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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Tue Jan 30, 2018 7:03 pm 
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Joined: Tue Aug 02, 2011 12:08 pm
Posts: 2901
Location: Norn Iron
ECU Model: No ECU
You can use these, they come in various pressure ranges ( or just change the gauge yourself ) for testing spring pressures.

Either installed valves, or springs on a bench either in a vice, press or other suitable piece of equipment.

https://www.summitracing.com/int/parts/ ... /overview/


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Wed Jan 31, 2018 9:08 am 
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Joined: Fri Feb 28, 2014 1:03 pm
Posts: 1119
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79
I have better things to do with my life than try and talk to companies that don't listen.

Borla wrote:
Glad you're heading in the right direction now (did you see what I did there). :-)


Oh dear. :lol:


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Wed Jan 31, 2018 11:34 am 
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Joined: Thu Jul 28, 2011 4:10 am
Posts: 856
ECU Model: S100 Pro
80mm long springs on a road type car, that can't be right, I'm guessing its some sort of strut.


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Wed Jan 31, 2018 11:43 am 
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Joined: Mon Aug 01, 2011 6:45 am
Posts: 502
Location: Lancashire
ECU Model: S100 Pro
Distributor: Mefmotorsport
Firmware Version: 79
has anyone found that the emailed links from this thread no longer work? It’s the link that takes you to the latest post on this thread. The other link that takes you to the start of the thread works ok


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Wed Jan 31, 2018 2:29 pm 
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Joined: Fri Feb 28, 2014 1:03 pm
Posts: 1119
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79
Rob Stevens wrote:
80mm long springs on a road type car, that can't be right, I'm guessing its some sort of strut.


The springs are mounted away from the damper, closer to the pivot point than normal. Ratio is .63 IIRC, so not much travel where the spring is mounted.


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Thu Feb 01, 2018 5:27 pm 
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Joined: Tue Jan 16, 2018 9:38 am
Posts: 52
Location: Aberdeen
ECU Model: S100 Pro
Distributor: DTA
Good move taking the car to someone who knows their suspension - it does sound very likely the mental rear springs are the source of your handling woes.
Really interested to see the work improves the handling.

Borla - for measuring spring rates, I use basic bathroom scales and my hydraulic press. pretty basic but with a few repeats I get repeatable results. Measure at 1/2 inch increments. The first bit of compression may be eratic so perhaps start at 1/4 inch, and keep going as far as you can safely squeeze it.

(I may be lucky that this is easy with my puny 125lb and 250lb springs used in the Saxon).

Steve


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Fri Feb 02, 2018 4:53 am 
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Joined: Tue Aug 02, 2011 12:08 pm
Posts: 2901
Location: Norn Iron
ECU Model: No ECU
I'd love to see bathroom scales handle 1000lb springs lol


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Mon Mar 12, 2018 4:17 pm 
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Joined: Fri Feb 28, 2014 1:03 pm
Posts: 1119
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79
Time to get up to date.

After a few email conversations with Matt, things progressed.

Matt weighed the car, and it is currently 1096kg, 687kg at the front, 409.6kg at the back. So 63% at the front, 37% at the rear.

The fronts were almost identical to the originals, slightly softer, but also slightly longer.
The rears were MUCH softer. I will admit, I was skeptical at this point, they seemed too soft, based on what everyone else was running.
However, Matt will have forgotten more than I'll ever know about suspension, so went with it.

When the new springs arrived, Matt found the rears were to short. Matt quickly realised why.
With the old hard springs, the rear of the car was only compressing the springs 3mm! No wonder I was struggling.
This explained something else. When the KWs were first fitted, the rear was far too high. No wonder, when the correct spring rates were fitted, the car settled much more.

Corner weighting was also done, with a perfect 50/50 diagonal set up achieved.


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Mon Mar 12, 2018 4:17 pm 
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Joined: Fri Feb 28, 2014 1:03 pm
Posts: 1119
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79
Next up, noise reduction.
I'd supposedly hit 108dB on drive by at Donington. While that's very unlikely, the car was loud.

Thanks to yoof, who put me in touch with a contact of his, I had a repackable silencer made up and sent over.
I dropped the car off at Stealth to get it fitted. Unfortunately my measuring was less than ideal (OK, it sucked), so the silencer didn't fit where I wanted it.
Stealth did the best they could with what I'd provided, but had to modify it to make it fit. As always, they did a fantastic job.

This meant the car was ready, but I had no usable treaded tyres. The AO48s resembled 50p pieces after Donington.
I decided to treat myself to a new set of boots, but couldn't justify new DZ03s or the new AO52s, so went with some R888Rs all round.
I managed to get them fitted on Saturday morning, which meant I could book on a track day with some confidence. Not much, but more than before.


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 Post subject: Re: Audi A3 Hill Climb car
PostPosted: Mon Mar 12, 2018 4:20 pm 
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Joined: Fri Feb 28, 2014 1:03 pm
Posts: 1119
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79
So, to Bedford we go. All ready:

Image

I set off in torrential rain. Perfect weather for a first test of brakes and suspension. Not. :!:

Nothing I could do about it, so I got there, signed on and went for noise testing. 96dB/97dB, the same as my noise meter I'd bought. Higher than I'd like, so I'll have to look at that again.
After drivers briefing, I went over to the pits, unpacked and went on the sighting laps.

Which immediately raised an issue. I have no demister. 2 slow laps, and I couldn't see where I was going. I need to order some RainX.
I did some brake tests, and was able to modulate well enough, but it was very slippery. This also meant I was able to test the traction control, which worked well.

I came in, wiped down the interior, and propped open the passenger side window half an inch.

Back out, and this worked well enough. I did a few laps, exploring the conditions, working out where the grip was, and where I could brake. I spent most of the day braking far too early, but wanted to drive it back on to the trailer.

First impressions.
Matt at Spires knows suspension. The car behaved exactly as I'd asked him for. It's neutral, but I can induce the rear out if I want to.
This thing is ludicrously fast. It was too fast for the conditions today. I managed 130mph at half throttle!

Image

The bottom graph is the traction control working. That's a pull down the back straight, from second to sixth. Yes, the traction control is stepping in at 120mph in sixth over the bumps! :shock:
The traction control works really well. As it was wet, I've set it to be super restrictive. I was able to roll on to the throttle, looking for the limit of adhesion.
However, when it broke traction, instead of having to get out of the throttle again, I simply held it and let the ECU keep things under control.
Then repeat until I had to brake for the next corner.

Mid corner traction was immense. I could barely get the tyres warm, but never really felt short of lateral grip. If the rear started to go, it gave plenty of notice, and was easy to control.
The front was rock solid on turn in, and coped with the power well on corner exit. The traction control obviously helped.
I was even able to lift mid corner when someone spun in front of me, without any real drama.

Braking was a little trickier, but a large part of that is me still getting over the previous issues. The good news is the fronts now lock before the rears. A cone is testament to this.

I managed 4 good sessions this morning, and wasn't passed once. I passed quite a few others, so was happy enough with that.

I ended up leaving at lunch time to get back to the office.

I'm hoping to get to Rockingham this Sunday, as the sprint series I'm entering has it's first meeting of the year there on the 25th.

Future Plans
Redo exhaust system so that I can do some proper testing at a track day. Although I'm probably OK for most tracks now, I'd like a safety margin.

I want to do some proper driver training, so I can start to use the potential of the car, and learn more.

I need to get the cage redone, as Bill has condemned this one.

I have an SQS Shifter, which will allow clutchless upshifts in conjunction with the ECU.
If I'm also able to fit our E-Shift unit, I'll have clutchless up and down shift via paddle shifting. Otherwise I still have the MME pneumatic system, which will give me the same.


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