Scott.T

iTrader: (2)

The standard UK map for a pre96 Impreza has approx 90%, dropping to 70% duty cycle between 0rpm and 2950rpm. Then runs preety level at 60%(ish) right accross the range (see below).


A Jun? Performance Map is very different. Appart from the initial 0% duty cycle, the low/mid end of the throttle/rev combination sits at about 40% - 50%, then rises to 60%+ after that to give the required peak boost setting (see below).


If I want to get better spool up is it best to have a low duty cycle until approx 7psi or a high duty cycle.

A low duty cycle will allow more boost to be seen at the actuator, so it will be creeping open and boost will bled away.

A high duty cycle will bleed boost away from the actuator, but boost will still be lost via the boost control solenoid.

Chris.Palmer

Scott,

The Boost Maps are also very different - could these be posted side by side - may help to explain what they are trying to achieve?

Chris

Scott.T

iTrader: (2)

UK95 Boost


Jun? Boost



Note : Pre96 PPP Duty Cycle is very similar to UK95

dowser

Does the Jun map include any hardware changes too (boost control/turbo)?

On the later cars a higher duty bleeds more air away from wastegate - but if you're too aggressive then the turbo spins up too fast to be controllable, overboost & fuel cut quickly follow

Richard

Scott.T

iTrader: (2)

Yep understand that...
I think the Jun? maps are set up to give you more a kick as the boost cut's in quite aggressively. Wheras the UK is more subtle.

This will give the impression of going faster, but won't actually be any quicker.

I'm going to change my MAP to give approx 90% duty upto approx 2,000 rpm then gradually drop it down as the revs build to max.

Pavlo

roll on eprom emulator...

Chris.Palmer

Kinda Like this?

Scott.T

iTrader: (2)

Chris...

Can you mail me those Values... it'll kinda save me a bit of time.
Might want tweeking down a bit between 3800 and 5500 tho'.

Cheers Mate...

[Edited by Scott.T - 8/22/2002 5:26:23 PM]

carlos_hiraoka

Can someone post any of the MY97-00 (TD 04 turbo) was solenoid duty cycle tables ?????

Thanx,

Carlos H.

Chris.Palmer

Scott,

YHM m8.

Understand your concern - however - a Dawes is even more extreme 100% then 80% ish.

Trout...

I wish the Link had 3-D mappable boost duty cycle.

You simply set target value and against a 2-D boost profile map.

Trout

john banks

Don't knock a 2d target boost system like your Link, David. It is much easier to map. I use a Dawes instead of JECS and am delighted with the boost control - esp the lower gears and in different conditions. Bob and now Dowser have three port solenoids and better results. I have swapped two JECS remapped cars to run Dawes now, and the performance is improved. Not right for everyone as you lose the ability to drop boost with uncontrollable knock/engine faults, but the Dawes gives the best boost control on the track of all the methods I have tried and the best overall performance. With a heck of a lot of fiddling and a three port I am sure the JECS can do well.

Trout...

John,

interestingly I was using a three port with the Link - and have now gone back to the two port - boost control is very good - but the spool up area could do with some encouragement

Trout

Pavlo

Early cars have 3 port solenoids, I have found the jecs to be fine as far as boost control goes.

Paul

john banks

Trout is that because your turbo is the size of Yorkshire?

Trout...

Maybe not Yorkshire...

...MidLothian?

You will have to come down to Yorkshire when I move up and you can see it - increases the car by about 300kgs.

Trout

dowser

Even with 3 port, is still a PITA to set-up (for me, anyways ) - but man, once it's right it is a wonderful thing

Richard