opinion on tune issues

[vltrb-0]

Wondering if someone could review my setup and give a 2nd opinion

engine is stock 99 LS1, pac springs, single gt42 turbo, short 3.5" dump, powerglide, 2 bar SD, 7 psi gate spring, E85, siemens 80lb injectors, referenced regulator, A1000 aeromotive pump

Other than the above completely stock motor

had the opportunity to complete some initial tuning and im running across a few issues

1. picking up 0-1 worth of KR (refer logs) is it possible it's not real knock?, conservative timing, no boost yet and only 4000 rpm, gut feeling is my exhaust might be touching a chassis rail

2. car is missing at around 4000rpm and can't seem to pin point why, doesn't appear the ecu is pulling timing and AFR's are good, would i be on the right track putting in 2 range colder plugs and gaping to 0.8?

with regards to the miss you can hear it in the last 10 seconds of this clip
http://www.youtube.com/watch?v=U_ZRh...&feature=g-upl

Feedback would be much appreciated

[kyphur]

The "last test" log that I looked at looked alright. I saw the KR drop the timing but I also noticed that when you accelerated that your timing dropped about 5 degrees while your kr drop was only around 1 degree of timing.

I would think it was either your timing table is messed up or you have something pulling timing somewhere else. In the scanner whenever I am searching for something like that I load as many of the timing and retard pids that I can and do a test run. That way I can understand what table is pulling or at least point me in the right direction.

When I tune older setups such as carb/distributor configurations, I've always understood them to pull MORE timing as they accelerate with lower timing at idle. I would assume that fuel injected systems would perform in the same manner. So if your timing is not being pulled due to retard then it is a timing table issue.

DISCLAIMER: I am by no means an expert on HP Tuners. My comments are my opinions and suggestions and can be misconstrued as intelligent but more likely will be a few IQ points shy of a sheep with a labotomy.

[mowton]

With no boost, that is pretty rich at .74 (frame 81 of last log) which ocurred at 4K rpm as well. Seems Boost enrichment is kicking in even though you only reach 47-50kPa which seems low as well.That can cause miss/low power.

I would check the tune out as it seems to be very rich per the WB readings. The MAP reading seem a bit odd as well.

Ed M

[turbo 6l]

i would bring your commanded air fuel ratio up to 11.0 or 11.5 instead of 9 wow that is rich and yes a colder plug with a 0.020 gap would be good ..i would look at your ve table too.. in my opinion it is a little rich in the non boost area ie 60kpa at 4400 rpm over 100 percent ve hth

[vltrb-0]

Thanks for the replies the feedback is more than appreciated, i'm sorting out the plugs and setting up a few other small things to try rule out any false knock

i would bring your commanded air fuel ratio up to 11.0 or 11.5 instead of 9 wow that is rich and yes a colder plug with a 0.020 gap would be good ..i would look at your ve table too.. in my opinion it is a little rich in the non boost area ie 60kpa at 4400 rpm over 100 percent ve hth

agree with the richness side of things, wanted to sit with caution and sort the knock out, i'll try the plugs and pull some fuel out

with regards to the commanded afrs could you clarify that a little so i can look into it more, i tune in lambda just not sure what fuels those ratios are refering too. For E85 9.8 is stoich, i know at some points my afrs drop to 0.74 lambda which is roughly 7.2:1. Next time around im aiming at a maximum richness of 0.8 lambda on boost hope to hover around 0.85

[Maxwell Power]

Let me start by saying I've done a lot of e85 tuning.

Things i have found:
More than 3 degrees of timing over pump gas is usually a waste.
Richer than .79 Lambda is too rich. I try for .8-.81
You don't need colder plugs usually as the fuel removes so much heat on it's own during the intake charge AND the high octane.
Gap around .030" is a good place to start. Then open up from there until it misfires then shrink it back down.
Too rich with e85 will cause misfires.

Remember the richer your afr, the more dense the charge in the chamber is. Neither fuel or air conduct electricity. So the more boost and the richer the mixture, the larger your effective gap becomes. This means it takes a whole lot of coil to push through that gap if you're too rich.