Times for 10/16/11

[Welacey]

Tac has our times posted. Great job C. Sorry about your motor Rick.

[JohnW8]

They got them from here Wally.

Our T&S team is on it already.

https://axwaresystems.com/axorm/calendar_main.php?

[c-evoVIII]

Thanks Waley!! Sara was just having an OFF day, and Matt wasnt in SM that day. Im sure I'll have to work harder the next event!! C

[zukitek]

yeah thems the breaks . Broke #1 piston again . Same spot , same way as last time . Broke the ring lands between top,second,and oil control rings. I dont get it ...2,3,&4 pistons fine . Definitely didnt lean out . Detonated for sure but Im scratching my head on what would make #1 more proned to detonation than the other 3???? 2 differant heads,differant set of injectors , differant tunes, differant pumps . I should have it back together tomorrow or Wednesday.

[c-evoVIII]

Have you check the timing? Normally when you boost the ka ( back in the days when I was still playing with them) rule of thumb used to be 1 degree retardation of timing per 1 psi of boost, and 1 psi of fuel pressure per 1psi of boost. C

[TouringBubble]

Are you still running EGR and PCV? Where do they re-enter the system? Both oil and recycled exhaust will reduce the octane value of the fuel mix. So, if they dump really close to #1 ...

[zukitek]

Are you still running EGR and PCV? Where do they re-enter the system? Both oil and recycled exhaust will reduce the octane value of the fuel mix. So, if they dump really close to #1 ...

Egr is gone as well as PCV. I am just venting PCV to atmosphere . EGR is capped. Car is back up and running now so time will tell.

[zukitek]

Have you check the timing? Normally when you boost the ka ( back in the days when I was still playing with them) rule of thumb used to be 1 degree retardation of timing per 1 psi of boost, and 1 psi of fuel pressure per 1psi of boost. C

total timing at 150kpa(8psi boost) was 22* at 40psi of fuel PSI. Now total timing is 20* max . I am not using a rising rate regulator . AFR is pretty steady between 11.5 and 12.5 under boost . I am absolutely certain it didnt lean out unless something odd happened while I wasnt watching but looking at the damaged piston there is no sign of leaning out or preignition . It looks like plain old detonation damage . It fractured the ring lands clean and did not melt anything. Its just very odd that it broke this piston in the same exact place as the other one on the same cylinder with so many things differant between the 2 occurences . The only common threads are the supercharger/intake setup and the megasquirt/wated spark setup.

Im exploring going down a couple heat ranges on the plugs and maybe even go full sequential so I can control timing and fuel on each individual cylinder. At any rate ...I am getting way too good at putting pistons in this motor .

[TouringBubble]

I'd suggest a few things ...

For E85 (with gasoline stoich calculation), try to air for around 12:1 across the board.

If you are using NGK plugs, you should be in at least the 7 heat range. 8 might be too cool. If you are on a 5 or 6 and running 12.5:1 up top then that might be your issue.

And get a 1:1 regulator! Pretty much any boosted car will have one from the factory. They work.

As for sequential fuel, I don't think you need it. Are you also going to monitor AFRs in each runner? If not, then it's useless. Make sure your intake is in good shape and not gunked up, and richen it up a touch and verify everything else before just throwing money at the problem.

[zukitek]

its got bkr5xxx plugs in it now since that wa the oem number but I just got some 7s delivered so Im going to put those in . The regulator I am using is from a volvo 850 turbo so it may be a 1:1 and I just didnt know it . I am not running a fuel pressure guage in the car so I am not sure what the pressure is under boost . That is my next purchase .

I have the capability of going semi sequential on the spark (COP) but I really and truly dont think that is the answer. Maybe it is overheating the spark plug electrode and it is preignition but it darn sure doesnt look like preignition. Intake is clean as a whistle . Had it hot tanked at the machine shop when i was adapting the supercharger. Backside of the valves are spotless too . E85 certainly does an efficient job of cleaning away gunk if nothing else . Burns like a mother if you get it in a cut too!!!

[TouringBubble]

Last time, you said you burned a hole in the middle of the piston. That could have been the hot plugs.

And 2 bank fuel injection and wasted spark works fine when the right components are there. there is just something that doesn't agree in your setup and you have to find it.

Are you using some kind of torque measuring application to set the timing? You will not be able to tune to the knock threshold on E85 as you will reach MBT before knock in most all cases. Hot plug and over-advanced timing would cause the issues you are having.

[zukitek]

It did melt at the edge of the crown but I cant say that it wasnt due to the actual lean condition I had at that time . At that time I had 270cc injectors and a stock pump that wasnt up to the task even on gasoline .

Ill get it figured out . I just hope I dont break anymore pistons before then . I do not have a torque measuring device to set timing to MBT. I have up to now been running what I considered on the safe side on timing but evidently not but then again 16-20*at 8psi on a 9.5:1 motor with rich ratios on E85 doesnt seem ambitious to me but maybe they are or maybe I am getting the detonation somewhere else such as between 90 and 140KPA.

[TouringBubble]

Octane can't protect from preignition. If you are trying to compress against peak cylinder pressure, you're screwed and stuff breaks.

I suggest getting DataLogLab or another torque measuring tool and starting from low timing and working up. You should get 3-5 ft/lb from every degree of timing you add. When you stop gaining with increased timing, back off a degree or two and that's your tune.