Getting some kind of hard cut on the track?

[s2d4]

Originally Posted by moto-mike

a much more effective method is to alter injector scaling or fuel constant (i.e. nissan).
.

Thanks for your reply, here are more questions if I may.

So how would one know that their injector scaling is off for E85?

Is it not possible to use how much extra E85 in percentage is required to create the same amount of energy as pump, then apply that to the scaling? then use maf scaling to actually sort out the intake characteristics/engine volumetric efficiency?

Also, are we not actually creating more cylinder pressure/load by adding more timing?

[Jesse36m3]

Stock fuel pump? You might be at its threshold, especially with E85.

[dave-]

Originally Posted by moto-mike

It's a technique of last resort (i.e. when you can't directly alter injection values) but a much more effective method is to alter injector scaling or fuel constant (i.e. nissan).

Mike, when you talk about injector scaling do you mean port value (that has been lowered 30% compared to stock tune) or one of the DI tables ?

Originally Posted by Jesse36m3

Stock fuel pump? You might be at its threshold, especially with E85.

Yeah it is but if I was at that limit it would do it constantly and many others would have mentioned it. I'm still running stock headers which many others aren't.

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But this is now less about my hard cut issue and more the inconsistency found in logs. I'm starting to think that the quality of E85 when we tuned the car and what I've filled up with since is quite different (same brand but different locations).

This is the same custom E85 tune but reflashed to reset everything, not the same fuel batch as above. LTFT's are average
http://www.datazap.me/u/dave/e85-res...g=0&data=12-20

This is the OFT E85 Stage 2 tune flashed yesterday on same batch of fuel as logs above. LTFT's are even worse, total rubbish even. I basically went up and down the fwy on cruise control at 100.
http://www.datazap.me/u/dave/e85-oft?log=0&data=10-18

But if I go back to some logs I did immediately after the car was tuned for E85 on the dyno, still running the same fuel that was in the car from when it was tuned, the logs look quite a bit different. LTFT's were good. Both cruising and giving the car a belt on a really hot day.
http://www.datazap.me/u/dave/e85-cus...g=0&data=10-18

Will finish off the E85 in the tank and switch back to stock tune and log to see if there is anything suss with the car and go from there. Might be time to stick a wideband in somewhere, getting access a dyno isn't easy.

[steve99]

If you using OFT maf scaling on united E85 tunes your ltft are always going to be around 10% positive as the usa dont have a guaranteed e85 mix like united. Their fuels are arround 60 to 75% average it appears so thats what the tune was set up for around 70% ethanol. United being e85 to E90 will result in high fuel trims on standard maf scaling and injector scaling levels. I think the oft guys also jack maf values a bit to make ure the tune will run an the rich side when ethanol % changes.

unfortunatly jacking the maf values also increases the ecu load calculation as moto mike says and it does appear you hitting load limit which is likely the cutout.

if your tuner rescale your maf to suit the consistly high e85 your using the load calc will be less and you will probably not test the load limit.
and you open loop fueling will follow the commanded afr like its supposed to and not be about 10% different and your closed loop fueling will be corrected and your ltft will be low like less than 4% on united e85..

better to fix the problem than alter mare stuff tryng to bandaid it

pi scaling is injector scaling brz
di scaling is di fuel presure targets.

after maf scale you may have to adjust fueling and timing again.

then see if that knock goes away and your iam stays at 1.

most tuners set iam initial to one as its a hassle to run the car for a few minutes to get the iam to 1 after a flash so you can do dyno pulls and check timing ect.

if they have iam initial set to o.7 and dont let it get to 1 before dyno pulls your tune will then advance the timing 3 or 4 degrees in places once the iam returns to one after some driving posibly causing knock problems.

i am starting to think this is what your tuner did as on the track your iam is at 0.7 whereas after a bit of sedate driving you can see the iam quickly go to 1.

ie your tuner has tuned for max timing with iam at 0.7 instead of 1.

[dave-]

Yeah I won't be playing with any of that stuff, was more curious on which tables were being spoken about. I compared the OFT tune and mine while looking for scaling etc. The OFT tune must have been used as a base because the differences are primary ol fueling, timing, intake/exhaust avcs, calculated and requested torque. The rev and knock tables have been taken from the stock tune however. So the MAF scale is identical to OFT Stg2 EL A01G v2.061.

Interesting theory about the IAM and timing, makes sense as you're doing dyno pulls and flashing changes constantly so never long enough for IAM to reach 1 in that scenario which in hindsight isn't ideal.

I'm thinking finish the E85 off, switch to stock tune and do the MAF scaling process on BP98. Tuner can use that scale and and retweak timing/fuel with IAM=1.

If we can't organise dyno time, a friend mentioned I can have his Innovate LC-1 Wideband. If I can replace the secondary O2 in the factory header with that then great otherwise will have a bung welded in somewhere.

[dave-]

Went back to stock tune to see if there was anything suss going on after the fuel trims differed so much between initial E85 tune and a few tanks. Car threw P0420 Cat Efficiency code after less than 20 miles and an hours run time. Have the factory header with Invidia over pipe and catted front pipe.

Have noticed a bit of condensation leaking from the exhaust between overpipe and frontpipe so wouldn't surprise me if the bit between the header and overpipe was too. Bolts are tight so must be poor flanges/gasket. Either that leak is enough to throw the rear O2 out or the stock header cat is stuffed?

Process of elimination now, what a pain in the ass.

[steve99]

Originally Posted by dave-

Went back to stock tune to see if there was anything suss going on after the fuel trims differed so much between initial E85 tune and a few tanks. Car threw P0420 Cat Efficiency code after less than 20 miles and an hours run time. Have the factory header with Invidia over pipe and catted front pipe.

Have noticed a bit of condensation leaking from the exhaust between overpipe and frontpipe so wouldn't surprise me if the bit between the header and overpipe was too. Bolts are tight so must be poor flanges/gasket. Either that leak is enough to throw the rear O2 out or the stock header cat is stuffed?

Process of elimination now, what a pain in the ass.

i would just change gasket between overpipe and header, unlikely its between block and header if its never been off. I suppose its possible the primary cat is stuffed , think csg mike stuffed his cats on stock car stock tune on petrol on the track.

but a gasket costs stuff all and pretty veasy job and you can probably shine a torch in and see if the cat has disintergrated or their is bits floating arround in the overpipe.

[dave-]

The car has done a lot of track days (20+) so it hasn't had an easy life that's for sure.

Looks like I gotta find some hoist time tomorrow and try the gasket. Wonder if I can get a bung for the wideband O2 done at the same time...

[dave-]

So found the cause of trims going to shit and cat efficiency code....

Factory cat had totally disappeared and also had a leak between front and over pipe flanges, though the lack of cat would have to be the issue here.

Seems they don't like constant tracking but really hate the sound of every aftermarket header I've heard!

[steve99]

Originally Posted by dave-

So found the cause of trims going to shit and cat efficiency code....

Factory cat had totally disappeared and also had a leak between front and over pipe flanges, though the lack of cat would have to be the issue here.

Seems they don't like constant tracking but really hate the sound of every aftermarket header I've heard!

Be worth checking second cat its probably stuffed as well or has all the bits of front cat jammed in it. at least you know what problem is

[dave-]

Originally Posted by steve99

Be worth checking second cat its probably stuffed as well or has all the bits of front cat jammed in it. at least you know what problem is

The cat in the front pipe looks absolutely fine, not clogged up or anything so no idea where the primary cat disappeared to....

[dave-]

Blasted air through the front pipe and muffler with the compressor, got a lot of particles which were probably remnants of the OEM header cat. Haven't decided on what to do with the header as yet but we replaced the over pipe (flange was warped) which fixed the exhaust leak. Obviously it threw the P0420 CEL after about 30mins of driving but not concerned with that right now.

Car has OEM A01G tune in it with no alterations. Did 2 log sets:
http://datazap.me/u/dave/stock-oem-a01g-tune
http://datazap.me/u/dave/stock-oem-a01g-tune-pt2

I know the OEM tune had some minor knock on our fuel so I'll flash the OFT V2 Stg1 A01G T K S 98 ROM to start with and do another set of logs tomorrow as a baseline.

[steve99]

Originally Posted by dave-

Blasted air through the front pipe and muffler with the compressor, got a lot of particles which were probably remnants of the OEM header cat. Haven't decided on what to do with the header as yet but we replaced the over pipe (flange was warped) which fixed the exhaust leak. Obviously it threw the P0420 CEL after about 30mins of driving but not concerned with that right now.

Car has OEM A01G tune in it with no alterations. Did 2 log sets:
http://datazap.me/u/dave/stock-oem-a01g-tune
http://datazap.me/u/dave/stock-oem-a01g-tune-pt2

I know the OEM tune had some minor knock on our fuel so I'll flash the OFT V2 Stg1 A01G T K S 98 ROM to start with and do another set of logs tomorrow as a baseline.

performing inline with stock tune by the looks of log bit of knock and iam around o.8.

just disable the p0420 code in the T K S 98 TUNE as its for catted header so not disabled.
some guy on this forum just cut and welded a pipe where the cat was to make it flow better than a gutted cat. Aparantly it performed pretty well on par with catless header.
sinceyou likesound of stock header probably an option then just run the CatlessEL header tune and make timing andtemp compensation mods similar to the tune above.

should work fine and cost sod all.

[dave-]

Yeah that was what I'd hoped. I checked the rom before and noticed the code, easy done.

Had that idea today but didn't have pipe or welder handy hehe.