Supercharged VT 355 afm tuning

[shane1]

Hi Guys ,
Just starting to set up a blown VT 355. It currently runs std ecm and AFM but tuned. Makes 240rwkw N/A,
we are now fitting a blower and running 10psi.
We have tuned plenty of VTs before but never tried keeping an AFM and std ecu once boosted.(most customers turn up with an aftermarket ecu).
The Std AFM runs to 9800hz at 6300rpm (limiter) and maxs the G/S to 256 around 5900rpm.
MY question is how much further will the std AFM run ?.part number 89873678355.
i also have LS1 and LS2 afms lying around but if i can get close with the std AFM and the enhanced tune then i will.
I noticed that the VT enhanced tune xdf doesnt have the 850-1600 tables listed like they are in the V6 xdfs. Is there a later version floating around or do i have to convert numbers to make it work?
Cheers,
Shane

[antus]

I think you will be ok with 10psi on stock maf, but could probably benefit from swapping to a larger (ls1) maf. the1 could give you more information. Also see the docs in his thread here: http://pcmhacking.net/forums/viewtopic.php?f=27&t=2518 With the enhanced code you should be able to run the stock MAF at close to 15khz and can support a lot more g/s.

Edit: I see the v8 tune is classified NA. Had better wait for the1s input.

[shane1]

I was thinking the std maf may do the job(, with the enhanced software , also as its metal i may be a little more durable on the boost side of the intake, compared to the plastic LS1 or LS2 ones. I have read all the enhanced forum and used the v6 s/c software just havnt seen/ heard much about the VT V8 , it really was the almost model, it almost got a map sensor and almost got an LS1

[The1]

stock MAF should be good for atleast 10,000hz, havn't seen any that havn't made it to atleast that, some even make it to 11,000hz but not many, LS1/2 MAF's i think are the same as stock just larger pipe, still limited to 10,000hz, beyond this look at the LS6 Silver Badged Delphi MAF, part number in the PDF on the enhanced page, good for atleast 14,500hz.

The VT V8 enhanced is good to go for the full 16,226hz @ 510G/S new limit, other than that i have not coded in anymore yet but will happen at some point. So you will be limited to the stock 850cylair tables but alteast you can scale the fueling still past this with the MAF spreadsheet if you need to tweak the fueling. I will add the updated spreadsheet back into the OP post in the enhanced thread tonight.

[shane1]

If the std AFM is at 9800 already then i may as well fit the delfi one. (i have every maf ever made kicking around here somewhere after so many LS mafless tunes .Ill check the spreadsheet later can you post a link?. Will the spark tables just finish at the last reference point once past the written Tables? I.e put the desired boost timing in the last line of the std table?
Cheers,Shane

[The1]

now uploaded, yes from 850 up will use the end row spark value

[shane1]

Hi Guys,
Well finally have this Vt on the dyno and have struck an issue. It runs fine till 4500 rpm and 11200hz,
then goes real lean real fast. Injectors are only opening to 8ms .ive tried bumping the inj rate constant but it still does it have i missed something in the converting of the std tune to the enhanced tune??
It has fuel pressure and all the basics ,just goes way lean real fast .Any ideas?

[VL400]

Have you got a log of it going lean?

[0081(2)]

What maf did you end up using??

[shane1]

i have used the delphi maf so that shouldnt be a problem , it seems more like the software wont respond past the factory limits??