Problem with Tune = Low Hp and High A/F

[SuperG]

After 3 attempts, I finally got my '97 on the dynojet and was thoroughly disappointed, although glad to have the results.

Car dynoed at 336 Hp, roughly 65 Hp lower than my peers' setups. Worse, though was the a/f was 13.5 across the rpm range!! If I remember correctly, this is too lean for normal operations. BTW, the a/f was taken with the shop's O2 sensors.

So...is the tune bad? Could there be something else wrong? Can the tune be erased due to a dead battery?

A few thousand miles have turned over since this tune was installed...What kind of neat things happen to an engine that runs lean for a long time?

Your comments are greatly appreciated!

 

[ju015dd]

are you having any codes? also, check your imrc's. when we first started tunning for my setup the computer keept pulling timing and only make 255 at first. finally found out one of my cables for the imrc's was sticking. maybe you will get lucky and that will be all it is.

 

[SuperG]

are you having any codes? also, check your imrc's. when we first started tunning for my setup the computer keept pulling timing and only make 255 at first. finally found out one of my cables for the imrc's was sticking. maybe you will get lucky and that will be all it is.

Now that's interesting, because my imrc's stick at 3200(ish) rpm's...looks like it's cleaning time, then rerun that dyno...

 

[Toasty]

Now that's interesting, because my imrc's stick at 3200(ish) rpm's...looks like it's cleaning time, then rerun that dyno...

IMRC deletes from na_svt. Do not pass go, do not collect $200 until you do the deletes.

 

[ju015dd]

IMRC deletes from na_svt. Do not pass go, do not collect $200 until you do the deletes.

indeed:rockon:

 

[James Snover]

14.7 is stoichiometric. Anything less is rich, anything more is lean. Performance cars are usually set up rich, Ford goes to 12:1 at WOT, in stock trim.

Jim Snover

After 3 attempts, I finally got my '97 on the dynojet and was thoroughly disappointed, although glad to have the results.

Car dynoed at 336 Hp, roughly 65 Hp lower than my peers' setups. Worse, though was the a/f was 13.5 across the rpm range!! If I remember correctly, this is too lean for normal operations. BTW, the a/f was taken with the shop's O2 sensors.

So...is the tune bad? Could there be something else wrong? Can the tune be erased due to a dead battery?

A few thousand miles have turned over since this tune was installed...What kind of neat things happen to an engine that runs lean for a long time?

Your comments are greatly appreciated!

 

[Cookieman00x]

for a sc you want 12.5-12.0:1 ...

 

[SVT Lurch]

for a sc you want 12.5-12.0:1 ...

Seriously. I wouldn't go anywhere near WOT until you get that tune fixed.

 

[SuperG]

Driving it like an old lady until I get that new tune!!

But what does happen to the cylinders/pistons at this ratio?

 

[James Snover]

They melt. It's tough on the heads and valves, too.

Jim Snover

Driving it like an old lady until I get that new tune!!

But what does happen to the cylinders/pistons at this ratio?

 

[SVT Lurch]

They melt.

Perfectly worded. :lol:

 

[Red98CobraStang]

holy balls! 13.5 a/f ratio on a s/c car... do not go WOT with that car or it will blow up over time.

I run an 11.7 a/f ratio on my car. I may lean it out to a 12.0 when I up the boost from 6 psi to 8psi. Im hoping to hit that magical 400/400 mark.