-305 LO3- SCR 9.5:1
mods list
LT1 Cam
Hyper pistons
081 heads (slight pocket porting/cast clean up/gasket match)
Street dominator Intake (gasket match)
TBI to Carb'd intake adapter
TBI MOD (stock injectors)
1 5/8 2.5" collector (currently open headers)
That's about it...

I'm curious how far out the parameters will go from where stock normally ran. I mean, Based on MODs and using the stock tune, is the ECM correcting enough to where I can drive it and not worry about BIG issues or should I wait to get a TUNE before I do any serious driving.

I have a scan tool and can post the parameters it runs at currently if that will help answer the question.

 

With the non-swirl heads additional spark advance should be dialed in. Can cheat until tuning gear is had by setting the base distributor timing to 6* BTDC.

RBob.

 

It should be fine to drive. Might run a little rich

 

Spark table will need some work like RBob already pointed out.

Fuel, fueling tables and fueling system will need some major work, I used the LT1 cam in a low miles stock LO3, with all supporting moods, the engine was producing somewhere around 240fwhp.
Yours should produce at least, the same numbers, wich will require drastically more fuel then the stock TBI was set up for.
IIRC I was running around 24 psi of fuel pressure. Here you can see my first steps, maybe it helps https://www.thirdgen.org/forums/diy-...o3-lt1cam.html

 

Few questions.
1. Do I need to go with bigger than stock injectors?
2. Different fuel pump?
3. Does the ECM ever go in and out of closed loop?
4. Does ECM ever experience limp mode with mods like these.
Reason I ask is cause I went for quick ride and the trans didnt seem to wanna shift outta 1st... I did not mess with detent.
Fumes seem to point to running rich, but scan tool shows it spends more time on lean side.... around 450 to 500 or 550 ish mv.

I will check your thread out. THANKS

 

Could try bigger injectors, the TBI pump builds up around 16psi maximum.

For more fuel delivery you either need to increase fuel pressure with the existing injectors or use higher flowing injectors.
In order to increase fuel pressure, need to use a TPI fuel pump or similar.
Both ways will require serious tuning, to make the whole upgrades wort it, otherwise you will end up bashing on the TBI system like everyone else that has no clue how to make it work on an upgraded engine.

The TBI ECM is not a performer, but with a minimum of a decently custom tuned chip your set up should still run nice.
If you can afford to upgrade to EBL flash it is totally worth it, it is the main key for performance TBI set ups.

If the trans does not shift, check and inspect the transmission. It is not TBI related, except for the TV cable.

The stock TBI tune on your engine will run lean in the upper rpm's and rich in the lower rpm's. The low rpm issue will mainly be cured with adding SA. For the upper rpm's it is probably safer to leave the SA as is until you do some fueling upgrades.

 

Thanks for the replies... I'll be back on here once I can figure out the multitude of mechanical issues I'm currently experiencing. Then I'll start to look at potential upgrades... No point in upgrades right now if I can't even get the current bugs ironed out. THANKS.

 

Plan on buying or building a ALDL cable. Download winALDL or TunerProRT for tune software. With that you can work on the fuel tables while in closed loop seeing BLM updates.
that is what i was going to ask next. Are you getting crosscounts? 02 mV should be cycling across .450 repeatedly. does your scan tool show CL or OL? With headers you may benefit from a heated NB02.

 

Software and hardware have been acquired. Not sure on what crosscounts are yet... Also not sure on the type of O2 in the header. The headers/O2 were on my other camaro when I purchased it. The scan tool was showing between .450 to .650. The car took a while to get into closed loop, once it did, it would ocassionaly show open loop, then back to closed loop. Also, on the scan tool it shows rich or lean... when watching the O2 mv's based on what I seen it seems as once the mv's crossed 600 to 625ish then it stated rich briefly but quickly jumped back down to 500ish. At least based on what the scan tool stated, about 75% of the time it stated lean. Sure as heck didn't smell lean in the garage.

 

I would check fuel the pressure.

 

Gauge states 12 PSI pressure.

 

Well I FINALLY got the major issues worked out and was able to take another test drive. Referenced the scanner while driving and for some reason the o2 readings seem to have changed drastically. A lot more fluctuating goin on now than before, not sure why. I guess it's time to move over to the DIY PROM forum and start getting her tuned in. Thanks.

 

The fluctuation can be considered normal.

My question for Rbob is in the analysis we dont see the swing. How does analysis convert to a average(?). Is it an average?

 

Nice, what was it?

 

Amateur mistake on my part, forgot front expansion plugs behind cam gear. finally got decent oil pressure. 2 things I still dont like. Temp gauge if wrong, using an obd scanner I see true temp and based on temp and when fan turns on seems like its off. Maybe I'm just paranoid. 2 more importantly where the trans is shifting. I had to modify stock throttle/detent bracket to work with my setup (carb'd intake with TBI spacer. My geometry might not be correct, or again I may just be paranoid. 1-2 shift @16 mph, 2-3 @ 26. Can't remember 3-4.