Turbo Boost Question

[rdodd]

After installing old smokies power pin my boost went from 23# to about 27#. My question is when i am cruising about 70 and nail the throttle the boost keeps climing to 27#, but when i get to about 85 with the throttle still nailed boost starts dropping a few pounds. Is this caused by the governer cutting back or could i have other problems?

 

[Case500D]

rdodd,



I think you hit the nail on the head. The engine is starting to defuel. My W-250 tops out at 86 and then the boost starts to fall off. Even shifting gears in the W-350, you can tell when it defuels because the boost and EGTs drop and it feels like the rubber band is maxed out You can increase the high idle speed to 3,000 rpm by making an adjustment on the high idle sccrew on the pump. Gets you a bit more rpms before the govenors shut it down. Hope this helps.



Jeremy

 

[rdodd]

I have increased high idle speed to 3000 rpm but it still feels like it starts defueling at about 2500 rpm.

 

[rdodd]

I might add that even though it starts defueling at about 2500 rpm the truck still keeps slowly climbing speed up to about 95 mph before it tops out.

 

[tugboatphil]

rdodd,



I can't see where you're living, but around here, that's plenty fast enough to get a ticket.

 

[Greenleaf]

"""You can increase the high idle speed to 3,000 rpm by making an adjustment on the high idle sccrew on the pump. Gets you a bit more rpms before the govenors shut it down. """



There is much more to be had than 3,000 rpm. However, the pump will still begin to defuel without the addition of a gov. spring.



Scott