repost: (sort-of!) auto-sequential
06-19-02, 04:49 AM
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repost: (sort-of!) auto-sequential
OK I got a few PM's after posting this so I'll start a separate thread:
Theory of operation:
Starting from low rpm, the CCV is closed and turbo control is off (primary mode)
As boost comes up on the primary the pressure engages the precontrol and starts 2 feed the secondary. Positive pressure feeds through the check valve to the pressure side to the CCV this makes sure it is closed. This pressurized air is PERMANENTLY held onto the CCV.
As the secondary starts to boost it puts pressure on the vacc side of the CCV which soon starts to match the pressure side - this causes the CCV to open.
The secondary also applies pressure to the turbo control actuator causing it to open - this properly engages the secondary and it boosts away.
Well I finally got around to doing this - end result: good smooth boost from 2250 rpm to 8000rpm
This system is far from perfect because when you change gear at high rpm the turbo control disengages, as you grab the next gear it has to engage again. The end result is that you loose boost on gear changes. It's actually pretty frustrating
because it's like driving my brother's skyline where you have to rebuild boost after every change....
I'm back to full seq (I hate NS) for the moment since everything is running great on my car. The moment things go to **** you can be sure I'll be back to finishing off this system (or going single
)
-pete
I've been thinking - is there a happy compromise?
What if you could rig up the secondary turbo to open it's own gate when it's ready. I was thinking like this:
Charge control
------------------
vacum side: connect to secondary 4mm nipple
pressure side: connect through checkvalve to y-pipe
***This should allow the secondary turbo to BEGIN opening the shutter valve as it starts to make positive pressure - a big failure of the NS system
Charge releif
----------------
remove - as soon as the 2ndary is making good boost I want it to start pumping anyway
Turbo control
----------------
vaccum side: vent to air
pressure side: connect to 2ndary outlet where the charge releif was connected
** as the secondary starts to make good boost it moves it's own turbo control thus engaging itself.
Wastegate
--------------
as-is
pre-control
--------------
y-pipe connector -> t-piece (one side venting to air) to pre-control acuator (leave pill in the line)
-pete
What if you could rig up the secondary turbo to open it's own gate when it's ready. I was thinking like this:
Charge control
------------------
vacum side: connect to secondary 4mm nipple
pressure side: connect through checkvalve to y-pipe
***This should allow the secondary turbo to BEGIN opening the shutter valve as it starts to make positive pressure - a big failure of the NS system
Charge releif
----------------
remove - as soon as the 2ndary is making good boost I want it to start pumping anyway
Turbo control
----------------
vaccum side: vent to air
pressure side: connect to 2ndary outlet where the charge releif was connected
** as the secondary starts to make good boost it moves it's own turbo control thus engaging itself.
Wastegate
--------------
as-is
pre-control
--------------
y-pipe connector -> t-piece (one side venting to air) to pre-control acuator (leave pill in the line)
-pete
Starting from low rpm, the CCV is closed and turbo control is off (primary mode)
As boost comes up on the primary the pressure engages the precontrol and starts 2 feed the secondary. Positive pressure feeds through the check valve to the pressure side to the CCV this makes sure it is closed. This pressurized air is PERMANENTLY held onto the CCV.
As the secondary starts to boost it puts pressure on the vacc side of the CCV which soon starts to match the pressure side - this causes the CCV to open.
The secondary also applies pressure to the turbo control actuator causing it to open - this properly engages the secondary and it boosts away.
Well I finally got around to doing this - end result: good smooth boost from 2250 rpm to 8000rpm
This system is far from perfect because when you change gear at high rpm the turbo control disengages, as you grab the next gear it has to engage again. The end result is that you loose boost on gear changes. It's actually pretty frustrating
because it's like driving my brother's skyline where you have to rebuild boost after every change....I'm back to full seq (I hate NS) for the moment since everything is running great on my car. The moment things go to **** you can be sure I'll be back to finishing off this system (or going single
)-pete
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