tunedportcj5

iTrader: (18)

Anyone have some insight on why my torque number seem low? Most of the similar combos I see have equal or more TQ than HP. I have spent a lot of time tuning N/A cars but not much with FI. Any info would be great!

Here are some details:

08 LY2 4.8 9.2CR, stock long block, 243 heads
LS6 cam/springs
LS2 intake
80lb injectors
4L80e with FTI3600
front mount mpt70
14* of timing
11.5 AFR
93 pump gas
TR6 plugs
eBay IC
3" IC piping
88mm truck TB
Precision 46mm WG
LS3 MAF

E38/T42 tuned with EFILive. Currently a MAF only tune, no trims, 2bar VVE tables are sane in case of MAF failure.

Any ideas?

In addition... how much boost do you think I can run on 93 pump?

thanks,
David

Slowhawk

iTrader: (12)

The 4L80 kills power a good bit to start. The timing seems low for that compression and boost level. I would think 16-18 degree's would yeild a good gain.

HydroStream6

iTrader: (16)

Are you locking the converter when dynoing? If not, that's why. Converter flashes past peak torque when you romp on it. I wouldn't lose any sleep over it.

71 chevy

iTrader: (18)

post the dyno graph. where did the torque and hp peak at?

tunedportcj5

iTrader: (18)

here you go... thanks!

hellbents10

iTrader: (10)

Inertia dyno and a unlocked converter nothing to worry about looks like solid power for a 4.8.

tunedportcj5

iTrader: (18)

thanks guys... we were commanding the TC to be locked but it was unlocking (it looked like a downshift on the dyno chart). Its an issue with the 4L80e OS on the T42 controller.

HydroStream6

iTrader: (16)

You'll never see "true" tq numbers without a load dyno and a locked converter with an auto. My car "only makes 600lb/ft" but it's at like 4500 on the dyno. Since the converter flashes past the tq, you'll never really see true peak tq.

71 chevy

iTrader: (18)

for that low rpm range the motor is making some darn good power.

I would be more concerned about why the hp is peaking around 5200ish rpm on a 4.8

something is not right

tunedportcj5

iTrader: (18)

I was thinking the same thing. Our main concern on the dyno was to get the fueling safe. 18* of timing was commanded but only 14.5* was being logged. It was probably the IAT/ECT spark multipliers pulling it down. I'll post up my logs when I get them.

thanks,
David