ScoobyJawa

John,

We've crossed paths in a few other Dawes threads now!!
Wanted to run something past you if poss?

As you know myself and Scott W had the Dawes fitted b4 PE Rolling Road day and came away with 266bhp and 257torque. As I've previously mentioned this was running at just over 15Psi.

In one of the other threads I mentioned that still leaves us lots of leway(sp??) to the fuel cut and so could up the boost some more. You suggested to up it to the fuel cut and then back off a bit lol!!!

What I'm wondering is if we do up the boost from 15Psi to more like 16.5 what effect this would have on bhp/torque. Are we likely to see a rise in max bhp/torque or do you think it will remain similar and most of the increases therefore being seen in the midrange? Can anybody estimate what difference 1.5 Psi will make?

Also, if running around 16.5 does increase max power to something more like 270/275/280, is the standard ecu going to be able to cope with this? Thats STi power and the UK ecu was not designed for that power? Running 10% CO2 now which is nice and rich, is it likely to be rich enough to up the power more? Or should we leave it alone.........? Can we say that the Ecu will fuel fine up to the 1.25 bar fuel cut? (subjective I know and will change per car and the select monitor would be the only real way to know...)

Obviously, thats alot of Q's and you/anybody can only give your opinions on what you think, but I'd sure like to hear your thoughts on it

Cheers
Neil

john banks

I reckon it would be fine up to fuel cut hence my recommendation but to be sure you have to check every car.

You will probably not increase your peak power any more as it is flow limited. You will increase your peak torque by about 10lbft/PSI increase - that is a rule of thumb, and as you reach the limit it will be limited by retard and intake temperatures.

At PE 270-280bhp on a standard ECU has been seen with an EBC. An MBC should be no different. Boost is boost. I think that was Andy Tang's car and was running 1.18 to 1.22 bar.

Dave Brown runs 1.7bar in the midrange on std ECU with a Superchip and it hasn't blown up yet (had previously because of dodgy injectors). I understand he checks it regularly on the Select
Monitor. I think he must have ***** made of titanium Mind are probably a kind of mild alloy in comparison, but I stick below 1.25bar personally on a TD04L.


[Edited by john banks - 1/24/2002 11:31:18 AM]

ScoobyJawa

Thanks John, very useful info and much appreciated

@ the ***** though!!!

EvilBevel

I think he must have ***** made of titanium

Ah, the miracles doctors can do to damaged parts these days

OK, again time for a MY warning ... the MY99/00 can do wonders with the fuelling, provided the MAF is working OK. The ECU simply responds to the measured airflow by squirting in more fuel until you hit the limits of the injectors or the fuel pump (which ever comes first - not very likely with a TD04L and sensible boost, i.e. below 1.3 bar). The MAF on older cars can not measure the same flow though, and will max out earlier, so hence my weekly MY warning

ScoobyJawa

Thanks for that Evil

I'm running a MY99, which I didn't put in the original thread , so hopefully should be ok

Cheers
Neil.

Scott.T

iTrader: (2)

Evil,

Can you reiterate you MY warnings as I run an MY94 at about 14-15psi.
Although the AFR indicates good fueling at the moment as lights LED's 860mv, 880mv and 900mV at WOT.

john banks

Scott I would want to check your injector duty cycle. Select Monitor does it IIRC.

EvilBevel

Scott, if you are measuring things, then you don't need my unqualified comments.

If it measures OK, it will be OK. It was more meant like "at least I know for sure that on a MY99 you will have no problems, but as I have no experience whatsoever with other MY's, you may have to check for yourself"

I was honestly not tring to say "ooh, older car, you will have problems".

Hope I make myself clear somehow ... just trying to err on the safe side of things.

john banks

19 PSI held/peak in 5th today after actuator fiddle. I measured a 53-73 in 5th at 4.8 seconds. Unmodded was about 8.5. It is definitely quicker than before by some margin. There is now boost from 1700rpm. Everything measures OK. Fuel cut is about 1 PSI above that. Maybe my ***** will need to be titanium if I take it any higher but that would mean tampering with fuel cut which I have always said I wouldn't do. I am still 6 PSI behind Dave Brown. I wouldn't do this in the summer. Maybe I'll run about 18, but try and get it in every gear with the EBC.

Maybe I'll measure some intercooler temps and see where we are making good hairdriers. Cosie Convert had a very interesting thermocouple shoved in between the intercooler and the throttle body and it worked well. Maybe it is time for intercooler water spray. I could hook up a loop to my EBC and get it to squish it above a certain charge temp.

[Edited by john banks - 1/24/2002 6:00:46 PM]

Cosie Convert

John

Interesting as it is to monitor the charge temp, the thermocouple I have on my Exhaust up pipe is the most enlightning I think.
I have also just increased boost to 19 psi (from 17.5) and whilst charge temp only increased by 2 deg C my exhaust temp climbed by 40 degrees.
As a matter of interest, exhaust temp was stable at 670 deg C from 12psi through to 17.5 psi boost. This is the temp measured after an extended thrash up to 7000 rpm.
At 19 psi I now see 710 deg C.
I don't believe this is dangerous but it suggests I'm nearing the limit.
What I need to find out now is if this temp increase is
1 - Normal ?
2 - Due to the injectors maxing out or
3 - Ignition retard ?

Oh to have ALL the tools !!

cc (MY95 WRX RA TD05)

john banks

Where do you source your thermocouples? Are they K-type with metal wire for the high temps? Any suggestions where to tap it? I read on Autospeed it was best before the turbo. Where is yours again?

john banks

How about scoping your injector duty cycle? I can come and read the thing whilst you drive if I would be any use. I can usually find one end of a scope from the other

AWD motorsport in Perth have a select monitor - I guess they probably have the correct adaptors for your MY RA but you would need to check. That would tell you advance, duty cycle and lambda.

[Edited by john banks - 1/24/2002 8:09:05 PM]

Cosie Convert

Yes, they are K type. I'll check the catalogue at work tonight and post the part numbers (busy night shifts !!)
The stainless sheathed one in the exhaust is rated to 1200 deg C
I measure at the turbo inlet, there are differing views on where best to measure, No 3 supposedly being the weakest ?? although Bob Rawle does not share this view.
I considered that the collective temperature would also pick up any injector problems.
I think it's critical to get a fine wire thermocouple and ensure it is exposed directly to the gasses. A quick response is very important. On my set up, the display increases 50 degrees with a blip of the throttle and instantly settles again.

cc

Cosie Convert

May take you up on that offer this weekend. Mrs cc doesn't have the titanium parts required to co-pilot !

[Edited by Cosie Convert - 1/24/2002 8:27:14 PM]

Cosie Convert

The scope is dual channel. Would I be able to monitor timing advance/retard by viewing crank position sensor output signal relative to the ignition signal output from the ECU to the coils ?

john banks

Sounds like it is worth a go. New territory for me though. But I'm sure between us we could work it out. It may even inspire me to come up with a microcontroller program to show ignition advance on the fly. But then again, I could just get it from the serial port (select monitor). I will speak to Stephen Done on this. Do you have a laptop?

Scott.T

iTrader: (2)

John,

Why do I need to check my duty cycle ?

It was on the Select Monitor at PE running 14psi and all was fine ?

john banks

I forgot you had been on it at PE. Theo's comments about small injectors made me wonder.

Scott.T

iTrader: (2)

You had me worried there for a nanosecond.

I'm still NOT running the Dawes tho', as I find the Bleed Valve set-up I have very stable at 15psi. And u still keep some sort of ECU control with the Boost Control Solenoid still in circuit.

I think if you set the Bleed Valve at any less the Boost Control Solenoid works a bit harder and bleeds of some of the boost, hence giving the peak and constant boost situation.

I think my set-up is bleeding away quicker than the Boost Control Solenoid Maximum duty cycle and therefore becomes more stable.

P.S Also eliminated my hesitation problem.....cleaned the MAF with Brake Cleaner and a Cotton Bud...Big Thanks to Bob Rawle for that suggestion (I had tried cleaning it before, but didn't dare touch it with anything).

john banks

Are you going to put the Dawes back on?

I tried a bleed setup with and without the solenoid and it drives very smoothly either way, but you can get more boost if you take the solenoid out at least on late models otherwise the solenoid interferes.

Scott.T

iTrader: (2)

Nope, gonna try fitting it to a mates Volvo V40 T4 on Saturday. He needs some help to keep up :-)

Cosie Convert

The RS part No for the Exhaust thermocouple is 397-1236 £14.55 and the intercooler temp 363-0323 £ 4.00
I don't have a Laptop, just the portable dual trace oscilloscope.