hey folks does anyone know if there is any ecu's or goochy bits of kit out the that would automatically adjust thye revs for you when you downshift

m3 and gtr has it so it must be available

the gizzmo can launch and flat foot shift so there has to be soemthing

cheers

steve

 

M3 and GTR have it because it's designed into the engine and transmission control units from the start.

It would be very difficult to create a standalone plugin box that would do it properly, and even more so on a car that doesn't have drive by wire throttle. Launch control and flat shifting are comparatively much easier to implement

Not saying it's impossible, but the complexity of the job and the relatively small benefits it brings would probably mitigate against someone developing it as a separate item.

 

I believe the "Race Rom" feature on the new ECUteks for newer age cars has it.

Check the projects forums, Bob Rawle is currently testing it on a car he owns.

 

That's not quite the thing Steve was asking about. It's a preset throttle blip, so it gets part of the way there but to do it in the way Nissan and BMW do it the control unit needs sensor inputs that even the DBW Imprezas don't have.

 

im aware of the bmw m3 and gtr's having it obviously cause a lot of money has went into them

but i was wondering if it would ever be possible with certain mods

wouldnt that be great no matching revs anymore

steve

 

It's possible, if I had a mind to it I could make one, but I wouldn't be able to sell it to you at a price you'd be willing to pay - that's the catch.

The doing isn't hugely difficult, the hardware is all available off the shelf and the code in the microcontroller (which is fairly simple maths) would be easy enough to write. The problem anyone trying to produce it as a commercially viable add-on box for the Impreza would have is firstly you'd need to have hooks into the engine ECU - for the speed sensor, engine speed, and however you'd instruct it to raise the engine speed. So it'd almost certainly have to be developed in conjunction with custom ECU code. And then you'd also need to fit extra sensors to the clutch and gear selector mechanism in ways that were both affordable and reliable.

It's a lot easier to do with a sequential/SMG type gearbox as the extra bits you need are there already and the very nature of the box means that the logic always knows what gear is being selected next.

With a manual box the controller would need a way of knowing what gear you're in now, and what gear you're going for next - otherwise the system won't know whether you're going from fourth to third, or fourth to second, or indeed from fourth to fifth. The only sensor present as standard on the Impreza gearboxes is the neutral switch, which is no help in this scenario.

And you need a pot on the clutch pedal, or possibly even torque sensing built into the gearbox input shaft so the code knows when the transmission is re-engaged and your downshift controller can switch out of circuit and return control of the engine to the driver. And it all needs to work quick enough to calculate and match the speed in the time it takes you to execute the shift and begin to lift the clutch without interfering with the driver's input (or otherwise get in the way).

It's all possible, but it isn't simple and making it in a way that'd be easy for end users (or ECU installers) to fit, and within the context of a price you'd be willing to pay is the difficult bit. R&D costs time and so do small quantities of accurate, rugged position sensors.

Thing is, most people have either not been bothering at all, or use their foot, or heel to do that job, quite effectively, for decades. That's the main reason why features like this aren't exactly common.