Sam's build thread

**sambb** · 15-03-2018, 03:35 PM

AutoSpeed - The Audi's DIY Boost Control - Part 1

Like this? Yep makes sense. Cant find part 2 where they perfect it, but yeah I did do this a year or two ago. In part 2 they found that the pressure regulator was not exhausting residual boost fully and was trapping boost between itself and the wastegate. They ended up running a circuit (with a one way valve) back to the front of the pressure relief to sort this. I raided the pneumatics part bins at work and set it up and it worked great, but it was very bulky and hard to find the real estate to mount it. There will be a relic post I did on this forum maybe 2 years ago somewhere. Yeah you're dead right re the restrictor. That's what I was taught - that its ability to restrict is dependent on the rate of change of flow. That might be why it works so well at clipping the over boost peak when flow is fastest and changing rapidly but then has a diminishing effect later in the boost curve/load range/rev range where I guess it sort of hands ful control back the solenoid. I guess there is no reason why a pressure relief valve couldn't be placed in series before the boost control solenoid to guarantee that there is no premature wastegate cracking before the solenoid is absolutely needed.

No I'd rather the boost curve that the 10psi spring gave any day. Such a little turbo and such small turbine boost will always fall away but the stiffer spring did help. The 7psi spring still has improved things over the diabolical stock one though. But until I learn how to log/tune with Nefmoto I'm bit of a prisoner of my generic flash tune and had to use hardware to match the software ie getting my actual boost to resemble the tunes specified/expected parameters. Tomorrow if its not wet i'll get out and start to add timing.

**Sydneykid** · 15-03-2018, 04:19 PM

Part 2 = AutoSpeed - The Audi's DIY Boost Control - Part 2

I first saw this type of pneumatic boost control system on a turbo Porsche about 25 years ago. If I remember rightly it had a Bosch Motronic ECU that was water cooled because it got so hot running the engine. The Gibson Skylines had an Electromotive version that was also water cooled.

Cheers
Gary

**sambb** · 15-03-2018, 10:21 PM

glad you found part 2 - a good article for the records. Re the Porsche/skylines that's cool. May be archaic by todays standards but similar pneumatics fixed up my bosch Me7.5 managed MY2008 boost curve just fine for zero dollars. Since the bank owns my soul I'm pretty big on zero dollar fixes. Ive got to say when I did have those gizmo's fitted to my car it sounded pretty outrageous and looking back was the only way that ran my 12psi spring properly on the old car.

**sambb** · 18-03-2018, 12:43 PM

Gary was great to see the Civic run. I saw you guys in the garage at about 2pm and it looked hectic so I left you to it. I took the kids over to the grand stand to see their reaction to a proper eardrum rattling standing start and they just lost it when the F3 race started. Justin was certainly carving through the field like Verstappen at Interlagos a couple of years ago which was great to watch from the roof. My son (7yo) said in the car on the way home that it was the best day of his life so maybe i'll have to get a Kart for him (me?!)

**simon k** · 18-03-2018, 06:00 PM

Originally Posted by sambb

My son (7yo) said in the car on the way home that it was the best day of his life so maybe i'll have to get a Kart for him (me?!)

my girls all started motorkhanas when they were 12 - the eldest didn't like it and didn't want to stick with it, but the younger two love it
and are itching for next weekend's event

**sambb** · 18-03-2018, 10:47 PM

Yeah something I hope we'll do. I see so many double drive cars at the hillclimbs where its dad and son or dad and daughter or the dad is like the race engineer for the kid. Pretty cool. The funny ones are the double drives where the wife whips the husband - love it. The ribbing in the paddock is classic. Can you imagine having that thrown in your face!

**Sydneykid** · 19-03-2018, 08:06 AM

Originally Posted by sambb

Yeah something I hope we'll do. I see so many double drive cars at the hillclimbs where its dad and son or dad and daughter or the dad is like the race engineer for the kid. Pretty cool. The funny ones are the double drives where the wife whips the husband - love it. The ribbing in the paddock is classic. Can you imagine having that thrown in your face!

My wife won 2 x NSW State Motorkhana titles, I didn't win any.

Cheers
Gary

**simon k** · 19-03-2018, 03:08 PM

Originally Posted by Sydneykid

My wife won 2 x NSW State Motorkhana titles, I didn't win any.

Cheers
Gary

your wife is probably friends with a bunch of people I know.... you're not related to Cindy/Penny/Dean Cook are you?

**sambb** · 19-03-2018, 10:56 PM

A while back I'd talked about running pre turbo water injection. I want to run it pumpless in a boost pressurised config. Here's a couple of bench tests to help me build faith in it which I think worked out pretty well despite some leaky fittings. Droplet size is insanely small, literally a mist and way more consistent/smaller than my pumped 80psi system was with aquamist's smallest 0.4'C' 50cc nozzle. Next test will be to see how improved the droplet forming on the tube walls is when there's air rushing through the pipework simulating induction to the compressor.

YouTube
YouTube

post #167 on page 17 has the Julian Edgar diagram that I copied.