john banks

It is MUCH warmer today (freezing when 17.5 PSI), now about 13 deg C and the boost is down by 0.5PSI, so just about seeing 17PSI. Oh well. Still quick though.

GavinP

But John is that a bad thing ?

Does the Dawes "automatically compensate" for higher ambient temperatures and backs the boost off a little.....

What a clever valve !

Thanks

Gavin

john banks

LOL. However, I will be adjusting it for the summer. Looks like a good idea to set it 0.5PSI below what you want for every 10 degrees above the likely minimum temperature you want it not to overboost at?

GavinP

Being serious for a minute, IF the change remains linear (and in my experience it is roughly) and the controller drops boost by 1.0psi by the time the ambient is at 26 degrees C, it could prove to be a useful safety measure.

The risk of detonation increases significantly with high intake temperatures so not a bad thing IMHO.

Thanks

Gavin

HarryBoy

Gavin,

That's a very valid point. So it's a good idea to set the device up when it's cold!

Also, I have noted that it's good practice to keep the hoses as short as possible, like John has done. I took the opportunity to take approx 3" out of the overall length and my boost peak has been reduced by what appears to be .5 PSI.

Harry

PeterPerfect

Fab pictures Harry !

I'm going to refer to them when fitting the Dawes Device on Saturday

Luke

HEEEEEEEEEEELP !!!

Justin
Cheers, your post sounds just want I needed,BUT I dont get the Photos.... How do you open the Little box with the red cross???

I realy want to see them.

john banks

Try clicking these links...

http://secret.lab6.com/uploaded_files/1007816503.jpg

http://secret.lab6.com/uploaded_files/1007817382.jpg

Have also emailed them to you.

[Edited by john banks - 12/8/2001 5:12:15 PM]

Luke

John

Cheers, I really wanted to see!! They make my life a lot easier,and I am sure others wanted them too.

If I do not adjust the "DD" can I fit it without the use of a boost gauge????


Again ,Thankyou


Luke

john banks

No. Out of the box it will be set for very low boost, even if you link it with the factory boost control solenoid still operating it will be suboptimal. If you link it directly you need to be able to see what it is doing in different temperature conditions. Cheapest boost gauges are under £40, but many under-read - mine by 1PSI.

Bscoop

I didn't get this on the group buy but I would like some input if poss.
Have followed the instructions with the help of the photo's, but I didn't get a good result.
When I initially fitted it, it gave as was expected 7psi,so started to screw it down to increase the boost.Started with two twists at a turn and then some more until the boost came up to about 12psi.
Now it is very nearly closed as much as possible and this surely can't be right.
The boost would normally peek at 17psi which is what it was mapped to run at with the Unichip.
To maintain this boost I added another restricter along with the existing one.I use a DCNF Weber carburetter jet (1.17mm).
Now I didn't put any restrictors in the tubings should I have done.

I am at a loss to understand what I am doing wrong.

Thanks

Tom

Bscoop

Sorry I left one bit of info off my car is a U.K 2000 Turbo

Tom

john banks

If you have reused the factory black hose off the turbo nipple (with the bend in the pipe) it has a restrictor which needs to be removed. Have you also disconnected the factory boost controller that plugs into the T-piece?

If you have done both of the above I would unscrew and reassemble the device to make sure nothing is jammed and also remove the locking nut to give you a bit higher boost - for these things see the Dawes instructions page under problems.

SPEN555

On Friday and Saturday I fitted my Dawes device.

I initially fitted it the same as Harry's photo and on driving the boost only showed 5PSi. I adjusted the device bit by bit and now get ~17Psi according to my boost gauge. Like Scoop though my device is almost fully closed.

On the Saturday I shortened the hoses so that the device runs under the large hose (coolant hose?) and now I have two very short lengths of hose either side of the device. Driving the car with this set up did not seem to produce any difference. I also noted that at WOT I get 17PSi at 3000rpm. Spool does not seem any quicker than the OEM piping, but I could not imagine it being quicker judging the speed of the boost needle on my gauge.

I have the Lambdalink fitted and both before fitting and after fitting the readings show the last LED being lit i.e. 9%+ CO.

To me the car does not feel any faster even though I have an additional 2PSi. I did a before and after 30-70mph test up a steep hill and got 7.04 secs followed by 6.88 secs. So going by the stopwatch the car is quicker.

I am slightly concerned with the nut which supposedly 'locks' the desired boost in place. Could this not over a period of time move?

Thanks to Harry and John giving the necessary advice to be able to do this.

I have a MY00 PPP ECU, Full S/S Exhaust, K&N 57i Induction Kit.

p.s. I am currently spraying up a bonnet scoop and making a channel to feed cold air to the K&N and so I may need to turn the Dawes device down when this is fitted.

Damian.

john banks

I am amazed that yours does not seem drastically quicker Damian. I have MY00 PPP with Magnex/Falkland DP, K&N 57i. I now see full boost of 17PSI at 2400 rpm cf. 2900 rpm before fitting. I am holding 14-15 PSI up to the red line compared with 11PSI before. Spool up and overall performance is much quicker - my 50-70 5th is now 5 seconds compared with 6 before and 8 when totally unmodded, 30-70 through the gears is definitely quicker, 60-80 in 4th is similar to before as the midrange boost is unchanged - ie see the main improvements in spool up and between 2000 and 2500rpm, and noticeable extra shove beyond 6000rpm.

john banks

I could always feel a huge difference and noise between 15 and 17PSI. It feels to me like a similar benefit that you get from a decat downpipe - ie 10-15bhp. Sure there may be extra ignition retard but the net effect still seems to be a big gain from the "butt dyno" as our American friends call it.

john banks

Tom, when I tried the Dawes with a restrictor valve after it boost was all over the place - ot overboosted and then held a low boost. For a ball spring valve to work correctly it needs to see the full boost pressure through minimal non-expansile hose, open briskly and dump air onto the wastegate diaphragm again through a minimal volume. The response seems to be corrupted and problematic if there are other valves or restrictions involved.

I can confirm that on my car, a restrictor valve was nowhere near as effective as the Dawes. When used with the factory boost controller I would get boost fluctuation problems at 17PSI or just slightly over, boost ramp was less steep and delayed by 400RPM, with poorly controlled peaks. Similar boost in midrange, but low and high end is a different world.

The difference on my car now is like adding the PPP or a decat exhaust again.

PeterPerfect

Works for me...I've now got the gains I was hoping for

Just spend the last few hours tuning the Dawes device.....
Feels really smooth and quick now

Thanks again to Luke for sorting out the group buy, and to all you guys for providing pictures/fitting instructions !

Ta Pete

HarryBoy

Damian,

I am really surprised you have not noticed a big difference. This is a stab in the dark but what fuel are you using?

Harry

Jay m A

iTrader: (2)

To look at Harry's pics, or indeed any secret labs pic, right click on the box with the red cross in it, select properties, copy the url and paste it into your IE address bar. then replace the 'secretlab.com' bit of the url with 195.89.1.219 and click go.

Job done!

Justin

bumcrack

Where is this device sold and is it safe?

john banks

http://www.dawesdevices.com

I think it is safe - I am seeing the same midrange boost I did before with better control. It will stress your turbo more as it holds more to the red line, but received wisdom seems to be to stick to 17PSI check the fuelling and you are OK with a boost controller. My fuel economy has gone up - perhaps I am using fewer revs most of the time? Certainly not running lean.

PeterPerfect

Should I be using Shell Optimax after upping the boost with the Dawes device ?

Anyone running with this fuel for safety reasons ?

P.

john banks

I'm not cos you can't get it in Scotland. Wouldn't do any harm. Also mean to do an ECU reset.

SPEN555

Harry,

I am running Optimax in my car. After a few runs to work this week I am starting to be convinced it is quicker but haven't really had chance yet to really nail it yet(damn traffic and fog).

When setting up the car I did not really get chance to enjoy the driving as I was busy juggling between watching the road, boost and A/F ratio.

I will have to get up early one morning and get a chance to drive it to be more conclusive.

John,

I would be very interested in your results if you do an ECU reset.

Damian.

SPEN555

Now that I am running the Dawes Device I was wondering what the purpose of the Boost Control Solenoid is/was? By its very name it will control boost but how and if this controls boost then why is there a restrictor in the piping?

Can someone educate me?

Damian.

john banks

The boost control solenoid is pulsed with a duty cycle from the ECU dependent on throttle position and revs and sometimes boost. If the pipe is blocked off the boost would rise more slowly and not go as high as the solenoid bleeds air away from the pipe supplying boost to the actuator diaphragm. The restrictor also reduces the pressure that the actuator sees. So the restrictor gets you near and the pulsed solenoid does the rest.

Of course if you run a map in the ECU you can make whatever boost curve the turbo is capable of. With a MBC, the turbo makes whatever it can until the ball moves and the air goes through and shuts the wastegate.

SPEN555

Cheers John.

Damian.