Andy.F

There seems to be plenty choice here but how many of them actually operate with closed loop control ?
As far as I can make out, most of them just set duty cycles which can be tuned to particular RPM ranges.

Anyone know which EBC's actually look at the pressure via a pressure sensor and control to different pressures depending on RPM
?

Pavlo

a remapped jecs ecu

unless of course it came off a NA engine...

Andy.F

Sorry, forgot to include 'effective' in the request

Moles Dad

Andy, Please forgive the non tech...my HKS IV controller has a connection to the intake manifold (small vacuum)...I can hear the solonoid 'clicking' when the manifold pressure equals and the display goes from minus to plus (pos boost).

(I can see the answer now..)

Does that help at all?

Andy.F

Yes that sounds possibly closed loop, difficult to tell sometimes as the air pipe can be the supply for the solenoid supplying the wastegate. How does it connect to the wastegate ? Does it have different setpoints depending on RPM ?

Moles Dad

As far as I can remember...the (hks) solonoid has one hose going to the intake manifold, one to the actuator (removing the oe solonoid from the system) and one goes to the boost side of the ic hose...I think

It certainly doesnt get any throttle position feedback, only vacuum.
Also, it doesnt ALWAYS achieve 1.x, it depends on temps and humidity as per standard set up.
It has an 'off-set' mode to fine tune what the controller peaks and holds.
When you install and set up you have to 'teach' it the standard boost curve prior to inputting your 'upped' boost.

Any closer to an answer ?

(and I have learnt to spell solenoid )

[Edited by Moles Dad - 9/17/2002 9:54:57 PM]

Pavlo

Andy, what's ineffective about the Jecs with a 3 port solenoid?

I find it works well, but you have to map it properly, and it needs a sensible actuator too.

Paul

ustolemyname??stevieturbo

iTrader: (1)

I think the take off on most EBC's are purely for the digital boost readout. Not for a closed loop function. The new Blitz one ( cant remember the model ) does have closed loop, and I think that the Apexi one does too. Having said that the Blizt SBC, and DSBC, while being of open loop, do work very well.
Ive never used the HKS ones, but I assume they are pretty much the same.

Andy.F

MD - Well I thought I was till Steve replied

It's that bit of drift from warm to cold days or hot to very hot engine which I'd like to eliminate.

Paul - The problem with the JECS control is that if you change something, such as your desired boost level, you will need a remap not too practical.

I want something that I can set to, for example,1.2 bar at 3000 to avoid surge, 1.7 bar 4000 & 5000, tailing to 1.5 bar at 6000. This needs to happen the same in 3rd as it does in 5th, on a hot day or a cold day, on a track after 6 hard laps or on a drag run after sitting idling for 1/2 hour. Then turn it down to 0.5 bar for the other half to drive it home

If you tell me you can make the JECS do this.....I'll be down tomorrow

ustolemyname??stevieturbo

iTrader: (1)

I think both the Blitz SBC-id and the Apexi AVC-R also offer rpm/boost mapping

http://www.apexi-usa.com/electronics_savcr.asp
http://www.blitz-uk.co.uk/

They are however very expensive, and It may be better value to go for an uprated ecu ( as if you need one !! )
Not too sure how many of the ecu's do offer closed loop control, I had previously thought few of them did, but I am probably wrong on that.
I think Ian ( UKlegacyT ) has an Apexi, so maybe give him a shout. I think it may be what you are looking for.

I am using the Blitz SBC on mine, and while it does have a boost feed to the control box, there is NO boost display. It does however fluctuate very slightly depending on atmospheric conditions ( the weather ) Not by very much, but it does vary, although a simple **** sorts it out. ( Me ! )
Michaels legacy uses the Blitz DSBC, and while it too has a boost feed, and a boost display, it definately does not run closed loop, as the boost does still tail off slightly above 7000rpm. ( The turbo should easily be able to supply enough air to maintain a steady boost pressure throughout )
Both are however excellent products, although they do not allow you the adjust boost with rpm.


[Edited by ustolemyname??stevieturbo - 9/17/2002 11:42:05 PM]

Andy.F

Cheers Steve, I'll have a prowl around those sites

Was it yourself that bought a DTA Fast ECU ? How have you found it performs ? Does it have closed loop boost control ?

john banks

Pro Pro Pro The only two which have RPM based boost control are the Apexi AVC R and the HKS EVC Pro AFAIK. AVC-R uses a gear judge with a duty cycle offset, and boost targets. I thought the HKS EVC IV and Pro were supposed to have fuzzy logic and closed loop boost control. JECS will hunt out target and hold it pretty effectively if you give it enough duty cycle, but you end up with a peak at least in top gear even with a 3 port - if you want 1.7 bar will you be happy with a 1.85 bar peak? Most peaks alter their size depending on conditions, so again a bit out of control. I would look at the AVC-R for what you need at sensible money - the setup manual float around the web if you look in google.

[Edited by john banks - 9/18/2002 12:27:26 AM]

ustolemyname??stevieturbo

iTrader: (1)

The DTA P8Pro, is very good. It does have closed loop boost control, although I havent got it working yet. Too many other problems with the car. It certainly is quite easy to use, especially with the closed loop fuel control too, using AFR targets, controlled by lambda. It wouldnt fit straight onto a subaru though, as the crank signals etc wouldnt be suitable. You would need to make up a new crank wheel/trigger, along the lines of a 36-1 or 60-2 missing tooth setup. Shouldnt be too hard though. That would allow a non-sequential injection setup. A cam/phase sensor would also be required for sequential operation, although I think sequential doesnt really make much difference, being more emmissions friendly than anything. I do think a cam sensor is needed though for individual cylinder trims for ignition, but havent looked into it, as I am still using a Dizzy on mine.
You would also have to make up your own wiring loom, and probably add air/water temp sensors. Might be best to go for something like a GEMS that will plug straight in, and it certainly seems like an impressive bit of kit. Better value than the Motec anyway.

ustolemyname??stevieturbo

iTrader: (1)

APexi used to do a boost controller, which was only rpm based, via twiddly *****, like the old S-AFS, and S-ITC. I nearly bought one ages ago, but got scared at the price. SHould be loads cheaper now though. 5 ***** at different rpms, with an overall gain. Still open loop though, but easily adjustable, which is probably the best thing about all EBC's. Any ecu you get, wont be as easily adjustable from in car AFAIK.

NITO

I've been running an HKS EVC IV for ages and recently changed for the GEMS ecu. While the GEMS was very good, the boost control wasn't anything like as good as the HKS boost controller I've been used to but then it's relying on the crappy stock solenoid. At elvington half way through the day I reconnected the EVC as my boost was fluctuating all over the place somewhere between 1.1-1.5 going up the strip and you could feel the car surging back and forward with the power change!!

Running the GEMS with EVC has been excellent for me and is how I'll continue to run it. The ECU is mapped to 1.6bar (disclaimer: don't do this on a uk car) and being just a load of look-up tables I can choose to run the evc at whatever boost I want, and the ecu will supply the fuel and timing mapped to that level of boost accordingly. There is no comparison in the accuracy of an evc compared to the stock solenoid. Wherever I've set the boost I get less than o.3bar fluctuation and in very different weather I only have to trim the offset slightly to bring it back in line.

Now I'm running this way I still need to have another map done to the car as there's just a base initial map there at the moment and I need to fine tune it all, another thing I noticed is how there is much more torque lower down with the evc as it brings in the boost much fatter lower down.

At Elvington the 0-500m times improved immediately by a consistent 0.5second after re-connecting this and I was running it at slightly less boost, the top speed also went up by about 7 mph.

Running like this I've got all the adjustability of an ecu while the convenience of an evc to turn the boost up and down as I like without having to pull out a laptop each time, I get better boost control and all the other nice GEMS features like anti lag

Nito

David_Wallis

Andy,

Would imagine we could make it do that.. You could certainly go back to the std map, but there was talk of making two maps in 1 chip and switching between them..

David

Pavlo

Nito, why not run the HKS solenoid with the GEMS ecu?

NITO

Hi Pavlo,

I would have to splice the wires and wouldn't know which ones are which as there are loads of wires going to the evc solenoid and not just 2 like the std one. This aside, The in car control unit is what I love about the evc and it's this that I want as it's so easy to adjust boost on the fly. There are more benefits for me to run the evc using the gems to suit than running the gems with boost control. The only benefit by using gems to control boost is that its mappable to revs. However, what I want is boost to come in as early as possible and hold as long as possible. With the evc boost tails off as you get close to the redline anyway, about 6krpm plus it starts to tail off. So this does everything I want and I use the gems to provide the fuel and I/T to suit what the boost controller is doing rather than get the gems ecu to try and emulate this with less success! - if that makes sense.

Rgds
Nito

ustolemyname??stevieturbo

iTrader: (1)

They may be expensive, but the ebc'c are worth it. Ive tried a few pneumatic types of boost control, and non of them compare. As Nito says, the fact that they can be adjusted so easily and accurately from inside the car, can be a huge advantage for different conditions. If det was to occur, on a hot track day, then its a simple case of turning a **** to fix. I also agree that I want my car to get boost as quickly as possible, for as long as possible. Boost backing off at high rpms, really does make the car feel slow, especially when subaru engines love to rev.
Get one, you wont be dissapointed, apart from going way over budget..

Andy.F

Interesting stuff guys ......and bloody expensive

I've got an adjuster in car on my Dawes set up, gives a range of approx 5psi which is handy

Seems like you need to spend £300+ to get a good closed loop type, even more if you want RPM mapping I guess that's on hold for the time being then !!

I'll just work on a wider range adjuster for my pneumatic system in the short term

thanks

Andy

UkLegacyT

my apexi avc-r senses speed, revs, intake manifold pressure etc.

you can alter the boost at every 500rpm point, also alter duty, and has learn gear function to avoid overboost in higher gears.
also has scramble boost function with timer.

ian

Moles Dad

I think my HKS EVC IV was £460 ish last January

But then I just had to have one

(no shopping around or 'for sale')