Jump to content
SAU Community

Jaycar Boost and Fuel Control


Recommended Posts

if u have a look at the left hand side of the graph you will see it corrisponds to a number. that number is the ammount taken out at any spacific load point. and the number is what the DFA gives you as a correction value

eg at loadpoint 56 i am taking -6 out of the fuel map using the dfa.

If you look at the dyno graph i posted you will see exactly how much fuel it is taking out.

it went from 9.5 - 1 to 11.5 - 1.

no pinging as i tuned it properly on the dyno

Link to comment
Share on other sites

  • Replies 1k
  • Created
  • Last Reply

Top Posters In This Topic

Cef11E - It seems like you picked up about 8rwhp throughout the rev range...i..e about 7rwkw. Can you notice this very easily? I would have thought maybe you would pick up 10-15rwkw...

Still good mod if you save some fuel aswell...

Just wondering how much you could expect to gain on RB25det - I was thinking about 15rwkw..I know my car runs down into low 10 AFR at the higher revs at present...and thats at stock boost. I imagine a little lower as the boost is wound up

Link to comment
Share on other sites

Cef11E - It seems like you picked up about 8rwhp throughout the rev range...i..e about 7rwkw.  Can you notice this very easily?  I would have thought maybe you would pick up 10-15rwkw...

Still good mod if you save some fuel aswell...

Just wondering how much you could expect to gain on RB25det - I was thinking about 15rwkw..I know my car runs down into low 10 AFR at the higher revs at present...and thats at stock boost.  I imagine a little lower as the boost is wound up

No comparison between the Cefie ECU and yours, note the AFR ratios where not so bad, even at higher than standard boost. On the Stagea, when I turned the boost up to 9 psi, the A/F ratios were in the 9's. Plus it went R&R and that actually lowered the power, what I found;

1. Standard boost = 105 rwkw

2. 9 psi boost = ~80 rwkw (savage R&R kick in)

3. DFA tuned = 135 rwkw

It could be argued that the DFA added 55 rwkw. Or that the increase in boost from 6 psi to 9 psi AND the DFA added 30 rwkw. Both are correct.

;)

Link to comment
Share on other sites

wow, its that savage?!

i may look into tuning my DFA sooner then later(waiting on exhaust), i need to improve my fuel economy, i think im getting around the 18L/100 area with 9psi boost!

but damn does 10 feel faster then 7 though...

Will i need to remap the DFA if i want to drop or increase boost in the future. Also, when i get an exhaust its retune time right?

Link to comment
Share on other sites

wow, its that savage?!

i may look into tuning my DFA sooner then later(waiting on exhaust), i need to improve my fuel economy, i think im getting around the 18L/100 area with 9psi boost!

but damn does 10 feel faster then 7 though...

Will i need to remap the DFA if i want to drop or increase boost in the future. Also, when i get an exhaust its retune time right?

Oh yes, they guzzle gas at 9psi with no A/F ratio correction.

Boost is irrelevant, the only thing that matters is airflow and the AFM measures that. So when you apply correction to the AFM voltage it is at that airflow. An example, the same airflow at 6,000 rpm on 6psi as ~5,100 rpm at 9 psi.

Lower boost is never a problem, the AFM voltage is "corrected" for that rate of airflow. But higher boost may result in higher airflow than has been mapped.

I am about to upgrade the exhaust on ours, so I will post up what changes it needed via the DFA.

:D

Link to comment
Share on other sites

Yeah I'm definately getting a savage R&R in my R33 at around 10psi!!

Even at stock boost levels I can feel a the power fluctuate a little if the ambient is quite low.

The sooner I get a PFC or one of these the better.

Before I upgraded to the R34 intercooler I didnt have the savage R&R at 10psi, maybe the extra aiflow from the new cooler is a contributing factor. Doesn't appear to be any boost leaking and the new intercooler led to about a 0.5psi increase in boost everything else remaining constant.

I don't think the intercooler has helped with power at all. I'm hoping it will give me a few kws when I increase the boost to 10psi and turne with DFA or PFC...atleast it will be a little safer I guess.

I dont think a Front mount is needed for this on standard turbo, right?

I have a 3" full exhaust (compliance cat though)

On 10psi and tuned how much extra power could you expect from FMIC compared to R34 intercooler?

I don't want to loose the crisp thrttle response.

Link to comment
Share on other sites

Cef11E - It seems like you picked up about 8rwhp throughout the rev range...i..e about 7rwkw.  Can you notice this very easily?  I would have thought maybe you would pick up 10-15rwkw...

Still good mod if you save some fuel aswell...

Just wondering how much you could expect to gain on RB25det - I was thinking about 15rwkw..I know my car runs down into low 10 AFR at the higher revs at present...and thats at stock boost.  I imagine a little lower as the boost is wound up

yep what SK said except its a Gloria not a Cefiro. i used to have a cefiro insted.

you can feel the power difference, but its the responsiveness you notice most. the car is more nimble. as soon as you put your foot down, because the mixtures are better it takes less time before it starts to accellerate. :P

and as SK said earlier, the car has no intercooler so as i was tuning it and doing 3 or 4 power runs back to back it was suffering from heat soak. so it probably is 10kw better everywhere. I probably should have left it to cool down a bit to do a final run but i had run out of dyno time and i am not really that interested in a power figure. i really just wanted better fuel economy. If you wanted i am sure you could tune for more power. :uh-huh:

Link to comment
Share on other sites

How much better fuel economy could you expect?

Are those load points that you would see on the freeway etc? I guess it is all open loop that you tune for. Im wondering if you're light on the throttle most of the time would you see much of a fuel consumption gain from this mod?

Responsiveness is nice!

Link to comment
Share on other sites

hey do u hook up the injector input at the ecu ie the gate of the transistor or the output of the transistor ie the injector itself ...cheers in advanced :P
Just splice into the wire at the plug that goes in to the ECU.
Link to comment
Share on other sites

yeh checked all my wiring and circuit board ...checked resistors...checked diodes all good ....put 12v + across to input and led goes off ...im sure because on the r33 ecu ,the injector number 1 wire (which ive done a continuity test to the injector itself ) that goes to the gate ,hasnt got enuff grunt to trigger off the input ,as looking at the ignition drawing for the r33 it triggers a gate which then switches 12v across the power transister to the primary coil on the coil pack....which is 12 volts ...so will be supplying the input straight off the primary side of this coil 2 morrow to see if it works

Link to comment
Share on other sites

ahh well figured it out .....wrong ecu pin ...bloody number1 spark not injector ..for fks sake ...one lesson in this ..dont try and figure things out when your on call and had 9 hours sleep in 2 days ...its not a good mix

Link to comment
Share on other sites

Hi guys,

just had a quck query i just finished building my kit, but have one resistor left over.

Its a white block type one it says on the resistor 10w-10RJ

Does anyone know what its for?

cheers

hetz

Link to comment
Share on other sites

Hi guys,  

just had a quck query i just finished building my kit, but have one resistor left over.

Its a white block type one it says on the resistor 10w-10RJ

Does anyone know what its for?

cheers

hetz

yeh mine had the same ...cant for the life of me find where it goes

Link to comment
Share on other sites

Lol, cheers mate for the reply!  ;)  

All i need now is to go find me a cable to connect the controller to the main unit.

fingers crossed it works!

Hetz

yhe make sure u get the straight thru 1 ...no fancy crossovers

Link to comment
Share on other sites

you prob find 1 at your local pc place ...if not they could get 1 in easy as ...25 pin serial cables aint sommin u find everyday now because its all usb and firewire now ...i git 1 here from a local electronics place ....was bout 14 bucks for a 3 metre one

Link to comment
Share on other sites

yeh mine had the same ...cant for the life of me find where it goes

Most applications will not use the big resistor. You dont install it on the circuit board anyway.

CAnt remember where its used, ill look in the book tommorrow.

Link to comment
Share on other sites

yeh mine had the same ...cant for the life of me find where it goes

I assume this is the DFA - looking at the board there were two 10ohm resistors in the power supply section (bottom left hand corner of the board) - I assume you have both of them on the board?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



×
×
  • Create New...