Need help settling a debate on another group. Guy says a simple waste
gate adjustment will give massive power improvements, as much as 40 HP
on a turbocharged engine. I say he is full of it and will gain nothing
unless he also adjusts the fuel delivery and timing.
Jerry
The OTHER Kevin in San Diego - 08 Oct 2004 18:53 GMT
>Need help settling a debate on another group. Guy says a simple waste
>gate adjustment will give massive power improvements, as much as 40 HP
>on a turbocharged engine. I say he is full of it and will gain nothing
>unless he also adjusts the fuel delivery and timing.
Common sense says more air requires more fuel. Adding boost will
effectively provide more air to the engine and without an increase in
fuel, the Fuel/Air ratio will be too lean. If it was as easy as
turning an adjustment screw, everyone would be driving 600hp
monsters..
Spdloader - 11 Oct 2004 03:34 GMT
Those Cummins guys are shimming their wastegates and getting very noticeable
gains.
I have seen that first hand.
Not enough to make me give up my SuperDuty, though.
Spdloader
> Need help settling a debate on another group. Guy says a simple waste
> gate adjustment will give massive power improvements, as much as 40 HP on
> a turbocharged engine. I say he is full of it and will gain nothing unless
> he also adjusts the fuel delivery and timing.
>
> Jerry
Jerry - 11 Oct 2004 06:22 GMT
> Those Cummins guys are shimming their wastegates and getting very noticeable
> gains.
> I have seen that first hand.
Shimming the waste gate???
Jerry
Spdloader - 11 Oct 2004 13:16 GMT
Yep, I don't know if it was shimmed shut, or shimmed open.
Your question prompted me to ask him today what exactly he did.
I'll get back on it when I talk to him.
Spdloader
>> Those Cummins guys are shimming their wastegates and getting very
>> noticeable gains.
[quoted text clipped - 3 lines]
>
> Jerry
lugnut - 11 Oct 2004 15:23 GMT
>Need help settling a debate on another group. Guy says a simple waste
>gate adjustment will give massive power improvements, as much as 40 HP
>on a turbocharged engine. I say he is full of it and will gain nothing
>unless he also adjusts the fuel delivery and timing.
>
>Jerry
You don't specify gas or Diesel. If it is gas, don't screw
with the waste gate. If it is a Diesel, the max turbo
pressure can be changed by manipulating the waste gate. The
waste gate is used to limit boost pressure for various
reasons including emissions. Another reason for the waste
gate is to use a large enough turbo to get strong boos off
the bottom end while limiting the boost as the engine speed
increases. Without a waste gate, the turbo is configured to
match the intended peak engine output and load. The more
induction pressure, the greater the power output. You
cannot have a lean condition in a Diesel if it is running
since the intake is not throttled anyway. Engine output and
speed are controlled by the fuel system. That does not mean
the engine cannot be overstressed or overheated with too
much boost. There is a limit to what it can handle.
Jerry - 11 Oct 2004 15:52 GMT
> You don't specify gas or Diesel. If it is gas, don't screw
> with the waste gate. If it is a Diesel, the max turbo
[quoted text clipped - 11 lines]
> the engine cannot be overstressed or overheated with too
> much boost. There is a limit to what it can handle.
The engine in question is a gas engine. I have a diesel myself and I
know on that if the waste gate is changed by installing a boost elbow
(fooler) of some type that fools the ECM into thinking the waste gate
signal is still below max then the boost can be increased but still the
fueling and timing must be changed to match the boost or all you are
going to do is produce more smoke and higher egt's. On a gas engine I
would suspect the same applies in some form but I don't know this for
sure. Now the person is claiming that on the Lightning a simple pulley
change can produce another 130 HP with no other changes needed. This
just doesn't seem right to me but as I said I'm not familiar with these.
Seems to me the manufacture of the Lightening would have set the ECM
to throw a code if boost over design were reached just as Dodge has set
the ECM to set a code and start defueling for the Cummins in addition to
set a code the service people will see if you break it. Makes sense to
me Ford would have something to protect their warranty limitations.
Jerry