sevenin7

My FD produce 312 hp with 12psi and a/f 12.3
Is safe this tuning or not ?

Sesshoumaru

iTrader: (1)

danger

sevenin7

Its better to loose 10hp and running 11.5 - 11.7 ?? with the same boost (10psi )

sevenin7

12 psi ! sorry

spoolin93r1

i had 11.5 with 306rwhp, bumped it to 12.5 and got 313. 2 months later i lost a motor. your call

sevenin7

Agree. 300hp at the wheels with 12psi and 11.5 - 11.7 a/f is the best .

kyle@insight

Give 'er more fuel.

wickedrx7

iTrader: (14)

Keep it below 11.5 To be safe, 10 HP or new motor? You make the call.

rynberg

You can't just give a single number and have it mean anything.

It would be much better to post a graph or at the very least, a set of values at different rpm points. Also, how was this A/F ratio measured, and with what?

skunks

danger, add more fuel

jspecracer7

I don't like seeing a/f higher than 11.4

Sesshoumaru

iTrader: (1)

rynberg is right

that's fine for idle but not at 6000rpm under boost

i assume it was wb due to dyno but that is also important.

i also say 11.4 is a good number to shoot for under full load.

sevenin7

I use every time 100oct fuel . I think its o.k with 11.5 a/f and 12psi of boost !

darkside7

iTrader: (12)

so whats a safe a/f for rx7?????

Choser

Isn't stoich something like 14.7? How come that isn't the # to shoot for. Of course, the reason is because things in practice differ soemwhat than things on paper but I was wondering as to why exactly.

rynberg

14.7 is the stoichiometric ratio for fuel/air and will result in the most efficient combustion. Unfortunately, it will result in exhaust gas temperatures hot enough to kill the motor. That is why ALL engines under load run a much richer ratio. The extra fuel cools the combustion temps. Even n/a motors run in the 12s:1 under load, turbo motors need to run richer than that. Most factory turbo cars are running in the 10s:1, even piston engined turbos.

Choser

Damn cool, awesome.