Tuning Afrs

[DVS JEZ]

from what I've read to keep the pistons cool, the quicker than move about the more friction & heat it will cause right?

richening up the tune up the top will keep the pistons/rings/ring lands in tack but this sacrifices power output.

and from what toshi has said before and after cat, yes there is a difference, I've had my car on a dyno and the A/Fs were different to what my wideband was reading (pre cat).

Most tuners are save time/money by tuning at the exhaust tip, but I don't believe that's the best way to do it.

I personally have pumped in extra timing after MBT, for my old setup it was around 5600rpm, and the timing for row 17 read something like

Row vs Timing 10/13 11/13 12/13 14/13 15/14 16/14 17/15 18/11 19/11 20/11

did you heck this on a dyno to see if it made an improvement?

im puttin my car on the rollers tonight to see how my street tuning is going, ill try add some timing after MBT and will also richen it up slightly there too.

ill post my results later

[JonnoHR31]

I always ask for AFR 11.5 when I go to get a tune. It always comes out at 12.0 or higher. No idea why tuners insist on running leaner for a few percent power and end up with higher temps if you ever use it on the track or highway.

everyone has their different opinions. your workshop might think you've read something on the net and just because of that insist on 11.5. so they ignore you and go with what they think is best.

i'll be doing a little experimenting with afr's and timing when i get my car going. mainly gonna try using a little extra fuel in cells that occasionally knock, but not enough to drop a full degree of timing

[T04GTR]

(Well the aussies general rule is to tune rbs to a full load afr of 12 and then tweak ign timing to suit for max power where as the japs throw in a shit load of fuel eg 10.5-10.0(keeping in mind that their pump is 100+) and then throw in a shit load of timing on top of that..)

one might say your question is, do you want a sas tune or a crd tune. both very good but both very differant.

[Guilt-Toy]

what the main reason behind richening it up after what i assume is peak torque?

im guessing just to cool it down a little?

do you add more timing in during the enrichment after 6500RPM

this rb25 has a very big turbo and stock head. it does not make decent power untill around 6k. thats why its like that. to keep it cool when its on heat.

and from what toshi has said before and after cat, yes there is a difference, I've had my car on a dyno and the A/Fs were different to what my wideband was reading (pre cat).

Yes because your $300 wide band is just as good as the Autronic Wide Bands they use on Dyno's. That makes this test very accurate and relevant.

[Don Dada]

Had a look the other day at one of our "better" tuners on a stock turboed Rb26, 1bar and pfc

From the word go ie. low rpm coming into boost he set afrs to 10.8 to 10.9 all the to limiter...when asked why he said it makes more torque that way

Is it that he is just playing it safe or is he just plain lazy to tweak the timing from the off to on boost transition, from which i understand is a little tricky to get perfect in that area???

At the end of the day it made 360rwhp(dynojet), knock was no higher than 20 and this is on 95 ron

Guilt toy mentioned richen it up on top because of the shit fuel.....u guys would not have a problem as u run 98 but we here with our best being 95 i think the only other way to add some knock resistance it to richen it up a bit....we have an excuse....still not sure about the japs

I see if a can get the tune for u guys to have a look

Edited September 21, 2010 by Don Dada

[SS8_Gohan]

where are you exactly? as 95 in the US is the same as 98 in Oz

[KiwiRS4T]

Guilt toy mentioned richen it up on top because of the shit fuel.....u guys would not have a problem as u run 98 but we here with our best being 95 i think the only other way to add some knock resistance it to richen it up a bit....we have an excuse....still not sure about the japs

They did design and build the cars and have many very fast RB's!!!

[Don Dada]

where are you exactly? as 95 in the US is the same as 98 in Oz

Nah....not in the US

Our 95 is shit....although running it with the base pfc map at 11psi on the 26 still not produce more than 25-30 knock...Strange!?!

Edited September 22, 2010 by Don Dada

[SS8_Gohan]

maybe it is equiv to our 98

ours are labelled RON, US is labelled (RON+MON)/2 i believe.

RON is more of a controlled test rating, whereas MON is tested in more 'real world' conditions i guess you could say.

so what country are you in?

[Guilt-Toy]

where i am there is no liablility. so the guys working / own the fuel stations can chuck in 100 litres of water into the 98 octane tank to make some extra bucks blow up 200 cars and get away with it without having to pay a cent! if you asked for money they would just laugh at you.

I get soo paranoid that I listen to my engine with k-mon when i change fuel stations just in case they are doing the dodge.

[Rolls]

where i am there is no liablility. so the guys working / own the fuel stations can chuck in 100 litres of water into the 98 octane tank to make some extra bucks blow up 200 cars and get away with it without having to pay a cent! if you asked for money they would just laugh at you.

lol you do realise that they get randomly audited for things like that.

[MrStabby]

lol you do realise that they get randomly audited for things like that.

Not where Guilt is...Georgia, Eastern Europe.

[Rolls]

Not where Guilt is...Georgia, Eastern Europe.

LOL my bad, I'm surprised you don't end up with kerosene in your tank half the time!

[Guilt-Toy]

LOL my bad, I'm surprised you don't end up with kerosene in your tank half the time!

who knows what they put in there, but there is one fuel station that sells good fuel here, and it has a very very very strong smell.. even stronger then race fuels i have seen.. do not know what additives they are putting inside it.

[juggernaut1]

who knows what they put in there, but there is one fuel station that sells good fuel here, and it has a very very very strong smell.. even stronger then race fuels i have seen.. do not know what additives they are putting inside it.

Uranium?

[Don Dada]

maybe it is equiv to our 98

ours are labelled RON, US is labelled (RON+MON)/2 i believe.

RON is more of a controlled test rating, whereas MON is tested in more 'real world' conditions i guess you could say.

so what country are you in?

Yeh i know the difference.....Definitely 95 ron and i'm as far as u can go south on the Caribbean chain

We got some fast shit here too....stuff from Trial, Signal etc and some good local projects too....but they dont seem to last very long

[Guilt-Toy]

Uranium?

Please do not give me any ideas.... and this one is a BAD one

[STATUS]

Yeh i know the difference.....Definitely 95 ron and i'm as far as u can go south on the Caribbean chain

We got some fast shit here too....stuff from Trial, Signal etc and some good local projects too....but they dont seem to last very long

i seen a few import when i was in the carribean a few weeks back.

[XRATED]

i seen a few import when i was in the carribean a few weeks back.

I get soooo exited everytime I see a 'tuned' import in Sint'Maartin, BVI's, St Kitts, Barbados, Trinidad, Jamaica etc... even the Dominican Rep.

My 5000hp MTU's just don't cut it in a big ass superyacht!

Ah man I missssss my GTR!

[Don Dada]

I'll be more than happy to show u guys around if u come down here.....its really nice

and i'm sure we can even find time for quick tune too

I remember Hitman was down here a while back and tuned my mates 13b....best that car ever worked!!!