Jump to content
SAU Community

Recommended Posts

I was at the place where i get my car scerviced today and there was a kid there with his silvia on the dyno.

I got to talking to him as he was tuning his car and i was curious as to what he was doing.

He was doing a power run, looking at the AFR's and then putting a resistor between the AFM and the ECU!!!! he would do another power run and check the AFR's.

I informed him this would lean out the AFR's right accross the range and he looked at me like i was an idiot!! and said to me Look at the afr's man, its rich right accross the range, sure enough he was right!!!

He was upping the resistance value each run by 0.02 of a watt.

I saw the figures, before and after, and he went from 152rwkw to 164rwkw and his afrs were still below 12:1

He said by doing this he had illiminated boost cut, advanced the timing, and was using less fuel.

Not bad for 6cents for the resistor...

why is it stupid if done monitoring the AFR's?

it is doing the exact same thing as a safc except right accross the rev range. and providing you don't go too lean what the hell is wrong with it?

I think in the right application it is fine.

I mean, if worst comes to worst hes only going to blow up a CA or even better an SR. Good for him!

At least he is smart enough to test it, not just read something on the net saying use a xx resitor, it will help.

I wouldn't use a pot, apart from getting the right value, as there's vibration, moisture issues etc...

Once you have the right value, measure the resistance, then put in a fixed resistor - You don't want your afr's changing at every pothole, of it it rains :-D

yeah thats what i was thinking about a pot. as soon as you bump it you lean out.

CA's have feelings too! just because they are a bit "special"!!! there seems to be no love for the CA anymore:(

Its just as dodgy as bleed valve boost control. Plenty of people use that without concern.

Both too dodgy in my opinion, but those using bleed valves for boost or fuel cut defender are just as bad. He is loosing flow of electricity instead of air.

[qoute] Its just as dodgy as bleed valve boost control. Plenty of people use that without concern.

Both too dodgy in my opinion, but those using bleed valves for boost or fuel cut defender are just as bad. He is loosing flow of electricity instead of air. [qoute]

haha! that means I am a bad man... I have a turbotech bleed valve, I am a very bad man...

BMW's group A cars back in the 80's were tuned using the same method, it worked well for them.

Thats very interesting. I used to love those John Player Special little black BM's:)

Edited by CEF11E
Its just as dodgy as bleed valve boost control.

*sigh* i love these types of un-educated comments.

How can you even remotely say that?

I was running a bleeder of my gate upto 24psi... 7psi through the valve and a hold in the line for a bit more

It never spiked, never changed the level of boost, never gave a reason for me to think i'd wasted $10

Correctly done a bleeder can be of the same level as an EBC without the mammoth expense.

I'll point out what i see as an issue with this idea.

he is adjusting the AFM reading accross everything. It is not dependant on RPM / Load / Temp / Conditions.

Sure he is testing on the dyno I assume full power runs at full throttle.

I would say he could get that quite right.

I doubt he tested all rpm / load conditions at all temps.

If he leans it out with this method, everything is leaner !!

Things like close loop driving will be leaner. Light throtle leaner. Cold start leaner etc etc ....

Sure he can leave a "buffer" but as you can imagine it would not be an ideal way to do things.

Closed loop wont be leaner. It will adjust fueling based on 02 sensor output!!

It's dodgy but hey if you dont go too far it should be ok. I mean you wouldnt do it to an expensive engine..

for the cost of a jaycar DFA or SAFC you are smarter to do that...

ahhh, silvia owners. Got to love it.. where their wallet is as small as their brain..

you might want to take that back moron.. sure some silvia owners are stingy bastards but you gotta remember were not all like that

im also sure there are skyline owners just as stingy out there aswell

asswipe

Wazz

Edited by Wazz

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


  • Similar Content

  • Latest Posts

    • Ok i will get those 310mm. I found one but on a different site. This is the description on those...is it ok? Technical parameters: - Axle: front. - Disc type: ventilated. - Number of holes: 5. - Disc diameter: 310mm. - Total height with center: 54mm. - Thickness (new/min.): 30/28mm. - Designed for brake calipers manufacturer: Sumitomo.
    • You Gregged a whole racetrack!?
    • Look for broken wire or bad connector at the motor. Might not be it, but is worth starting there, as it is easy.
    • Hi everyone, I’m having an issue with my R32 GT-R. Sometimes, when the car goes over a bump or experiences some vibration, the 4WD warning light comes on the dashboard. When I check the code from the control unit in the trunk, it shows Code 19 – ETS Motor. However, everything seems to be working fine — if I turn off the engine and restart the car, the light goes away and everything functions normally. Has anyone experienced this before? Where should I start troubleshooting this issue? Thanks in advance!
    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
×
×
  • Create New...