Wastegate Mod!?
Senior Member
Joined: 07-31-2007
Posts: 101
From: MI
The pcm can adjust fuel trim at idle, and at any place LESS than full throttle, but since the HHRSS does NOT have a wideband O2 sensor, you are going on a programmed fuel delivery curve under full throttle, which would definately be leaner if you turn up the boost with no other changes. The mass air sensor picks up some of the additional air flow, but isn't going to compensate completely. And the engine load calcs will eventually reduce boost to keep torque numbers within the range programmed. Beware of the "easy" fixes.
LNF turbo motor. Like all cars, it has pre and post O2 sensors and the pre sensor IS a wide band O2. Since fueling is so critical in a high boost motor,
it was critical to know a/f, thus they added a wide band sensor.
I have both a DashHawk and HPT interface and software and the DashHawk can read both the commanded airfuel ( what pcm wants) and the actual
delivered air fuel as measured by the wide band
turbofreak
Senior Member
Joined: 10-02-2005
Posts: 1,245
From: VA
What turbofreak said.... and...
The MAF sensor will report a proper air mass as long as the limitations (think it's about 910 g/sec if I recall) of the ECM tables are not exceeded.
Most GM calibrations tend to go "pig rich" due to COT parameters, which are very conservative to prevent excessively high temps and possible failure, which means that GM has to warranty the cat if it fails. The COT table on the E69 has some wild values that jump on top of the normal PE values on a hard pull.
Just got the latest beta build (dated 4/4) of HPT yesterday to deal with other issues on a boosted LE5 I'm working on and noticed no additional parameters on the LNF yet. Talked to them and we can't expect anything worthwhile in the soon to be released public version. Hopefully the next development round will give some love to the LNF.
It seems right now that BSR (European, with rumored Bosch insider connections) offers a good tune package, though it's expensive and a "canned" tune and Lyndon Wester has made some good progress. Hopefully HPT will get it more complete soon.
The MAF sensor will report a proper air mass as long as the limitations (think it's about 910 g/sec if I recall) of the ECM tables are not exceeded.
Most GM calibrations tend to go "pig rich" due to COT parameters, which are very conservative to prevent excessively high temps and possible failure, which means that GM has to warranty the cat if it fails. The COT table on the E69 has some wild values that jump on top of the normal PE values on a hard pull.
Just got the latest beta build (dated 4/4) of HPT yesterday to deal with other issues on a boosted LE5 I'm working on and noticed no additional parameters on the LNF yet. Talked to them and we can't expect anything worthwhile in the soon to be released public version. Hopefully the next development round will give some love to the LNF.
It seems right now that BSR (European, with rumored Bosch insider connections) offers a good tune package, though it's expensive and a "canned" tune and Lyndon Wester has made some good progress. Hopefully HPT will get it more complete soon.
Senior Member
Joined: 07-31-2007
Posts: 101
From: MI
Diagram of HHR SS and GXP Engine management
[
Most GM calibrations tend to go "pig rich" due to COT parameters, which are very conservative to prevent excessively high temps and possible failure, which means that GM has to warranty the cat if it fails. The COT table on the E69 has some wild values that jump on top of the normal PE values on a hard pull.
For those of you with a technical bent, here is a diagram from a SAE paper
on the turbo LNF motor showing the pre and post O2 sensors. Note, it
confirms the use of a wide band O2 sensor.
[IMG]
[/IMG]
turbofreak
Most GM calibrations tend to go "pig rich" due to COT parameters, which are very conservative to prevent excessively high temps and possible failure, which means that GM has to warranty the cat if it fails. The COT table on the E69 has some wild values that jump on top of the normal PE values on a hard pull.
For those of you with a technical bent, here is a diagram from a SAE paper
on the turbo LNF motor showing the pre and post O2 sensors. Note, it
confirms the use of a wide band O2 sensor.
[IMG]
[/IMG]turbofreak
Senior Member
Joined: 07-31-2007
Posts: 101
From: MI
Look back a couple pages. I did mod and reported on it. The pcm unlearns
some of mod but several weeks later , I still have the additional power and
boost.
turbofreak
PS: Monitoring the pcm with Dashhawk, I collected and plotted knock
data and do not have any knock associated with the mod. I use 93 octane.
some of mod but several weeks later , I still have the additional power and
boost.
turbofreak
PS: Monitoring the pcm with Dashhawk, I collected and plotted knock
data and do not have any knock associated with the mod. I use 93 octane.
Senior Member
Joined: 07-31-2007
Posts: 101
From: MI
It is fairly simple but very hard to twist your arm up in there and then I had to cut a 10 mm wrench to a short length to have room to twist it. I have a hoist which made it easier
Too bad it is taking HPT and Westers so long to get to the areas of the
program that allow boost change with pcm control and not have to resort to
a wg mod which is partially tuned out anyway.
I had a bad battery and slow crank. Dealer replaced and SS runs better and seeing 19 psi now and then.
regards,
turbofreak
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