Audi A3 Hill Climb car

Document your project with images, pictures, etc., and share with others.
Post Reply
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Audi A3 Hill Climb car

Post by Alex DTA »

I've been planning to go racing for a while. With everything that's happened over the last year, it's time to make that happen.

I want to build a car that will be competitive eventually, a little different, and something I'm fairly familiar with. My background has always been VW, starting with an early 70s air cooled Beetle for my first car, and Mk2 and Mk4 Golfs over the last decade.
I also wanted something I could use to showcase all the various options we support, such as traction control, launch control, anti-lag, cam control, etc, etc. I also want to run an STC.

Fortunately, a friend decided to sell his Audi A3 Quattro track car. It is something I'm familiar with, and I know the car. It has a lot of stuff done already, so I decided to buy it. Here is the advert.

This was bought in August last year. I took it to Curborough for a scrutineer to look at to see what was needed to race. Fortunately there was very little to do to actually race it, just removing the airbag steering wheel, and tidying up some wiring. As I plan to remove all the wiring anyway, this wasn't a problem.

The steering wheel was replaced with an OMP Uno wheel with space for two momentary switches, and a quick release boss.

Image

Image

I've now started removing the wiring loom. :shock: It's never ending. However, I've made good progress.

Here are a few pictures.

Dash out:
Image

Wires galore:
Image

Image

Image

Image

Image
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Audi A3 Hill Climb car

Post by Alex DTA »

I've now started removing the wiring loom. :shock: It's never ending. However, I've made good progress.

Here are a few pictures.

Dash out:
Image

Wires galore:
Image

Image

Image

Image

Image

Everything from the steering wheel to the tail lights is now either detached or I need it attached.
The loom running down the passenger side floor is completely detached apart from the rear wheel speed sensor. Unfortunately, this appears to be magnetic, not hall effect. If this is the case, I'm going to have to either replace them, or use a converter to change the signal to a square wave.
The loom running along the roof, including the alarm wiring, is completely detached, and in the footwell.
The driver side still has the wheel speed sensor, fuel pump and fuel level sender wiring all attached.
I've stripped the loom out the passenger door, and most of the driver's side door is loose, ready to be removed.

Next up, the engine bay loom, including lights and engine.
I don't need any front lights, so that will all come out. I then need to work out what I can remove from the engine. All I need is for it to start, so the fans can be disconnected as well.
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Audi A3 Hill Climb car

Post by Alex DTA »

The suspension is a bit tired, and the car is too low. The suspension arms point up at rest, and are level at best at full extension.

Full extension:
Image

At rest:
Image

It already has the Golf R32 arms and hubs, so the only way to keep it this low is to get hold of some H2Sport hubs (they're no longer being made), or move to TT-RS front uprights like these on the right:

Image

However, that requires different front shocks, and new brakes, so I'm going to bother for now. I'll just raise it back up to a sensible level to get the roll centres back where they need to be.

I'm ordering some KW suspension next week.

The engine is currently fairly standard, but I'll be having a new one built this year. I have some of the parts already. It will make around 450 to 550bhp depending on tune, which will give similair power to weight as the Golf. I'm more interested in a smooth delivery and good spool, headline figures don't mean much.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Audi A3 Hill Climb car

Post by stevieturbo »

I hate wiring !! LOL

But for the wheel speed it would definitely make more sense to retain OEM pickups and sensors and just run signal converters...the little yellow Vauxhall parts probably handiest, as you could bet a multi -relay holder and just wire everything through that

Anywhere in that power range though will make for an exciting drive. Presumably it isnt a road legal class anymore ?
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Audi A3 Hill Climb car

Post by Alex DTA »

Thanks Stevie.

Yup, there are a number of signal converter options.

No, it's straight in to Mod Prod, so slicks, frontal head restraints, etc.
gnutz2
Posts: 190
Joined: Tue Jul 03, 2012 2:33 am
ECU Model: S100 Pro

Re: Audi A3 Hill Climb car

Post by gnutz2 »

Looking good :D

Have you thought about how the traction control will work on the 4wd car? The only way I can think of getting the road speed is through the shaft sensor and allow the alternative traction method like on the s60.

Another method I thought of was a using one of these on the undriven wheel input www.c-a-i.net/Sky_Drive.php

Cheers Baz.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Audi A3 Hill Climb car

Post by stevieturbo »

GPS only gives a speed input, not a wheel rotation reference

There's a unit in the US that they claim is patented etc. Davis traction control.

Whilst largely aimed at drag racing and 2wd cars etc...

They essentially monitor propshaft rpm and what they look for is a rate of change of speed for any given shaft rpm. Exceed a threshold for this rate of change and it is deemed wheelspin.

I can see pros and cons for this, there are learning and non learning models

Their cheaper unit can be interfaced to other ecu's to allow fuel/spark adjustments to reduce power.

One advantage is it only needs a single input, ie propshaft, although I guess you could build a system that looks at more speed signals
But even prop speed on a 4wd car would give good usable info as long as it didnt have an open centre diff.

The rate of change would need monitoring to optimise the setup though, but any TCS system will need fine tuning anyway, so no big deal.

As to whether pulling timing alone will be enough to keep traction in check...that will depend. As to how it deals with powerslides, drifting etc...I dont know either.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Audi A3 Hill Climb car

Post by Rob Stevens »

Traction isn't going to work with the software as it is, if this car is 4wd.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Audi A3 Hill Climb car

Post by stevieturbo »

It wouldnt work perfectly, but I think it would still work to a degree.

front wheels will still be more likely to spin, so there will at times be a difference with undriven vs driven wheel speeds. You'd just need to guess at which speeds would be best used for driven and undriven

Really though with 4wd and slicks....TCS is not needed unless pushing serious power.

I guess in some ways the S60's version where it uses rate of engine rpm change as a direct link to wheelspin or not is maybe similar to the Davis setup I mentioned ? At least I think that's how it works ?
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Audi A3 Hill Climb car

Post by Alex DTA »

Ah, I forgot to mention the car is currently in FWD mode, so TC will be used.

I may move back to 4WD later, but we'll see.
Post Reply