P&L catted header - cam timing?

[PantsDants]

So I've got some small knock that just will not go away no matter how much timing I take out at 3200 rpm, 0.6-0.7 g/rev. I'm thinking I may need to revise my cam timing in that area, as I was able to sort out the rest of the knock I was getting in other areas through retarding base timing <2 degrees.

Car has a Phantom ESC and P&L EL catted header, running OFT ESC 91 octane tune. Mechanic didn't find any exhaust leaks or anything that could be rattling around, so that's why I'm thinking it's in the tune. If anyone could post up a better optimized cam timing map for a catted equal length header, I'd be very grateful. Thanks!

[aznatama]

you sure you're using quality fuel? Try increasing octane by 1 or 2 and see if that helps, or try a different gas station?

[PantsDants]

Originally Posted by aznatama

you sure you're using quality fuel? Try increasing octane by 1 or 2 and see if that helps, or try a different gas station?

92 octane is the best I'm able to find in WA, and the brand of gas I use doesn't seem to have an effect either way on the knock; I don't fill up at the same gas station every time. It's also just this one very specific range that I can't seem to eliminate completely, which is why I don't think it's fuel-related.

[Kodename47]

Is it FBKC? Could it be on tip in?

[PantsDants]

Originally Posted by Kodename47

Is it FBKC? Could it be on tip in?

It is FBKC (I think? I dunno what else it could be because it's not FLKC), but it's showing up in fairly steady state situations. Check out this log: http://datazap.me/u/pantsdants/12-13...=0&data=1-4-11

That log is with around 3.5 degrees of base timing taken out in the area, which seems like a lot, and it's still seeing knock.

[phrosty]

P&L does their own tuning, have you sent them an email?

[steve99]

Originally Posted by PantsDants

It is FBKC (I think? I dunno what else it could be because it's not FLKC), but it's showing up in fairly steady state situations. Check out this log: http://datazap.me/u/pantsdants/12-13...=0&data=1-4-11

That log is with around 3.5 degrees of base timing taken out in the area, which seems like a lot, and it's still seeing knock.

Yes its FBKC or knock correction , just as you get on the throttle. @Kodename47 called it right.

On low grade fuel its very difficult to completly eliminate. your only showing -0.69 degrees max correction in that log and your iam is solid at one. With 91 fuel its going to be almost impossible to eliminate completly, but its very low level knock .
If thats as bad as it get dont worry, if it was 2 degrees and dropping your iam to less than one then you wyld be concerned.

you could try small adjustment to the tip in tables but its not something i have done so maybe someone who has altered those can advise you.

I dont think cam timing will fix this its more to do with volumetric efficiency.

[PantsDants]

Originally Posted by steve99

Yes its FBKC or knock correction , just as you get on the throttle. @Kodename47 called it right.

On low grade fuel its very difficult to completly eliminate. your only showing -0.69 degrees max correction in that log and your iam is solid at one. With 91 fuel its going to be almost impossible to eliminate completly, but its very low level knock .
If thats as bad as it get dont worry, if it was 2 degrees and dropping your iam to less than one then you wyld be concerned.

you could try small adjustment to the tip in tables but its not something i have done so maybe someone who has altered those can advise you.

I dont think cam timing will fix this its more to do with volumetric efficiency.

This is still considered tip-in knock? On two of those instances I'm actually letting off the throttle it seems, and the other one is literally less than a 1% increase in throttle position.

I hear you on this not really being a big deal. It's just bizarre that I've been able to basically get rid of all of my knock in other map regions except this one spot where it consistently crops up.

My reasoning for it being possibly related to cam timing was simply that I know header design has a big impact on how you set that up, and that the OFT map I've got was created with an uncatted, unequal length header, while I've got a catted, equal length one.

[PantsDants]

Originally Posted by phrosty

P&L does their own tuning, have you sent them an email?

I haven't tried that yet because I got the header used from a member here; I wasn't sure if I'd be entitled to their tuning info.

[steve99]

Originally Posted by PantsDants

So I've got some small knock that just will not go away no matter how much timing I take out at 3200 rpm, 0.6-0.7 g/rev. I'm thinking I may need to revise my cam timing in that area, as I was able to sort out the rest of the knock I was getting in other areas through retarding base timing <2 degrees.

Car has a Phantom ESC and P&L EL catted header, running OFT ESC 91 octane tune. Mechanic didn't find any exhaust leaks or anything that could be rattling around, so that's why I'm thinking it's in the tune. If anyone could post up a better optimized cam timing map for a catted equal length header, I'd be very grateful. Thanks!

I think you problem will be you have mods not catered for with the oft phantom sc tune,

even if you get info from p&l its probably not gioing to be set up for phantom sc, you best bet is probably a custom e tune from shiv as he is the one most familiar with phantom sc.

[akyp]

Same header, similar problems (FLKC everywhere unless I dial base timing WAY back). Emailed P&L about cam timings and basically got a NO as answer. Recently been filing up with Esso instead of Shell V-Power which alleviates the problem a good bit but still I guess a dyno tune is inevitable. Running OTS Stg 2 with timing pulled at high rpms.

[PantsDants]

Originally Posted by akyp

Same header, similar problems (FLKC everywhere unless I dial base timing WAY back). Emailed P&L about cam timings and basically got a NO as answer. Recently been filing up with Esso instead of Shell V-Power which alleviates the problem a good bit but still I guess a dyno tune is inevitable. Running OTS Stg 2 with timing pulled at high rpms.

Did they say no as in they don't have the maps, or no as in they're not giving them to you?

[akyp]

Originally Posted by PantsDants

Did they say no as in they don't have the maps, or no as in they're not giving them to you?

They said they don't provide that information. So they probably have it.

Btw, looked at your log at home and I wouldn't worry about it at all. Mine looks way worse: http://www.datazap.me/u/akyp/20141215-stg-2-a00g-06

[KoolBRZ]

Knock virtually eliminated with new PI to DI ratio table. Read the thread here http://www.ft86club.com/forums/showthread.php?t=71506 and copy the table from here http://www.ft86club.com/forums/showp...&postcount=112 . I have tried to tweak it in little ways to improve it, but I can't find any changes that actually improve it. I'm adding in timing and I still have a steady IAM of 1.0. @thambu19 really knows his stuff.