The LNF Tuning Guide

**oldskool** · 10-13-2009

Lol I had to draw it out on paper too - don't feel bad man!

My (unfounded) theory on the VE airflow PID - it works fine when all of the sensors are within their ranges, and all the factory controls are in place. With the pill mod, you are effectively bypassing/altering the factory boost control. I think the same thing probably happens to those with manual/electronic boost controlers - the VE airflow is skewed.

You custom PID divided by 20 should yield "relative cam angle". subtract exhaust FROM intake and divide by 20 and you should have change in lobe separation angle. With those formulae you see that in the highest load column, the overlap decreases with increasing RPM. The overlap is even less at idle, and significantly more (four degrees) in the midrange. By making the exhuast more negative and the intake more positive, we are further decreasing the overlap. If we change both cams by the same value in the same cells, we are not changing overlap, but rather advancing or retarding the cam events with respect to the crank.

Back to the big picture, the problem that most of us are battling is the stock turbo not maintaining power up to redline. Moving the cams may change the position on the efficiency map, but that is still a steep learning curve for me.

**mkriebs** · 10-13-2009

When I had my MBC it did that with the VE too.

**BackyardTurbo_FTW** · 10-13-2009

Hmmm. I dont get why Im reading what seems to be an accurate VE. Another car I tuned with the pill also read similar VE to mine. But I did have that one that made wacky VE numbers too.

**Gimpster** · 10-13-2009

I bet the 3 bars will fix all of this, maybe someday GM will get CARB approval to get that Cobalt Stage1 OS out there

EDIT: Sorry for killing your thread btw, if a moderater wants maybe the should split this thread?

**Terminator2** · 10-13-2009

Here are new cam tables I am trying out on my car today. Retard intake cam and advance exhaust cam.

**BackyardTurbo_FTW** · 10-13-2009

You going to dyno those Term?? Or you just plan on literally trying them on the car??

**Terminator2** · 10-13-2009

Originally Posted by BackyardTurbo_FTW

You going to dyno those Term?? Or you just plan on literally trying them on the car??

Just trying them on the car for now. I wish I had more time to go to the dyno. I work too much sometimes. Did you try anything like that with the cam tables last time you were on the dyno?

**BackyardTurbo_FTW** · 10-13-2009

I tried going the opposite way of the original tables you posted above 5K and still showed a loss in power. I was shocked!

**Tom** · 10-14-2009

Ok, this is killing me...if anyone has time, please check out this log. Towards the end I roll into boost starting at about 4k in 3rd, and it instantly knocks badly. I hear it right from the engine bay, and this time I got it on the log. Bear in mind it does this randomly...usually there is no knock at all.

I've done multiple 2-3 runs, and the only KR is 2-3* at the very top of 3rd, which I'm working on eliminating. All the numbers seem to check out - timing is only increased 1* from stock, cams are untouched. I can post the tune if needed as well, but just looking at the log makes no sense to me...

Thanks in advance guys~
Tom

**BackyardTurbo_FTW** · 10-14-2009

That some wacky looking KR too!!!

Have you tried lower the tip-in timing at all?? Can you email me your tune also?? Ill take a look and comment on the timing

[email protected]

**Terminator2** · 10-14-2009

Originally Posted by BackyardTurbo_FTW

I tried going the opposite way of the original tables you posted above 5K and still showed a loss in power. I was shocked!

I am not that shocked actually. I have never seen any real big gains on any of the cam settings I have tired and I have tried a ton of different settings. Advancing the intake cam up top adds a couple whp up top. Sometimes retarding the intake cam and advancing the exhaust cam nets a small gain in the low end to mid range power.

**Tom** · 10-14-2009

Originally Posted by BackyardTurbo_FTW

That some wacky looking KR too!!!

Have you tried lower the tip-in timing at all?? Can you email me your tune also?? Ill take a look and comment on the timing

[email protected]

That's where I was going to look next, actually. Tip-in is still stock, but I went ahead and changed it all to -3 for the next time I flash. I'm at work, but I'll send it your way as soon as I get home tonight. I greatly appreciate your help!

**Terminator2** · 10-14-2009

Originally Posted by Tom

Ok, this is killing me...if anyone has time, please check out this log. Towards the end I roll into boost starting at about 4k in 3rd, and it instantly knocks badly. I hear it right from the engine bay, and this time I got it on the log. Bear in mind it does this randomly...usually there is no knock at all.

I've done multiple 2-3 runs, and the only KR is 2-3* at the very top of 3rd, which I'm working on eliminating. All the numbers seem to check out - timing is only increased 1* from stock, cams are untouched. I can post the tune if needed as well, but just looking at the log makes no sense to me...

Thanks in advance guys~
Tom

Lots of part throttle and lift throttle KR as well. My car knocked like crazy when I first installed my MBC. It has all gone away now so 25-26 psi in third gear 17* of timing and 0.875-0.883 lambda and no KR right now.

**Tom** · 10-14-2009

Originally Posted by BackyardTurbo_FTW

Can you email me your tune also??

**Gimpster** · 10-15-2009

I was thinking maybe as a section 3 some torque mgmt stuff might be useful? I've more/less know what its all doing by reading a few old threads, but thought maybe that could get consolidated here too.

EDIT: http://www.hptuners.com/forum/showthread.php?t=20339

Thats the thread I had bookmarked I reference often.

**mkriebs** · 10-17-2009

Wow, I set a new personal record for MAF and VE lbs/min tonight! I tried the first cam tables that TERM posted, and held 30.5+ MAF lbs/min from 6300-7000 rpms. I also hit slightly over 29 lb/min on the VE. Pretty dense cold air though as well. My previous bests were mid 30's and quickly tapering off on the MAF, and low 28's on the VE.

I think I like my tune the way it is. Should be getting it dynoed this coming Friday, so I will be sure to post up some numbers if I do get them.

**Iam Broke** · 10-25-2009

I took the time today to crawl under and over the car, took the wastegate solenoid loose and ran 2 1/2' of tubing from the solenoid to the source for the remote pill install. This way I can adjust or eliminate it in a minute. I'm looking into getting a needle valve to make it adjustable.

Hopefully the extra length of tubing won't add too much delay.

I tried to get a pic of the source tap, but angles and lighting sucked.

Excuse the dirt, it rained all week.

**Iam Broke** · 10-25-2009

Boost spikes to 25 psi in third, 24 in second. Holds 20 psi at redline now instead of ~18 pill less.

This is with a .047 (1.2mm) pill. Need a .040 to try.

**BackyardTurbo_FTW** · 10-26-2009

Trapped 114 running my pill tune over the weekend. My local track sucks fat cocks tho and I can't get the car to hook up for shit at the line. So Im going to try another track and get a damn 12.9 already lol...

**fr0stb1t3** · 10-26-2009

Originally Posted by BackyardTurbo_FTW

Trapped 114 running my pill tune over the weekend. My local track sucks fat cocks tho and I can't get the car to hook up for shit at the line. So Im going to try another track and get a damn 12.9 already lol...

Holy shit, 114? The kappa's do 14@99 stock. What kind of airflow were you seeing during the runs?

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