05HD

I don't have a bunch of LT1 specific speed density experience but you may have a trim or a constant out of whack on your tune. It could even be something you can't see with your definition file. My stock speed density '93 doesn't do that and neither does any other speed density platform I have experience with. If there is a quick, radical change, it may need to get a new key on engine off baro reading but that is about it.

gregrob

iTrader: (8)

This is on my LS1 car

05HD

Something is definitely up then.

gregrob

iTrader: (8)

Whats up is that speed density varies whether people want to believe it or not. A lot of guys who pay close attention to their tunes will tell you that.

Also you can talk to a lot of well-respected tuners who are NOT on the speed density band wagon.

Does it have its place? Of course it does, but not on a mild street driven setup IMO.

05HD

Meh, I tend to believe GM over well respected tuners. They have cranked out plenty of speed density vehicles with no issues. I own 2 of them currently.

gregrob

iTrader: (8)

Never said they had "issues" I said the tunes fluctuate.

quik95lt1

iTrader: (7)

just food for thought....neither a mass air meter'd car or a SD car have a way to measure air density........its a calculation made between incoming air and temperature......on key on engine off the baro re-calculates to atmosphereic pressure which gives a baseline whether its 100kpa at sea level or 95kpa up in elevation.......so the only variable between the SD and MAF tune is the lack of the MAF sensor giving and accurate measurement of actual incomming air........if the VE table is correct it will work just as well.....but if the VE table is off even a small amount < 3-4% it will not run correctly in all types of air even with the system in closed loop......

gregrob

iTrader: (8)

VE table was perfect in my app. Tuned it with a wideband and auto ve with all corrections turned off. I spent half a day making sure the VE tables were perfect.

quik95lt1

iTrader: (7)

huh.....yea thats what i did too.....u saw the pic i put up lol.......wonder why then......only issue with SD can be low speed drivability around idle speed/kpa because there is no load indexing on the LS computers.......my fast xfi runs load indexed mode off of the TPS also and its by far the best SD tuning platform ive ever used.....

gregrob

iTrader: (8)

EFI Live has a TPS VE Custom OS that is supposed to work awesome. I would try that but putting a maf back on the car completely transformed it. It just doesnt need SD being near stock.

djm_e22

iTrader: (2)

Well I get my cable in Friday. I have read and still am reading about how to tune. Hope you all don't mind me asking questions as I go through this tuning for the first time.

Wicked94Z

iTrader: (26)

pm me your email address and I'll send you a decent tune for this setup

05HD

Heh, if it wasn't an issue, we wouldn't be talking about it!

You are running corn on the LS1, right? How did you account for that in the tune?

quik95lt1

iTrader: (7)

in EFI live there is a target stoich parameter in the injector tab you can change to make that easier......just fyi lol

05HD

I know that. I also know that isn't the only adjustment that needs to be made to make the car run right *all the time*.

gregrob

iTrader: (8)

91 pump gas