this has been bothering me for a while now but if the dawe device is that much better than the soleniod for controlling the boost why did not the manufacturers use it? surely they are trying to build the damn thing as cheap as possible. if they did they would have researched and managed to find a way to make it work and would have saved JOHN BANKS alot of hassel

sam

 

It is not as nice to drive as the original ECU unless you bleed it also. Why do Subaru limit you to 14 PSI in the midrange and single figures at the top end? So they can sell you a PPP to put it up to 17 PSI? Limp home mode is disabled if you disconnect the solenoid. Perhaps there are problems if you use a Dawes at high altitude or very extreme environments.

It would cost Subaru no more to put a solenoid map in the ECU that drove like a PPP out of the box would it? And I think the MY01 especially needs that since it weighs more.

 

Anyway Sam, what else is there to do on dark cold winter nights than play around with a bit of amateur driveway tuning ? I can think of a few other things...

It's just that you do it with the proper kit and get better results, but the fun is all the same. It's been a good learning curve for me, and I have learned a lot from you and others through the process. What else is Scoobynet for if you can't throw a few whacky pseudo-technical ideas about and argue boost curves and circuit diagrams?

 

Sam, I've wondered about this, too. I think Subaru could probably come up with plenty of official regulations that excuse them from putting out standard cars like this, but what puzzles me is why it's not part of the PPP kit, nor does it seem to be on the menu offered by the UK's leading tuning companies.

I don't believe that they're simply trying to flog us a more expensive electronic boost controller, and that John is somewhere near the mark when he talks of varying performance in different conditions, possibly dangerous if you've already squeezed it to the limit.

And I also wonder about long-term reliability. How long will that spring retain it's tension, what about when the ball wears its seat or some dirt gets in there?

Any ideas?

Richard.

PS Edited to add that if you cost John Banks' time at commercial rates, his Dawes is the most expensive boost controller on the planet Maybe it is just that they're a pain to set up properly/reliably and might therefore cost more than an electronic device in real terms?

[Edited by Hoppy - 12/30/2001 9:13:38 PM]

 

Mine has had a load of oil in it from the piping and still worked fine.

It would be very easy for Prodrive to make an ECU that holds more boost at the top end and comes in more agressively low down. Just needs a change in the duty solenoid map - but they obviously chose not to and concentrated on a powerful safe midrange, and left the big (power limiting) taper at the top end. This is the main gain the Unichip and Link cars get over a PPP - hardly anything seems better in the midrange. Theo's Unichipped car (when he had the original turbo) with boost targets at RPM intervals was running very similar boost to mine - and I reckon would probably be similar in performance, but would only be quicker than a PPP car at the top end.

The alternative is buy a Link or get an EBC. MRT rally does a TMS1 which is very reasonable indeed although basic. I have thought about building an EBC as a means of learning how to program PICs as well as an end in itself. The parts would probably cost about £10 plus a suitable solenoid which might be the factory one replumbed. If I did this I would make it all open source. Literally the electronics would be a few pounds on a PIC chip which you can program using your PC and a few wires into your serial port. The programming is in assembler but need not be over complicated. Could do it in under 50 lines of code I reckon. You would take inputs from RPM, TPS and MAP, and output a duty cycle. It really is not that clever.

[Edited by john banks - 12/30/2001 9:27:33 PM]

 

"PS Edited to add that if you cost John Banks' time at commercial rates, his Dawes is the most expensive boost controller on the planet Maybe it is just that they're a pain to set up properly/reliably and might therefore cost more than an electronic device in real terms? "

It is all fun to me. Costs nothing. I enjoy it. A home made EBC would be very expensive also, but a lot of fun to make and design.

 

John, you're heading for divorce

 

She helped me solder some LEDs the other night. How romantic

 

i am not sure if it is the ECU that limits the boost or is the size of the turbo. i am very impressed by the dawe it seem to be making the turbo to spool up a lot quicker than standard or even than with a boost controller unless if off course you programme some over boost in.

i would not even trying the dawe, will it work with the boost soleniod at all ?

it is just the dawe seem to be such a primitive way to control the boost. i am sure manufacturers have tried at some point, maybe in the past ?

sam

 

We consider it primitive because we believe that electronic solutions are best. I never realised how much could be done with pneumatics.

The Dawes is a form of closed loop boost control, so using the solenoid would interfere with that unless the Dawes was set to a very low setting just to improve the initial bit of spool up.

I don't think the Dawes is a better method of boost control. I think the right solenoid duty cycle map in the ECU would be best. Obviously stretching my turbo that bit more will shorten its life a bit, but looking at the compressor maps at no point am I going way off the efficiency map.

The standard ECU is limiting boost across the range - even at the top end by opening the wastegate a little bit, I don't think you ever see the flow limits of even the TD04L on the standard or PPP ECUs.

[Edited by john banks - 12/30/2001 10:42:30 PM]

 

bloody hell you think you can make an electronic boost controller as a DIY job and you not calling this a big deal !!!!!!!!!!! just buy the damn thing and save yourselve the hassel.

i think one of the main reasons that i my engine stayed in one piece is even though it ran up to 1.35bar over boosting to 1.45 it never help anything above 1 bar over 6500rpm, actually the boost tappered down to 1.2 at 6000rpm. this way it is safer at the top end. have you ever heard of an impreza blow up at 3000rpm? most of them blow after a sustained revs/boost period. now if you can design me an EBC that will do that for a £10 i will give £100 for it

 

I only get 0.9 bar at 6500rpm - helps by having a small turbo - just keeps the wastegate shut at the top and it sorts it self out and by luck seems to be also what people would map their boost for.

 

John

I follow your posts in detail and it makes a very interesting read. On my EVO I'll fit the Turboxs HPBC which combines a bleed valve and ball/spring device. Over the big pond it's very common and used instead an EBC. My mates has it on his EVO and can reach 1.4bar already at 3500rpm with the Sports ECU and no boost spikes!
If you find the time to look into it let me know your opinion

\http://www.turboxs.com/ , it's the HPBC

Cheers

Mike

 

Blimey John, you have been busy!

Just read all the other Dawes threads, I have been away over the Xmas hols.....

Re the DIY boost controler, it's already been done! No details on the web site though!

http://www.force8.demon.co.uk/impreza/index.htm

Good to see you have positive results with the Dawes plus bleed, I'll give this a try when I get some time...


Harry


PS. Happy New Year to all.

 

john banks and I played around with the in hose boost restrictors yesterday(my standard ECU MY00,solenoid connected,no Dawes,before tests 15psi/14ish held) and although we could get higher peaks,held never moved from 14psi on gauge.we ended up just over 16.5psi peak(gauge under reads slightly)and the solenoid kicked in gently bringing boost to 13ish then back to 16ish,then down to 13 then 16,this happened until it held 14 and then pulled smoothly.

as I do not want to run over held 15psi on my gauge I wonder if I could use a Dawes and keep the solenoid connected.this will not work on john banks car or anyone wanting to run higher boost.I think that if everything stays below a true 17ish psi the solenoid should not pull the boost back,what do tou all think.

 

Mike the TXS is basically the same as a Dawes with an integral bleed valve. Has a good reputation on I-club.

Obviously you need to check all the safety aspects of running such boost levels, but more importantly the boost curve you will end up with as you go through the rev range. In setting mine up I have checked the best estimate of a compressor map for my turbo, checked my fuelling off the lambda sensor, tried it in different environmental conditions, checked ignition advance at different loads and engine speeds. Although a simple/cheap device, I would only be happy with it on my car if I had checked all these options, so effectively it does not work out quite so cheap. But if your friend has already done it you can scavenge a lot of his findings if he has looked into it

UK Scoobs are lucky in that with the late models at least the turbo seems to be able to flow just what you would want it to and the MAF sensor and RPM keep the fuelling OK.

Harry the boost controller site has always intrigued me but there are no circuit diagrams or code on it. Mine was going to be a bit simpler without different performance settings (fuel is cheap if you don't drive mega miles ), but have programmable boost depending on RPM, being scaled by TPS.

 

Hi John

thanks for your reply. You're absolutely right in stating that changing or upping the boost curve the ECU must be cappable of handling it regarding fueling, ignition etc. The "Sports ECU" from Ralliart is cappable of running this kind of boost (up to 1.5bar and around 340-350hp/310-320lbs, something similar to the Prodrive ECU) but the standard boost control via restrictors isn't capable of handling faster spool up (I've got a modified shorter air intake, exhaust etc) and high boost. On my car this resulted in fluctuating boost in the low-midrange and boost creep in higher gears which I found very annoying and unsatisfying.
My mate had very good results with the HPBC, using it on the road and track without any problems. To err on the side of caution he also made his own det cans, egt gauge etc to monitor everything and got it checked on a dyno.
As soon as I've installed the HPBC I'll get my car on the dyno to get all the relevant values checked. I'll even install a fuel pump which is able to flow more than the standard one.
I hope to achieve faster spool up and steady boost over the whole range by fitting the HPBC. Fitting the stuff and setting it up gives you more fun and more satisfaction and in the end you get to know your car better and how it works.

Cheers

Mike

 

Forget to add that the TD 05 used on the EVO VI RSII with the titanium compressor wheel is cappable to flow around 370-380hp and around 1.7-1.8bar boost before becoming inefficient so still enough for my current application. One of the main advantages of the EVO compared to the Scoob is the FMIC which helps reducing the charge temperature. Additionally we've got 98RON fuel of good quality everywhere available in Switzeland.

Cheers

Mike

 

Sounds like it will be a rocket ship.

 

very interesting
scoobymike
why do you say that the RA ecu is only mapped to 1.5 bar ? does it have fuel cut above that level ? the reason i am asking is that the sport ecu which is fitted to the extreme runs at 1.6 bar unless of course they are completely different ECUs?

my E7 boost up to 1.2bar as standard 18psi, but it does not seem to be controlling the boost well at the top end. so i think i may try one of these kits to start with.

the lambda link and knock link will be fitted in the next few weeks to see how things are going to start with before i decide which route i would want to go.

sam

 

ok Sam tell me what you are going to turn that E7 into a monster then!

David

[Edited by Davvers - 12/31/2001 4:45:57 PM]

 

John

I'm developping it step by step, in the current state of tune it's already quite devastating but as you know you get used to it very soon. Best investment still driver tuition

Sam

is it the Extr. VI or VII you're talking about? It's new to me that the Extreme boosts to 1.6bar. Considering the power and torque figures published I doubt it runs that high. My mate already reaches these figures with 1.35bar with his EBC and Sports ECU (340hp at 7180rpm and 420NM at 3780rpm, measured at 33deg. Celcius and atmospheric pressure at 968mbar). I know 1.5bar is quite the maximum you can run sustained also taking into account turbo-efficiency. The problem with the Sports ECU is more the zone between 2750-3250 when boost builds up. Here it can run quite lean. In other rpm areas is quite on the safe side. It doesn't have fuel cut!
My intention is to run it from around 3500rpm with 1.4bar boost held with no overboost/spikes to get a nice flat torque curve and better driveability. This is what I bought the HPBC for after getting the hint from my mate which uses it with good success. As I've got the Sports ECU for an excellent price (340quidd from Co-Ordsport Autumn sales) complimenting it with the HPBC will (at least I hope so) the results I've been looking for. Good torque low down and still enough topend grunt for track use combined with reliability without beginning to change internals, turbos etc.
Currently my car is stored but in March I should be able to sort everything engine related out (suspension and rear brake upgrade aswell). If there's some interest I'll happily keep you uptodate with my progress.

Cheers

Mike

 

Where's my brain?! Sam do you get the Lambda link from BRD? What's the cost of it?

Cheers and a happy new year to all

Mike

 

hi Davver
i hope you are feeling better. i got a ralliart car so i really have to go for a lot of stealth mods to keep the warranty. i have learnt my lesson after all the problems i had with my scoop as you know.

mike
i would love to know the progress of your car. so far my 7 is very standard apart form the cat pipe. the air filter is going on next very soon after that. well see ultimately i am looking for link/gems but the EVO LINK for the 7 is only a prototype just now.

340£ for sports ecu is an absolute bargin !!!!!! i would love to get one for that price.
when you say to runs lean between 2700-3200rpm on full boost what co% are you talking about here ?

i have been told by a ralliart dealer that seem to know a little about his EVOs that the VII extreme runs 1.6 bar which is higher than the EVO VI because the car is heavier as they wanted to give similar power to weight ratios. and the other thing to keep in mind the the EVO VII has got a slightly smaller turbine housing 9.8t compared to the VI 10.5t which means it will not probably flow as much air at the top end.

sam

 

mike


you have mail

 

Hi Sam

you've got e-mail too!

I've seen your post on the Lancer Forum. I don't post a lot there anymore as my Movit story upset some peeps.

The tuner (Swiss Rallyprep) who gave me the info only told me it runs around lambda 0.90-0.94 around 2750-3250^rpm depending on the exhaust. So far he had one customer who had problems after fitting a complete exhaust. So taking into account how many cars run Sports ECUs only in the UK it's quite marginal. My mate has lambda values of 0.9 at 3000 rpm dropping to 0.8 at around 4000 rpm and from then on it stays around 0.75. Boost with EVC IV was set at 1.35bar but he usually ups it. This was measured with a separate lambda probe drilled into the exhaust. He runs without cat but with standard downpipe. He only drives the car on track and did more than 100 laps with this setup on the Ring without the slightest problem. Before he had the same boost problems as I had. Clive, who gave me all the hints, runs his car with a Magnex downpipe, no cat and the HPBC and no problems. He runs 1.4bar at 3500rpm and 1.5bar held to the redline!!!!!
I'll have to check mine on the dyno to be safe or getting a lambda link which would be anyway a good idea.

Cheers

Mike

PS: Also fitted the ARP conrod bolts, not afraid now to rev it to 7500 rpm when necessary
PSS: Hope I don't spoil the Dawes discussion, sorry

 

hi scoobymike

these figures are a bit different from what i usually used to with the link. usually >0.9 is very rich, 0.88 is 8+%co (11:1) and 0.86 is around 6%co (12:1, 0.8 is 3% and 0.76% is 2 %co (13.8 roughly)

sam


[Edited by Sam Elassar - 12/31/2001 6:41:20 PM]

 

"The problem with the Sports ECU is more the zone between 2750-3250 when boost builds up. Here it can run quite lean. In other rpm areas is quite on the safe side. It doesn't have fuel cut!
My intention is to run it from around 3500rpm with 1.4bar boost held with no overboost/spikes to get a nice flat torque curve and better driveability."

I am not at all knowledgeable about Evos, BUT: please note that if you set an MBC to run 1.4bar it will keep the wastegate shut until that boost in reached no matter what the revs. Therefore your spool up between 2750 and 3250 will probably be substantially quicker - you will be making as much boost as your turbo can produce - so I am a little bit concerned about the leanness in this area as it could be worsened substantially. The other aspect of course is that your wastegate will shut again at the top end and you will hold 1.4bar as long as your turbo will produce it. This may or may not be too much. If you want to be able to set boost levels at different RPMs you need one of the more sophisticaed EBCs - the Apexi AVC-R is the only one I know for sure that does this, but there are others as well I believe.

 

Sam

what is your analysis of those lambda values? Lambda 1 is around 14.1:1 so doesn't it mean the lower the value the more fuel compared to air is burnt, the richer the mixture?

John

you're right what you say. My only concern with this setup is the boost build up area, in the other areas fueling and ignition for this kind of boost are sufficient. I run already this kind of boost from about 4500 rpm on. Especially above 6000rpm the ECU retards to be on the safe side. Evos run quite rich and don't run that much advance as the Scoobs. Ralliart obviously run even higher boost and they use apparently a different wastegate actuator from the 3000 GT to get better boost lowdown.

Mike

 

There are four ways of measuring lambda (air fuel ratio, voltage of lambda probe, % CO, or AFR divided by lambda 1 which is 14.7 for a petrol engine IIRC). Sam and I seem to work with the 2nd option, you are quoting the 4th. So lambda 0.9 is about 13:1, 0.84V or 5% CO.

I was also worried about lean running during spool up since I am spooling up so much earlier. Select monitor showed no excessive ignition retard all over, but during spool up at between 2000rpm and 2500rpm (by which time I get full boost) the car doesn't **really** shift for a few more hundred revs, and I don't see the richness I expect on full boost until it does pick up its skirt and fly. I can still get 50-70 (indicated 53-73) in 5th in 5.0 seconds with no bleed off the Dawes, but it feels sluggish - although that figure is virtually unmatched in the pages of Autocar. Never quite sure why, but all Scoobies seem to have a fair bit of boost before they rabbit punch you in the back.

http://www.mrtrally.com.au/performance/docs/WRX-V5.pdf page 24

This is what Sam and I seem to work with. Default Link ECU voltages for zones 29-31 are 0.83, 0.85, 0.87V. My lambda meter uses three LEDs at these points for 3-9 9-15 and 15+ PSI.

[Edited by john banks - 1/1/2002 10:20:27 AM]