecu only being able to control 1 pwm, and at high load the pwm would be so large the 2 batchs would over lap on the pulse, so it changed to all 6 and use the 1 large pulse.

If that makes sense?

[Dose Pipe Sutututu]

My mods are a hypergear r33 high flow turbo, and a 3 inch exhaust. I only intended to ever have light mods, though even that seems to be too much for the stock ecu.

You're over thinking it and it appears you're going to end up wasting money on a full sequential ECU like a Haltech, Link, Vipec, etc.

There's no need.. for what you're achieving a Toshi remap would be more than enough, get him to burn you an off the shelf ROM and socket your ECU - pop it in and happy days.

Considering you're using stock injectors, stock afm, etc.. that would be more than sufficient - ram down 1 bar worth of boost and you'll probably make about 220kW

Also FWIW... I'm running a No Frills Adaptronic ECU tuned by myself (only has 4 channels) and it batch fire, batch injector in pairs.

With my self tune running a SS2 Hypergear turbo I can get around 400km+ per tank on 98 OR 540km (best ever) highway driving.

At the moment, I'm running E85 and getting close to 350km per tank (normal civilised driving)..

[zoomzoom]

What car do you have?

S1 Stagea auto, hence the problem finding an ECU....

[zoomzoom]

You're over thinking it and it appears you're going to end up wasting money on a full sequential ECU like a Haltech, Link, Vipec, etc.

There's no need.. for what you're achieving a Toshi remap would be more than enough, get him to burn you an off the shelf ROM and socket your ECU - pop it in and happy days.

Considering you're using stock injectors, stock afm, etc.. that would be more than sufficient - ram down 1 bar worth of boost and you'll probably make about 220kW

Also FWIW... I'm running a No Frills Adaptronic ECU tuned by myself (only has 4 channels) and it batch fire, batch injector in pairs.

With my self tune running a SS2 Hypergear turbo I can get around 400km+ per tank on 98 OR 540km (best ever) highway driving.

At the moment, I'm running E85 and getting close to 350km per tank (normal civilised driving)..

The adaptronic e440d is one of the main options. I haven't looked into a remap, because I did like the idea of a tuneable (even flex fuel) setup. I figured a read-only remap would be a bit of a risky guess in terms of results, but I am open.

[Dose Pipe Sutututu]

I believe the adaptronic does not support automatic transmission (correct me if I'm wrong).

If you also look, Nistune has unofficially released the Type 6 board - have a read here (I'm a fan of Nistune, really easy to tune and the software is awesome):

http://forum.nistune.com/viewtopic.php?f=9&t=2719

[Dan_J]

i think the type 6 board has halted as the guy working on it was sick or the likes

[zoomzoom]

I believe the adaptronic does not support automatic transmission (correct me if I'm wrong).

If you also look, Nistune has unofficially released the Type 6 board - have a read here (I'm a fan of Nistune, really easy to tune and the software is awesome):

http://forum.nistune.com/viewtopic.php?f=9&t=2719

It would have to be piggy backed to retain the auto functions.

[Dose Pipe Sutututu]

What are you trying to ultimately achieve?

If it's just a highflow with stock afm, stock injectors etc.. a simple hack job like this might work (of course not everyone's cup of tea).

Get a remap from Toshi to suit your turbo, motor, etc. then install a SAFC or similar with a wideband and tweak AFRs till your happy. Also reduce timing by retarding the CAS by 2/3 degrees as when you bend the AFM signal TP Load references lighter cells.

Like I said, not everyone's cup of tea but works.

[zoomzoom]

Once I get most of those parts, it wont be far off the cost of a tuneable ECU anyways. The tuneable ECU will be more future proof, and useful in other projects, and even has the ability to run a flex fuel setup. I know I wont be maximising the functions of an ECU immediately, but it seems to be the proper way to go about fixing up the stock timing and fuel maps.

[KiwiRS4T]

Best bet for an auto S1 Stagea is Greddy E-Manage (or an HKS F-con if you have a tuner handy who has the necessary licences software and experience) piggy backed on to the stock ecu. Better still get a manual box!

[Ben C34]

Or a full manual valve body.

[Dose Pipe Sutututu]

Food for thought... sometimes it's just not worth spending (I'll make up a dollar value) $3k on a standalone + tune on a pretty stock motor (using typical $1000 tune & $2000 Haltech for reference).

Same logic can be applied with software development, does this image look familar?

[89CAL]

I need to learn to read lol......