someone knows this please help me i tried to increase all by .05 and it helped a littel but when i go WOT i get like 9 deg of knock!

 

what where your 02's reading before you touched it?

if they where around .85 or so

multiply the whole table by 4%
so you would type in 104 and multiply it and then confirm changes.

 

Guys what does it mean at part throttle if most of the time I get 0 KR and then SOMETIMES it will jump to 3 degs and then if I stay on it it will decrease to 0. Should I be worried about this? And then at WOT I got like 9 deg of KR. Should I just scale the PE vs RPM table???

 

OK guys I scaled my PE vs RPM table by 4% and now I am getting O2's at WOT of about .89! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Looks good to me. And the timing went down to 7.5 deg or so at WOT from 9. I need to know if you guys think I should retard the timing at WOT or what else I should do? BTW, my pulsewidth was about 21 at 4000rpms. Let me know what you guys think!!

 

Hey guys I have searched the forums and came up with 2 ways to tune the PE vs RPM table and I am wondering which is the way to do it?
One is to take the first 2 cells and add .05 and then log and continue doing this until you reach the perfect A/F ratio.
The second is basically to scale the entire table by 7% and log then go another 7% if that isnt right and I just wanna know what is the "correct" way to do it??? Let me know what you guys think.

 

GUYS PLEASE HELP ME!!! A/F ratio is about .89-.90 at WOT but still getting KR. The duty cycle of my injectors is about 70% which is still good. So my question is would my last option be to retard timing a little??? Please help!

 

OK guys I went down like 3 degrees of timing from .52gm/cyl to .84gm/cyl from 3200rpm to 5600rpm. Also I multiplied the whole PE vs RPM table another 4% which is a total of 8%. I am still getting about 7.5 deg of knock at WOT. Please advise!!!! Thanks!!!!

 

Will - Where is your IAT sensor located? Is it reading ambient air temp. or boosted air temp.?

If its reading the boosted air temp. could you find out what your air temp is at WOT/full boost.

If you start with 100 degree ambient and then compress it to 9psi? without some sorta intercooling effect your bound to get some knock. Read this thread for some more info.

https://ls1tech.com/ubb/cgi-bin/ulti...;f=20;t=000656

Please take my advice and put some unleaded race gas in to see if its real or false. If its real you need to lower your boost until you can come up with some way to lower your boosted temps.(intercooler, water/alky injection, N2O)

If you keep retarding timing you'll eventually be shooting flames out the exhaust since you'll be pushing your still burning charge out the exhaust manifold. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Just my $.02

Good luck man

John

I don't want to see your motor go boom. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Oh yeah, one more thing.

Pull your plugs and see what they look like. If they are pitted or extremely white things are not good in the combustion chamber. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

John

 

Actually dude I am running 6psi right now and sometimes at part throttle I will get 5degs of KR and then it willl go down. And my IAT is BEFORE it is compressed. Any suggestions?

 

Wow, that seems kinda strange that your getting that much kr with 6psi. Your running this on a truck right(~9.5:1cr)?

I was running 4psi on my SS and could run 21 degrees of timing with 10.1:1 cr on pump gas.

[broken record mode on] <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> j/k Seriously though, Check to see if its real or not by running unleaded race gas. [/brm]

If its not real than you have a bad knock sensor or something else is setting it off. If the knock is false you can desensitize the sensors with LS1edit right?

Before you try any more tuning stuff though I think you need to find out whether its false or not. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

John

PS - Have you posted anything about your situation in the forced induction section? Somebody might have some suggestion in there. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

PSS - I apologize if my other post sounded condescending, it wasn't meant that way. Just trying to offer some help. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Your running some type of forced induction right? How much boost?

Blown motors like alot of fuel to help keep things cool. First, get your O2's around .920 and see if your still getting alot of knock. I would go get on a dyno with wideband and see where the A/F ratio is instead of using the O2's but, get them around .920-.930 anyway and see if that helps.

If not get some unleaded race gas and see if its real knock or false.

If its false you may just have a very sensitive knock sensor or something rattling causing it.

If it's real you might want to back off the boost a little while your running pump gas. I think you're running like 9+psi thru a whipple(no intercooler) right? If so the air entering your engine is going to be extremely hot(very bad). <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

This is just a suggestion of what I might try in your situation.

Try backing the boost off a couple of psi. I know you don't want to but, hang on. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> You will probably get rid of the kr, lower your intake temps(helps keep knock away), be able to add some timing(really helps on blown motors), and run pump gas. You may not lose as much power as you think if your able to raise the timing a little and the air temps will be lower which means more power. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Just something to think about.

If you still want to run high boost thru a whipple I would seriously consider trying to fab an intercooler, run some sorta water/alky injection, run a mix of race/pump gas, or lower the boost and spray a small shot of N2O in the intake(not very practical for the street) <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> . I think most of your problem is probably due to manifold air temps.

Let us know what happens. Be careful with that motor. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> It didn't take my friend long to pop his 4.7L Dodge with a 8psi Kenne-Bell.

John