Dawes boost in 1-3rd gears
17 January 2003, 10:17 PM
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I believe the standard boost control limits boost in 1st, 2nd, 3rd gears to protect the box, and only allows full boost in 4th and 5th. Does this feature get overridden with the dawes, and if so does it increase the risk of eating up the box?
17 January 2003, 11:21 PM
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The ECU by design does not limit boost in lower gears. The boost control has no gear judge facility as standard although it has been added by Ecutek as an experimental facility to MY99/00 ECUs.
Using a decent solenoid and the right combination of duty cycle, turbo dynamics and boost targets, target boost can be achieved in gears 2-5 with a little more overboost in 5th gear. With the experimental system you can actually have more boost in lower gears if you want.
The Dawes is actually a proportional closed loop boost controller with a large dead zone (ie ball stays on seat and then progressively moves to reach equilibrium).
The factory system is a PI system, with the experimental process it becomes effectively full PID (ie the mutt's nuts
)
Presently I am running 1.4 bar in 1st gear (I estimate it is putting out about 300 lbft in 1st gear since the revs are quite high by the time it reaches 1.4 bar) and the box is OK, but I tend to use gears 2-5 which run 1.5 bar held. So far my box hasn't complained - neither has the factory clutch
Only a matter of time for the latter, and some would say the former.
In short, don't worry about your box in low gears if you treat it nice with a Dawes IMHO.
Using a decent solenoid and the right combination of duty cycle, turbo dynamics and boost targets, target boost can be achieved in gears 2-5 with a little more overboost in 5th gear. With the experimental system you can actually have more boost in lower gears if you want.
The Dawes is actually a proportional closed loop boost controller with a large dead zone (ie ball stays on seat and then progressively moves to reach equilibrium).
The factory system is a PI system, with the experimental process it becomes effectively full PID (ie the mutt's nuts
)Presently I am running 1.4 bar in 1st gear (I estimate it is putting out about 300 lbft in 1st gear since the revs are quite high by the time it reaches 1.4 bar) and the box is OK, but I tend to use gears 2-5 which run 1.5 bar held. So far my box hasn't complained - neither has the factory clutch
Only a matter of time for the latter, and some would say the former.In short, don't worry about your box in low gears if you treat it nice with a Dawes IMHO.
18 January 2003, 01:12 AM
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Cheers for the informative reply... it's been a while since I done any control stuff but I just about grasped the stuff about PID etc
Ideally I would have went for a remap cos I'd feel safer with ECU control but it's the old MY98 story so remap's outta the question. Dawes goes on once I get the boost gauge plumbed in, already got AFR and it runs rich as hell on boost so shouldn't be a problem there
While I'm at it is it worth fitting a knocklink with the factory sensor? Not too sure if I'm competent enough to add the new sensor myself, the thought of any work on that boxer engine gives me the shivers
Ideally I would have went for a remap cos I'd feel safer with ECU control but it's the old MY98 story so remap's outta the question. Dawes goes on once I get the boost gauge plumbed in, already got AFR and it runs rich as hell on boost so shouldn't be a problem there
While I'm at it is it worth fitting a knocklink with the factory sensor? Not too sure if I'm competent enough to add the new sensor myself, the thought of any work on that boxer engine gives me the shivers
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