Fuel injectors were cleaned by witch hunter. Did a good job.

I try to find out what fp is at wot

Think it'd.be best to go with the larger injectors or spring?

 

I say keep inj's as is and add the stronger spring($13?)...

 

Picked up the spring from TDS. Havent installed it yet im doing it tomorrow morning. Just finished installing LS1 brakes on the firebird, not on topic though.

So when i install this spring, and up the FP, if it does solve my too high injector DC would i just pull fuel out of the ve table at idle to not run too rich? If not how will i work out fueling at idle?

 

It may or may not help the high DC%. you will find out in spring. If still over 85% at higher new FP then you need larger injectors.

It will and should show a lower BLM (pulling fuel) requiring that you pull a % from the Ve table.

Yes you may need to pull fuel at idle rpm and surrounding cells. Watch the BLM that occurs at idle in CL and respond accordingly. A solution to ovely fat idle AF is the vafpr.
I run 26 lbs with 75 lbs injectors so vafpr helps that. I idle OL at 13.5/1

 

Ok so the new FPR fixed just about everything. Every ve learn shows 0 or +-2 in a few spots.

Low Speed


High Speed


Now to my question. So ive been working on my SA Main and Extended tables. Whats with the factory SA advance table and the mountains? Ive basically been adding spark and then retarding 2* if i saw knock(which i havent yet). How can i get away from simply adding spark to this entire factory tables(minus the places i kept at 0*, and truely finding MBT?

Original SA Main table


New Main table


I know theres other factors to spark advance, but it seems my main tables are simply more advanced table of the original(which it is lol).. Where should i go from here. Engine feels smooth as well throughout the powerband, no pinging, loss in power, no real gain by feel either. Any advice?

 

I see you VE high table at WOT over 3200 rpms fuel drop off? Like 85 down to 77. Mine has a flat line over 4500 or so to 6200. Would not you need more fuel at rpms goes up? granted no leaning there unless a WB.

2000 rpms at 60 M is only 20 d SA? Hyway cruise could be there. Why so little timing?
I need to dig up my SA table. I believe I am using a LT1 iron head F body Sa table. OK I did. I am at 31dSA there.

I do not think we can tune SA totally other than on a dyno. WOT can be done at a drag strip logging MPH with appropriate datalogs carefully changing A/F and SA. There is a write up on that in stickies I believe(Traxion).

 

Whats up Ronny.

This is all done by NB. Wideband bung is still attached to the hooker header y pipe. Im not having any fueling issues from what i can tell. When accel in closed loop my BLM and INT numbers hover around 129-131. Which i didnt think was too far off, right?

As for SA, i need some advice. I see the low spark areas your talking about, all ive done is add spark across basically the entire table. I havent done any real "aggressive" changes toward my SA tables. Tuning for SA on the street sucks, hard to focus, pretty much impossible, and hit all the required engine speeds/loads i need to ensure theres no knock and positive gain.

Im more wondering in what areas should i keep advancing and in which areas should i not be advancing too much?

Edit* checking out that stickie you mentioned now

 

Well it is intuitive. I started day one with some serious mods. I used a truck SA table(7747). Very conservative. then went to EBL with a 305 auto table. Again very consevative. This past season I moved to an iron head LT1 table. then I compared to the alum LT4 and added about 2 deg SA to iron LT accross the board. No knock. I have new version of EDEL RPM heads 64cc and -6cc pistons about 10.0-10.5/1 compress. I may jump to Alum LT4 in spring and increase SA retard for N20. I pretty much copied existing GM tables.

 

Havent made any progress yet. Any SA tables i should look up to get an idea of what direction i should go with mine? Think that it could make a huge difference in the performance of the engine, i think this SA table is very conservative

 

Looks like basically stock L03?

Run stock SA tables and or run 91-92 octane and add to tables globally maybe 3 deg and see if KC appear. If none add another 1 deg. I would add maybe half in main table and the other half in PE adder.

 

Basically what ive been doing. Ill keep working on it and post back when i get something done.

 

No knock counts yet, anywhere, seems odd? only counts i get is on shutoff, at 400RPM and low MAP





Could use advice, Rbob, Ronny, where are ya ?

 

I built a 10:1 305 running 187 TBI heads and ran a LT4 production cam in it. Timing was right at 28* at WOT and it liked 20* from 1,000 RPM and beyond at WOT. No detonation, knock counts, or pinging on 93 octane. That was pulling around 5,500 lbs of Chevy Van.

I prefer not to use the PE adder table at all. If you bypass the PE fuel delay and set the PE TPS entry point appropriately there is no real need for PE spark.

 

Think you could go more into depth about setting the PE TPS entry point appropriately?

 

Do some datalogging of RPM vs MAP vs TPS and chart it out so that you are in PE by the time you reach ~80 KPA MAP. Treat the TPS PE entry point like the power valve of a carb. The driveability and torque will increase and so will the fun.

 

Am i using the PE- TPS% enable Threshold table to do this? dont think its to the TPS% Hysrt table.

Also, any info on the spark tables i posted? Not sure if i should leave my idle ranges alone and the higher RPM ranges alone and simply add spark advance to my mid range area.

 

Not made for your engine, but this could represent what a rough starting point might look like.

 

Thanks for that, gives me a good idea on where to start.

Heres what i got from that example xch2no2. Havent ran it yet though.



Another one i just did. This one im too scared to even try to run haha. Thoughts?

 

I like a little flat shelf for stable idle timing.

I think you can add some more, I would keep adding lead untill it objects (knock counts), then back off as much as maybe 4* to stay safe.

Try to get all the timing in as early as possible (making the flat top as large as you can).

The table I posted could use smoothing...it has none.

 

WS: dont overlook the PE SA adder.

 

Working on it now. Ill post back with results. Working with the pe table now but to be honest Idk how my changes in the table are effecting performance if that makes sense

 

I'm not using any PE-SA modification.

PE fueling is best observed as WB AFR in logs.

 

Think im SOL for now on pe. Wideband bung is still attached to the hooker y pipe until the headers go back on.

Ill show my results tomorrow hoping it doesn't rain.

 

So im running that second table that i posted in post #68. Theres a big difference in the way the engine pulls around 1800-2000RPM's. Its very noticeable, even put the factory spark table back in and had a friend drive it, then switched it back to that SA table and he could feel a better pull without me saying which was which.

Im thinking if maybe i went a little more like xch3no2 suggested it would be more beneficial. Kind of impressed to be honest. Think its worth having the car dynoed after i get this a little more dialed in to see what gains are made over the factory tune?

 

Certainly that is a good idea.

Unfortunately the General spends many hours on dyno to perfect the tune for emishions and performance. Only practical way for us to do off dyno is top speed. I wonder if a performance analyser like G Tec would do that. A WB would confirm A.F at 12.75/1 during a 1/2 mile pull. I have a pod mount which I glance at when doing a safwe pull. I can log AF as well through software. But changes in SA would be hard to evaluate. This past season I went to a LT1 SA map and then looked at LT4 and moved 1/2 way toward it. NO KC when heavy on throttle. Peak TQ I think I had a few but nothing serious.

 

Thanks Ronny. Decided now isnt the best time. Figure I should install the headers i have with the wideband as well and fine tune it then go for an hour or two of dyno tuning.

Ive been using that table like i said and it really makes a difference. Im going to add more SA in the mid range and go from there.

The throttle response and overall speed of the engine is a lot better now. I know its slow compared to say a 350 with a better tune but it doesnt "feel" slow. I keep up with cars that have higher HP ratings than this l03. Ill post back this week with the new SA.


EDIT: Went out and made some changes to the Main SA table.



Needs smoothing and more work, but its a start i think.

No knocking, "feels" to have more power from a roll(30mph right under 2k RPM). From a dig it "feels" to have more power as well.

tuning by "feel" though doesnt really give me much to go on. Think i might have to hit the dyno to see if im actually making progress.

Suggestions? thoughts?

 

headed back out tonight, an advice before i go?

 

No love?

Well im going to set up the base tune for the 61hr injectors I have. For the ve tables should I just keep what I have and start with learns or should I subtract an "x" amount firs?t

 

Change the "BPC - BPC vs VAC" table to match the new flow rate.

RBob.

 

Thanks for the reply. I've already changed the BPC I was worried about the fuel pressure. Leave it at 14.5 or lower it because im using larger injectors or leave it as is and subtract an "x"amount from my ve tables

 

??? Set the BPC accurrately and forget it. I believe dynamic offerred a utility to calculate the value(s). Theoretically if you recalc the BPC for any change of inj/cid/fp it will not affect the VE table. Sort of balances out.

 

Thanks I wasn't aware of that. Learned something else. Appreciate the input ill post back with more questions later

And why is it that changing the BPC doesn't effect ve? I thought they were directly related?

 

Id like some more input on this. I have not installed the 61lb hr injectors yet, and feel there is still more power that i can bring out of this LO3.

The car is noticably faster and has more mid range torque/power. It feels a lot faster than the factory tune, but i think i can squeeze more power, just not sure where to look.

The PE adder table is still stock, should i start here? Also the LM SA tables are stock as well. Or should i still be focusing on the main SA tables?

any input?

 

To know whether larger injectors are required, several items need to be taken into account. First is the injector duty cycle (DC%), once over 85 more injector flow is required.

However, this is only if the AFR is not too rich. If too rich then lower the injector PW will also lower the DC%.

For the current tune, you may be reaching the area of diminishing returns. The LM SA table can be changed to see if a better hole-shot can be had.

Same for WOT SA, a little more may help, but again, it may not.

If you can do consistent 2nd gear pulls, they can then be compared against each other. Can use either the performance graphing and measurements, or Excel to look at the data.

One trick is to open 2 sets of the WUD, performance graph each of the two different data logs. Over lay one graph exactly on top of the other. Then flip between the two of them via ALT+TAB.

Observe the RPM & MPH traces on the graphs and you will be able to see the differences easily. The one with the higher rate of acceleration is usually the better tune.

Note that the same stretch of road and the same weather conditions help in getting repeatable results.

RBob.

 

Thanks for the input Rbob. Holding off on the bigger injectors till i install the wideband to verify WOT AFR. DC is high though.

And i think your dead right about this current tune being at its "peak" id say. Guess i need to look elsewhere for power(supercharged 305 doesnt sound bad). Appreciate the input here.

So what your saying is to datalog and use the performance reports from the WUD to see what gains are being made? i didnt think of that.