Fueling & Injection - With all these H/C cars

How many are still running with the stock injectors?

i would assume most to be honest...unless your running forced induction the injection system can handle most of the needs and with ls1 edit enough can be done to make things work aok :)

lata
Bill

Stock injectors are fine with H/C cars. According to the year (different years have different pumps and injectors) and type (tranny makes a difference for example) of car, the stock injectors are good for 475-530 RWHP.

With my minimal mods my injectors are running at 80% (sometimes 90%) and greater duty cycle and all I have done is a LID/FIlter and muffler out the back. Right now I am in disbeleif that the car is outflowing the injectors and I have nothing done. I guess when I spring for H/C I am gonna have to upgrade them


2000 Camaro SS M6 # 2497
Blowmaster muffler, SLP Pulley,
Whisper Lid, 160 T-Stat, Cags,
TB Coolant Bypass,
Rear end cover, 4.10 rear end
SLP High Capacity Radiator,
Fernco Coupling

With just bolt-ons, you're NOT as close as your injector pulse widths might seem to indicate. I've seen for years that injector pulse widths just do not tell the whole story, elsewise we'd start running lean at HP levels WELL below where we actually do. I can only theorize as to why this is the case, but I do know that it is the case.

my car got s2 H/C (400RWHP,N/A)and 150 wet kit
in a 2000 A4 still got the fuel system

I only say that because with my pulse widths the way they are now i am getting 4* KR in the higher RPMS and this is where my PW seems 80% and better sometimes seeing 90.

Can this be moved to the fueling section

I seriously doubt your KR is not because of your PWs. What are your O2 readings at WOT (B1S1 and B2S1)? KR is very common in these cars and can be cause by a variety of things. You KR might even be false (caused by something other than detonation or pre-ignition.)

here are a few logs taken

Full Log
http://151.200.241.44:8080/923.csv

KR Log
http://151.200.241.44:8080/923KR.xls

Edit file
http://151.200.241.44:8080/IFR90.LS1

Looking at your KR log...

Your O2 readings appear to be on the rich side if anything. The lowest it dropped was .910 mv.

Your KR is making your timing advance low. 24.5 degrees at 6000 is not so good.

You don't appear to be getting a 100% throttle opening. High 80s to low 90s.

Your Ltrims look nice.

You were speeding at 85 mph! Shame on you! ;) :jest:

Do you have any suggestions by any chance? Do you think false KR is the culprit. Also since getting edit. I have turned off COT and EGR before edit when these were enable the knock values were less. Disabling them has bought KR to its highest at 4*. When getting KR before edit I saw the COT compensating for the lean condition at WOT (O2's got richer once KR set in), so I am prolly gonna have to rule out the false knock for nowl. Any suggestions will be greatly appreciated. I havent gone to the track since I found out why my car was falling on its face around 5-6K :(:(:(:(

Could this be happening

http://www.ls1tech.com/threads/showthreaded.php?Cat=&Board=UBB43&Number=544488&pa ge=&view=&sb=5&o=&vc=1

That guy had a stock engine with a Hotcam. He is NOWHERE near the limits of the injectors.

COT...that's Cat Over Temperature. I don't see what that would have to do with anything.

EGR, you removed it and then removed the code, I take? I don't think this has anything to do with it either. I've removed the EGR before and it did not pose a problem.

The first thing to do is to find out if the KR is real or false. Run your tank low on gas, put a few gallons of unleaded racing fuel in the tank. If it still has KR, your KR is almost certainly false.

BTW, do you have cats (not the furry kind)?

My Injector Duty Cycle According to EFILIVE is hitting 100% @ 6400 rpm and I shift at 6600rpm. Should I go ahead and upgrade to a single intank walbro and some 36lb injectors now? -- note I plan on some more bolt-ons and then adding a procharger in the future.

But I am curious if possibly I am loosing power now. I will be adding the FAST intake as soon as it comes out and changing to comp cams shaft mount rockers.

That guy had a stock engine with a Hotcam. He is NOWHERE near the limits of the injectors.

COT...that's Cat Over Temperature. I don't see what that would have to do with anything.




I am aware of COT the reason why I mentioned it was before I disabled it and logged WOT runs I noticed that my O2's would go real lean and then the KR would start falling off slowly (about 1* per 500-700 rpm) this lead me to believe that COT was kicking and to save the cats by dumping extra fuel into the mix. And this is why I beleived the O2's started getting richer and the KR started falling off



EGR, you removed it and then removed the code, I take? I don't think this has anything to do with it either. I've removed the EGR before and it did not pose a problem.



Yes, I have removed the codes and the EGR (turned it off). when i first got the car in 2000 I blocked off the EGR with a plate and the car pinged audibly and set SES light so i removed the block off plate. I mentioned that also because now that it isnt in the picture anymore and the engine is getting a better charge of air and fuel it is causing it to detonate harder thus giving me higher KR values. The COT and the EGR were example to to disprove the false KR theory but I guess I wont find out till i get some race fuel and see :D. Another question what good would the race fuel do if in fact it is running out of fuel. I guess in that case I would see substantially lower values.



The first thing to do is to find out if the KR is real or false. Run your tank low on gas, put a few gallons of unleaded racing fuel in the tank. If it still has KR, your KR is almost certainly false.



Will do ASAP :D




BTW, do you have cats (not the furry kind)?



Yes I do everything is stock except for what is listed as mods in my first post.

Sorry if it seems like I am going back and forth. I guess I am after more of a reason how my engine seems to be outflowing stock injectors and at the same time I am learning about the cars and how the computer interacts with it :D

Listen to me and trust me on this one. I've been around these LS1s a long time and I've done alot of trouble shooting on a variety of setups. :) Don't get hung up on injector pulse widths. I've seen 'em run ALOT higher than 100% with no problem. Sometimes I wish that parameter was unviewable. It throws alot of people off that take it literally.

You can check the fuel pressure at WOT if you'd like at the fuel rail (should be around 55-60 psi but even 50 is ok.) That is the ONLY way that you could possibly be maxing the injectors out is if your fuel pump was not being able to supply enough pressure to the injector rail for some reason...and we've ALREADY seen that your O2 readings indicate a normal to slightly RICH condition at WOT so I can tell you that this isn't the case.

If you were running lean with race gas you would see it with your O2 readings. If the O2 readings are anywhere above .800mv (yours are above .900mv) then you are rich enough not to have ping with race gas. If it has KR with race gas and you again see that your O2 readings are fine, your KR is false. Find this out and we'll go from there.

Lemme know, I want to help you fix this problem. :)

BTW, the reason I asked about cats is that getting rid of them helps with real KR tremendously. Of course, that's not an option for many people.

Ayee Ayee sir will find race gas asap and we'll go from there

I cant find any 100+ gas station in my neck of the woods would some Xylene work in raising the octane enough to resist detonation

edit found some at the speed shop 107 octane 32.00 for 5.00 will let you know what happens either today or tomorrow

http://www.rceng.com/technical.htm

A good rule of thumb is that injectors will continue to work all the way to 100% duty cycle. However, for best results keeping them @ 80% and below is optimal. This is why many of the Z06 guys immediately upgrade to 30# SVO injectors. The stock injectors are pretty much maxed out in our cars.

I am not against injector upgrades at all. There is plenty of discussion on injector duty cycle out there if you do a search.

I'm not against injector upgrades either. It's just that I've been well acclimated to the real world findings of fuel system limits as compared to the theorized limits found from calculations.

People calculate all the time what these fuel systems should be able to do, but in the real world, they handle a minimum of 475 RWHP and in some cases as much as 530 RWHP. How far past the theorized maximum limit of 100% duty cycle does that put us?

Well my Fuel Pressure hits 58-59 psi at WOT and sits at 62-63psi at Idle. -- However someone told me that just because the pressure is there doesn't mean the flow is there. I've been talking around and to friends and a well known engine builder told me that he runs stock 28lb injectors up to 600hp and then upgrades, he just puts a bigger fuel pump in.

I think I'm just gonna upgrade now and be prepared for later, with a LSX intake and AFR heads in the future + a blower I know I'm gonna need it at some point.

"However someone told me that just because the pressure is there doesn't mean the flow is there."

Why? The only reason I can see the flow wouldn't be there if the fuel pressure made it to the injector would be if the injector were faulty, locking up, or clogged.

Well tonight I should have some results approx 7:00 est. Colonel were there any issues with the SLP underdrive pulleys causing a false knock?

There were serious issues with the Whisper UD pulleys. I know, I was unfortunate enough to have one of the POSs. :mad: It caused all kinds of false KR.

I haven't really heard any negatives about the SLPs. I know the ASPs are great (what I run) but I don't know if that's where SLP gets theirs. I certainly wouldn't rule out that possiblity.

Here is the new file. From the looks of it, it seems to be a real spark knock. With 93 I was getting around 4* of KR with 107 I think I got a max of 1.5*


http://141.156.180.156:8080/926.csv

Here are the logs


How should I approach this using Edit shou I go a little fatter on in the IFR table or should I back off the timming in the High Octane tables

I have seen mustangs at much lower fuel pressure make 300rwhp on their stock injectors.. Which are 19#ers. I have seen many go to 450rwhp with al years of our cars on stock injectors and pumps. Now I feel anything over that you have some money in it anyways just put some SVO 30#ers in and a walbro intank.

I am putting 30#ers in mine now only because I have a hung injector and have a new motor in the works.


Darrell

440rwhp and I still have plenty of fuel left with my setup.