Supercharged LS2 Tuning

[koolky]

I'm working on tuning a supercharged LS2 and hope you guys can help me with a few things. I've done some NA tuning before but this is the first boosted gas engine I've worked on. The engine specs are: LS2, LS9 cam, Magnacharger Radix intercooled, 90mm TB, LS2 knock sensors, short tube headers, cats, 4L60E, 2002 LS1 ECM, COS5 (02020005), return-less fuel rail. I believe the Radix unit has 42-43 lbs/hr injectors and is supposed to put out 6psi. I'm using an AEM 30-0333 WBO2 analog (couldn't get serial to work...) and V8 scan for logging. At this point I've only corrected the VE.


1. B4001 (injector flow rate) I re-scaled this table for the Radix injectors with return-less rails, although the 2006 Radix Superchips tune that I found has this table set at 5.250 in all cells. Which way should this tabled be set?

2. A0014 (IAT correction) I assume that this table cannot be populated until the VE is complete? Can you do Auto VE after this table has been set?

3. I'm nervous about turning with the LS2 knock sensors. I copied B6226 and B6227 from a 4.3L tune, set B1402 to Flat response, modified B6244. Without repining the ECM to the flat response pin locations I register knock. I am going to re-pin to pin 9 and 10 and see what happens.


60 Wagon COS5_0012.ctz
LS1B9.pld
60 Wagon COS5_0013.ctz

The data log was taken while tune version 0012 was loaded, 0013 is what I have loaded currently.

[joecar]

( BTW: AEM 30-0333 does not do serial comms, it does CAN bus )

1. B4001 (injector flow rate) I re-scaled this table for the Radix injectors with return-less rails, although the 2006 Radix Superchips tune that I found has this table set at 5.250 in all cells. Which way should this tabled be set?

I would recommend a return fuel system with a manifold referenced FPR, otherwise you don't have enough axis on B4001 to cover boost (axis does not go negative).

42 lb/hr @ 43.5 psi (3-bar)...?

For rail pressure 58 psi (did you measure your rail pressure...?): 42 lb/hr * sqrt(58/43.5) = 48.5 lb/hr = 6.1 g/s

with manifold referenced FPR you would set B4001 to have 6.1 g/s in all cells.

with un-referenced FPR, B4001 has to be set according to sqrt((400+VAC)/400)*6.1 g/s.

2. A0014 (IAT correction) I assume that this table cannot be populated until the VE is complete? Can you do Auto VE after this table has been set?

It might be easier to do VE first.

3. I'm nervous about turning with the LS2 knock sensors. I copied B6226 and B6227 from a 4.3L tune, set B1402 to Flat response, modified B6244. Without repining the ECM to the flat response pin locations I register knock. I am going to re-pin to pin 9 and 10 and see what happens.

I don't know the answer here... you may have to do some experiments.

[joecar]

In B3647: in this table, any cell set to stoich will cause STFT trimming... this will undermine your tuning efforts.

[koolky]

In B3647: in this table, any cell set to stoich will cause STFT trimming... this will undermine your tuning efforts.

Even with B3801 and B4108 set to disable?

As for the injector data, I assume they are either 42 or 43 lbs/hr at 58psi (based on what information I can find online). This lines up with the data from a 2006 Radix Superchips tune that I found where B4001 has all cells set to 5.250 g/s (41.7 lbs/hr) even though it would have been return-less.

[joecar]

Even with B3801 and B4108 set to disable?

...

Yes.

[joecar]

... B4001 has all cells set to 5.250 g/s (41.7 lbs/hr) even though it would have been return-less.

( flat B4001 is for return system i.e MAP-referenced )