Help with tune before track and dyno this weekend!

I am going to the dyno this weekend and to the track the following week. Please give me some tips and things to do while I'm on the dyno. This is my first dyno. I promise to post up my results after the dyno and track.

What do you guys think about my timing? I don't believe my timing is very aggressive but I have been seeing knock here and there so that is why the timing is where it is.

Does knock look like its not real knock? I have the stock ls1 high compression but with meth injection and I am running 110 octane for now so I wouldn't think it would knock. I have open wastegate dump so my car is pretty loud.

Note that Meth injection 50/50 12gph nozzle on 10% at 2psi and on full after 5psi. Speed Density, open loop, no PE. See signature for more info.

So above 115kpa my boost VE table is hacked to lean the car out when the meth is spraying. Might be a better way to do it but thats how I did it for now.

Its been warm and very humid out during these logs, the ambient air temps have been around 85 degrees F. I do realize my IAT's have been getting high. I have no intercooler and rely on the meth injection. I think I am going to change my nozzles to inject about 25% more meth/water here pretty soon to try and keep IAT's down more. I do realize my timing is getting pulled often at my current IAT's.

Download my files here
Attachment 8663 Tune file
Attachment 8666 8psi 1st - 3rd gear launch
Attachment 8665 8psi highway pulls
Attachment 8664 8psi file with knock at the end
Attachment 8662 Raised boost to 9psi

Make sure AFR is logged by the dyno software (get him to log as much as he can/will).

well this is a group dyno event with like 20 cars @ only $25 a pull. The operator said he wasn't going to hook up the wideband to save time. I have my own AEM wideband though.

http://www.importevolution.com/temp/...rbo_medium.jpg

ok, that's dirt cheap for a dyno pull, log your own wideband.

I'll can look at your files later on my other PC.


[ I like your rad cap ]

What are you doing for PCV/crankcase venting...?

Also my wideband is logged in the above logs using the PLX wideband pid's. Are the dyno widebands a lot better, maybe I can convince the dyno operator to use his. PCV/crankcase is vented to the atmosphere for now.

Wouldn't hurt to verify what your wideband is reading compared to his.

Normally, seeing knock on the log with a lean spike a frame or two later you would say it was real knock. However I notice a lot of lean spikes in your log that match the spike during KR perfectly. So you either have a voltage issue with your wideband, some serious misfiring going on or maybe even airleaks in the exhaust. I will look through your tune fileshortly.
Mick

well i have noticed some lean spikes and I don't know whats causing them. I see a lean spike right after knock on log_0072 But other than that I don't really see the correlation with lean spikes to the knock in the other areas but maybe you can specify where you are looking. I see lots instances of 1 degree KR with no lean spikes. I also see a lot of knock at not very high loads like 50% throttle, sometimes less, and under 2psi and do you think real knock could happen at that low of rpm and boost on pure 110 octane even if it was lean? I'm just trying to figure out if this is phantom knock.

Examples would be frames 6396,6370,6799 etc. Those types of lean spikes are right through log 72.

Personally, I would use PE to set your fuelling under boost so you do not need to fudge the boost VE table. Set PE to come in at 100kpa & put whatever AFR you are after under boost in B3618. EG 11.3:1. This will keep your cylinder airmass estimation much more accurate.

Quote:

---

Originally Posted by 5.7ute

Examples would be frames 6396,6370,6799 etc. Those types of lean spikes are right through log 72.

---

Ok, I thought you were saying my lean spikes were causing my knock but now I know what your were saying.

Rich and lean spikes show up everywhere like 5.7ute said, something is not right with your wideband or its connections.

would a bad wideband o2 sensor do that? Mine is only 6 months old but I was running really rich for a while on pump gas because I had a coil unplugged and didn't know it. And now I am on my 2nd tank of leaded fuel so I wonder if my sensor could be going out already? Do you guys think I can dyno my car still or is this something dangerous I need to fix?

That may be the problem... it may be fouled... hard to clean because of the steel shield, could try spraying MAF cleaner in there.

could buy another sensor, they're something like $50... if that's not the problem, keep it as spare since you will need a replacement in the long term.

Thinking about what I said, I'm not 100% sure that your AFR waveform is correct... but may be it is.


I think when you run OL then two widebands might be good (one in each bank) to sanity check against each other.


I think you can still dyno... but, even if the AFR is correct (sufficiently rich at load), if there is audible knock then back off immediately.

I'm not sure what you mean about the afr waveform, do you mean your not sure if I can use the plx PID?

Should I get more aggressive with my timing on this 110 octane? I'd really like to make sure I get at least 500whp. And I'm at 9psi, stock cam, stock ls1.

The AFR_PLX2 pid's waveform in the pic in post #12 above... if you look at the steady throttle/airmass areas, AFR_PLX2 seems to be moving about (regardless of spikes).

http://www.importevolution.com/temp/rx7_dyno_514hp.gif

Download tune and log here
Attachment 8730
Attachment 8731

Final pull to get over 500whp I had to go to 11psi and 20 degrees timing peak. What do you guys think of the log? Is 20 degrees timing to much for a stock motor?

http://importevolution.com/temp/efi_live_chart.gif

Anyone know why my timing gets pulled like that. Its not in my high or low octane table, not from my IAT table, not from my boost timing table, and I showed no knock??

I'm heading to the track tomorrow afternoon so let me know what you guys think.

I looked thru your file to see if timing correlates to any table... in some places it does (B5913), but those dips seem to be about 3° short... I'm looking at burst knock, but it doesn't seem to be coming from there either.

20° advance without knock is good, AFR is still in the safe range, ECT is stable...

IAT dropped... any particular reason...?

Thanks for posting dyno chart... :cheers:

meth injection is why the IAT's dropped. I have no intercooler, without meth the IAT would be well over 200 I'm sure. I thought about burst knock too but I know only little about it. Do a lot of people just zero out that table?

Quote:

---

Originally Posted by ryans1000

Anyone know why my timing gets pulled like that. Its not in my high or low octane table, not from my IAT table, not from my boost timing table, and I showed no knock??

I'm heading to the track tomorrow afternoon so let me know what you guys think.

---

Burst knock + Boost timing table. The cells are interpolated so even if the tune tool shows it is in the lower cell, as soon as map goes above 175kpa it will start pulling a percentage of the timing from the next cell.

Ran a best of 11.6 at 127mph with a 2.1 60 foot, couple other passes were 11.9's with bad 60's also. I really need to get some decent tires. da was 3500, it was really hot out. My IAT's got to 200 degrees at the end of the pass even with the meth injection. Also ran out of gear so next plan is to wait for it to cool down and run with some taller drag tires . Little dissapointing but it was the first time out with this car.