Tuning Dawes setup

[Dr Gary]

I have my dual Dawes setup installed and running. A couple of issues I have to resolve
(1) When I manually run the high boost valve only, and REALLY punt it along, it pops (as it should) but I get a quite abrupt hesitation for a split second. Is this "normal??"
Comments please.

I am happy with performance and EGT as I have so far done minimal tuning. Just need the high boost to come in at a lower pedal position (TPS voltage) and that is a simple adjustment-a bit fiddly as it is trial and error until it is "right"

[mudski]

I have my dual Dawes setup installed and running. A couple of issues I have to resolve
(1) When I manually run the high boost valve only, and REALLY punt it along, it pops (as it should) but I get a quite abrupt hesitation for a split second. Is this "normal??"
Comments please.

I am happy with performance and EGT as I have so far done minimal tuning. Just need the high boost to come in at a lower pedal position (TPS voltage) and that is a simple adjustment-a bit fiddly as it is trial and error until it is "right"

When and where do you get this? Low revs, while the boost is about to rise, at full boost?

[Dr Gary]

When and where do you get this? Low revs, while the boost is about to rise, at full boost?

This occurs when the boost is at maximum boost, and the Dawes appears to "pop" at the set maximum pressure and drop the boost for less than a second.
Sounds logical but wonder if anyone else sees this.

[mudski]

This occurs when the boost is at maximum boost, and the Dawes appears to "pop" at the set maximum pressure and drop the boost for less than a second.
Sounds logical but wonder if anyone else sees this.

What rev range are we talking. Mine does this at around 4k, give or take a few hundred. Just reminds me to change gears. Lol.

[Rumcajs]

That sounds weird I have never experienced that but could it be just a boost bounce. Do you have HD spring the high boost Dawes valve?

Mine switches to "high boost" at 1.6V TPS or 21% TPS and drops out again at return to 13%TPS (hi/low hysteresis)

Cheers

[Dr Gary]

Thanks guys--sounds like all is standard. I have the "new" Dawes with ceramic balls, and higher tension springs.
It happens at "maximum" revs, whatever that is--probably around 4k. I think it is more to do with boost levels than revs.
My TPS was set at 1.6 on and 1.0 off, but I now have a "technical" issue--the switch quit working so I need to remedy that. Temporary fix is a manual switch.

[kyle86]

That was an awsome read thanks

[Dr Gary]

I have been talking with Darren Dawes, and he does not think the sudden pop is normal. He has suggested either contamination inside the valve, or the spring or ball binding inside the barrel. Given my low boost does not act this way, I suspect he is correct. Next steps: remove and clean inside valve, check for any binding, road test. More later.
BTW manual switch works fine IFF you remember what it is switched to