009's all done @110% Duty Cycle? (T+ tuning)

[Steve Wood]

Actually, Bruce, you usually give a glib answer and invite people to figure it out for themselves....It is very nice to see you actually give consideration to a question and a reasoned reply.

The fact that you so seldom give a reply based on real data is actually immaterial to me as the theory is interesting. It is your normal arrogant glibness that prevents you from reaching a broader audience. I hope this is the beginning of a new leaf for you as your views, when actually presented with some support, are very thought provoking.

The fact that injector sizing can actually be computed by anyone using simple arithmetic based upon a range ofaverage fuel consumption per horsepower from real data generated and measured during dyno runs would probably be too simple a concept for you but Joe L's chart could be made much more meaningful if the bsfc was change to .6 from .5 #/hr which at 80% duty cycle probably comes close to your number.

I see that since the last time you informed me that technology has advanced greatly since the time of Tomn Chou and the GM engineers you have discovered the wisdom of their AFR tables and are giving them some credit. It is nice that the 55#/hr injector is approximately twice the size of the factory units so observant guys like you can cut the scaling by half and retain all the benefits that the original guys designed in.

I would not be surprised to see a little binary gain recovery at work in the future and suddenly we can use even larger injectors and measure 768 gms of flow.

 

[TurboJim]

Originally posted by bruce



Wellll,
Just for grins, since you seem interested in this, I ran a few chips on the ecm bench to actually put some numbers to this.
editors not: Steve turn away, we don't want to blinded by any real data, ie that stuff that doesn't make a HP or ET claim.

Given a set of normal operating conditions for temps, and TPS values.

Using an injector size of 55PPH, and a MAF of 160 to acheive a commanded AFR of 12.5:1

At 3K RPM, the DC is 63% and at 5K 62.6%

Now to repeat that with a MAF of 255 we get
At 3K, 98.4%, and at 5K 100.1%

Only problem I have with the math is this. Back to the pressure thing. If your pressure is such, that the injector is only going to flow 45# of fuel, then yes, you may near 100% DC to achieve your commanded AF.

For ****s and grins I plugged some numbers into my arguably accurate HP calculator and at 500hp, you need 55# injectors at somewhere around 75% DC. Yes, this is JL's spreadsheet based on .5 BSFC. Ok, even .6, lets give or take even 10%. I'd think 425-450hp is more believable in your case, so I plugged those numbers in and you come in somewhere between 60-65% DC for 55# injectors. I'm not talking about RPM, I'm talking needing 60-65% of the fuel available from injectors flowing 55# of fuel. Now lets drop the fuel pressure so our 55's flow 48. Now were using 80% of those injectors. Because depite being 55's, you're limiting their max flow BY PRESSURE to 4x#. Thats my point in this instance. You got 55's, but you're only making them flow 48 or even 50, the PW will be what you want for your AF, but there will still be more in the injector. That is my basic point. In the case of 009's, there is enough fuel supplied by them, again at .5BSFC to support 500hp at ~98%. This is all in a perfect world etc..etc..yada..yada...but thats my point. Are we really flowing 42# of fuel per cyl in this engine? Either were not, or something is amiss and the fuel isnt being burned.

In a perfect world, I guess you'd haveta say tuned properly, 009's SHOULD provide enough fuel for 11.30's at around 120. Which is what Ken Mosher was doing 10 years ago. 55's should fuel you to 650hp or 10.45 @ ~130. Again, perfect world, .5 BSFC etc..etc..etc...

If you're running 55's, even NEAR static, either you're MAKING that kinda power, theyre NOT flowing 55#, or the engine is wasting a lot of fuel.

So what does that really mean?.
If you want to peg the meter, fine, but when you peg it you've just about totally wiped out getting any resolution, with the 255 entries there is just nothing left. You can't change a darned thing.

I dont think that is a totally accurate statement. Every car I tune can peg the MAF at under 4000rpm. I have ALWAYS been able to fuel those cars with no problem. With direct scan I got the curve down in 3 tries tops, and in remote instances (stock IC etc) will need a few % of FAPE enrichment. I think you can say once the MAF is pegged, the ECM doesnt KNOW it needs more fuel, or, doesnt know how MUCH to add, thats accurate, but I can and DO add fuel up to 5600RPM or wherever the table stops. I ASSume over 5600 fuel is the same, or interpolated to some value, I really dont know. You'll haveta state that value.

HOWEVER,
Look at what happens when you limit the MAF reporting to 160. You still have PW to play with. Lots of time to add PE vs TPS, or RPM.

Theres the genius behind a translator BUT, you've posted yourslef that the ECM starts to wig out at as low as 140gps, so even at 160, innacuracies are exxagerated, and accurate PE/RPM setup is a must.

Bob's fix is genius. Add fuzzy logic to the MAF readings to smooth things out. Only thing is for a really elaborate program (such as resolution to 760gps), we need room, which we dont have. With exception of those running romless. <grin> Adding piggy back boxes like Reds raptor may change things, but still do NOT remove the ECM's limitations. I dont care what he says.

Now do things make more sense?.
If you want to run on a pegged MAF that is a valid option, but your hands are tied for what you can do.

I think you mean the ECM's hands are tied, and you better know how much fuel you're going to need, theres no safety net once the MAF is pegged.

NOW, to continue........

Since we're at 24 PSI +-, those 55s are more like 70s.
So we'll run the MAF at 160, and we get
At 3K 49.7% DC, and at 5K 49.4%

Now the run the 255 value,
and we get
At 3k 78.5%, and at 5K, 77.9%

If you want I can probably get flow numbers for 55's. I think PTE tests em from 40 to 70 or 80psi. But, I am pretty sure (no I wont bet a paycheck on it) they dont flow 70# of fuel at 65-70psi.

So now whatdawedo?.
Let's see we know what DC give up what AFRs, for a Given injector. We know when our boost begins, we know the injector's new flow at max boost, and the DCs we need to get a desired AFR, so we just need to figure out if we want to add the fuel via RPM or TPS.

I dont know about that. You'd really need again, to know flowrate at various pressures with PW static, to guestimate actual fuel delivery. But I see where you're coming from. Pressure doesnt really matter unless you're pushing it. Your point is in YOUR setup, to achieve the 12.5 AFR YOU needed 70% DC at YOUR FP etc..etc..etc... But you might not, at the pressure you run, actually be flowing 55# of fuel at static, nor will your car, lets say in full HP trim, be able to make the 650hp that 55# injectors are capable ON PAPER or fueling for. And I think that was the starting point of this thread. Why were we out of fuel with 009's. If he needs 42# of fuel, then he's either making a lot of power, or wasting a lot of fuel NOT making power.

This is what I make of all this.

 

[bruce]

Originally posted by ijames


By this I assume you mean that the boost is 24 psi so the fuel rail pressure has gone up 24 psi from the base setting? However, the intake manifold pressure that the injectors are spraying into is also up 24 psi and so the pressure difference across the injector hasn't changed so they still look like 55's. That's the whole reason for referencing the fuel pressure regulator to the intake manifold, so manifold pressure/vacuum is removed as a fuel delivery variable.

Your right.
Was starin at too many numbers and trin to write.
Arrgh.

 

[bruce]

Originally posted by Steve Wood
Actually, Bruce, you usually give a glib answer and invite people to figure it out for themselves....It is very nice to see you actually give consideration to a question and a reasoned reply.

Got anything too actually contribute?.

You accuse me of not contributing, and being glub and then in the same letter you get glib. Lets hear about the 768 thing, is it something you actually doing?, or just reporting on someone else's work?.

Let's hear the details of the 768 stuff.

 

[bruce]

Originally posted by TurboJim



For ****s and grins I plugged some numbers into my arguably accurate HP calculator and at 500hp, you need 55# injectors at somewhere around 75% DC. Yes, this is JL's spreadsheet based on .5 BSFC. Ok, even .6, lets give or take even 10%. I'd think 425-450hp is more believable in your case, so I plugged those numbers in and you come in somewhere between 60-65% DC for 55# injectors. I'm not talking about RPM, I'm talking needing 60-65% of the fuel available from injectors flowing 55# of fuel. Now lets drop the fuel pressure so our 55's flow 48. Now were using 80% of those injectors. Because depite being 55's, you're limiting their max flow BY PRESSURE to 4x#. Thats my point in this instance. You got 55's, but you're only making them flow 48 or even 50, the PW will be what you want for your AF, but there will still be more in the injector. That is my basic point. In the case of 009's, there is enough fuel supplied by them, again at .5BSFC to support 500hp at ~98%. This is all in a perfect world etc..etc..yada..yada...but thats my point. Are we really flowing 42# of fuel per cyl in this engine? Either were not, or something is amiss and the fuel isnt being burned.

In a perfect world, I guess you'd haveta say tuned properly, 009's SHOULD provide enough fuel for 11.30's at around 120. Which is what Ken Mosher was doing 10 years ago. 55's should fuel you to 650hp or 10.45 @ ~130. Again, perfect world, .5 BSFC etc..etc..etc...



I dont think that is a totally accurate statement. Every car I tune can peg the MAF at under 4000rpm. I have ALWAYS been able to fuel those cars with no problem. With direct scan I got the curve down in 3 tries tops, and in remote instances (stock IC etc) will need a few % of FAPE enrichment. I think you can say once the MAF is pegged, the ECM doesnt KNOW it needs more fuel, or, doesnt know how MUCH to add, thats accurate, but I can and DO add fuel up to 5600RPM or wherever the table stops. I ASSume over 5600 fuel is the same, or interpolated to some value, I really dont know. You'll haveta state that value.

BUT, you've posted yourslef that the ECM starts to wig out at as low as 140gps, so even at 160, innacuracies are exxagerated, and accurate PE/RPM setup is a must.

I think you mean the ECM's hands are tied, and you better know how much fuel you're going to need, theres no safety net once the MAF is pegged.


I dont know about that. You'd really need again, to know flowrate at various pressures with PW static, to guestimate actual fuel delivery. But I see where you're coming from. Pressure doesnt really matter unless you're pushing it. Your point is in YOUR setup, to achieve the 12.5 AFR YOU needed 70% DC at YOUR FP etc..etc..etc... But you might not, at the pressure you run, actually be flowing 55# of fuel at static, nor will your car, lets say in full HP trim, be able to make the 650hp that 55# injectors are capable ON PAPER or fueling for. And I think that was the starting point of this thread. Why were we out of fuel with 009's. If he needs 42# of fuel, then he's either making a lot of power, or wasting a lot of fuel NOT making power.
This is what I make of all this.

Guess it's jus preference.
Just for grins thou, any one have any document where they even hint at being able to reliably going static with an injector?.
Last I saw was as you approach 90% they can get to not fully opening, so what do you do?. Jump to static from what, an 90% DC, 85%DC?.

 

[wicked6]

Bruce,

I have been reading and want to clarify something. so what you are saying is that one should program the chip with 42 constant if they run a 009 and a 55 constant if they runn 55#s. The starting point is to not lie to the ECM!!! Then from there you work on the PE tables???

 

[TurboJim]

Originally posted by wicked6
Bruce,

I have been reading and want to clarify something. so what you are saying is that one should program the chip with 42 constant if they run a 009 and a 55 constant if they runn 55#s. The starting point is to not lie to the ECM!!! Then from there you work on the PE tables???

No. He means to tell the ECM that theyre 42's and trim the MAF tables to trim the fuel curve. IN his case, knowing what his target AF is and having a wideband O2, this is done by setting the car open loop and making changes until things fall where he wants them. In a closed loop deal, it would be similar with exception you'd be watching the BLM values. PE is just that, power enrichment, its not really a base fuel tool. Its like the secondaries on a Bog-O-Jet, extra fuel on demand.

I myself like to lie to the ECM. Less changes, less things to screw up. Of course in some cases MAF tables must be modded to clear up some issues. If I can get BLM's to be in an acceptable range when I lie to the ECM, thats fine with me.

 

[bruce]

How did this happen?.
I thought I'd been clear on this, but I guess not.

Yes, one point was telling the ecm the 42s are 42s, and that 55s are 55s.
Second was then,
in the MAF tables limit the max value to say 160 grms/sec..
And Finally
Use the PE enrichments to trim the fuel curve.
that way you can use the MAF for perfect street manners, and have lots of adjustment for dialing in the WOT fuel curve.

Doing that basically allows you to turn the system into an Alpha-N and MAF system.

This allows for good street manners, and WOT tuning.

 

[TurboJim]

Oh....

I must have misunderstood. I thought you tuned the MAF tables similarly to the VE tables of a SD system. Then once the fueling was where you wanted it you added necessary PE fuel.

My bad.

 

[Fred 86 GN]

Cool.

After your last post, Bruce, I now understand! I think!

Tell the ECM the proper size injector.

Trim the MAF back to 66% of maximum by rescaling the tables related to it.

Use the PE function to add fuel per the needs of the AFR (based on how well the engine breathes).

MAF for drivability, power enrichment (PE) for extra fuel...all under control with plenty of injector capacity.

Sounds like a logical way to do things...

 

[bruce]

Re: Cool.

Originally posted by Fred 86 GN
After your last post, Bruce, I now understand! I think!

Tell the ECM the proper size injector.
Trim the MAF back to 66% of maximum by rescaling the tables related to it.
Use the PE function to add fuel per the needs of the AFR (based on how well the engine breathes).
MAF for drivability, power enrichment (PE) for extra fuel...all under control with plenty of injector capacity.
Sounds like a logical way to do things...

You got it!.
The 160 gm/sec is just what worked for me.

 

[azgn]

but, how fast do you go?

jeeze...what a bunch of crapola

and please don't tell me I am putting you down Bruce, because I am! This is the biggest bunch of psycho babble I have ever seen!

I will repeat.....wanna race?

take your car to the track and tune it ....or slip your slide rule around and come up with 160 gm/sec and a/f at 12.5 and be happy!

bah!

( and I thought Steve would freak before I did....)

 

[boostcreep]

and what's really bad is that there are some people here that believe all this crap! This has got to be *the* worst thread I've ever read!

Nick

 

[Dean]

Originally posted by TurboJim

If the MAF isnt pegged. it will add fuel to achieve programmed and calced AF ratio. Its all about load/RPM/scalers/trims = final PW. If it (the MAF) IS pegged, which I'm sure it is, it comes down to how well your chip guy knows your cars fuel requirements.

MAF is not pegged (~340 gps... Translator+ & Extender), which is why I don't understatnd why mroe fuel is not being introduced, even though there is more to be had.

Originally posted by bruce

HOWEVER,
Look at what happens when you limit the MAF reporting to 160. You still have PW to play with. Lots of time to add PE vs TPS, or RPM.

Now do things make more sense?.
If you want to run on a pegged MAF that is a valid option, but your hands are tied for what you can do.

NOW, to continue........

Since we're at 24 PSI +-, those 55s are more like 70s.
So we'll run the MAF at 160, and we get
At 3K 49.7% DC, and at 5K 49.4%

When you say to "limit the MAF reporting to 160", that is just the reporting of the gps, not the actual?

:-Dean

 

[JS87GN]

Originally posted by Intercooler
What kind of times are you guys running? 12.5@109 is okay with stock injectors. I ran 11.78 with 40's and had a little left so I sense something is wrong there.

I have ran 12.30 @ 105 w/1.60 60ft on stock injectors@54psi/stock turbo 20psi & intercooler, no internal motor either!

 

[Steve Wood]

First, I would like to apologize to Bruce, and the other members of the list, for allowing his posting personality to get under my skin. This is simply an online forum after all and my perceptions of him probably have no basis in real life. If posting personalities were to mean anything, I would certainly come up on the short end of the stick with my own sarcasm and argumentative tendencies.

Therefore, once again, I am sorry for my posts in this thread.

Secondly, with regard to Bruce's announced theories for tuning. Based on the lack of presented empirical data, it is difficult to evaluate the potential other than taking his words at face value.

Trying to understand what he has presented, I don't see why it won't work other than the patience required by the chip burner and the iterative effort required working with any given combination.

If we are to discount his efforts summarily because they are based upon theoretical calculations, then we would also discount the Thrasher, the MaxEffort, String Theory, and Einstein's various contributions to science, etc.

I suggest that time will be the proof of this pudding like all others. Perhaps, Jimmy T, or others, will take the idea to the track and those of us that prefer performance data to theoretical calculations will accept the results as they fall.

I would hate to discourage innovation simply because we do not like/understand the presentation package.

 

[TurboJim]

Thats the Steve Wood I know and love....

I dont use a ECM anymore, but if I find a guinea pig at Etown or Island this year, you can BET I'm gonna play.

 

[bruce]

Originally posted by azgn
but, how fast do you go?
jeeze...what a bunch of crapola
( and I thought Steve would freak before I did....)

Other then revealing your feelings, care to actually talk about the tech end of things?.

 

[bruce]

Originally posted by boostcreep
and what's really bad is that there are some people here that believe all this crap! This has got to be *the* worst thread I've ever read!
Nick

And what's even worst are the ones that are so stuck on what worked a decade ago.

 

[bruce]

Originally posted by Steve Wood
First, I would like to apologize to Bruce, and the other members of the list, for allowing his posting personality to get under my skin. This is simply an online forum after all and my perceptions of him probably have no basis in real life. If posting personalities were to mean anything, I would certainly come up on the short end of the stick with my own sarcasm and argumentative tendencies.

Therefore, once again, I am sorry for my posts in this thread.

Secondly, with regard to Bruce's announced theories for tuning. Based on the lack of presented empirical data, it is difficult to evaluate the potential other than taking his words at face value.

Trying to understand what he has presented, I don't see why it won't work other than the patience required by the chip burner and the iterative effort required working with any given combination.

If we are to discount his efforts summarily because they are based upon theoretical calculations, then we would also discount the Thrasher, the MaxEffort, String Theory, and Einstein's various contributions to science, etc.

I suggest that time will be the proof of this pudding like all others. Perhaps, Jimmy T, or others, will take the idea to the track and those of us that prefer performance data to theoretical calculations will accept the results as they fall.

I would hate to discourage innovation simply because we do not like/understand the presentation package.

I still invite you to post something original. Lets hear just one new tech idea from you. You mentioned reading to 700+ gm/sec., OK, lets hear about it.

I suggest that this forum get back to being technical. Where things are discussed in an adult manner. Leave your personal hangups outside. If you want PC, read the times.