ls1_chevelle

iTrader: (9)

Figure I'll get more response in here. Gonna delete my post in the tuning section... If its supposed to be in the efi tuning section, please move back.

Hey guys. Heres the combo

6.0l LQ4. ARP hardware in the bottom end
motron 60lbers
oil cap breather, breather on drivers side, breather on other passenger port. Intake plugged.
4l80e
t76 .96 turbo
JGS 40mm gate and 56mm bov
342 gears, yadda yadda

I am running the AEM tru boost set at Spring pressure 4.5lbs and duty cycle at 10% giving me 5psi, yet my gauge reads me 7lbs. The spring in the gate is 7lbs I believe. Its the lowest JGS ships their gates with.

Any other setting on the tru boost, the car completely rejects and knocks hard. Pulls 6 degrees of timing and the car slams off a 13.2 pass.

Air fuel is 11.5-11.8.

I also tried running the car straight off the gate by disconnecting the top port, and the car rejected that aswell and knocked, then pulled time. We data logged the car, so thats how we know that its knocking and what amount of timing it is pulling.

What are you opinions on this?

cablebandit

iTrader: (37)

how much timing and what gas?

Schantin

iTrader: (6)

Hard to tell what you're asking. Concerning spring/boost....I don't think that any boost controller can maintain a constant boost setting less than the wastegate spring pressure. If you want 5PSI, you need a 5PSI spring. Go to 10PSI, then the boost controller can modulate it, etc, etc.

Tune...really need some diagnostic feedback. What are the IAT's when the car is pulling timing/knocking? High IAT's (over 125) will require less timing + a touch more fuel to prevent knock. Also, if the knock sensor sensitivity is set to STOCK levels, the car will automatically pull timing and register knock events because the amount of air entering the cylinders at even part-throttle is WAY more when FI. It is not uncommon to see a .50 or more g.cyl increase in a single cell change. The stock sensor values map knock as an event when the g/cyl increase in the .20 range per cell. You can go into the knock table and set the sensitivity to .40-.50 or so....this will remove "false knock".

Good luck fining the problem.

hellbents10

iTrader: (10)

Right on with above, also it will be hard to hold that thing to 5psi. As far as afr goes tahts fine for now but if you up the boost more I would shoot for a low 11:1 afr.

ls1_chevelle

iTrader: (9)

The car is at 16 degrees of timing currently when running the way it should. It wouldn't take anymore. We are running pump 92. Same as the other 76mm turbo ls1s that were with me on the weekend.

IAT were 108 at the highest point, roughly 10-15 over ambient.

I'll have to ask my tuner about the knock sensitivity value dealio.

Thanks for the help thus far.

Schantin

iTrader: (6)

Yep, I'd check the knock sensitivity, cause the other #'s look pretty good....except possibly the 92 octane gas. My car is tuned for 93 and I had to add octane booster when on the Hot Rod Power Tour in states that had 91/92. That one little point in octane rating made a big difference on my car.