unable to tune out ping at low (<50) map 2000-3000rpm

[jjdalynh]

11.05:1 CR static, TW-8 cams, rear cylinder running very rich from coming back from tuner and i can't it to stop pinging with lowering timing, changed to vrod plugs, gapped down to .025.  i can feel it cruising around town it feels rumbly,and when i get up over 3k it smooths out (no more knock retard registered) and really feels like it pulls strong.  timing doesn't change drastically at that rpm (a couple degrees or less).

[HD/Wrench]

So you are 100% sure the AFR is correct , cam timing is correct ?  Cannot remove ping be lower timing HMMM that does not sound right . I think you may need to have it tuned else where if there are no  mechanical issues .  11.1 with a 8 cam is stout for sure , I would think the lean AFR range which is 50 KPA ( cruise) would not want much timing .

More info on build  would be helpful


Why do you say its super rich on rear ??

[jjdalynh]

So you are 100% sure the AFR is correct , cam timing is correct ?  Cannot remove ping be lower timing HMMM that does not sound right . I think you may need to have it tuned else where if there are no  mechanical issues .  11.1 with a 8 cam is stout for sure , I would think the lean AFR range which is 50 KPA ( cruise) would not want much timing .

More info on build  would be helpful


Why do you say its super rich on rear ??

example: commanded AFR is 13.3, AFR read from PV AT Pro is 10.994 a couple ms before spark knock detected (32kpa @ 3400rpm, 6%tps).  timing is 27.5 deg.

i agree it should be pretty stout, (FM level B heads, 107").  guys at fuel moto didn't indicate it would be a problem, i know timing will need to be correct though.  93 octane around here.  probably easier if i post the tune and a sample of data logged.  IVO is set to 7, IVC 58

[HD/Wrench]

kinda confused as to how you are at 32 KPA at 3400 short of decel pretty hard to get there and in decel you can get some odd AFR readings .. light throttle cruise should be in the mid 50's   look at your log it should idling in the 35 range-40 range .

Unless you have cams out of time ??

[jjdalynh]

kinda confused as to how you are at 32 KPA at 3400 short of decel pretty hard to get there and in decel you can get some odd AFR readings .. light throttle cruise should be in the mid 50's   look at your log it should idling in the 35 range-40 range .

Unless you have cams out of time ??

you're right that was on the tail end of a decel to steady throttle.

[HD/Wrench]

 Ok so add fuel to that VE area , the AFR is showing wrong  most likely without see the map and looking to see what is going hard to know . But the Injectors may be off  or on . off is a guess but seeing the AFR hit 10 on a decel is not uncommon . Many time you will see guys posting ve tables and and the ve is 127.5 in some areas on decel .

ok but that is not 50 KPA   what am I missing here

[jjdalynh]

steady cruise @ 2800rpm, map 34ish kpa, 5%tps, Commanded AFR mid 12s, rear AFR 10.7, timing down to 20 deg, 4 deg spark knock.  (limited to 4 right now)

[jjdalynh]

Ok so add fuel to that VE area , the AFR is showing wrong  most likely without see the map and looking to see what is going hard to know . But the Injectors may be off  or on . off is a guess but seeing the AFR hit 10 on a decel is not uncommon . Many time you will see guys posting ve tables and and the ve is 127.5 in some areas on decel .

ok but that is not 50 KPA   what am I missing here

can't imagine the cams are off, i've done them before (these are gears,BTW) and it dynoed at 112/110 (which i thought was a bit low)

[Hossamania]

For peace of mind, maybe do a compression check just to verify cam timing? I have no tuning advice, just the "keep it simple to start troubleshooting" principle.

[jjdalynh]

For peace of mind, maybe do a compression check just to verify cam timing? I have no tuning advice, just the "keep it simple to start troubleshooting" principle.

good advice, i'll do that. 

[jjdalynh]

more info: HPI 55mm Tb, 6.2 injectors (i know they are a bit large for this application, it's what i had) dragos 2:1 2.55" baffle exh.

[HD/Wrench]

Something is off , its not going to be at 34 KPA at steady cruise . That is a fact  and  that cam at that comp ratio with stock heads would make more tq than that and  most likely more Hp as well .

So  , first off make sure no intake leak ,   then do a CCP test that should make in the 200+ . 

What is the CI of the build what heads do you have on it .. A stock 103 with cam will make 95-100 Hp and 110-115 tq .. bang the comp ratio that high and it should be doing well beyond that .


tuned a 107 kit on a dyna so 46 mm T/B dd fat cat 10.1 comp ratio woods 555  101/117 .. I would think that you have ported heads as you opted for a larger TB

[jjdalynh]

Something is off , its not going to be at 34 KPA at steady cruise . That is a fact  and  that cam at that comp ratio with stock heads would make more tq than that and  most likely more Hp as well .

So  , first off make sure no intake leak ,   then do a CCP test that should make in the 200+ . 

What is the CI of the build what heads do you have on it .. A stock 103 with cam will make 95-100 Hp and 110-115 tq .. bang the comp ratio that high and it should be doing well beyond that .


tuned a 107 kit on a dyna so 46 mm T/B dd fat cat 10.1 comp ratio woods 555  101/117 .. I would think that you have ported heads as you opted for a larger TB

107"
Fuel Moto Level B heads. 
usual method of finding intake leaks (some fuel or other around the intake ports at the head?   (i've found them this way with my carbed build, i presume EFi it would be the same).

[jjdalynh]

another thing, initially the cam estimator had IVO at 8, but i had map at idle over 40 and hard starting.  when it got changed to 7, it started easier but that may been due to adjusting the cranking params and IAC. 

[HD/Wrench]

I do not have much in the 107 with the 8 cam but I have 555 with the B head and SE cnc heads etc..

but again your KPA is way off .   IVO does not effect starting in my opinion with all other items setup correctly .


Well post up your CCP  when you get it , do not forget disable ACR or un hook them   

[jjdalynh]

will do.  (it's a 2003, so manual CRs)

[jjdalynh]

looks like tomorrow is going to rain so i'll be doing some diags.  hate when i loan tools out, now i have to go get a new compression tester.  🙄

[Hossamania]

looks like tomorrow is going to rain so i'll be doing some diags.  hate when i loan tools out, now i have to go get a new compression tester.  🙄

Could you get a free loaner from an auto parts store?

[jjdalynh]

looks like tomorrow is going to rain so i'll be doing some diags.  hate when i loan tools out, now i have to go get a new compression tester.  🙄

Could you get a free loaner from an auto parts store?

yeah, but for $30-$40 id rather not have to make the return trip.  i've been meaning to replace the one that went missing anyways. 

[Hossamania]

looks like tomorrow is going to rain so i'll be doing some diags.  hate when i loan tools out, now i have to go get a new compression tester.  🙄

Could you get a free loaner from an auto parts store?

yeah, but for $30-$40 id rather not have to make the return trip.  i've been meaning to replace the one that went missing anyways.

I tend to agree with you. I'd rather just have a new one as well, though the auto parts store is only about a mile or two from my house, so pretty painless for me.

[jjdalynh]

it's at least a 15 min ride and dealing with traffic blows, sometimes it's closer to 30 on a weekend return trip with all the lights. 

quick check for intake leaks with propane and a rubber hose yeilded no results. if the idle isn't going to jump more than 50 rpm it'll be hard to tell this cam is pretty lumpety. 

wouldn't i be seeing lean conditions in my AFRs through the wideband sensors?

[jjdalynh]

compression check shows about 180psi on both cylinders. 

[HD/Wrench]

180 is a fair amount off on CCP  What is your elevation ?? you said no ACR  manual release  , they have to be closed & throttle open crank until it stops moving the needle ,... the programs are just to get you close but if your Comp ratio is that its 20+ PSI off so a tooth on the out side  retarding cam would do all kinds of crazy things .. Also that cam should have hit like a hammer out the gate for tq with a good pipe

[rigidthumper]

IMO, that combo should be closer to 210 @ sea level.

[Durwood]

compression check shows about 180psi on both cylinders.

Is this with the TB propped open?

[jjdalynh]

 

180 is a fair amount off on CCP  What is your elevation ?? the programs are just to get you close but if your Comp ratio is that its 20+ PSI off so a tooth on the out side  retarding cam would do all kinds of crazy things .. Also that cam should have hit like a hammer out the gate for tq with a good pipe

i agree.  we are <200' above sea level.  if it was a tooth off i guess it would have to be both retarded?

[jjdalynh]

compression check shows about 180psi on both cylinders.

Is this with the TB propped open?

yes, cable driven. 

[kd]

To be sure of your numbers, check your new gauge against a known correct (or at least more correct) one. I recently experienced 2 new compression gauges that read low.

[jjdalynh]

To be sure of your numbers, check your new gauge against a known correct (or at least more correct) one. I recently experienced 2 new compression gauges that read low.

i know, that's my next thing.  this is a cheap unit from HF.

[jjdalynh]

so, if they are both off the same amount and low on gear drive cams, it'd have to be the outer gears, right?

[jjdalynh]

quick check against my shop air good regulator shows it's pretty on. 

[rigidthumper]

Equal but low would be worth checking- cost of a gasket + a little time

[jjdalynh]

seems ok to me...

[jjdalynh]

some more info, 10psi shop air into the cylinders and i can hear some air coming from the crankcase.   the rings should be able to hold that wouldn't it?

[rigidthumper]

10 PSI may not be enough to push the rings against the cylinder. Leak down tests are typically done at 100 PSI

[jjdalynh]

10 PSI may not be enough to push the rings against the cylinder. Leak down tests are typically done at 100 PSI

hm, having kind of a hard time keeping the rear wheel from moving when i apply 100psi (5th gear and brake on). 

[jjdalynh]

wet compression test yields same 180psi. 

[rigidthumper]

I use one of these:
https://www.amazon.com/Jims-USA-Mighty-Bite-Flywheel/dp/B009WD9FHU

[jjdalynh]

I use one of these:
https://www.amazon.com/Jims-USA-Mighty-Bite-Flywheel/dp/B009WD9FHU

that's pretty cool.  i suppose if i had the primary cover off i could use the locking tool for that

[jjdalynh]

outer timing marks are line up correctly, so the rear timing can't be off (unless the cams are ground wrong), front timing mark looks to be in the right place.  both cold cranking checks for both cylinders shows same results.  checked pushrod adjustments, seems correct (able to spin them on compression stroke after bleed down)....

i guess i really need to do the leak-down check to see if air is really going someplace.  what would be a good range for leak-down?   a couple percent?

[HD/Wrench]

Out of town so hard to look through all post did you post a data log  ?? Kia numbers seem way off   And yes the cam can be ground wrong as well mid machined slot in cam gear.  Went through this two years ago woods 9B. Was told impossible right up to the point I put a timing wheel on it   

Very rare though anything can happen  again  data log.  Btw did you get your free map deal ??  If so put that aside and use your OEM cal change CI reload that and see what the KPA does

Just a test  I have a idea but need an answer on that first old map is kpa and cruise OEM map idle and cruise

[jjdalynh]

fantastic.  haven't degreed a cam since i rebuilt my BBC. time to buy a new degree wheel i guess. 

i'll post up a log when i get to my pc. 

i really appreciate the help and insights from all.  this is gonna make me nuts.

[jjdalynh]

log attached.   knock retard on this tune was limited to 40kpa and above....

[jjdalynh]

and the tune....

[HD/Wrench]

Well looking at the logs and your map its clear that A the map needs to be repaired , not sure who did that but I can see how it would create issues .  If your trying to tune and have knock on that is not going to work either . as if you get ping its going to pull timing and when that happens your AFR is going to sway.

I can see if I can sort the map out , but this one is not the best , I see  many issues , send me your Stock map you pulled from the bike  gmrperf@gmail.com

Let me see what I can do also send me any and all build specs that you have , Pipe etc ,

and stop using the interpolated function is just making a mess of the map , Its clear that the map is not close and your changing cells that may not need to be altered .. I call that function the guess button at this stage .   I would rather you use the blend function if you feel the need to see it smooth .

[jjdalynh]

yeah, it is kinda the 'guess' button i know. 

originally i was street tuning with knock control set to 50.4 kpa min and my VE numbers were much lower in the cruise range, had them to within a percent or 2 run to run before it went to the dyno.  i'm wondering if the richening up of the VE was done to try and deal with pinging at low throttle?   AFR tables weren't changed by dyno operator from what i gave him. 

[HD/Wrench]

well it will give you very bad MPG , the AFR is not needing to be any where near that rich the timing tables are a total mess , I can it fighting you and not wanting to target much of anything . Timing bouncing around AFR super rich  I guess to " fix " it  and want to just bury it in fuel that is one way..  Just stating what any tuner can see .

post the map you got or email it to me that was your base file . Might be better for you to work from that , no idea if the tuner  knew what he was doing or not as this is not a map that I would send out as a complete item .

[rigidthumper]

6.2 injectors in a 107? Way too much dribble at low/mid duty cycle, will cause issues. If that's what's installed, would be worth it to switch to 5.3s and start over.

[rbabos]

well it will give you very bad MPG , the AFR is not needing to be any where near that rich the timing tables are a total mess , I can it fighting you and not wanting to target much of anything . Timing bouncing around AFR super rich  I guess to " fix " it  and want to just bury it in fuel that is one way..  Just stating what any tuner can see .

post the map you got or email it to me that was your base file . Might be better for you to work from that , no idea if the tuner  knew what he was doing or not as this is not a map that I would send out as a complete item .

One quick look and I made my decision.
Ron