Rick

Switch - something similar. The system that Dave has is fully adjustable for boost rise and boost pressure. The Mech Turbosmart system is good in that it eliminates creep. This isnt always ideal. Anyone thats gone from a -31 to a -34 will know that with the -34 the boost comes in with a bang. With the TS - the boost will always come in with a bang. On dave's u can taylor it to come in more slowly, making it easier on the transmission.

Switch

mmm thats interesting, so running my -34 will help the boost hit harder and quicker?

Dave Henshall

ha HA!

found the setting up info....

1. screw the pressure relief valve fully anticlockwise.
2. screw the pressure reg fully clockwise.
3. drive the car and bit by bit (test after each ajustment) turn the pressure reg anticlockwise until you hit the desired(SAFE) max peak boost.
4. lock the reg by pressing the top "click"down.
5. screw the relief valve clockwise bit by bit (with a test run after each ajustment).
6. As you do point 5 boost will rise quicker and quicker - but keep eye on peek boost as this may need tweeking back down slightly when you are happy with the boost climb rate.
7. lenght of hoses should be kept as short as possible to attain best throttle /boost response.

CosRush

Dave Henshall

thats the kiddy

the full details are now "pay only" on the site i got it from last year.

Kelv

iTrader: (4)

CosRush

Unless you happen to have them saved on your computer

Dave Henshall

i

CosRush

www.Autospeed.com

Archives if i remember correctly

CosRush

Part1 http://www.autospeed.com/cms/A_0670/article.html

Part2 http://www.autospeed.com/cms/A_0685/article.html

Dave Henshall

that is only part of the original one though, i was about 6 pages long with a list of parts etc and setting up procedure. those are now in the pay only areas of the site.

CosRush

Yes it is

But you could always pay the £15 and get all 300 articles...

Or if you're lucky like me, you've already got ALL of the article saved....

Dave Henshall

ket them loaded up on here u skin flint

CosRush

Using cheap off-the-shelf pneumatic engineering products, this new DIY boost control system allows you to set how quickly boost comes on as well as how high it goes. If you want, you can reduce wastegate creep to zero, giving extraordinarily quick boosting.
This week we change the pressure reg and add a new valve to give even better results.
The complete boost control system was covered last issue, so it's important that you read that article before you look through this one - especially so that you understand the details of the tuning process. You'll find Part 1 at "The Audi's DIY Boost Control - Part 1". While that system worked very well in giving an adjustable wastegate anti-creep function and then holding boost fairly constant, I thought that the boost regulation could be improved a little - and that boosting after each gear change could also be made to occur faster.
Refinements

To improve full-load boost regulation, I sourced a slightly more expensive - and sophisticated - pressure regulator. Made by Italian company Metal Work Pneumatics, the MR BIT SR ¼ Micro Regulator (with mounting bracket and gauge port plug) cost A$77 (including GST) from Metal Work Australasia Pty Ltd (Metal Work has outlets worldwide). While not a very expensive instrument level precision regulator, the BIT SR regulator has better regulation and faster blow-down than normal miniature regulators. When you order the reg don't forget to let the supplier know that you want to regulate low pressures - up to a couple of Bar max.
With the BIT regulator in place, the system held boost more accurately. A side benefit of the more expensive reg is that it is also nicer to use, with a higher quality feel.
After driving around for a few days with the new boost system, I decided that my personal preference was to have boost come on a little more gently. Certainly in a high power two-wheel drive car, if you set the system to give no wastegate creep at all, it would be easy to break into wheelspin when exiting corners - with a well-matched turbo, the boost comes on just so hard! To reduce the surge of power that even little throttle twitches gave, I opened (ie turned anticlockwise) the pressure relief valve a little, until the boost response was as I prefer. This setting still gives faster boosting than the factory system, but also retains good throttle control, with the engine providing a fairly linear torque delivery.
The beauty of this boost control system is that the speed with which boost builds up and the height to which boost rises are both independently adjustable - within the physical constraints of the turbo, anyway.
After Gear Change Boosting
With the IMI Norgren pressure relief valve (see Part 1) and the Metal Works pressure regulator in place, the boost control worked very well. However, after a few more days of testing, I noticed that an odd characteristic occurred in the Audi. In first and second gears, boost quickly built to the set 1 Bar of pressure, but after the full-load change to third gear, boost took much longer to rise to the max level. After the third/fourth, fourth/fifth and fifth/sixth changes, boost rocketed straight back up to its peak. So on just the third/fourth change it was almost as if some wastegate creep was still occurring.

I considered what might be happening to hold some pressure on the wastegate during gear changes. What if the boost was being trapped between the pressure relief valve and the wastegate, holding it open by a small amount? This could occur if the pressure after the relief valve fell below its unseating pressure, and was also below the pressure at which the regulator starts to 'relieve' boost (ie vent it to the atmosphere). After all, if on a quick gear change any pressure were trapped in the system for even half of a second, it would negatively affect the boost build-up following that gear change.
Adding another valve to the system removed this problem. The new one-way valve is plumbed into place so it connects the outlet of the pressure regulator to the inlet of the pressure relief valve, as is shown below. The valve is orientated so that flow is permitted from the wastegate line to the input of the pressure relief valve.

While initially it looks as though it will act as a bleed (ie lowering the pressure being seen by the wastegate under boost conditions), this isn't so. Why? Because whenever boost is occurring, the pressure pushing against the normal flow direction of the one-way valve is greater than the pressure being regulated by the pressure regulator, so the valve stays shut. But when boost falls (ie you've taken your foot off the throttle to change gears), any residual pressure that might be trapped against the wastegate is immediately exhausted through the new valve. This closes the wastegate and so makes the next boost event occur more quickly. Note that this system assumes that you have a throttle-closed blow-off valve working on your engine. If you haven't, there will still be boost present in the feed hose and so the one-way valve may not open.
The one-way valve that was used is an Italian-made brass York 23151-06 3/8-inch check valve, fitted with 5/16th inch barbed hose fittings. While an in-line brake booster valve would probably be adequate, the York valve has an extremely low opening ('cracking') pressure - just 7 kPa or 1 psi. It is also suitable for temps up to 80 degrees C and uses a 304 stainless steel internal spring. Complete with the barbed hose fittings, it was just A$14 (including GST) and was purchased from my local pneumatics supplier - BL Shipway & Co Pty Ltd.
With the one-way valve installed, the wastegate anti-creep behaviour was now consistent from gear to gear, allowing very good throttle control after every gear change.
Installation

With the system working as I wished, I mounted the two adjustable valves and the one-way valve on an aluminium bracket under the bonnet. (You may be able to mount the regulator in the cabin, but expect the system to behave slightly differently with the extra air volume contained in the longer hoses.) Because in the Audi the only free location was near to the turbo, I added to the mounting bracket a polished stainless steel heat shield and a layer of high temperature ceramic fibre insulation to protect the components. Note that the Norgren valves are rated to 65 degrees C, while the Metal Work reg is rated at only 50 degrees C (but that's when running max pressure of 145 psi!). Either way, you should take care to heat shield the valves or mount them on the cool side of the engine bay.
I also insulated the boost control hoses, using Pyrotek Pyrojacket sleeving, which comprises a layer of high-grade silicon rubber over knitted glass sleeving. This stuff is so good that you can place some of the sleeving over a finger - and then for a minute or so, aim a heat gun set on 'high' straight at the insulation. Oh yeah, and not burn your finger.... The sleeving is available in a number of internal diameters, with PJ8 (12mm ID) being a tight fit on the 5/16 rubber fuel hose used in this application. However, at A$28 a metre, the insulating material is quite expensive. Besides hose durability, another reason that I fitted the sleeving is because I suspected that the heating of the air in the hoses was giving variable boost behaviour in some situations.
On-Road Performance

As can be seen by this second gear acceleration graph, the wastegate anti-creep setting that I finally chose provides more of a boost rush than the standard electronic system, but not as much as it's actually possible to get. (Note that this full throttle graph is a little deceptive, in that it is the part-throttle boost behaviour that is changed by the greatest amount when adjusting the anti-wastegate creep pressure relief valve.)
The chosen setting allows good drivability, without boost suddenly booming in at half throttle. In fact, to get positive boost in normal driving, it still takes a deliberate attempt to put your foot down a bit further than normal. However, the way in which the torque then increases is very satisfying indeed - at part throttle the car feels so much stronger and more driveable than in standard form. An example - when cornered very hard, the Audi can be made to four-wheel drift a little on the corner exit. With the boost control set to give this very throttle-sensitive extra mid-range torque, the car can be cornered in second gear with both the front and back progressively sliding - without having to nail the pedal to the floor to get full boost and while still retaining good throttle control.
Conclusion

The final system gives excellent control over the rate of boost increase as well as over maximum boost. Boost increases after gear changes are always quick, and the rate of boost increase in each gear is consistent. Finally, all the parts are readily available (and are cheap) and installation is straightforward.

XRTypeRS

Good to see this topic is still alive!!

Dave on the Auto speed article it says if you use the 2 Norgren valves you need a weaker spring for one of them. Did you manage to find somewhere that does the 10 PSI spring?, I looked all over the net but could not find any reference to it so I havent bothered progressing with this yet.

Cheers,

Stu

Dave Henshall

dont think it was a 10psi spring, the one in RS components gives an output of 0.3 to 7 Bar (4psi to 100spi roughly), thats the one is use.

space hoppers

Eboost controller lot of cash can tell all the madettes on this topic .got greedy b spec controller myself same as simon norris uses told it can run high boost (simon from secs can verify)

RANJ

this had probs when rods was on the dyno me thinks

Dave Henshall

how you doin with your controller rik? got it fitted yet?

leecavturbo

just get one of these apexi jobs avc-r
you set it to what ever you want and where you want , you can have what ever boost you want at the revs you want it ,or self learn feature learns the curve of your turbo coming on boost or boost dependant on revs/speed/gear

rs shawn

Just to add..was gonna post bout Dawes Devices..then saw that Dave had posted about them. A friend had one of those fitted on his old Scooby & worked very well. You can import tem direct from the manufacturers: info here: www.dawesdevices.com/UK.html