New to V6's and EFI

[polishdog]

I've done slight improvements to my '84 caprice, like roller rockers and a cam that sort of thing. but its carburated and it seems to be alot simpler. I just aquired an '02 Malibu with the LG8 v6 and a 4T40-E tranny. I'm looking to bump it a bit over stock but not so much that I will have to run premium fuel or beef up the drive train. All the research I've done so far has not yielded much enlightning information. All I know is it's an LG8 v6 191 CI (3,136cc), 170hp 190lb-ft iron block with aluminum heads with 9.2:1 compression with the 4T40-E final drive ratio is 3.63:1. What I need first is more information and to learn how to properly tune an engine with efi. anyone know where i can find in depth information on this?
thanks.
Dave

[no_doz]

headers, bigger tb, cold air intake or short ram intake, gasket/port matching (because stock castings are well...questionable) as well as an exhaust that can flow it well, & you should get some pretty nice gains as well as better mpg when you try for it.

you should look into megasquirt at www.diyautotune.com, they should have equipment to help you with this. also www.megamanual.com is the site that tells you virtually everything youd need to know about how to tune everything with megasquirt, & will give you a better idea about tuning EFI.

i used to think carb was far similar, but once you have a computer that you can tune the MPFI, TPI, or SFI-its all a matter of learning when the fuel injector(s) should start their pulse, how long that pulse will be, and what kind of spark advance/retard you will need to achieve the proper burn.

carb is less reliable & id imagine EFI (at each intake port) allows for better mpg as well as throttle response.

also i wouldnt toy with the compression until you learn what you need about the whole injector pulse/spark advance & retard-system.

[robertisaar]

i personally don't like the MS setup for a few reasons

1. NO KNOCK DETECTION!!!
2. no tranny control
3. GM has MUCH more sophisticated ECUs.

i'd stick with the OBD2 computer before anything else. you'll be paying big bucks for HPT, but its a proven/reliable setup with lots of support.

the rest of no_doz's post: agreed, its pretty simple to see gains on these cars from basic stuff like that. once you get around to cam/headwork/high comp pistons, they you'll NEED to know what you're doing.

[no_doz]

if you switched to OBDI then www.moates.net has a programming utility that you could buy to tune it/read trouble codes yourself for like $150 or less shipped for everything, but i know im going to catch hella-flak for suggesting switching from OBDII to I, so you could always pay the $500-600 to go with HP-Tuners, everyone i know thats used them is a big fan once they get over the $$ sting.

[robertisaar]

if you switched to OBDI then www.moates.net has a programming utility that you could buy to tune it/read trouble codes yourself for like $150 or less shipped for everything, but i know im going to catch hella-flak for suggesting switching from OBDII to I, so you could always pay the $500-600 to go with HP-Tuners, everyone i know thats used them is a big fan once they get over the $$ sting.

switching from 1.5 to 1: fairly straightforward, now easy process
2 to 1: NO, especially with all the other computers in the car that rely on the PCM for converted values.

and are you refering to the autoprom? cause thats around $330..... or do you mean the ostrich? thats more in the 150 price range. can't burn chips with it though...

[geoffinbc]

Agreed Keep OBDII if you have it. Its flash memory and does not need chips every time you change something. Not to mention a late model car will shit a brick if the original PCM is missing. Plus you will fail emissions if you don't have it.

[robertisaar]

X2 with all of that, except changing chips is a 10 second process, i don't see anyone having a problem with it. how long does it take to flash a OBD2 PCM?

[Superdave]

how long does it take to flash a OBD2 PCM?

More time than it takes me to click the up arrow in Tunerpro to update my Ostrich.



polishdog, start with the bolt-ons first. a upper intake from a '04-06 3500 V6 coupled with a 65mm TB would be a good place to start. Also, unbolt your exhaust downpipe and see if you have the funnel restrictor in there, if you do then do whatever it takes to hack that POS out of there. Some of the downpipes are reduced to as little as 1 7/8".

After that i'd look into headers, there are some made for the Grand Am GT that might fit decently.


If you still aren't satisfied then visit www.wot-tech.com and check out the cam selection, and ported top ends. At that point you might be hitting the limits of your trans though. You will need tuning after adding a cam or ported heads.

[Superdave]

i used to think carb was far similar, but once you have a computer that you can tune the MPFI, TPI, or SFI-its all a matter of learning when the fuel injector(s) should start their pulse, how long that pulse will be, and what kind of spark advance/retard you will need to achieve the proper burn.

carb is less reliable & id imagine EFI (at each intake port) allows for better mpg as well as throttle response.

also i wouldnt toy with the compression until you learn what you need about the whole injector pulse/spark advance & retard-system.

all this from a guy who has never tuned anything in his life! Amazing!

[robertisaar]

he is learning quick though...

it seriously takes me a total of 15 seconds to blank a chip, burn it and have it installed..... and that includes me limping my ass from the seat to the hood!

i've heard of flashing PCMs taking up to a minute or more?

[IsaacHayes]

Superdave has good ideas.

Yes OBDII flash takes minute or more depending on what all you do. My ECM is behind the glove box under the dash hidden, not so easy to get to to swap chips... for me the ostrich would be better.