Max Afm Voltage Etc?

[benl1981]

My car is an R33 gtst with 9-10psi, r34 cooler and turbo back 3" exhaust.

Cruising last night and a hard run in 2nd (only to 5500rpm though) saw a peak on the PFC hand controller of 4.85v and injector duty cycle peak of 77%

Is this normal - I havent had it tuned yet so it is on the base map.

I thought 4.85v was pretty high (especially in 2nd gear not going to 7000rpm)!! injectors pretty low... I thought they would be near maxing out at close to 5v?

What do people think?

Thanks

[Sydneykid]

5.1 volts is max for AFM, plenty left. AFM voltage is not linear, in airflow terms 4.85 volts is not 95% of 5.1 volts. It is actually around 80%.

The 77% is a bit high, but will drop when it is tuned. They usually need leaning out a lot, so less injector duration required. Between 70% and 75% is common after tuning for your mods.

cheers

Edited October 10, 2005 by Sydneykid

[benl1981]

Thanks mate - very informative:) . Not reving it too much till I get the tune. Taken a couple of degrees out of the timing each time I start up on the powerfc as I saw 94 knock once but I dont know if the check engine showed..Is it only a quick flash??

Car does drive a lot better on the PFC even base map compared to std ecu. The std ecu is pretty weak as you ad mods

[Sydneykid]

Thanks mate - very informative:) .  Not reving it too much till I get the tune. Taken a couple of degrees out of the timing each time I start up on the powerfc as I saw 94 knock once but I dont know if the check engine showed..Is it only a quick flash??

Car does drive a lot better on the PFC even base map compared to std ecu. The std ecu is pretty weak as you ad mods

<{POST_SNAPBACK}>

The PFC warning light flash default for Knock is 60. But it takes more than one single knock level over 60 to flash the light. The 94 could have been a rogue one off. I haven't had any issues with the default PFC mapping with the standard turbo at 10 psi. Give it a try.

cheers

[benl1981]

Isn't it a bit risky to rev it out hard on the base map? Maybe it was a one off knock and thats why the check engine didnt flash. ..like you said

Is there any way to check if the "check engine" flash is working?

How much quicker do you think the car will feel after a tune? It feels a bit better now..compared to std ecu.

Cheers

Ben

Edited October 10, 2005 by benl1981

[justin911]

I just had my fc tuned a few weeks ago....

You will absolutely love it once its tuned

Its so much more responsive and heaps more fun to drive

Isn't it a bit risky to rev it out hard on the base map?  Maybe it was a one off knock and thats why the check engine didnt flash. ..like you said

Is there any way to check if the "check engine" flash is working?

How much quicker do you think the car will feel after a tune?  It feels a bit better now..compared to std ecu.

Cheers

Ben

<{POST_SNAPBACK}>

[benl1981]

Thats great! I've been waiting for the tuner to update the Datalogit software for almost 3 weeks(not his fault - it's the software company)! I'm Getting edgy now...

My powerfc was second hand but it's still so many version newer

Edited October 11, 2005 by benl1981

[RB power]

hi my afm voltage reaches 5.1 very frequently is this bad for the engine?

mine is also on the base map of the pfc...

how much power would one expect once its tunned?

[siksII]

mine needs a tune too. No idea on if it has been tuned, but it runs very rich and obviously not enough timing. I added 4 degrees last night with no sign on knock as usual so it must be way off. Maybe the base ingition timing has been pulled back(CAS)

[benl1981]

It was wierd - I thought I saw another 4.85v but this time it was lower like in the 65% range injector duty cycle.

Maybe I didnt read it off right.

Looking forward to the tune. On the base map knock doesnt seem to go above about 30 except for that freak 94. Is this normal for base map?

Anybody ewlse find the tune makesa heap of difference compared with base map?