blacken_rotary

i have a s5 t2
wit a bnr stage 1
rtek1.7


i have a aem wideband but dont know how to read them well or wat to look for


whats safe and whats not ?
what reading should i stay away from denotin my motor?

Idle: ?
Light to moderate load (out of boost): ?
Heavy Load (out of boost): ?
0 PSI - 6 PSI: ?
7 PSI - 10 PSI: ?
11 PSI - 15 PSI: ?
16 PSI - 25 PSI: ?

blacken_rotary

any help?

RotaryEvolution

iTrader: (30)

Idle: as high as you can get the AFR before the engine starts to hunt for idle
Light to moderate load (out of boost): as high as you can go before the engine starts to surge to maintain speed
Heavy Load (out of boost): see above
0 PSI - 6 PSI: 12.5:1 as conservative, sometimes i shoot for 13-13.5:1 to aid in spooling reaction speed.
7 PSI - 10 PSI: ? 11.5:1
11 PSI - 15 PSI: ? 10.5 -11:1
16 PSI - 25 PSI: ? why ask? your stage 1 won't make any more power in this range. you also need AI or race fuel to accomodate it.

blacken_rotary

i ask to have the knowledge of it

blacken_rotary

what ratio do i stay away from at

0 PSI - 6 PSI: ?
7 PSI - 10 PSI: ?
11 PSI - 15 PSI: ?

RotaryEvolution

iTrader: (30)

anything higher than the posted figures.

for moderate boost you can still be semi lean, for high boost you need to be in the sweet spot which is between 10 and 11 AFRs, anything much richer(lower number) will misfire, anything much leaner(higher number) will pop the motor.

blacken_rotary

See this is why I ask I was told by other member of rx7 club

That 12.5 and under I. Should be good at max boost of 10 psi

RotaryEvolution

iTrader: (30)

you might get away with it but it isn't a conservative figure. if the fuel system starts to get dirty and lean out the mixtures you have that much less room for error. i usually will start to richen things up a bit around 7psi, up to that the AFRs aren't all that critical.

arghx

iTrader: (3)

Karack has some good baseline figures. Here are some charts I put together in the Power FC software. Note that this is for pump fuel only. Idle and cruising areas will vary a little bit with each engine. These charts in the Power FC pressure/boost units "PIM" which are based on kg/cm^2 absolute pressure. So here is a unit conversion table for the pressure units:



Here's what I call "conservative"



Here is "moderate"



Here is "somewhat aggressive"





In the "conservative" chart, AFR gets richer as rpms increase and richer as boost increases. This mimics the kind of fuel maps you find on a stock ECU. In the "moderate" chart, AFR gets richer with boost increases but stays mostly steady as rpm increases. This is probably the most common strategy you will see tuners employ. In the "somewhat aggressive" chart, AFR is richest in the middle rpms which tend to produce peak torque output while also having the highest risk of knock.