Tuning a 93 3.4 Firebird

[tkoforpresident]

if you're running without EGR, the only cell you need to change is the 0% cell... assuming you disable it by making the coolant temp enable temp an impossible number...

it's not tough to do, it's all simple math. isaac is working on a guide specifically for doing the obd1 swap to L cars and there is an exact method in there that we devised through a bit of IM chat...

VE: you could take a fairly educated guess at what the motor wants, but datalogging will be necessary for a good tune.

Right now the EGR is actually working fine, but i can certainly disable it easily the way you are suggesting.

I'll go ahead and data log before asking VE suggestions.

thanks

[robertisaar]

if you're running without EGR, the only cell you need to change is the 0% cell... assuming you disable it by making the coolant temp enable temp an impossible number...

it's not tough to do, it's all simple math. isaac is working on a guide specifically for doing the obd1 swap to L cars and there is an exact method in there that we devised through a bit of IM chat...

VE: you could take a fairly educated guess at what the motor wants, but datalogging will be necessary for a good tune.

[tkoforpresident]

it would be more intelligent to change the BPC rather than the VE tables, or not at all, when adjusting fuel pressure.

think of the BPC as this: it tells the relation between the injector flow and engine size.

example. a 3.5 with 10lb/hr injectors at 50 psi would want a BPC of 256(example, do NOT use this as an actual basis), while a 3.5 with 20lb/hr injectors at 50psi would want a BPC of 128. there is double the fuel flow, therefore the BPC needs to be cut in half.

since you are increasing the pressure from the rated psi of 43.5, you'll need to lower the constant a little, the exact amount depending on the exact pressure you're running.

as a little test: what % change do you expect to make for using 19lb/hr injectors at 47psi?

EDIT: exact terminology will vary depending on who wrote the XDF. i don't rememebr which one i usually do, but they are analogous.

Ummmm, if it will make things easier i'll just set psi to 43.5 and run 210 BPC straight across the board.

It's easy to do with my holley adj. fpr and autometer gauge.

btw Robert, you bring up VE. From what i have read this is a major issue considering what i have done with my heads/cam. How will i go about changing the VE? I'm assuming you will have to data log first?

[robertisaar]

it would be more intelligent to change the BPC rather than the VE tables, or not at all, when adjusting fuel pressure.

think of the BPC as this: it tells the relation between the injector flow and engine size.

example. a 3.5 with 10lb/hr injectors at 50 psi would want a BPC of 256(example, do NOT use this as an actual basis), while a 3.5 with 20lb/hr injectors at 50psi would want a BPC of 128. there is double the fuel flow, therefore the BPC needs to be cut in half.

since you are increasing the pressure from the rated psi of 43.5, you'll need to lower the constant a little, the exact amount depending on the exact pressure you're running.

as a little test: what % change do you expect to make for using 19lb/hr injectors at 47psi?

EDIT: exact terminology will vary depending on who wrote the XDF. i don't rememebr which one i usually do, but they are analogous.

[tkoforpresident]

What fuel pressure do you run stock? If adjusting for fuel pressure, use witchunter.com's calculator. It's more realistic as after a while higher pressure doesn't increase flow a whole lot.

I think A1$ is 16.7lb/hr. Opening BFUZ bin shows 224 for the BPW vs EGR at 0% EGR.
So for 19lb/hr injectors we take old injectors/new (16.7/19 *224) = new constant for 3.1L with 19lb/hr injectors. 196.88421 ... Now to adjust for larger displacement.

3.1L is 3136cc, 3.4 is 3350cc (have to use actual CC to be accurate). This time take new displacement, divided by old, times constant. (3350/3135*196.88421)=210 BPC. In TunerPro RT you can apply your adjusted value across the whole EGR table in case you want to enable EGR.

I can run whatever psi i want (well, up to 60 psi that is)

stock calls for somewhere in the range of 42-47 so i can adjust it to whatever i want. I suppose i'll put it at the high end of the range at 47, so would that change my BPC at all? (which you figured out to be 210 up there ^)

Also, the boxes that need to be changed are going to say what?

BPC? or BPW vs. EGR?

thanks

max

[tkoforpresident]

as you can see, isaac already posted it. that is the easiest and most foolproof way to do it.

thats it? cool, thanks.

[tkoforpresident]

Wow, you finally built that thing huh?

I will check it out when i have a moment.



Cam specs are:

valve lift- .451/.456

Dur @ .50 - 224/230

Adv Dur : 275/273

LSA: 109*


these specs are for stock ratio rockers ^^
i'm running1.6 roller rockers

[60dgrzbelow0]

...lol good old Bob from Clearwater... I'm glad to finally meet up with you again.

Thanks for your concern, honestly. That was a picture I had taken so that I could verify that I had it in the "wrong" position. I did end up moving it over a tooth or two and got it correct. Just trust me that this camshaft is the main problem (aside from the injectors)

Same here...Max...! You are finally among "Friends" while visiting this place...

Whew... I'm glad its NOT the Timing Set...since that involves so much more to get to and fix. But as for the camshaft issue... Have you got a scan or a photo of your Grind Card? It might be interesting to see what is so "Radical" about it on paper....and then let the "Tooners" have their way with the numbers and see what's what.

And as for the Injectors... Man... 19 Lbrs vs, the Clock Stock 17.7 Lbrs will run as "Rich as Croesus" and without a way to manage how much gas you're dumping into the motor... the engine oil is going to get as thinned out as my hairline!

Speaking of Electronic Fuel Injectors... Can you guess what Bobby just finished building?....! Yup! I finally got my Home Made EFI Cleaning Machine working perfectly! (I call my "Frankenstein Design" of it "The FrankInjector Machine") When you have some time ...please check out the thread for the videos, photos and other information about it here:

http://60degreev6.com/forum/f97/home-made-fuel-injector-cleaning-machine-t42889

It's nice to hear from you again:MAX... aka tko4president!

[robertisaar]

Care to share ??

as you can see, isaac already posted it. that is the easiest and most foolproof way to do it.

[tkoforpresident]

lol good old bob from clearwater.

I'm glad to finally meet up with you again.


Thanks for your concern, honestly. That was a picture i had taken so that i could verify that i had it in the "wrong" position. I did end up moving it over a tooth or two and got it correct.

Just trust me that this camshaft is the main problem (aside from the injectors)

[60dgrzbelow0]

That could very well be an issue, and I agree, it looks like it is off by a tooth. Nice eye, Bob!

Why...Thank You, Sir!

Max and I are old friends from another forum... and we have worked on similar problems going back over almost a year, specifically covering 4th Gen F-Body Engine related stuff . I think that was the only reason I spotted the problem!

[bszopi]

That could very well be an issue, and I agree, it looks like it is off by a tooth. Nice eye, Bob!

[60dgrzbelow0]

The cloyes timing set cogs look gollywogged

Max... Welcome Home...!!! "Teek"

(It's your Ol' Buddy... --==Bob==-- )

Like you... I don't know Car Parts from Cow Paddies about the GM V-6 Engine Tuning side of things, but I've just looked over your photo-bucket images and saw something disturbing that caught my eye about the alignment of your Cloyes "True Roller" Timing Set. Without knowing whether you've re-done anything to your motor since those tear down images were taken, ...it appears that your Timing Sprockets are misaligned by at least one tooth...with the Small Cog on the crankshaft being off-set by one tooth just left of center and not being at "12 O'Clock High" and in line with the Big Cog Marker at "6 O'Clock Low". Call me crazy here... but if the engine is running a little ragged and unsteady, power-wise, beyond what you'd expect from the normal lope of your CompCam... (Better make that "Forced-Firebird's Killa-Kamshaft") with the CompCam Roller-Tip Rocker set up... wouldn't this discrepancy help to explain the problem? AFAIK... The Cloyes key ways are pre-set between +4 Degrees Advance to -4 Degrees Retarding...and according to everything I was able to determine before installing mine... the GM setup does NOT require any tinkering with A/R to make it work correctly with the CompCam 260H Camshaft. With no "Tuning" insight... Am I right about the idea that being off even one tooth would cause the problem here, guys?

[tkoforpresident]

Oh yeah, if you change injectors from stock everything goes out the window. My injectors are still stock. I don't have anything like a huge cam or different injectors, I know that would be impossible to drive on. But as it sets it's drivable. The new motor will be drivable but only if tuned of course.

What fuel pressure do you run stock? If adjusting for fuel pressure, use witchunter.com's calculator. It's more realistic as after a while higher pressure doesn't increase flow a whole lot.

I think A1$ is 16.7lb/hr. Opening BFUZ bin shows 224 for the BPW vs EGR at 0% EGR.
So for 19lb/hr injectors we take old injectors/new (16.7/19 *224) = new constant for 3.1L with 19lb/hr injectors. 196.88421 ... Now to adjust for larger displacement.

3.1L is 3136cc, 3.4 is 3350cc (have to use actual CC to be accurate). This time take new displacement, divided by old, times constant. (3350/3135*196.88421)=210 BPC. In TunerPro RT you can apply your adjusted value across the whole EGR table in case you want to enable EGR.

I don't like the slammed look either, but I like even gap around the sides and top

Did you just figure out my BPC for me??

What's your paypal addy?




jk

[tkoforpresident]

Hey Max, glad to see you migrated here

Robert, you may have gotten the swap done first, but how you like my cam I designed for Max? Mowahaha.

John, the cam is so nasty in person it's UNREAL. That vid clip makes it sound way tinnier (think i just made up a word) than it really is.