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Metering 900 g/s airflow with MAS ???
Posted: Sun Jan 13, 2013 11:50 pm
by CKATM
Hi,
I'm new to the forum (and ECU programming), and I'm keen on getting a VRAM
board for my VS V6 which I'll be installing a fairly serious turbo to.
I've read through the getting started thread but have some questions and I'm
hoping someone can help.
Some people have told me that the Delco ECU lacks range in some areas for
what I want to do with my engine. (not sure if they just don't understand
the system, as no one will back up their claim with any specifics).
I'm going to be initially running about 20 - 25lb turbo boost to try and
acheive around the 700 HP mark. Also planning to upgrade turbo to larger
unit to acheive 1000 HP (for the strip and limited street use).
The car's automatic which I want to retain (in modified form), as I know of
some well built turbo700's running behind 1300 & 1500HP engines so I'd like to stay with the VS PCM if possible.
I know the Delco factory ECU's are very good with lots of control, but
being VS with a MAF I'm thinking my biggest trouble may be finding a
compatible MAF sensor that can metre 900 g/s, or does anyone have or know of a MAFLESS 2 bar or 3 bar bin,
or do I need to go to an earlier ECU ? Or even Kalmaker??
I'd really appreciate any advice anyone can give me here.
Cheers.
Re: Metering 900 g/s airflow with MAS ???
Posted: Mon Jan 14, 2013 9:39 am
by The1
the enhanced mod does alow the use of LS1 MAF
the highest boost i have run it with it is 16psi factory supercharged and it metered the MAF upto a max of 11200hz and it has a range of 14000hz, 10psi usually meters upto around 10000hz, but these obviously lacked engine work which will alter the flow alot.
The problem with vs code atm is there is no spark control beyond 593 cylair, i havn't written the code in for either n/a or s/c bins, if your not worried about the bcm security, then vs/vt are similar in wiring so you could swap to VT ecu and enhanced mod will alow spark control upto the max of the MAF. It could handle 20-25lb but never had anything like that to test it more than that you'd be looking at 4 bar MAP and i dont think even kalmaker goes that high? But good luck to you if you get that power out of a v6
Link
https://pcmhacking.net/forums/viewtopi ... =27&t=2518
Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 1:49 am
by CKATM
Thanks for that info THE1.
Yeh, I know the target HP seems over the top, but I'm pretty serious about the figures I'm aiming for. I built quite a few stout V8's in my time (I was running mid 11's with a NA 550 hp 308 streeter 18 years ago- ravenswood days, I had to fabricate a lot of stuff back, including the intake manifold).
I've already got most the gear for the engine, I'm just waiting for some stuff to come over so I can start to fabricate the Turbo manifolds. Hoping to get it going in about 6 months time.
Hey, putting the LS1 MAF sensor aside, will the VT enhanced mod go above 14000hz with a higher scaled MAF ??
Cause Im pretty sure that I'd need to be metering around 640 g/s min for starters (for 700 hp) which I think is out of the LS1 range.
Do you know if there are any MAF's designed to metre higher flow ??
I'm also concerned now about what you said " 20-25 lb being 4 bar". Kalmaker does do a 3 bar program, as you know (which I was thinking would be my resort if I couldn't get it to work with the MAF).
I'm not sure if I'm missing something here, but by my calcs, 2 bar equates to 29psi, 3 bar 43.5psi- Does something need to be deducted from the MAP range ??? (ambient atmospheric pressure 14.5 psi ??) .
Cheers
Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 6:35 am
by Holden202T
yeah 1 bar map sensor = 14.7psi negative pressure, from there 2 bar is 14.7psi positive, 3 bar is 30 psi positive etc.
Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 6:36 am
by antus
yeah thats right, some people talk bar above atmospheric, but in the delco world 1 bar is the factory NA sensor, 2 bar is about 14psi, 3 bar is about 30.
im not an expert in VS but im pretty sure the t700 is the trans from the VN, and thus you might be better off looking at 12p on an 808 with 3 bar to start with as you wont need the 4l60e stuff in the vs pcm?
Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 8:10 am
by CKATM
So using a MAP, I'm basically limited to 30psi boost. Thats some fairly respectible boost.
Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 8:17 am
by The1
T700 uses hall effect? So setting the tune to standard manual would be fine.
I havn't seen a MAF that can go above 14000hz yet.
So your safest option would be 3 bar kalmaker or convert to 12p with a 808 3bar.
Sorry i dont play with MAP much but yeh thought 3 bar would be about 30psi and with 1000hp would think you'd be looking at pushing that?
I know of one guy running a factory s/c all ported and engine work done, 21lb getting around 450RWHP
http://forums.justcommodores.com.au/vr- ... -pack.html
So im guessing your stroking it for start then? and more boost, lumpier cam ontop to start making higher than that? Will be interesting to see all your work, not often someone goes full on. Keep us posted

Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 8:27 am
by Holden202T
and when it all happens there must be pics otherwise ....

Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 9:05 am
by CKATM
That makes a whole lot more sense now.
I need to play with both systems to learn how they work I guess, probably on a stock car for starters.
On the note of limitations, does anyone know if there's any limit on injector size in the injector table?
Also, is there "basics of tuning guide" for VS ??
Re: Metering 900 g/s airflow with MAS ???
Posted: Tue Jan 15, 2013 9:25 am
by antus
I dont think there is a relevant upper limit to injector size, beyond what you can physically buy. 60lb and 80lb siemens deka injectors can be easily bought on ebay and people here use them with good success, and you can get bosch 210lb/2200cc either as bosch brand, or injector dynamics brand
http://www.injectordynamics.com/ID2000.html which should flow more than enough fuel even for very high horsepower engines. The injectors just need to be high impedance (those ones are).