Jaycar Boost and Fuel Control

[resonance]

Impressive power curve there grepin

What's that on? RB26/25?

[grepin]

Impressive power curve there grepin  

What's that on? RB26/25?

On a standard RB25 bottom end.

I have head work however.

[Sydneykid]

Yes that is right. I have actually measured the exhaust housing pressure to be around 40psi. I have what is quoted actuator of 20psi however what I do know is with the PFC set to less than 1.4 bar it cuts, indicating as you know it would be around that as a base value.

What confuses me is that by just putting compressed air into the housing against the spring pressure it wont lift off until it reaches 20psi. However in normal operation I can physically see the actuator lift off at around 5000rpm. I have provided a pic of the boost curve with the standard 1 bar HKS actuator. One thing i know is if I held the actuator closed it ramps up nice and hard. Must be something to do with the physics of the wastegate flap being quite large compared to most providing a large surface area. As you can see the turbo is still holding power with boost dropping off so is not running out of puff I guess.

Cheers

Hmmm, a bit of theory here...........

The exhaust back pressure, at 40 psi, is way higher than I would want. It is 20 psi higher than the boost. Normally I would expect to see 4 to 6 psi higher, 20 psi higher means a lot of restriction in the turbine.

MY guess is that the boost pressure is not opening the wastegate actuator prematurely. What is happening is the back pressure in the turbine is pushing the wastegate flap itself open. The 20 psi above boost acting on a large surface area wastegate flap is too much for the wastegate actuator spring to resist.

I would suggest a chat with your turbo supplier may help. Some relief in the turbine back pressuire should give big rewards, both in maintained boost levels and less restriction. So you may cure both problems, wastegate creep and tapering off boost at higher rpms.

[JD_R33]

Out of curiosity I picked up one of these kits and spent some time examining the components. The kit is a fairly straightforward design, and as has already been mentioned it should do a pretty good job of controlling boost once set up properly.

The problem that I have with it is this - what happens if something goes wrong with the controller unit and it stops producing an output signal? The components aren't exactly high grade, and all it would take is a failing resistor or even a dodgy solder joint and the normally closed solenoid would stay closed, thus allowing the boost to climb and climb.

I know this would be reflected on the boost gauge, but I must admit that I don't spend all my time watching the boost gauge especially when driving hard.

Maybe I'm missing something here, but I'll certainly be looking at other installation options - maybe making some changes to the ciruitry and using a normally open solenoid (although that has it's own problems) as a fail safe mechanism.

[benl1981]

Wont the car boost cut before anything dramatic happens???

[benl1981]

Or cut engine due to high airflow/??

[Oosh]

 

...

The problem that I have with it is this - what happens if something goes wrong with the controller unit and it stops producing an output signal?  The components aren't exactly high grade, and all it would take is a failing resistor or even a dodgy solder joint and the normally closed solenoid would stay closed, thus allowing the boost to climb and climb.

...

Maybe I'm missing something here, but I'll certainly be looking at other installation options - maybe making some changes to the ciruitry and using a normally open solenoid (although that has it's own problems) as a fail safe mechanism.

Yeap, i *had* similar concerns, but got over em. They're certainly valid ones though.

As for using the "Normally Open" types, it's already supported by the kit, you just need to swap a link/jumper around. The problem is you end up with significantly more solenoid wear so it's a toss up.

Wont the car boost cut before anything dramatic happens???

Or cut engine due to high airflow/??

Probably not, because these are the first things to go if you want to get the most out of the boost increase the IEBC is providing.

If you're running some big setup capable of huge boost i might be worried, but personally I just have a stock RB20 turbo atm, so my turbine wheel is likely to fly apart before ramming 20psi of superheated air down the engine's throat!

[Sydneykid]

Out of curiosity I picked up one of these kits and spent some time examining the components.  The kit is a fairly straightforward design, and as has already been mentioned it should do a pretty good job of controlling boost once set up properly.

The problem that I have with it is this - what happens if something goes wrong with the controller unit and it stops producing an output signal?  The components aren't exactly high grade, and all it would take is a failing resistor or even a dodgy solder joint and the normally closed solenoid would stay closed, thus allowing the boost to climb and climb.

I know this would be reflected on the boost gauge, but I must admit that I don't spend all my time watching the boost gauge especially when driving hard.

Maybe I'm missing something here, but I'll certainly be looking at other installation options - maybe making some changes to the ciruitry and using a normally open solenoid (although that has it's own problems) as a fail safe mechanism.

If you are using the IEBC with the standard ECU it will go "rich and retard" to protect the engine. Just as it would if the standard vacuum hose to the wastegate actuator leaked or was broken. If you are using it with a POWER FC then the excessive airflow and knock warnings would flash the engine check light on the dash. Depending on the model of Skyline, the PFC will also use the boost correction map to protect the engine.

Having tested it during the set up process on the Stagea, the standard ecu protection is quite savage, you wouldn't need to be looking at the boost gauge to know something was wrong.

[JD_R33]

Thanks SK, that's a relief. Just out of interest - how high could the boost go theoretically before the ECU did it's thing?

[Sydneykid]

Thanks SK, that's a relief.  Just out of interest - how high could the boost go theoretically before the ECU did it's thing?

High............I saw 2.5 bar.

Long...........a couple of milliseconds

Knock..........maybe 2 or 3 pings

Then............the ECU killed the fun, like a light switch

But..............I did it again, just to make sure

Again...........the ECU killed the fun, like a light switch

Show off......ho, ho, ho, a standard turbo makes 2.5 bar

Damage.......I pulled the plugs and there was ZERO signs of detonation

So................I didn't worry any more, the standard ECU will save me

[JD_R33]

High............I saw 2.5 bar.

Long...........a couple of milliseconds

Knock..........maybe 2 or 3 pings

Then............the ECU killed the fun, like a light switch

But..............I did it again, just to make sure

Again...........the ECU killed the fun, like a light switch

Show off......ho, ho, ho, a standard turbo makes 2.5 bar

Damage.......I pulled the plugs and there was ZERO signs of detonation

So................I didn't worry any more, the standard ECU will save me

So it was the Knock Sensor killing it?

[Sydneykid]

So it was the Knock Sensor killing it?

The primary load source, as always, is the AFM. The voltage goes straight to 5.1volts (max) and the ecu reacts very quickly.

There are two issus here, the max voltage is the first, this tells the ECU something is wrong, the AFM voltage is simply too high. But the Stagea ECU (remember it's a hybrid R33/R34 ECU) also seems to do little comparison between the rate of climb in AFM readings, the engine RPM and its rate of climb and maybe even throttle position and gear. This also tells the ECU there may be something wrong and we get rich and retard engine protection.

I found this second set of programming, when tuning the DFA, maybe have a read of that post as it goes into a little more detail on how to get around that problem.

[ecl]

hi

i'm looking into one of the ebc kits as i think it'll be fun to put it together and set it up into the car

just a question tho... does the handcontroller read boost? i dont have a boost gauge right but can i use the handcontroller to read the boost when i adjust it to the right level??

[Sydneykid]

hi

i'm looking into one of the ebc kits as i think it'll  be fun to put it together and set it up into the car

just a question tho... does the handcontroller read boost?  i dont have a boost gauge right but can i use the handcontroller to read the boost when i adjust it to the right level??

Nope, the Controller shows load points and correction factors. You will need a boost gauge, every turbo car should have one:cheers:

[Jay95R33]

There are two issus here, the max voltage is the first, this tells the ECU something is wrong, the AFM voltage is simply too high.  But the Stagea ECU (remember it's a hybrid R33/R34 ECU) also seems to do little comparison between the rate of climb in AFM readings, the engine RPM and its rate of climb and maybe even throttle position and gear.  This also tells the ECU there may be something wrong and we get rich and retard engine protection.

I found this second set of programming, when tuning the DFA, maybe have a read of that post as it goes into a little more detail on how to get around that problem.

Yep, the ECU on these things are very smart. We clamped the voltage on the AFM to 4.8 volts as a quick test and it still knew what was going on and started retarding the ignition timing.

J

[xRHETTx]

Got my r33 gtst boost solenoid in the mail today, all i need now is for funkymonkey to hurry up his group buy and im away.

Have many people installed IEBC's in r32 gtst's? I think i remember oosh saying he has? Where is a good spot to mount the solenoid? I got the bracket with it so that helps...

[Oosh]

Got my r33 gtst boost solenoid in the mail today, all i need now is for funkymonkey to hurry up his group buy and im away.

Have many people installed IEBC's in r32 gtst's? I think i remember oosh saying he has? Where is a good spot to mount the solenoid? I got the bracket with it so that helps...

I got the bracket too, but removed it, mine's just tucked in loose between power-steering reservoir and airbox, but then I haven't 100% finished installing it yet.

I'll do something a little better once i get a proper garage to work in (2 weeks), I want to take photo's of the whole install process, and write up a little something for the DIY section while I'm at it.

[Panikin]

The primary load source, as always, is the AFM.  The voltage goes straight to 5.1volts (max) and the ecu reacts very quickly.

There are two issus here, the max voltage is the first, this tells the ECU something is wrong, the AFM voltage is simply too high.  But the Stagea ECU (remember it's a hybrid R33/R34 ECU) also seems to do little comparison between the rate of climb in AFM readings, the engine RPM and its rate of climb and maybe even throttle position and gear.  This also tells the ECU there may be something wrong and we get rich and retard engine protection.

I found this second set of programming, when tuning the DFA, maybe have a read of that post as it goes into a little more detail on how to get around that problem.

Does the R33 have the same protection,i.e, rich and retard if I pull to much fuel with DFA?

Have no dyno around,I but have data scan. An LM-1 A/F meter coming. so reading air/fuel and engine stats is soon no problem.

[xRHETTx]

I got the bracket too, but removed it, mine's just tucked in loose between power-steering reservoir and airbox, but then I haven't 100% finished installing it yet.  

I'll do something a little better once i get a proper garage to work in (2 weeks), I want to take photo's of the whole install process, and write up a little something for the DIY section while I'm at it.

A tutorial would be a great help. Keep us informed.

Thanks,

Rhett

[Tommyk]

Has anyone tried jaycar's digital mixture display kit ?

For air/fuel ratios ?

I know it wouldnt be that accurate for tuning, but what do people think of it

http://www1.jaycar.com.au/productView.asp?...x=&SUBCATID=347