Dawes device and the ecu bug
 

Just ordered my dawes device and afr meter. Going on a my99 with full decat.

so i've got a few niggles which i need to iron out.

as i understand the standard boost is around 13.7, i see 12psi on my guage 90% of the time.

Is this guage inaccuracy or does it seem about right given that 13.7 is only a target?

From a previous post, i think John Banks said 15 psi is a sensible maximum. Does everyone agree?

What is the absolute maximum before fuel cut?


and the final question...


the ecu bug...the one where... quote from sidc faq...

There is also an apparent protection system built in to the ECU to prevent damage to the gearbox under hard acceleration in 2nd gear. When travelling at a constant speed for a period of time between 3,000 and 4,000 rpm(more than 5 seconds), pressing the accelerator can result in less than full boost being delivered until 5,000+ rpm is reached.

I've had this a few times, and although easy to correct while the car is standard, what happens when the ecu limits the boost and the dawes has control?

will it cause fueling problems etc.. or am i being paranoid.


Thanks in advance.

eddie.

When the dawes is fitted, the ecu no longer controls the boost, you do!! However, when I had one on mine I had it set to just a smidge over 1 bar, and all was well, I've now got a my99 ecu in my my00, and it's way better than it used to be, so much so that I've taken the dawes off!!! the boost seems to be higher now, and as the boost map is different I don't feel the dawes gives me enough extra to warrant having it!!


Fit the dawes and afr and enjoy!!
be aware though, that you need to fit it and get it adjusted in cold weather, cos cold air is denser than warm air!!

Standard boost is 11-12psi, not 13.7psi.

As long as you're monitoring for det (knocklink), 15psi will be easily achievable without too much risk. You'll probably be OK on the standard hoses as well.

As RON says, the Dawes bypasses the wastegate solenoid, so the ECU will have no way of controlling boost if things start to go pear-shaped. That's why it's imperative you keep an eye on what your engine's doing whilst you're "enjoying yourself". A boost gauge, preferably an AFR gauge, and definitely a knocklink.

It fuels fine during 2nd gear half boost when it then has a Dawes and runs full boost.

Thanks all,

Maybe i'll get a knocklink out the group buy.

The missus is gunna kill me.

eddie

The 2nd gear boost limit was installed to meet certain Japanese drive-by noise emission tests....wish they'd removed it on the Euro cars, it's a serious b*stard on some tracks :)

Richard

She'd be far more pissed off if you melted a piston... :)