93 Skyline GT-S running lean please help.

[dipstickinva]

A friend of mine just got a 93 GTS a few months ago and he finally dyno'd it. It dyno'd about 186hp. but the problem is that it is extremely lean. here is a graph of the A/R



The car is just about stock. Well other then exhaust, intake and a Nissan 300TT fuel pump that I know of. And also the boost was at stock level at 6PSI.

What are somethings that can be done to richen it up some? I was thinking maybe bigger injector (what would be best?) and maybe a SAFC?

Anyone have any input?

[themadscientist]

That's not bad for an unmodified computer. An SAFC can help you richen it up.

[dipstickinva]

So your saying that running a 13+ A/f is safe?

I work on turbo'd Dodge Neons. When I tune them I try to get around 12, 12.3 A/F.

But also with the SAFC wouldn't you want more fuel then use the SAFC to pull the fuel out?

Then again with the cars that I have working on when you try to add fuel with the SAFC the computer always goes hay wire.

Forgive me for the stupid questions. I just never really worked on a car like this and dont want to mess something up.

[edthemanjp]

That always depends on type of engine, type of fuel, EGT, amount of boost, and amount of ignition. Is it completely stock with a stock computer??

[themadscientist]

So your saying that running a 13+ A/f is safe?

I work on turbo'd Dodge Neons. When I tune them I try to get around 12, 12.3 A/F.

But also with the SAFC wouldn't you want more fuel then use the SAFC to pull the fuel out?

Then again with the cars that I have working on when you try to add fuel with the SAFC the computer always goes hay wire.

Forgive me for the stupid questions. I just never really worked on a car like this and dont want to mess something up.

I didn't say it was safe, read what I wrote. Stock computers are not tuned for maximum power but rather for best balance of fuel economy and emmisions. Running the kind of AF ratios that make peak power you would never pass a sniffer.

[dipstickinva]

That always depends on type of engine, type of fuel, EGT, amount of boost, and amount of ignition. Is it completely stock with a stock computer??

lets see the engine is the - RB20DETFuel - 93 octainEGT - ???boost - 6 psi (stock)ignition - ??? stock computerstock computer - yes

the only thing done to the car is:

a full turbo back exhaust (was on the car when he bought it)300zx TT fuel pump (stock on stopped working)new spark plugs - not sure what type or gap he set them to.all fluids have been changedand a intake.

I didn't say it was safe, read what I wrote. Stock computers are not tuned for maximum power but rather for best balance of fuel economy and emmisions. Running the kind of AF ratios that make peak power you would never pass a sniffer.

im sorry i miss understood what you said then. but where im at in the state we do not do emmisions. so running richer is not a big problem. i just dont want something to happen to the motor from running that lean.

since the dyno this past weekend he has been afraid to drive the car cuz it was lean.

Now that you know what has been done to the car.

What would you do to help richen it up???

[themadscientist]

depends on your power goals. The more power you want the more serious you need to get about the parts you use.

[dipstickinva]

400 HP

[themadscientist]

Time to get serious then. Get a standalone.

[dipstickinva]

we figured that and a bigger turbo and built internals also.

but what about the main question with the A/F?

how do we go about lowering it? My friend uses this car for a weekend driver and drifts with it. So it pretty much gets beet on all the time.

[themadscientist]

Get a standalone.