Rb25det Power Fc Map/tune Discussion/development

[VB-]

im not a tuner but it seems like you have a fair bit of timing, not only in the cruise region but in the high load/revs area.

are you just using the PFC to monitor knock? your using a wideband to monitor A:F ratio? what gear have you been tuning in?

[frozenwaffles]

ok so i have checked alot of things. i now have my PLX wideband AFR setup installed (o2 sensor is in down pipe just before the cat)

fuel map seems to be more than fine...its just the default apexi map for the RB25.

i have strated again with the timing and will repost the timing up very soon...not going quite as hard as before. but event with the first post there was very little knock (all under 20)

[frozenwaffles]

ok so here are the new pages:

[VB-]

with the wanr settings:

injectors - is that 98% duty cycle?

AFM, doesnt the AFM top out before 5v?

[RPMGTR]

ok so i have checked alot of things. i now have my PLX wideband AFR setup installed (o2 sensor is in down pipe just before the cat)

fuel map seems to be more than fine...its just the default apexi map for the RB25.

i have strated again with the timing and will repost the timing up very soon...not going quite as hard as before. but event with the first post there was very little knock (all under 20)

You guys need to be very careful tuning using only the knock sensor. Although they are 'usually' quite good, we get many, many cars where they are asleep on the job.

We can often audibly hear knock way before the sensor picks up anything.

So best to double check before relying on the snsor alone.

cheers.

[zebra]

im not a tuner but it seems like you have a fair bit of timing, not only in the cruise region but in the high load/revs area.

are you just using the PFC to monitor knock? your using a wideband to monitor A:F ratio? what gear have you been tuning in?

I have a very similar map to that in the high load/RPM area...what the typical amount of advance used up there? Im thinking of pulling a cople of degrees out to make it 19-20deg total advance up there ( i have 8.7:1 comp instead of 9:1)

[Guilt-Toy]

Timing in the top end can vary from car to car. I have tuned a car that had 32deg of timing on 20psi of boost and i have tuned other cars that could not handle more then 10deg timing on 15psi of boost.

Timing on cruise. The reason why I like to run it a bit retarded is because after a long drive on the freeway say 20 mins, if i need to give it a blat to get around a truck or because someone made a mistake and i want to get out of the way, rah rah rah I dont want my cyl's to be cooked when i chuck in 25psi of boost into them....

A cool cyl is a happy cyl. You run them very hot, chuck alot of fuel into them.. what do you THINK your going to get??

If you dont know, i suggest uninstalling your fcedit software immediatly.

Sorry waffles i know everyone has to start somewhere, but looking at that map makes me cringe. I dont mind helping you get it in order though! dont get me wrong!

Does your wideband have pc software that gives you a dyno like graph read out ? mine does and if you set it up it can help you heaps when doing power tests.

Cheers

[frozenwaffles]

guilt toy... i would love you help!

my wideband goes straight into the datalogit (0-5V:10-20AFR)

i am only running 1bar of boost...and dont really wanna go higher...

as for how the cylinders reat to diferent temperatures well i dont know the exact science....but i will learn. and uninstalling the fcedit software is not how you learn.

if i blow up my engine i dont care....$1500 for a new one or less...whatever...i can hear rattle (as in i know what it sounds like) and i have made it rattle so i know where she absolute boundries are. i and will stay well away form them.

i dont want to just drive my car, i want to know 100% how it all work and whats going one...i'll learn about the science too along the way.

so if you have any book you suggest i read or anywhere to look then please suggest.

have you seen the new map i'm running...the new map has no more than max 9deg adv in the area of n03:p03 to n12:p12 over the default apexi map...everything else is the same...

i may have to pull a little timing out of the higher p rows such as 15 onwards...

[RPMGTR]

" I can hear rattle ( as in I know what it sounds like) and I have made it rattle so i know where she absolute boundries are. i and will stay well away form them."

Rattle is easy to hear. It's the insidious tick,tick that you/sensor can't easily hear that slowly eats away at the engine.

It sometimes shows up as an extra 10-15 on the knock count, but also sometimes it doesn't.

cheers

[Guilt-Toy]

I think you should call me and organise to come for a visit and we can spend a few hours driving around and tweaking if you like. Do you still have my number? PM me if you need it again.

Maybe a couple of hours on the dyno will help you learn a bit

But yeah I would look at reducing the timing on your cruise part of the map. It would be a good starting point.

guilt toy... i would love you help!

my wideband goes straight into the datalogit (0-5V:10-20AFR)

i am only running 1bar of boost...and dont really wanna go higher...

as for how the cylinders reat to diferent temperatures well i dont know the exact science....but i will learn. and uninstalling the fcedit software is not how you learn.

if i blow up my engine i dont care....$1500 for a new one or less...whatever...i can hear rattle (as in i know what it sounds like) and i have made it rattle so i know where she absolute boundries are. i and will stay well away form them.

i dont want to just drive my car, i want to know 100% how it all work and whats going one...i'll learn about the science too along the way.

so if you have any book you suggest i read or anywhere to look then please suggest.

have you seen the new map i'm running...the new map has no more than max 9deg adv in the area of n03:p03 to n12:p12 over the default apexi map...everything else is the same...

i may have to pull a little timing out of the higher p rows such as 15 onwards...

[180or200]

i have mine pretty close, maybe a few less degrees on light load, ignore the top end i'm running gt30 at 18-20 psi

[Guilt-Toy]

when you do a power run on your car, does it go all the way to the bottom line?

i have mine pretty close, maybe a few less degrees on light load, ignore the top end i'm running gt30 at 18-20 psi

[180or200]

when you do a power run on your car, does it go all the way to the bottom line?

17 psi might run to row 15, 20 psi its goes to row 16, on a cold night might flash a couple of cells on row 17,

with a vg30 afm highest voltage i see is 4.7 - 4.8

what you thinking?

[Guilt-Toy]

if i were you i would drop line 17 down to 11, then on 18 go down to 8 then on 19 go to 6 and on 20 go down to 4...

You never know when your car might overboost and yours will keep running 12deg all the way which will cause unnessesary detonation when you shouldnt ever be going there unless something is wrong...

I do this on my tunes as a habbit for being over carefull i guess..

Heaps and heaps of timing on cruise too! makes the car feel good on cruise i must admit.

[180or200]

yeh good idea, i'm pretty sure the fuel does add alot extra as it goes lower!

as for the light load i keep a good eye on the count, only ever see low 20's if i load it up in too high a gear, so it cant be too bad!

a possible gain there would be better fuel economy, i only played in that area to get back what putting a bigger exhaust housing lost in spool time and did it over a few tuning sessions so its hard to say yeh i can feel difference!

[Guilt-Toy]

you can still use ignition to make the turbo come on quicker, which does not effect the cruise on the freeway where you have the timing in high 40's.

your tune, up to you ...

post up the ign timing map once you fix up the bottom to lower timing if you can.

[Kinks]

Rattle is easy to hear. It's the insidious tick,tick that you/sensor can't easily hear that slowly eats away at the engine.

It sometimes shows up as an extra 10-15 on the knock count, but also sometimes it doesn't.

cheers

thats the bit that has me worried. my car is 100% standard and 7psi boost in the midrange makes it ping hard sometimes (other times it's perfect). makes me wonder if stock (4-5psi) is ok *bites fingernails*

(timing has been checked - mine landed with 18deg and i put it back to 15)

[Guilt-Toy]

bring it to me i will fix it.

Your timing in the mid range needs to be checked.

thats the bit that has me worried. my car is 100% standard and 7psi boost in the midrange makes it ping hard sometimes (other times it's perfect). makes me wonder if stock (4-5psi) is ok *bites fingernails*

(timing has been checked - mine landed with 18deg and i put it back to 15)

[gtst25]

Timing in the top end can vary from car to car. I have tuned a car that had 32deg of timing on 20psi of boost and i have tuned other cars that could not handle more then 10deg timing on 15psi of boost.

Are you talking total timing or what you're seeing on the PFC? The 32 degrees sounds like total but if you were running 10 degrees total hell I doubt you'd make any power! Sorry but that comparison doesn't make any sence!

Most people I know set their 'lines to 15 degrees base with a timing light before doing any tuning. If you want to it makes comparing ignition maps a lot easier. It's surprising how many so called gun tuners don't even know what the car's base timing is. All well and good but if someone changes the timing belt or whatever and sets the car to the norm 15 degrees where before it was 13 then that's not much chop. Ping...

At the moment at full load I'm running 15 degrees base + 18 on the laptop so 33 degrees total.

I'm interested in seeing what other guys are running at full noise with similar turbos.

Cheers

Edited May 5, 2008 by gtst25

[RPMGTR]

"At the moment at full load I'm running 15 degrees base + 18 on the laptop so 33 degrees total."

Um no.....

You are running 18 degrees at full load which is about ballpark correct.

15 degrees is what the PFC feeds the engine at warm idle.

This is from a idle map activated by the tps being below .5v

Once tps value is >.5v, which basically tells the ECU that we are now off idle, it reverts to the main ign map.

This is why you can change the values in the first 3 x 3 cells and get no change in the idle timing.

So if you correctly set your 'base' timing to 15 degs (also checking on the H/C that is what timing is being delivered), then you are ensuring that the values you use in the timing map IS what the engine receives.

Hope that helps.