BugEyed

John

OK, I can go with that. as you say, the system is fairly simple .

Duncan

PS get round to building and installing this so that we can follow you asap.

[Edited by BugEyed - 3/2/2002 10:19:45 PM]

john banks

See below

[Edited by john banks - 3/2/2002 11:21:30 PM]

Paul_H

This is an update to the original thread

http://www.scoobynet.co.uk/bbs/threa...threadid=69632

I had some correspondence with the designer of the fuel cut defender, Kostas G.D. Chryssos Ph.D - today I was stunned to receive a fully built up example, delivered by air mail from Greece! This is what it looks like:



It gets better He has also sent me over 40 high quality circuit boards, that just need the electronic components soldering in i.e. like the board on the right:



I have bench tested it tonight and it works a treat. Here is it working at atmospheric pressure (the yellow meter reads input to the FCD, the black meter reads the output):



Here it is defending:



And here it is providing a new (higher) fuel cut:



NB these are initial levels for my car only. You can't just copy the readings, you have to calibrate it for your own car.

So - I have a supply of these printed circuit boards available for distribution to Scoobynetters. Free!

Here's the deal: what I DON'T want to happen is everyone to ask for one, and for them to then sit unused in your garage or shed! I want them to go to people who know what they are and who will USE them. To build the board up will require a little electronics knowledge - if you've built John Banks's DIY AFR meter, or similar, then you can build this. You will need a small soldering iron (the board is very small), a couple of digital voltmeters to measure input & output of the FCD, and a boost gauge. You will need to calibrate the FCD i.e. to set the defend point, and to set a new fuel cut limit. If you think you can do this, then email your address to me and I will post you one. And it will cost: nothing! - actually no, if you get one please send an email to Kostas to thank him: sv1bt@compulink.gr

I will post a list of the parts needed to build the board up when I get time later in the week.

Here's the disclaimer: of course, you all know that this is a modification that has the potential for causing early engine failure. There is no warranty of any kind, or guarantee that it will work, of any kind. If you melt your pistons or burn out your ECU - tough! Use it at your own risk - if you blow anything up then it it's down to you!

I am stunned by the help and the generosity that Kostas has shown - what a great guy. Thanks from everyone at Scoobynet

john banks

Indeed a great guy. I suggest that if people get these working and use them on their car we do consider putting together a little thankyou fund and sending it - a bit like shareware? What do others think? The development and the manufacture of these boards is not done for free, and even if we all chipped in £10 if we use it it would be a nice gesture.

Count me in will email you and test it initially off the car. With my present turbo and ECU I actually don't need to raise fuel cut, but for those with a Dawes or other EBC on a standard ECU WHO KNOW WHAT THEY ARE DOING AND ARE NOT NUTCASES (!) it could be very useful.

I suggest you check before-after fuelling and ignition advance on your car if you fit this. I also suggest you very carefully bench test it first.

Can you advise what you have worked out with the offset problems so far Paul?


[Edited by john banks - 2/6/2002 10:21:08 PM]

Paul_H

John

I had done some work on R8 and revised the value from 2k ohms to 180 ohms, this sets the zener to 5.01V. Thats as far as I had got - the next step was to adjust R7 to adjust the gain so that output matched input.

I don't need to now - I've got a working example in front of me, which works much better than the example I built. I need to adjust the defend point & fuel cut a bit more precisely for my car, then I intend to use it on my car - something I wasn't happy about doing with the example I built (using erroneous values etc). It works well.

I will dig out my resistor colour table and make a list of the values that are on the board that is working properly, and post them.

I agree with your comments above, John. I do feel a need to send Kostas something by way of a thank you - money is one way, or a gift of some sort. Does anyone have any suggestions?

AndrewC

I think we can do better than £10, how about we give him his marbles back

A.

mutant_matt

Paul,

YHM m8

Matt

Paul_H

Circuit diagram & instructions here:

http://www.mr2.com/ARTICLE/FCD.html

Parts list here. Please check all stock numbers on RS website before ordering.

Part-------Description-------RS Stock no---Price each---Quantity

NMA1212D---DC/DC convertor--- 592-537 -------£7.23-----------1
LM358N-----Op amp------------ 428-149 -------£0.29-----------2
AD781JN----Sample & hold amplifier- 296-576 -£11.59----------1
4011-------Quad 2 I/P Nand gates-------------£0.19-----------2
(CD4011BE or equivalent)

Multi-turn cermet trimmer 10k ohms 10mm? top adjust, triple leg (not in line). Something like RS stock no 160-095 - check leg pattern will fit PCB before ordering. 2 required @ £1.33 each

10K ohm resistors, 1/8W (larger may not fit)---------5 required
2K ohm resistor, 1/8W (or substitute 180 ohm resistor), 1 required
- see threads and advice from Kostas. This is resistor R8 which is
immediately next to the zener diode.
Zener diode 5 volts 0.1W, 1 required
Hook up wire - 4 colours required
Small plastic box to hold PCB
1 small grommet
1 fuseholder

Suppliers
RS http://rswww.com
Maplin http://www.maplin.co.uk

And again: there are no warranties, no guarantees. Use it at your own risk. You must bench test it thoroughly and calibrate it before fitting to your car. Use with caution!

john banks

Hmmm, how do I put this - quite a costly parts list by electronics standards. I thought it would be a few quid, but by the time you are finished it looks more like £30. I would have been happy to test it otherwise. Maybe you need to try it Paul and tell us how good it is?

Paul_H

John

I intend to! and so nice of you to offer my car as a test bed

I've got another board nearly completed, so I will finish it and post it to you. It would be nice to have a second opinion. Then you can either post it back or send me the price of the bits if you want to keep it. How does that sound?

I've had another email from Kostas:

I am glad the boards will find a host.

Please post that the offer of the boards is FREE and there is no requirement for any compensation. I thank everybody on the net for their acceptance of my work and this is sufficient reward for me. No other compensation will be accepted. Again thanks to everybody.

I will soon have a page with my car put up on a site for everybody to see the various mods i have been doing over the last 10 years on this car, though not driven very often due to lack of free time.

Hope I can be of further assistance ... and by the way if y run out of boards, there are still some more left over to be disposed of.

Greetings to all....

Kostas Chryssos

T-uk

this could give you the edge at the next Star day john and I would be willing to go halfers on a select monitor check at AWD.

T-uk

thats why I am thinking of front mounts with standard ECU and turbo.I do not really want huge gearbox eating power,just a safe compromise

Paul_H

I found a problem with the FCD while testing, thanks to Kostas it is resolved by this amendment to the circuit: it only adds 2 resistors and one zener diode, but I think should be considered as essential



This provides protection for your ECU. I chose to incorporate it by adding a little board to hold the extra parts. Here is the finished article:



I have delayed posting out the boards while doing this. I will post them out on Monday. Today I fitted it to my car and have done one run - and I hit a fuel cut at just over 1.25 bar, so I think I will need to set the defend point to a lower voltage. I am assuming that it just needs adjusting, and that fuel cut is not generated by MAF output as well...can you confirm this John?

Anyway I'm knackered now and can't be arsed at the mo......I think a beer is in order...

John, I'm waiting for some bits from RS which I can collect Tuesday, so I will post a completed unit as pictured above first class on Wednesday, so you should have it for weekend. Please test it thoroughly and post the results.

Wanders off in search of beer.......

john banks

All looks sensible. Fuel cut is only based on a timer of a MAP value above a certain point AFAIK. 1.25bar is a bit high. I would defend from say 1.15 bar to 1.35 bar or 16.7 to 19.5PSI or thereabouts. This would be similar to PPP in terms of fuel cut. No point in going higher on TD04L turbo.

john banks

I can log the input and output voltages and post some graphs.

There seems to be little interest in these things at least from the number of posts on the threads? Or is everyone upset by the idea of a fuel cut defender which is actually a lifter? Are you scared of the electronics? Would people rather buy HKS FCD or not mess with fuel cut at all? Is everyone waiting for Paul and I to get it right? Will anyone want the board I will test once Paul has sent it me or will I be sending it back to him? (my PPP ECU already has a decent fuel cut but I am happy to help test this device thoroughly).

I for one would like to know if a MY00 on a MY99 ECU with a 19 PSI fuel cut running 18 PSI is as good on the rollers as a MY99/00 PPP with 18 PSI. T-uk you up for it? If not anyone else in SE Scotland with a MY99 ECU?

Any comments welcome.

mutant_matt

John,

I'm already on the list for a board but if I haven't finished it/got it installed by the time you've finished testing, you can send it to me

Ta,

Matt

T-uk

up for it if ckecked on the select monitor.

I would feel the most interesting test would be to get the same car and test it with MY99 ECU+lifter,MY00 ECU+lifter and PPP ECU, all set at 18psi and get the fuelling and ignition maps for each.I actually think that the MY00 ECU may be safer with higher boost.

my Knocklink and Lambda stuff has not arrived yet as it was damaged in transit

I have to admit that I would rather buy a fuel cut lifter than make one,for peace of mind.

john banks

Your method seems reasonable, but perhaps rather more involved. Trouble is, testing on the road causes problems - even on the same stretch even if using a timer attached to the tachometer because of slightly different levels of boost each run - on the RR you can get a boost plot and read off peak power at the wheels where it is not limited by the controller.

Dave Brown's car was safe for fuelling and timing on a MY99 ECU at over 18PSI. AFAIK MORE ignition advance will keep temperatures LOWER. There is plenty of fuel floating about on these cars not to be too concerned I think, but we can get Dave to check it on the select monitor anyway.

I'll bench test the Fuel Cut lifter first and we'll take it from there?

john banks

John - we could go halfers on a rolling road session at Star and use either car in three configurations? Before hand we could nip up to AWD and see Dave and check out the MY99 at 18 PSI for safety, and when we run on the rolling road could check fuelling too. Could set the FCD up and put it on a bypass switch.

PPP at 18 PSI
MY00 ECU at 18 PSI
MY99 ECU at 18 PSI

T-uk

Star are meant to be getting better top mount cooling,so I would rather wait for it before doing another r/r run.

john banks

Well by the time I have benchtested the board, Star are up and running and you have knock and lambda links it might all come together. If you have a Knocklink fitted your car might be the better victim?

T-uk

"victim",do not like the sounds of that

john banks

We can use my car if you would rather. Whatever I'm not having anything blow up.

You got this Dawes off Sam yet? He has the racy one installed.

[Edited by john banks - 2/10/2002 1:52:32 PM]

T-uk

getting it next weekend at K/hill if all goes to plan.

if everything is checked on the select monitor and the cooling is in place there should be no problems.with a 2psi higher cut the only difference between our ECU's might be a pink sticker and a far higher price tag .

john banks

I suspect so. K/hill next w/e = track day?

Paul_H

OK - I've adjusted the defend point downwards and done another run. It works - no fuel cut.

I have read postings that say that fuel cut on a MY99 is about 1.25 bar - but it is lower than this on my car - or my boost gauge (RaceTech) is inaccurate.

I had taken these measurements of MAP sensor output:

Bar -------------------------------MAP sensor output
(measured on boost gauge)-----------(measured on DVM)
0.9---------------------------------3.63V
1.0---------------------------------3.78V
1.1---------------------------------3.92V
1.2---------------------------------4.07V
1.3---------------------------------4.21V
1.4---------------------------------4.36V
1.5---------------------------------4.52V

So on the first run I set the FCD to defend at 3.99V i.e. about 1.15 bar on my boost gauge - but I got a fuel cut. So either my boost gauge is wrong, or fuel cut is about 1.15 Bar or less. My car holds 1.0 Bar as standard (as measured on my boost gauge) and has an AE800 ECU.

So I adjusted the defend point downwards, to save time messing around hooking up meters etc, I set the defend point at 3.65V i.e. just under 1.0 Bar as measured on my boost gauge.

I wound up my Dawes, and engaged my best safety device - my brain, which is connected to my right foot! I have no intention of running silly boost levels, I intend to limit boost to about 18 PSI, (same as a PPP?) - this was purely to prove whether it works or not. I have seen 1.3 Bar held on my boost gauge with no fuel cut. I did this only for a few seconds (definitely long enough to trigger fuel cut) to prove the point then backed off. I am aware of the consequences!

Before anyone asks, I do NOT intend to do a similar stunt to check that the new fuel cut works!!!!! I have seen the voltage rise on the FCD enough times to believe that it will.

I've now taken it off my car, and wound my Dawes back to a sensible level. Before I use it I am going to check that the car is fuelled correctly.

So I think this is good news - it works, for me at any rate. The design is open source by Kostas Chryssos, which means that you don't have to pay royalties etc to use it. Quite the opposite - Kostas is providing circuit boards for nothing. However it also means that there are no guarantees whatsoever that it is fit for purpose. It is a DIY job i.e. if you do it yourself, and it goes wrong, then you blame yourself and no-one else. If misapplied it could result in ECU damage or total engine failure. It's your decision.

If correctly applied it could be a very useful piece of kit

Only 5 people have asked for these boards, when the results of John's testing are posted there may be more interest?

Sam Elassar

john/john
i think it would be sensible to run it on the road with the select monitor hooked up to check ignition retard at these different boost levels if you are using a standard ecu. on motorway run will hardly show you what is happening. you need to drive the car in anger to get it to knock as on track or on the rollers. ideally you would want the select monitor on the rollers ?

you will find that after a certain boost you will start to knock on track regardless how much ingtion retard is been set by the ECU.


just a thought

john banks

Good result. Of course you could change the second potentiometer to narrow the defend zone to prove that fuel cut works?

PPP runs up to 17, but fuel cut is over 19. I run 18PSI on PPP ECU and it all checks out fine.

john banks

I don't think that boost level will be 18 PSI though Sam? Dave ran 25 PSI for a fair time without knock AFAIK and his turbo got dodgy before his engine. I would never go over 18-19 personally.

Maybe we should try and get Dave with the Select Monitor at the rollers then.

Paul_H

Good point - didn't think of that. I 've set the new fuel cut at 1.4 bar i.e. about 20 PSI to give 2 PSI safety margin if I run 18 PSI. I don't fancy a fuel cut whilst overtaking!

I could do this, but then I would have to recalibrate it back again.......just takes time... and I have spent a lot of that on this project already! And I have seen the output rise at 1.4 bar enough times....

Can I leave that to you? Will post the unit Wednesday..