Newbie... what to get. twin turbo ls build.

[jks67ss396]

guys

im about to start on my 408 ls twin turbo build. i need to know what to buy...

I had a FAST b2b system on my BBC, and liked those VE and spark tables. easy to use.

So for this twin turbo build (2 bar to start), do i just modify the tune on my ecm (03 Sierra lq4 ecm going into a 67 Camaro) or do i need one of these custom OS's? how much do those cost?

will i use the MAF on the turbo setup? or straight speed density? id like to get nice mpgs when off boost. its a 5 speed car.

I need to buy from someone who can help with the tuning..especially turbos. ill have a lot of questions at first. im in the LA area, so it would be nice to buy from/know someone here that can help if needed.

its just the one car. so i dont need to tune anything else. what do i buy and do i have the capability to log data and then make changes?

thanks guys
jeff

[joecar]

Hi Jeff welcome to the forum :cheers:

If the PCM is from a 2003 Sierra LQ4 then you can use either of these:
- FlashScan V1 (cheaper, LEDs only, BBL only, analog wideband).
- FlashScan V2 (LCD and LEDs, BBL and BBF, serial comms wideband, SD card slot for logging/flashing).

V1 will work, you will need your laptop in vehicle to read/flash the PCM; able to do BBL (black box logging (i.e. no need for laptop in vehicle)).

V2 allows BBF (black box flashing (i.e. no need for laptop in vehicle)) and BBL [i.e. no need for latop on logging trips].

V2 also has serial comms AFR support for the most popular widebands (the AFR/Lambda is read directly from the wideband using RS-232 serial comms protocol, avoiding analog voltage/ground offsets).

Of course, both V1 and V2 allow passthru reading and flashing (i.e. with laptop in vehicle).

I'm not sure about 2003 COS (custom OS), but it seems that 03190003 would work on the 2003 LS1/LQ4 style PCM (I'll ask tech support).

COS's are free (no cash required, no PCM/VIN license required), there is a tutorial for installing the COS (see attached).

[joecar]

It looks like COS 04073003 might also work.

[jks67ss396]

so with these COS's, do i use the MAF or just speed density?

Can i map timing and AFR?

where are you in So Cal? Who do you use to tune?

thanks!

[ScarabEpic22]

The COSs let you run up to 3Bar of boost in SD, you will probably max your MAF out quickly with a 408 TT.

You'll need a wideband of course to get your fueling in check, yes you can log spark timing and see knock, map fueling to see what your A/F is. Also, you should perform an AutoVE and get your VE table dialed in properly N/A then move onto boost fueling and timing.

[jks67ss396]

Ive got dual widebands... so does EFI do autocorrection based on what the wideband O2 says?? can i command an AFR based on rpm and map?? my old classic FAST efi setup had an AFR table....

Is AutoVE included with the V1 and V2? or is that extra or more $$

who should i buy this setup from? Id like to have a good guy available to help with this FI tune.

thanks

[Taz]

Minor point … wanted to confirm you are aware all 2003 and newer LS1-B truck tunes are DBW (Drive by Wire) only. If you want to use a DBC (Drive by Cable) setup, you have two choices - use a 2002 LS1-B PCM and truck tune, or access a 2003 Express / Savana tune that used DBC (some were DBW).

All 2002 512Kb LS1-B PCMs supported DBC and DBW tunes. Not all 2003 and newer 1Mb LS1-B PCMs will support DBC tunes.


Regards,
Taz

[joecar]

What Erik said.

You can use the either MAF or SD, but if MAF max's out then go SD... here in LA there isn't any problems running SD.

[joecar]

Taz has a good point on electronic vs cable throttle... you might need a 2002 LS1 PCM, part # 0411.

This PCM has COS3/02020003 (boost) and COS5/02020005 (boost, nitrous, throttle position VE) available.

[jks67ss396]

so my 2003 truck ecm might do dbc? how would i know if that were possible?

thanks!

[jks67ss396]

can i still get good mpg with SD?? (off boost of course)

thanks

[Taz]

If you have a 2003 LQ4 truck (Sierra / Silverado) tune it is DBW only. The PCM you have MAY support a DBC tune - from an Express / Savana.

Post the service number (Serv #) and hardware number (HDW #) affixed to your PCM and I’ll check compatibility.


Regards,
Taz

[jks67ss396]

got all that stuff at the machine shop getting the block cleaned up.. if i am stuck with dbw, can efilive adjust the "sensitivity" of the throttle signal? i dont want delays....

[Taz]

No sure what you mean by “adjusting the sensitivity” of the ETC (Electronic Throttle Control). DBW and DBC work equally well - comes down to the physical setup you want / have in place.

In a boosted application DBC is easier to tune - as you don’t have to worry about ETC “limp mode” being triggered by excessive / unexpected air flow.


Regards,
Taz

[jks67ss396]

well, maybe its just my experience, but in the dbw cars ive driven, seems like if i punch it, the computer slows the acceleration and "slowly" opens the throttle. Can i tune that out?

what is excessive airflow that would trigger limp mode? vac leak or something?

[Taz]

It may be helpful to invest some time reading the threads in the "Forced Induction" portion of this Forum - as well as the user manuals for both the Tune Tool and Scan Tool. You could then make an informed decision as to whether you want to undertake tuning the vehicle yourself - given your comment about not wanting any delays. Tuning it yourself is rewarding, and can be cost effective if you are cautious, but it will take time.


Regards,
Taz

Edit: the perceived throttle delay you described in some DBW vehicles could be the traction control system - which is also tuneable.

[jks67ss396]

ha! by delays i meant the "momentary" delay felt by dbw throttles that i seem to experience. im coming from a metal throttle rod and then cable on my 67 camaro, so im used to punching it and going sideways... not this "computer controlled acceleration (delay)" that ive felt with some new dbw cars...

i tuned my SD 540 BBC using the Classic FAST efi system and liked that a lot... i definitely want to tune this new setup myself. i will poke around the other forums though

what i would like to know is who in So Cal do i buy this from that knows turbo tunes? just in case i have questions...

thanks!!!

[jks67ss396]

traction control is a good thing. but sometimes i just want to light them up :)

[joecar]

...

what is excessive airflow that would trigger limp mode? vac leak or something?With DBW differences in various airflow/throttle sanity check tables may trigger reduced power mode... DBW tuning requires special attention to these other tables.

As Taz said, your PCM's service/hardware numbers will determine if your PCM can run a cable throttle OS (from a Savana/Express file).

[joecar]

can i still get good mpg with SD?? (off boost of course)

thanksIn SD if you correctly tune the VE table(s) using a wideband then MPG will not suffer... in OLSD you have the opportunity to set cruising AFR's leaner, giving you improved MPG.

Some points:
- many people have observed the same HP/TQ between running with SD or MAF.
- some people have observed the smaller diameter MAF's may impose a small airflow restriction (due to the airfoil).
- some of the earlier [LS1 ] PCM's limit the MAF airflow values to 512 g/s.
- if using MAF, you will still need VE corrected (since PCM falls to VE during transients throttle).
- running in SD is a failover/error mode, it alters the operation of some other things like adaptive spark/knock (unless you run a COS) and transmission operation.

Which transmission will you run...?

[joecar]

...

what i would like to know is who in So Cal do i buy this from that knows turbo tunes? just in case i have questions...

thanks!!!I'm not sure... a vendor will chime in.

[jks67ss396]

Im planning to run a beefed up version of my TKO 5 speed (manual, and mechanical linkage)

when i get my ecm back, ill get the codes for you guys to see if i can use a van tune with cable...

within the COS, how would i flip over from MAF to SD?

thanks guys


In SD if you correctly tune the VE table(s) using a wideband then MPG will not suffer... in OLSD you have the opportunity to set cruising AFR's leaner, giving you improved MPG.

Some points:
- many people have observed the same HP/TQ between running with SD or MAF.
- some people have observed the smaller diameter MAF's may impose a small airflow restriction (due to the airfoil).
- some of the earlier [LS1 ] PCM's limit the MAF airflow values to 512 g/s.
- if using MAF, you will still need VE corrected (since PCM falls to VE during transients throttle).
- running in SD is a failover/error mode, it alters the operation of some other things like adaptive spark/knock (unless you run a COS) and transmission operation.

Which transmission will you run...?

[joecar]

It will run in SD if any one of these are true:
- you physically don't have a MAF connected,
- set the MAF sanity/failure tests to fail immediately (C2901/C2902).
[ either of those cause the PCM to throw a MAF DTC which then causes the PCM to run in SD mode ]

Have you downloaded/installed the software to play with it (it lets you view/edit calibration files, see www.holdencrazy.com (http://www.holdencrazy.com) for files).

[ScarabEpic22]

The sluggish throttle opening you're talking about is the Torque Management system GM implemented. Reduce the torque reduction in the engine and trans sections and the throttle is much more responsive.

It doesnt work like that in GM PCMs, you cant simple set a table to command a certain AFR and have everything work. You need to do the AutoVE tutorial (yes its free, just need a GM PCM and a wideband) so that the PCM knows how much air the engine can get at a certain load point then with the proper injector information it can command the proper pulse width to get the AFR you want.

[jks67ss396]

Thanks!

So where is the AFR information in EFILive then? Surely, if there isnt a table of AFR for map vs rpm, then theres gotta be somewhere that i can specify that AFR vs load on engine..... or is that behind closed doors and you need this AutoVE thing to manipulate a host of plots and parameters to get you what you want?

If i need the engine to be running to gather information to feed into AutoVE, how will i know that what the ecm has in the calibration currently wont blow up the engine while im gathering data to then feed back to the ecm? gotta havea target AFR somewhere!!!????

thanks

[joecar]

In the COS files, table B3647 gives open loop AFR for MAP vs RPM... do you want to see a file...?

Prior to doing AutoVE, you have to guestimate what the new VE would be; also you will set the OL AFR and PE AFR richer to avoid going lean at high load.

During AutoVE you will then do a pass upto 4000 rpm (say), apply the throttle transient filter, and observe the trend, extrapolate the observed trend; then you do a few more passes each time observing the correction to see if you're on track; you will eventually do a few WOT sweeps to correct the upper parts of the VE table.

Dyno time is very handy for doing this with major mods.

A wideband is required.

[jks67ss396]

thanks Joe!

that makes sense. if you have a COS file that has the B3647 table, yes, that would help a lot!

from your first post, it seems like EFI Live CAN do real time logging/display, right?

i do have the widebands... do you know which sensors are supported? Sounds like i need to graft in a special connector to the truck harness for a WB O2 that was never there....

thanks

[joecar]

that makes sense. if you have a COS file that has the B3647 table, yes, that would help a lot!There are COS's only for certain OS's... see the table on page 4 of this document: COS tutorial (http://download.efilive.com/Tutorials/PDF/Custom%20OS%20Upgrade%20Tutorial.pdf)


from your first post, it seems like EFI Live CAN do real time logging/display, right? Yes, real time logging/display in the software scantool passthru mode and in V2 BBL/standalone mode... the LS1 PCM allows itself to be logged as fast as 10 samples/second per pid channel for upto 24 pid channels (some pids use 2 channels).


i do have the widebands... do you know which sensors are supported? Sounds like i need to graft in a special connector to the truck harness for a WB O2 that was never there....
thanksV2 has serial comms support for these widebands: supported widebands (http://www.efilive.com/index.php?option=com_content&view=article&id=138&Itemid=143)
You need the following:
- power/ground to the wideband,
- serial comms null modem cable from wideband to V2.

The wideband serial AFR/lambda is an "external" pid... V2 reads the AFR/lambda/eqratio from the wideband via the serial comms cable.

[jks67ss396]

so when you say serial port to WB.. you mean serial port to wideband controller ... not to the sensor itself? My FJO WB controller has the capability to output serial data. so thats where the EFI Live would hook to?

Also, can you attach a COS that has that AFR vs mpa vs rpm table?

thanks

[joecar]

Yes, correct... the term "wideband" is being used as shorthand for "wideband controller" (to which the actual wideband sensor plugs into)...

I'm sorry for the confusion. :)

[joecar]

Attached is COS5/02020005 file that I run on my stock 2001 TA (everything stock other than long tube headers w/cats).

[jks67ss396]

wheres the AFR vs map/rpm? i cant seem to see that ...

thanks man!

[joecar]

wheres the AFR vs map/rpm? i cant seem to see that ...

thanks man!In the search box enter B3647 and press Search.

[ searching B3647 (i.e. uppercase) takes you to the table, searching b3647 (i.e. lowercase) takes you to the string "B3647" ]

B3647 is at Engine Calibration->Fuel->Mixture->Commanded Fuel in Open Loop.

[jks67ss396]

Hey guys,

the Serv number is 12582605 and the HDW number is 12580786

Can you let me know if its possible to go drive by cable with this ecm?

thanks



If you have a 2003 LQ4 truck (Sierra / Silverado) tune it is DBW only. The PCM you have MAY support a DBC tune - from an Express / Savana.

Post the service number (Serv #) and hardware number (HDW #) affixed to your PCM and I’ll check compatibility.


Regards,
Taz

[Taz]

Service number 12582605 was a commonly used 1Mb LS1-B style PCM in 2003 Gen III trucks. I believe it will only support DBW tunes.

Some service numbers for 2003 LS1-B PCMs that should support DBC tunes are:

12576106
12581565
and no doubt - a few more less “common” service numbers

Any 2003 to 2007 Gen III PCM will work with the BLUE & GREEN PCM connectors of your wiring harness. There are select PCMs from 2003 to 2007 that are DBC compatible.

You could also use any 1999 to 2002 512Kb LS1-B PCM - these are all DBC compatible - but you would have to switch the GREEN PCM connector to a RED PCM connector - and repin the wiring harness as necessary.


Regards,
Taz