New tuner... new tune!

[Brad Campbell]

I'll certainly get you the actual dims. Played a little more Saturday. I added a couple degrees of timing because my wot pulls were not crisp, but the afr was fairly close. 13 to 15 degrees of lead seemed to make all the difference in the world... probably more to go, but I just want it to sound and feel crisp before it gets on a dyno. I also had a near miss when a 4500rpm pull chucked the serp belt. Lucky that A) the belt was still in the engine compartment and not on the side of the road B) my hands are strong enough to get the belt back on without tools, and C) it didnt get super super hot before I noticed. All in all progressing nicely. I have a katech manual tensioner coming tomorrow. My belt setup has a custom idler, and I think the angles on the tensioner aren't ideal so this should fix the belt issue. Boost is steady at wot at about 180kpa and comes in dumb fast even with the 87mm turbine wheel and 1.3 back housing. I'm thinking another couple street sessions and I'll be ready to hit the rollers. Hopefully I have enough fuel for the current setup... only going to pull to 6200 for now.

[Brad Campbell]

The filter is 8 inches long not including the flange, which adds another inch. I'll also add my current tune.

[Brad Campbell]

OK Played a little over the weekend. Installed my new belt tensioner, and everything seems to be hanging on. I'm thinking about switching to the 55gpm electric pump though... also in the works will be an additional fuel pump to safely support the 60 pound injectors at the 55psi base pressure. I ordered some fresh NGK TR6 plugs to replace the Autolite AR103's. I had started my tuning at 13 degrees of lead up top, but quickly realized that the engine wanted more. Once I hit WOT above 3800RPM and full boost acceleration flattens out. The exhaust note sound heavily retarded to me. I increased lead to 15 degrees and that seemed to get me further. Perhaps it's a combination of lack of ignition lead and a rich afr, but the engine just isn't crisp. I will change out the AR103's (pulled a couple and they look fine) as soon as I get the other plugs, but regardless I have increased lead to 16 degrees. Only timing retard from KR I have seen was part throttle in spool, so I pulled a degree out around the trouble areas. Any input would be appreciated.

[Nitroused383]

You may want to run a non projected tip plug like a NGK BR7EF. Tr6 might be a little hot for what you're running. What heads are on this? Have you tried performing a case relearn on this at all? This syncs up the ecu and the crank sensor, like verifying timing with a timing light on a distributor. Getting your afr around the 11.5-11.8 range will help crisp things up, also since you can log your boost curve you can play with your timing curve. Say run 24 degrees with 100 kpa and pull a degree of timing out for ever lb of boost that ramps in, that will make it feel much snappier. You can probably run almost 20 degree's of timing with your compression and boost but always a good idea to start conservative and check your plugs as you go.

[Brad Campbell]

Heads are worked 941's with oversized valves. The Tune that was on the car with the supercharger at 5.5 pounds was at 18 degrees up top, and there was no issues with that. Granted I never pulled a log on that setup, and I'm running more boost, but I see zero increase in IAT so far. The part throttle ramp into boost feels great and sounds crisp, but as soon as you peg it and the gates open that's when it feels less ideal. I have never done a case learn, nor have a checked the timing with a light. I can preform that next time I have the car warmed up, but my instinct would tell me that whatever it's running with normal driving and spirited part throttle pulls is sufficient. Just seems to be the gated boost pressure and wot. I will try the TR6 plugs when they come in, not ignoring the suggestion on the masked plugs, just want a fresh starting point. Again, I'd say the car behaves really well, and the only issue seems to be the wot rpm>3800ish and full boost. I couldn't ask for anything else as far as the part throttle spool is concerned. Keep the suggestions coming though as I log everything into my mental toolbox!

-Brad

[Nitroused383]

Not saying this is your problem but my car had ignition issues when in boost it would break up and feel like it had a miss. I diagnosed the issue on the dyno and found my stock LS1 coils were junk. Swapped over to a buddies LS2 coils and went from 500 rwhp to 580 rwhp on 7lbs. I also run the plug gap around .024-.028. Also make sure your valve springs are up to the task, a turbo has back pressure on the exhaust side and tends to float exhaust valves while trying to stay seated if you're not running ht proper seat pressure.

[Brad Campbell]

They are Manley NexTek springs. I may pull the gates this weekend and drop down to like 4-5 pounds. As an fyi I was having no problem supercharged in stock config at 10 psi and built at 5.5... obviously I'm moving much more air/fuel now. Let me know your thoughts on the springs. I also got the new plugs in so i'll install them and go from there. Also put a stock temp thermostat in as im not a fan of the 160 creating large temperature fluctuations.

[Brad Campbell]

Wow! Changed the plugs, and the car is much more responsive. I will need to drive it again to verify, but I'd say that issue is solved
(still at 10-11 pounds). Backed the ignition down to 14 degrees of lead. The stock thermostat is nice too. Temperature is much more stable. Nice progress.

[Brad Campbell]

I actually used the afr timing correction to remove the lead up top. Basically as the afr approaches that of the higher boost levels I have it pulling out up to 5 degrees which will proportionally bring me from 16 back to 14 degrees at 175kpa does that sound correct?

[Brad Campbell]

OK... I keep on just adding posts here, but I'm actually making progress. I pulled my compressor cover this morning and added a tap for my wastegates. I was concerned that I was shielding the signal to the gates a bit at part throttle as the outlet is on the manifold right behind the thorttlebody. I expected a drop in boost as I'm running around 11-12 pounds on what Tial calls a 9 pound spring. Adding the signal port does give me a more repeatable manifold pressure regardless of throttle position so that's good... it's settling around 10 pounds. Here is a log a good pull starts at frame 8700.

[Nitroused383]

The way your latest tune is setup it will pull 5 degrees of timing from 16 degrees equaling 11 degrees, but this will only occur at 195 kpa. If you want it to pull -2 degrees you need to enter -2 in the 1.3 column and set your boost enrichment table to be 1.3 @ 175 kpa. Or does it actually only pull 2 degrees when you enter 1.27? When you reference the intake manifold you will see additional boost as the turbo is over coming the pressure drop across the piping and intercooler. If you reference the compressor housing and see a difference of 2lbs of boost it means you have approximately 2lbs of pressure drop across your cold side. How is the car running with the new plugs?

[Brad Campbell]

The timing adjustments are proportional verified by the log. 1.27 is 40% of the timing delta (5degrees) 0degrees at 1.25phi and -5degrees at 1.3phi giving 5(.40) = 2degrees. With truncation it was showing 13.5 from 16degrees on the log.

...and roger that on the pressure drop. I was just expecting something more. The real issue I was trying to solve was the inaccuracy I was seeing based on throttle position. I was getting slight over boost with part throttle, but wot was fine. I attributed this to the position of the wastegate reference signal, and sure enough moving it to the compressor outlet solved that issue as well. So in reality not counting part throttle over boost I went from about 175 to 173. Not too shabby.

Plugs are awesome. What a difference all over. Improved light throttle cruising and completely solved the wot full boost issue. I went out after yesterday and did another pull with 15.5degrees instead of 13.5 and saw some detonation. I’m thinking I’m going to purchase the plugs you are running and try them out. These may still be a bit too hot. I wouldn’t expect this engine to detonate at 15.5 degrees. I’m not increasing lead after peak torque, but I’m thinking I need to feather out the lead after peak torque as that’s when I was seeing detonation.

Thanks again for the help, it’s coming along great!

[Nitroused383]

Ah thats great to know about that the pcm does interpolate inbetween those two boundaries. After you posted I was thinking about it and it did make sense how you see 2 degrees from using a value of 1.27. Something new to play with They have some ngk non resistor plugs in the 8 range, so far though at my power range the 7's look to be the correct heat range. It's nice they are a resistor plug too. I wouldn't expect your engine to detonate at that timing or boost level either really. Could be the plugs or maybe a crappy batch of fuel?

[Brad Campbell]

I don't think it's the fuel... I only use shell or mobil 93. Plus the detonation was after peak torque at the same timing angle, which is confusing. I have a set of the plugs you listed on your dyno thread(ls1tech) on the way. I also still need to either run the case relearn or throw a light on it... maybe both. I you don't mind could you share a log file of that dyno run? I'm interested to know your max dynamic airflow value and the corresponding engine speed.

Do you have any insight into dropping off timing after peak torque? Most setups I see are flat all the way out or in some cases feathered upwards.

[Nitroused383]

Most stuff I've seen detonate is always around peak torque, which with a convetional LS style intake is around 4500-5000 rpm. On my particular car when I see knock it's usually at 4000 rpm, so I run less timing from 4000-5200 rpm and I add in 2 degrees to 60000 rpm. Peak cylinder pressure occurs at peak torque, which is about the same piston speed as the flame speed burn rate of high octane pump gas (4000-5000 rpm). Normally as piston speed increases past peak torque you need to increase the timing to try and maintain the proper burn. If you have a detonation issue past peak torque I am curious if it is false knock or something real.

I can post my dyno run if you'd like to see it, it's a bit scarey though lol. My afr was bouncing all over the place, which I think is from a slight miss I have sometimes or from my methanol pump pulsing. My dynamic airflow values are way off because I'm spraying a lot of methanol, in which I have to cut fueling from the ve table so it looks really whack Figure the M15 nozzle I'm running is rated at 15 gph @ 100 psi, my pump runs at 200 psi so it's now a 30 gph nozzle! That throws off some numbers for sure. Here is the log though and if you want to know the custom PID's let me know.

[Brad Campbell]

Yeah I'm going to try your plugs, timing light, and I also have a phormula knock listening device that I may try out with the headphones and such.

What I had researched about flame velocity after peak torque is that the added air velocity and swirl turbulence actually starts to decrease the speed of propagation. Kind of makes sense intuitively because if it didn't the max cylinder pressure would continue to increase and so would mbt?

I also have been working on the startups. I have tried lots of different stuff to get my flare to a (what I call) reasonable level. I have actually completely zeroed out the friction table and started to add flat flow per the startup table with 30 cam revs to get me about 4.5 seconds until closed loop idle kicks in. I have the flare control at the stock level, multiplier as well. I imagine that I’ll find some nominal percentage of raf that I can use as an adder for startup. I.e. multiply raf table by .75 and use those values as my startup airflow.

[Nitroused383]

The case relearn procedure isn't too bad at all either you can do it in a few minutes with the vcm controls. The instructions on it are no real clear but you need to hold the foot pedal the entire time, even before you start the car. Hey peak cylinder pressure at max rpm would be nice though Kinda explains why it's easier to make more power on pump gas with more rpm. The further you get from peak cylinder pressure the less chance of detonation. Are you sure you're not burning any oil at all, from the turbo or pcv system, that will cause some detonation at times.

I wonder what the deal is with the start up flare? Are you sure your timing and ve cells in the start up area do not have any steep transitions between cells? That can often cause idle instability.

Here are the case learn instructions:

CASE Learn: To use the CASE learn function please follow these steps:
Put the vehicle into park (auto) or neutral (manual).
Turn off all accessories and A/C.
Turn the vehicle off.
Apply the parking brake.
Press the brake pedal. Keep the brake pedal depressed during the entire procedure. REQUIRED for successful test completion
Start the vehicle and let it idle.
Press Begin.
Gradually rev the vehicle to fuel cutoff (around 4000-5000 RPM's) over a period of about 4 seconds. When fuel cuts out, immediately release the throttle.
Allow the engine to come back to an idle.
Turn the ignition off for at least 15 seconds. This step is required for the VCM to store the newly learned configuration.

[Brad Campbell]

So I read that someone had equated dynamic flow to whp. Your dynamic flow is off up top from your meth, however if you extrapalate out with your max cylinder flow of 1.7g/cyl 1.7g/cyl x 4cyl/rev x 6250rev/min x min/60sec you get 708g/sec. Considering that's based on dynamic flow just before peak torque you would expect cylinder filling to increase a bit more... not too far from your actual results for what it's worth.

[Brad Campbell]

The engine isn't consuming oil and the turbo is bone dry. PCV system is two vent lines (sorry EPA). The crank ve is based off my tuned ve. Timing is 22 flat in the idle table. Cranking is still stock. When the car first starts cold the rpm rings like 3 times before it settles in and is perfect. After changing the friction table to 0 and adding .05lbs/min at a whack of startup airflow with the 30 cam revs it gets me almost perfect startup. I can always go back an and split the startup air with the friction air once I find what values work well. I dont really see the difference in the two. I just keep trying to think of this as a carb setup or the imports i've done with no idle control. What does you cold startup look like?

[Nitroused383]

Can you explain how you came up with 708 g/sec, you totally lost me on that math as I came up with something way different. Keep in mind dyanimc cylinder air is based off of your VE (of course), but with a setup like yours that uses a boost referenced fuel pressure regulator you're having to add less VE fueling into the positive map pressure regions. My car made 676 uncorrected rwhp, and since I'm at elevation I know the SAE corrections are off for a turbocharged engine as there is far less loses vs n/a. There for my fueling requirements are based off of 676 actual hp and not a corrected 717.

Look at this dyno run, maxed out fuel sytem, made 729 rwhp but only 5 degrees of timing, oops forgot about the afr correction spark table pulling 10 degrees. That was probably a good thing though as my stock 130,000 mile engine is still alive I dont have any cold starts files on this laptop (other one died) so I will go get one real quick for you.