help Tuning VT LS1

[Jayme]

Hi all, looks like I may be tasked with trying to go mafless on a VT LS1. I know very little about these presently, just wondeirng what software everyone uses? from what ive looked at - there are no free options?
also, how well do these things respond to timing etc. got any tips for someone who has only been tuning the old 5 Liters?

[delcowizzid]

talk to mick i think hes the LS1 nutta i do have some software somewhere might be on the old HDD

[GM Tech]

I use EFI Live for all my LS tuning, you can download a demo from their website and have a look at some tune files from holdencrazy.com

[XR Pilot]

I second that, Efi Live is excellent. Jump on holdencrazy.com as GM Tech said, download a few of the later VX-VY HSV tunes, these will give you an idea on where to go as far as ignition timing and fuel is concerned. You will need to flash in a later Efi Live custom OS, VX-VY based OS's will flash in perfectly fine. You will basically want to use a HSV fuel/ignition map as a base with the rest of the calibration data copied over from the VT map into the YX-VY map. You will need to disable a number of DTC's before removing the mafless sensor. They respond very well to tuning, but the early VT era LS1's are limited with a poorer flowing inlet manifold, your looking around 280-300rwhp with a tune for a stock/very mild setup.

Auto or manual?

[Jayme]

6 speed.
ive been looking and omg.... the old delcos are childs toys compared to these ls1 PCM's how does ignition timing work when you go mafless? from what I could see, it works off grams/sec, so does it use your VE table to calculate grams/sec then use the normal ign table or is there a second spark table that is kpa vs rpm?

is a common mod to put a later model intake on them for better flow? which intake flows best?

thanks for your help

[XR Pilot]

Heh yeah, there is a LOT of calibration tables in the newer PCM's.

From memory (its been a fair while since I touched one) the EFI Live custom OS uses the map sensor and air temp correction to calculate an estimated airflow value in g/sec, and the ecu then uses this for the ignition table. You don't really have to worry about this too much, the custom os' have that pretty much sorted. Just load up a custom OS, load in say a HSV VY calibration and copy over what you need from the VT cal, eg speed sensor info, fuel sender info etc and start tuning. The map sensor is also already fitted to the car, makes life easy

A common mod I believe is to fit either a later model LS1 intake (post VT iirc) or an LS6 intake. Double check tho, and once you remove the maf you can run an over the radiator intake. PM me your email address, I can probably make a base file to get you started. Also be aware that the Efi Live gear isn't cheap, but its really the best way to go about it.

[Holden202T]

so is efilive a better option than vcm suite ?

i don't even know if efi live supports the alloytec ?

i'm looking at vcm suite for the alloytec, but if efilive is going to be better i'm happy to go that way ?

[GM Tech]

I've used both and EFI Live has a better custom OS range for LS pcm's, from VT to VE. VCM supports alloytec and some aussie Fords so it has more coverage. The only time I use VCM now is for Ford and Alloytec. If your tuning a standard OS LS1 it only uses the low ocatne timing table in mafless speed density, a custom OS fixes that.

[Holden202T]

vcm suite it is then thanks!

[jca]

Hi, we use both efi live and vcm , I do prefer efi live , but vcm is good for alloy tecs and fords etc, if u need any pointers I'm happy 2 help or jump on the efi live forum there is heaps of infora. regards jason