EGTS Up Why?

[Bidja]

Pulled the dawes apart again today. Measured the spring, 18.75mm. Stretched it to about 24mm.

Put it back together. Wound in the needle valve right in, the actuator no longer bounces off the stop screw. Set the rod to just sit on the stop screw and wound out the dawes, about the thickness of the lock nut. Test drive gave me nice linear boost up to 16psi while accelerating up to 100kmh. Took up the same stretch of road and am now getting 14-15 psi at 100kmh with cruise on, up from 11psi.

Boost is peaking at around 16-17 psi which is where it should be if I understand correctly.

EGTs are under control, high 200s low 300s.

Going to keep an eye on it and chase up some springs to keep in the spare parts bag.

Thanks everyone for the help.

Yes needs a replacement spring as proven. As said earlier, contact Darren Dawes for replacement spring _ worth a try:

Darren Dawes had a replacement spring for the early Brass Dawes boost controller. Send him an email and he may send you one for elimination purposes (explain the boost situation briefly) _ info@3BarRacing.com

Not surprised that you have high cruise boost (14-15psi), vanes are most likely nearly closed all the time, yes lower EGTs at the expense of high exhaust manifold pressures and reduced air flow rate (grams/sec). Worth checking that the actuator lever is still just resting against stop after adjusting.


Also worth improving your air intake in time to let it breathe easier, this will bring cruise boost down as well. Aim for a nom 12psi cruise boost.

Do check your intercooler as it most likely does leaks.

Be interesting to hear how she goes with a serviceable boost controller. Room for improvement yet though.

[10G]

OK, a follow up, been a few weeks now.

Fitted an upgraded IC. Fits the same mount as the stock IC but is deeper.

Sits on 14-15 psi boost everywhere now. Very noticeable improvement in performance, best it's ever driven.

Brake pedal has come up as well, so vacuum must be in better shape than when I started.

Also noticed a reduction in lag between changing gears.

EGTs are under control, sits in the low to mid 300s when doing 100kmh.

The 2 things that made the biggest improvements were, 1 - stretching the spring in the Dawes, 2 - New IC.