Axoid

I'm declaring my winter project finished. I upgraded my L03 with and LT1 cam, World Torquer 305 heads, and an Edelbrock Performer intake, plus some odds and ends like timing chain, two piece timing cover and a Fluidamper balancer. I finished last night with the WOT tuning on a dyno. In the end it put out 212.8 rwhp @ 5400 rpm and 251 rwtq @ 3800 rpm. This is max'ing out the stock injectors, so when I want more, I'm going to need new injectors.

The red graph is the first pull of the night when the AFR was dropping to a low of 9 to 1.

Dewey316

nice numbers!

now i am worried about my injectors, what dudy cycle are you running on the upper end? also what is your fuel pressure at?

ShiftyCapone

iTrader: (7)

Axoid

You just completed what i will have done by the end of the summer. I plan on getting mine Dynoes as well. I am going with the LT4 cam instead of the LT1. I am also going with a set of pro magnum rockers. What did you use in your valvetrain? ALso, do you have a link to that intake you used. I already have the performer TBI intake but it looks like you have a adapter plate on a carb intake. I am thinking about switching intakes when the heads and cam go in.

Axoid

Dewey316:
Fuel pressure is at 13 psi, I have a pressure regulator but even turned all the way up I can only get 14.5 psi. As for duty cycle, I don't know. The ECM doesn't output that information and I don't know how else to get it.

ShiftyCapone:
I reused the factory lifters, rods and rockers. I'm planning to getting Crane self-aligning rockers and new rods sometime later this year. The intake is the Edelbrock #2101, a Quadra jet intake with a Holley TBI adapter plate. I had to have the intake drilled and taped for the temp sensor and added an additional vacuum line on the right side to go to the break booster. I decided to use pre-87 style heads because it gave me more options on intake choice. I may end up with a multi-point injected single plane some time in the future.

ShiftyCapone

iTrader: (7)

Great info, thanks.

I may try and bore the intake I have now to 2" so that i can eventualy use a larger TBI unit with my setup. I know that the edelbrock TBI intake has thin walls and water passages run right by the bores. How much power do you think you can get out of her. I have seen TPI 305's with stock heads put around 250hp to the wheels. Surely we can get past that can't we?

vjo90RS8

iTrader: (1)

what chip are you using?

kevm14

Does that answer your question?

Axoid

250 rear wheel is equal to about 290 hp at the crank, that's a good number for a 305. GM 80 lb. injectors at 13 psi are good for about 320 hp. So I think a TBI 305 can top 300 hp, but it would take a good bit of tuning.

A friend of mine that has a LT1 firebird gave me the stock ignition map from his car. I didn't use it as a strait replacement, but it was a big help. You might find it as a useful reference.
-------25--30--35--40-45--50-55--60-65--70-75--80-85--90-95-100
0400--16--16--27--28--28--26--24--24--20--20--18--14--12--11--09--08
0600--24--24--27--30--30--29--27--25--24--21--18--16--13--11--09--08
0800--27--31--32--33--33--32--29--26--25--22--19--16--14--11--09--09
1000--32--38--39--36--34--33--31--29--26--23--20--16--14--11--09--09
1200--34--40--39--38--37--35--34--33--29--25--22--18--16--14--12--12
1400--35--40--41--40--38--36--35--34--32--28--25--22--20--17--14--14
1600--35--41--41--41--40--38--37--35--34--31--27--23--20--18--16--16
1800--35--40--43--43--41--39--38--37--36--34--30--26--23--21--19--19
2000--35--40--43--43--41--40--39--38--37--35--31--28--25--24--23--23
2200--35--40--43--43--42--40--40--39--38--37--34--31--28--28--27--27
2400--35--40--43--43--43--41--40--39--39--37--35--34--32--31--30--30
2800--35--40--43--43--42--41--40--39--38--37--36--35--35--35--34--33
3200--35--40--43--43--42--41--41--40--38--37--36--36--35--35--34--33
3600--35--40--43--44--43--42--41--41--39--38--37--37--37--35--35--33
4000--35--41--43--44--43--42--41--41--39--39--38--38--37--35--35--33
4500--35--41--44--44--43--42--41--40--40--40--39--38--37--35--35--33
5000--35--41--44--44--43--42--41--40--39--39--39--38--37--35--35--33
5500--35--40--44--44--43--42--41--40--39--39--39--38--37--35--35--33
6000--35--40--44--44--43--42--41--41--40--40--39--38--37--35--35--33
6500--35--40--44--44--43--42--41--41--41--41--39--38--37--36--36--36
7000--32--36--46--46--46--46--46--40--40--36--33--30--29--28--27--26

ShiftyCapone

iTrader: (7)

Thanks,

That is awesome. Chuck on this board is tuning with his LT1 cam and vortec heads. He is about 5% there (or what he says) and he is still learning the whole burning process. I will pass this along to him so that later he can burn one for me

JPrevost

Glad you aren't just replacing the current timing tables with that from the Lt1.
Major differences; you vs lt1, 305 vs 350, dual plane vs mpfi, wet flow vs dry flow, standard cooling vs reverse cooling, different coolant spark maps, different heads. It is however interesting to take into account every table for a given engine condition and figure out the timing.

Pablo

iTrader: (1)

This is a real good post

I hate to interrogate you but im curious to know what you changed and by how much or atleast an idea of what steps you took.

That graph is great, Im guessing that huge dip in power around 3.5k is where it was real rich which would coincide with peak torque on the stock setup. If thats the case thats actually surprising to me I wouldnt have thought it would have been such a big difference. Was it on the stock calibration for that first pull?

What sort of % ve difference was the change that brought the AFR to where you wanted it in that area?

also, did you just shoot for a specific AFR for your WOT tune? I noticed on the first graph the power came back up round about 4.5 k and it actually looks like it was on a higher curve upwards than what you ended up with. Any explanation for that? Ive read many times that peak torque requires a richer AFR than peak HP, if you used the same afr across the board do you suppose that could be happening? (since it would be presumably be leaner up top with the stock cal than say around 12.8 to one or so which I tend to see alot of people aim for across the board)

Chuck!

What AF ratio should we be shooting for with n/a cars at wot?

Axoid

Before the dyno session I had only worked on tuning the Main Fuel Table and the Main Spark Advance (I had to add a load of timing to it over stock). After the first pull I altered the Power Enrichment AFR vs. RPM table to make the gross adjustments (there is only five values in this table). After the third pull I then altered the %Volumetric Eff. Adder table to try to smooth out the curve. I did shoot for around a 12.5 ratio.

I think the power came back on the first pull because the injectors had max'd out and the rpms came to the fuel ratio.

I only had the dyno for an hour, so the maps could still use some more work, but it's a hell of a lot better than it was.

This is the AFR graph (the ratio is really about a half a point lower than shown, because I'm running a high flow cat).

Dewey316

that really explains the sharp power drop a 3500.

also , maybe someone can answer another question for me, most dyno a/f graphs i have seen drop from right down to 12.5 or lower when you initial mash the gas, his seems to taper down rather slowly, would that indicate that he needs a larger pump shot?

i am fairly new to all this, and i was looking at the a/f from my dyno runs, and others i know and then looking at his.

Pablo

iTrader: (1)

The one that delivers the best performance.

Every car and combo is different but very generally, peak torque is going to be around 12.7 to one and peak horsepower is going to be somewhat higher... 13.0 , 1 , 2 ,3 even

Axoid, if you dont mind me asking you a few more q's, was the change on the pe AFR table anywhere linear to the actual change of the WB o2 sensor?
and just to get this straight, you made some changes to the part throttle stuff before but you didnt really touch WOT? Fueling wise anyways? When you did go into the ve#2 to fine tune how fine % wise were you using it to tune?

BTW I think you are right, just judging by that graph and the fact that you are at 12.5 across the board I think you could pick up even a little more power than you have now with a hair more fine tuning

anyways, thanks for replying

Pablo

Chuck!

Im kinda curious as to what helped more, too because Im doing 3 pulls in a few weeks and I'll be able to make changes, but I'll only be able to see what helped twice.

JPrevost

peak torque AFR should be between 12.7-12.9, peak power AFR should be between 12.9 and 13.1
If you've got a dyno and are REALLY concerned about gas milage you might want to try and go as lean as 13.6 or 13.8. We've found lean best torque on our small motorcycle engines to be right around 13.8. They are a different beast, so keep it under 13. If you go to the track after the dyno, remember the calibration (that's a no brainer) and play with the commanded PE AFRs.

Axoid

No, I don't mind. If I remember correctly (I don't have the file in front of me to refresh my memory) it wasn't a direct linear correlation from the PE AFR table and the WB O2.

No, I hadn’t messed with tuning WOT until I got it on the Dyno. I didn’t trust the readings that I could get from the stock O2 sensor.

As for the VE #2 table, from around 4800 rpm and down I only made some minor changes, but above that I had to make large and significant changes. Some changes as large as 30 or more points higher. The PE AFR table and ends at 4800 and with the VE #2 unchanged the engine started going lean above that.

Pablo

iTrader: (1)

Axoid: I really wish I had access to my own computer right now Id like to see what the bin looks like that you ended up with. I guess Ill wait another month or so till I get back to land (im on a ship right now) and have you send it to me if thats cool with you.

Just two more Q's, did you mess with the BPW any?
and
When are you gonna get that sucker back out to the track to get some new times? It should be way quicker in the 1/4 now

Congrats on getting it pretty much dialed in, if more TBI guys tuned their setups like this there would be alot faster tbi cars running around.

Axoid

Didn't mess with the "BPW Constant vs Vacuum (EGR On)". I have the EGR disabled.

Next week my F-Body club is renting out Norwalk raceway and two days later I have an autocross event.