Jaycar Boost and Fuel Control

[33driver]

yeah i gurss that makes sense, i guess my question is, how are you setting that 10psi, is that via the 70-80% on the input? so say 70% may equal 15psi but then 80% may be 20psi? (In theory not actual figures).

The boost just runs away if it wants to, I thought the vent was for setting you min. boost not max? The max boost is set via the boost controller which I belive is what the percentages mean. Correct me if i'm wrong. I like your idea about the needle valve though, might invest in that.

matt

[KiwiRS4T]

yeah i gurss that makes sense, i guess my question is, how are you setting that 10psi, is that via the 70-80% on the input? so say 70% may equal 15psi but then 80% may be 20psi? (In theory not actual figures).

The boost just runs away if it wants to, I thought the vent was for setting you min. boost not max? The max boost is set via the boost controller which I belive is what the percentages mean. Correct me if i'm wrong. I like your idea about the needle valve though, might invest in that.

matt

The vent affects the rate of building boost. If your boost solenoid is cycling at 100% some of the pressure is going out through the vent. At the same amount of boost being produced by the turbo if you make the vent smaller more pressure will go to the wastegate allowing more control of boost with less cycling.

I do all my setting of boost in 2nd gear (snow button on to stop kickdown into first) and with wide open throttle. I start at the bottom and watch the boost rise and increase the outputs at each stage to keep the boost (for example with a stock turbo) below 10 psi. This is why you need two people. Watch the boost guageand if it goes above 10 at any input stage increase the outputs at that stage. Later if the boost begins to fall away decrease the outputs to keep the boost up to 10. If you do this i 2nd gear this will happen very quickly so itis hard to read by yourself. If you do it in 3rd gear you will suddenly find yourself doing 180 and running out of road so best done in 2nd with another pair of eyes (unless you have a video camera trained on the boost guage and the handcontroller). I cold give you a map but it owuld not work for you becasue of different vent sizes and different intercooler flows and turbo out puts but typically the curve would go something like this ...but don't use this map it is just an illustration - you have to build your own one step at a time... (inputs first then outputs):

0=0

1=0

2=0

3=0

4=0

5=0

6=0

7=0

8=0

9=0

10=0

11=0

12=6 (less than 6 does nothing anyway)

13=10

14=16

15=24

16=32

17=42

18=54

19=64

20=66

21=68

22=68

23=68

24=68

25=68

26=68

27=68

28=68

29=68

30=66

31=66

32=66

33=66

34=66

35=66

36=66

37=66

38=65

39=65

40=64

41=63

42=62

43=61

44=60

45=58

46=56

47=54

48=52

49=50

50=47

51=43

52=38

53=31

54=23

53=14

54=6

55 onwards=0

[33driver]

hey mate,

thanks for clearing it up in my mind, it makes more sense now, I'm going to have to sit down and work out how to attack it now.

I thought it worth mentioning, i'm not driving a Stagea, R33 Series 2 is my ride.

I'll mess around with it this week and hopefully get somewhere with it, if not i'll look at a closed loop system

[BensDR30]

Well I finally finished building my DFA (I build the controller almost a year ago...).

Unfortunately, I'm getting the previously mentioned display fault (black boxes on the top row). I've double checked the circuit boards at home and at our electronics workshop at work (they've got better magnifying glasses), without finding any faults.

I've managed to calibrate the unit without the display, but now I'm stuck.

Does anyone in Adelaide have a hand-controller (or DFA) that I can compare/test against mine?

I might be able to convince my dad into buying one for his '33, but right now I don't have many more testing options available without getting access to another unit.

[KiwiRS4T]

Well I finally finished building my DFA (I build the controller almost a year ago...).

Unfortunately, I'm getting the previously mentioned display fault (black boxes on the top row). I've double checked the circuit boards at home and at our electronics workshop at work (they've got better magnifying glasses), without finding any faults.

I've managed to calibrate the unit without the display, but now I'm stuck.

Does anyone in Adelaide have a hand-controller (or DFA) that I can compare/test against mine?

I might be able to convince my dad into buying one for his '33, but right now I don't have many more testing options available without getting access to another unit.

I presume you have eliminated the two most common problems by

1. turn ing up the trimpot to near max

2. Getting the two ics the right way round (sorry, haven't got the reference material in front of me but can look it up if you can't tell which way they go) - they look similar but are programmed differently.

[BensDR30]

Yes, unfortunately(?) they have been eliminated.

The LCD trimpot responds ok - turn it up to max & it's a lovely row of blocks.

The DFA only has one PIC (running voltmod.hex). There are a number of other IC's all of which have been verified to be installed properly (and their function is critical for the calibration to occur).

[KiwiRS4T]

Yes, unfortunately(?) they have been eliminated.

The LCD trimpot responds ok - turn it up to max & it's a lovely row of blocks.

The DFA only has one PIC (running voltmod.hex). There are a number of other IC's all of which have been verified to be installed properly (and their function is critical for the calibration to occur).

I'd lend you mine but it would take a week to get there. last idea did you use the prescribed cable WC7502? Others have tried cables which fit the plugs but do not work.

[BensDR30]

I actually made my own cable, which tested ok, and has been subsequently replaced with the 7502 pre-manufactured model. Unfortunately no change...

I'm should be getting access to an IEBC & controller from another SAU member in Adelaide soon - this should narrow down the problem.

[Tommy Kaira RL]

Just wondering if anyone has tried this set up using the variable boost control that jaycar also sell which uses a trimpot to turn boost up and down. does anyone think it would be plumed the same as the IEBC one.

[KiwiRS4T]

Just wondering if anyone has tried this set up using the variable boost control that jaycar also sell which uses a trimpot to turn boost up and down. does anyone think it would be plumed the same as the IEBC one.

Not sure what you're talking about. Do you have a catalogue reference or name for this item? So far as I know there is only the IEBC (Independent Electronic Boost Controller). Maybe you are refering to the digital pulse adjuster which is operated by the same controller as the DFA and IEBC (not a trimpot). That can be used to reduce boost but is not a viable boost controller and does not come near the ability of the IEBC. It is only capable of varying a pulsed signal but has no ability to use the signal from the injectors to do so in any useful way.

[Tommy Kaira RL]

Not sure what you're talking about. Do you have a catalogue reference or name for this item? So far as I know there is only the IEBC (Independent Electronic Boost Controller). Maybe you are refering to the digital pulse adjuster which is operated by the same controller as the DFA and IEBC (not a trimpot). That can be used to reduce boost but is not a viable boost controller and does not come near the ability of the IEBC. It is only capable of varying a pulsed signal but has no ability to use the signal from the injectors to do so in any useful way.

The kit is KC 5438 and all it does is supposed to extend the duty cycle of the solenoid from opening which the time can be adjusted by the trimpot. I wanted to know if it still gets to the same boost level but just changes how fast or slow it gets there and would you need to plumb it the factory way or plumb the solenoid like the IEBC kit

[KiwiRS4T]

The kit is KC 5438 and all it does is supposed to extend the duty cycle of the solenoid from opening which the time can be adjusted by the trimpot. I wanted to know if it still gets to the same boost level but just changes how fast or slow it gets there and would you need to plumb it the factory way or plumb the solenoid like the IEBC kit

Just looked it up . Maybe a new release. You use the stock set up and just cut into the circuit to the solenoid (pin 104). It will alter the speed at which boost is reached but not the max boost. It is relatively cheap. However you can get the same effect and also alter (if you wish) the maximum boost by the (free) 10 minute reroute of the hoses ( I can give you refs, links if you don't already have them).

[Tommy Kaira RL]

Just looked it up . Maybe a new release. You use the stock set up and just cut into the circuit to the solenoid (pin 104). It will alter the speed at which boost is reached but not the max boost. It is relatively cheap. However you can get the same effect and also alter (if you wish) the maximum boost by the (free) 10 minute reroute of the hoses ( I can give you refs, links if you don't already have them).

Can you give us the link please I cant find it

[KiwiRS4T]

Can you give us the link please I cant find it

post no 40

http://www.skylinesaustralia.com/forums/Ja....html&st=20

[Jezboosted]

Hi all, just wanted to let you know of my setup with the IEBC on a SII RS4-S. With out this thread i would probably still be stuck, and it definitely helps to read the paperwork twice !

Had no problems (so i thought) building the kit, made sure i didn't install the couple of links, didn't forget the link under the d25 connector either ! Then after reading through here a bit, i found out about earthing the crystals as well. Mistake no.1. After connecting up the IEBC and having the maps set at 0% i found i couldn't boost past 7psi. WTF ? Then after looking at SK's photo's, I realised i had the vacuum lines still as per standard. WOOPS. Mistake No.2. test drive no.2. 7 psi boost max AGAIN. Read entire thread and realised i should have cut solenoid wire off ecu. Mistake No.3. test drive 3.HOLY CRAP boost and lots of it !! ok time to start setting a map.

It took me about 1 hour to get a decent map. I am getting 12psi at about 2600 rpm, and holding through till around 5800rpm (about 60% solenoid duty cycle) where it drops down to 10 psi which is about load point 45. From that point up to 64 i have it still at 100% duty cycle so I need to bring those numbers down now. I will finish mapping it tomorrow but WOW what an amazing unit. Very impressed with it's capabilities. Thanks once again to everyone in here that contributed info.

Heres a couple of pics showing engine bay vacuum lines, and interior ( for tuning purposes only ). Once I have finished configuring this map and then do the next map, I will disconnect the controller and tuck the IEBC away somewhere.

[KiwiRS4T]

Well done! As you have noticed the first thing that strikes you is the ability to build boost really quickly. As you taper off the solenoid duty cycle at the top end of the rev range down to zero again it will hold boost as long as the turbo will make it. Best tuned with a passenger (or driver) - it can get very exciting watching the numbers on the controller, the rev counter, the boost gauge, and the speedo without noticing that the road in front of you is disappearing at a rapid rate!

[BensDR30]

Tell me about it - I also had a laptop reading consult data in front of me, the dyno operator was monitoring the boost & AFR's and we were both having trouble concentrating on all the information being presented!

But it's a good little kit, that's for sure. I'll be building another 2 for my other cars in the near future.

[Jezboosted]

Well done! As you have noticed the first thing that strikes you is the ability to build boost really quickly. As you taper off the solenoid duty cycle at the top end of the rev range down to zero again it will hold boost as long as the turbo will make it. Best tuned with a passenger (or driver) - it can get very exciting watching the numbers on the controller, the rev counter, the boost gauge, and the speedo without noticing that the road in front of you is disappearing at a rapid rate!

Thanks ! Your not wrong about boost building quicker, especially noticeable in the taller gears. Had a bit more of a play and set up a second map with same boost level just different characteristics to learn more about how that changes the boost hit etc. I will post up a couple of graphs once i am done mapping. 2nd gear on "The Panorama" @ Tallai is a great place for load testing, the northern entry hill is fantastic. dead straight 14%+ hill for what seems to be 300 odd meters then starts getting curvy.

Edited May 10, 2009 by Jezboosted

[benro2]

It took me about 1 hour to get a decent map. I am getting 12psi at about 2600 rpm, and holding through till around 5800rpm (about 60% solenoid duty cycle) where it drops down to 10 psi which is about load point 45. From that point up to 64 i have it still at 100% duty cycle so I need to bring those numbers down now.

I too was considering doing a boost curve similar to this. I spoke to SK about this and he said that even though you're not running 12 psi at redline, there is no way to guarantee that you're not spinning the turbo too fast at middling revs. I suppose a reason for this could be that the very restrictive SMIC (on a Skyline, the Stageas are FMIC stock, right?) can start introducing an excessively high (3-5 psi) restriction above 10 psi @ engine, making your turbo work (and therefore, spin) very hard above 10 psi. Maybe something to be aware of? Or, you've calculated that it's OK?

Just wondering, how does it feel with boost tapering off? Does it make the engine feel a bit "dead" towards redline?

Also, have you noticed any reduction in fuel consumption, even when off-boost?

I really want to get my IEBC and DFA installed - I stuffed something on both kits and SK's still got them... so ATM I'm running on wastegate spring pressure (about 4.5 psi) and it's slooooow

[KiwiRS4T]

I too was considering doing a boost curve similar to this. I spoke to SK about this and he said that even though you're not running 12 psi at redline, there is no way to guarantee that you're not spinning the turbo too fast at middling revs. I suppose a reason for this could be that the very restrictive SMIC (on a Skyline, the Stageas are FMIC stock, right?) can start introducing an excessively high (3-5 psi) restriction above 10 psi @ engine, making your turbo work (and therefore, spin) very hard above 10 psi. Maybe something to be aware of? Or, you've calculated that it's OK?

Just wondering, how does it feel with boost tapering off? Does it make the engine feel a bit "dead" towards redline?

Also, have you noticed any reduction in fuel consumption, even when off-boost?

I really want to get my IEBC and DFA installed - I stuffed something on both kits and SK's still got them... so ATM I'm running on wastegate spring pressure (about 4.5 psi) and it's slooooow

Bleed off some more air for more boost. 10psi is considered safe but some people have run 12psi for years with no problem. Depends on if you're feeling lucky or are looking for an excuse for a highflow!