[MrDave]

The Rabbit TDI Project Part 7: Drive By Wire

Or: people fear change


If you read the forum posts on people asking questions about 1.8T conversions,
everyone says "avoid the drive by wire cars: too difficult"

That's a load of crap.

All TDI engines are drive by wire.
It's no big deal. No, really.
6 wires to the throttle potentiometer.
1 custom bracket.
Total time investment for installation: well under 1 hour.

(I was so tempted to do a Mastercard spoof here, but decided not to)

The top bolt goes thru a hole in the firewall, the bottom bolts thru the original
cable pedal mount.

Sorry for the quality of the second picture, but it gives you an idea of the early
stages of wiring...

The only problem is that the pedal sits about 1 inch too far to the left. There is no solution without hacking up the pedal, because on the right it is almost hitting the airbox. I'm debating if I should bother messing with it.

Note: This is a car without A/C. I've never seen an A/C airbox, so I can't say
how everything would fit in an air conditioned car.

If you have big feet, it's easy to hit the throttle at the same time as you hit the brake.


Another addition as part of this project was the pedal cluster out of a Cabriolet.
The reason: Provision for the pedal switches for cruise control.

Basically, a lego swap.

More about Cruise Control later.

summary: DBW AOK

Stay tuned...

-Dave

Part 1: Introduction
Part 2: Installing the Engine
Part 3: Transmission
Part 4: Wiring 1
Part 5: Speedometer and Cluster
Part 6: ImmobilizerIII
Part 7: Drive By Wire
Part 8: Intercooler
Part 9: Intake and Exhaust
part 10: MFA and Cruise Control
Part 11: The Dash
Part 12: The Little Things
Part 13: The End (for now)
Part 14: 6spd transmission and brake upgrades
One Year Later
Dyno results
Who Needs a VR6
TDI Rabbit

 

[KiNEMATiX]

Re: The Rabbit TDI Project Part 7: Drive By Wire (MrDave)

wow that looks easy compared to what i have heard about it!!
thanks!

 

[Frenchguy]

Re: The Rabbit TDI Project Part 7: Drive By Wire (MrDave)

Ain't it better to replace DBW by a cable set-up? IIRC DBW forbids heel and toe. Not that I heel and toe much with a Diesel though...
Anyway keep up the good work!

 

[MrDave]

Re: The Rabbit TDI Project Part 7: Drive By Wire (Frenchguy)

Quote, originally posted by Frenchguy »

Ain't it better to replace DBW by a cable set-up? IIRC DBW forbids heel and toe.

On the TDI engine, if you go with full electronics, there is no other way to control the fuel pump than to use the DBW. There is no mechanical way to do it, other than replacing the injector pump with a manual unit, and that can be quite expensive, plus you would lose the real fancy stuff that the ECU controls.
As for heel/toe, when you clutch or brake, the engine kills power. I'm not sure if it's a 100% or 80% or something else for the power reduction, but the boost sure drops off fast... (Luckily, with the VNT, the boost comes back pretty quick too)
Anyhow, if the switches for the clutch and brake are disconnected, (or grounded, or put to +12, I'd have to check the wiring diagrams) the ECU would never know that you were clutching or braking, so you could still have your fun. I have the pedal switches connected, because I'm lazy and like cruise control for highway driving.
There is a guy who rallye's his TDI over on TDIclub. He did an interesting writeup once about the joys of overcoming the DBW shortfalls.

Quote, originally posted by Frenchguy »

Not that I heel and toe much with a Diesel though...

The TDI is no ordinary diesel.
I don't have the thing chipped yet, nor do I have upsized injectors,
and I'm still running the 1.5" OEM exhaust,
but I can spin the 195/50/15 wheels thru first gear, and chirp second.

-Dave

 

[Italvw]

Re: The Rabbit TDI Project Part 7: Drive By Wire (MrDave)

On my DBW 1.8T i didn't connect brake or cluch switchs and runs perfect! Heel and toe/ left foot braking is all good!