BCNUL8R

iTrader: (2)

I'm sorry I didn't know I was going to offend by not sharing my tune. I can't make a post or share any info I've learned without offending someone and this is why even pro tuners that do this all day for a living don't post much or share their tunes.

I went several years without posting maybe I should go back to lurking.

Ill leave you with this advice though. Knock sensors are good tools, but learn to read plugs they will never lie to you.

Lsxford

iTrader: (6)

Exactly, without a dyno trap speed is the best way. Start low and bump it a degree at a time watching trap speed. It is best to stay consistent with no wheel spin, like leaving in 2nd gear if your trans can handle it. If you spin 1 pass and dont the other your trap speed will change. Keep the boost low and when it stops gaining mph stop there. I havent done this yet but this is how i will attempt to do it, so im not sure how much you should pickup and keep adding or not. My guess is 2-3 mph is a good gain to try another degree. If you add a degree and it only picks up 1 or 0 mph stop there, may even pull 1 back out to make it safe.

Right now i have mine on 8 psi and 10*, 14-15 psi is prob my max. I dont have any meth yet but have thought about it. Ill prob just throw some race gas in at first and go from there. Gotta figure my other issues out first lol

ElQueFør

Does my spark table look safe and sane at this point? Haven't logged any KR with it setup as it is.

You didn't offend me, I was just making fun of you because you wouldn't share your tune. I certainly wasn't going to copy it. My tune is pretty good I think, but there are surely areas to improve so I wanted to compare it to mine. I have learned a lot by using the compare function in HPTuners.

I can't wait to play with those transient fueling parameters and see if I can lean out the idle. HOPEFULLY I'll be able to do that later today. Makes me wonder at what point meth would be a good idea boost wise

Lsxford

iTrader: (6)

I can't wait to play with those transient fueling parameters and see if I can lean out the idle. HOPEFULLY I'll be able to do that later today. Makes me wonder at what point meth would be a good idea boost wise[/QUOTE]

With the great high quality 93 pump gas we have these days it prob a good idea to use meth on a higher compression engine with no boost. The way i understand it depends, if you boosted an l33 with 10 to 1 compression stock (may be higher?) i would want it pretty soon. But with a low compression lq4 im not gonna go further than about 14-15 psi with my baby turbo. But theres a huge difference in 15 psi with a chinese 7875 vs a borg s480. So like everything else in life it depends lol

Lsxford

iTrader: (6)

Dont do that, i believe he was just being sarcastic. This forum would be nothing if theres wasnt people here that knows what theyre doing, like you. Well nothing but a bunch of newbies telling each other wrong info. We need you guys, not to do it for us, but atleast nudge us in the right direction every now and then. If something you say offends anybody then they probably needed to be offended, thats how i see it anyway. If they get offended then they are not looking for help, they want you to do it for them which is 2 different things. Again i do not believe ElQueFør was offended, just joking around which comes out different than intended sometimes. Especially through text, on the internet.

Jumping off the soap box now.

ElQueFør

The only thing I have around me is 91 octane. So you think 15 PSI on our LQ4s is safe WITHOUT methanol? Why is there a difference between one turbo and another? X pounds of boost is just that I thought?

Yep exactly, I was being a sarcastic smartass but only joking around. I wasn't offended! Just trying to learn and have a good time! I really appreciate and respect the discourse and exchange of information

ChopperDoc

I still haven't had a chance to look at your tune, but I'll try later to take a look. I'm at work though, so no promises there. It really just depends on your engine, and the cam changes everything. Putting a GM hotcam in a 2014 Camaro SS caused crazy amounts of knock on a stock tune. Just an example, since cams change the effective and dynamic compression ratios. It's all about when that intake valve closes.

All I'm saying is it just depends on the engine really. And boost adds another element, obviously, because of the increased compression.

One thing I do is add a few decimals to my KR histo to see if I'm getting even small amounts of knock. I'll know down to .01 degrees if it's detecting anything. I add a few decimals to my spark and VE tables as well to really smooth them out and dial them in.

ChopperDoc

For some reason it won't let me download your tune file. I've tried it in firefox and IE, and still won't let me save it. Not sure why. I don't usually download tunes from ls1tech, as normally I do it on hptuners, so it's either me or this website. I think it's the website though. Keeps giving me an error, and what I could download would open but also had an error as soon as the editor started up.

ddnspider

iTrader: (26)

If you're going to run around 1 bar of boost on crap 91 octane your timing better be in the single digits, especially at peak torque.

Lsxford

iTrader: (6)

boost is just a measure of restriction. the bigger the turbo the more air it will move at the same psi. a 91mm turbo moves more air than a 70mm at 10psi. in turn the 91mm will make more power at the same boost #, but its pushing alot more air in and can get alot more of it out. im not sure exactly how to explain it but i know ive seen denmah talk about it. people would ask him how much boost do i need to make 700 on my 5.3? it depends on a lot of stuff, but the size of the turbo is very important. ill see if i can find that video, but he has a bagillion. maybe someone else will come in and can explain it better, but it seems to be just us few folk the past few days

ChopperDoc

I'll take a shot at it... Why not?

Size of the turbo is very important when considering airflow, but, I will say "boost" is simply the amount of pressure you are now adding to your engine. Pressure is pressure, not airflow. You're right, a larger turbo will move more air at a specific pressure than a smaller one at the same pressure. If you think of the difference between a coffee straw and a 711 big gulp straw, the larger one won't require as much pressure to move the same amount of air as the smaller one. But back to talking about pressure, and what that can mean for your engine.

And N/A engine cannot exceed 105 kpa (1 bar) at sea level. That's because it can only pull in the amount of air that exists in the atmosphere around it. At WOT, the map will increase until it hits this pressure, and that's as far as it can go. When you have boost, like 2 bar, or 3 bar, then you are now "adding" in another atmosphere worth of air (1 bar or 14.7 PSI). That's why you need 2 or 3 bar map sensors in the first place. To be able to measure how much, and account for it.

What all this really affects is compression. Compression causes heat, and believe it or not, as the piston comes up and compresses the mixture, it gets hotter and harder to light. Lighting it too soon will cause even more heat because it will likely have secondary ignition points due to "hot spots" in the cylinder, like carbon deposits or other things. That as I'm sure you know is knock, which also causes heat. Here's another kicker, since compression causes heat, and boost is basically the measure of air compression, it adds even more heat to this.

So all of this heat, if left unchecked, will lead to catastrophic engine failure. Hence why there are intercoolers and meth injection set ups, and why many guys ice down their superchargers between rounds.

I agree with spider, don't even try to get into double digits on spark near peak torque on 1 bar, no matter what size it is. It's still up to you though, ultimately.

Here is a formula you can use to get an idea of what your static compression is under boost.

Static Compression / 14.7 + 1 * Boost psi.

Here's what 15 psi would look like on mine, with an 11:1 scr.

11/14.7=.748... +1 = 1.748*15 = 26.2:1 scr.

That's pretty crazy right? I don't think 91 is going to cut it there.

ElQueFør

I really apreciate everyone weighing in here. This is really helping me learn immensely. And thanks for being patient, I have quite a bit of experience wrenching, but this truck is the first ever turbo build I've done and it's been a big learning curve to say the least.

Doc, I'm going to repost a tune file, see if you can look at it or PM me your email address if you would please and I can email it to you.

Also, this LQ4 is totally stock, ARP headbolts and LS9 gaskets.

Spider, 91 is all we have around here at the pump and this truck is my daily driver so I want to keep it on pump gas. I'm on 6 PSI max boost now.... What do I need to do if I want to step up to somewhere between 10-15 PSI?? Methanol???? Switch to E85???? E85 just showed up around here recently.... Or the timing table changes you mentioned.... Are you talking about single digits EVERYWHERE or just in the bottom right area of the spark tables where "boost" occurs????

This is exactly why I have been staying at 6 PSI boost until I gain some better knowledge of what I can do to push say between 10-15 PSI of boost..... Like I said, for now I've been at 6 PSI and just 91 octane.

I do have a pretty massive A2A intercooler and now that we're talking about all this I need to revisit some logs and pay more attention to IATs.....

Thanks everybody!!

ddnspider

iTrader: (26)

I am a firm believer that you don't need e85 or meth to make HP....but it does limit how much timing you can run. I typically run in the low teens for turbo cars with a 76mm turbo up to around 14 psi with 93. So I'd keep it to around 10 degrees on 91 and read the plugs and see what the mark looks like on the ground strap. It'll tell you if you're getting close and make sure to look for speckling on the porcelain.

Also if you're logging boost remember you really don't need to fatten up the air fuel and drop timing until it has a couple PSI. Keeping it lean and keeping timing in it before that will help with spooling and part throttle.

ElQueFør

Cool. So if I'm staying with 91 octane and no meth or E85 then I need to drop that area of the timing table to about 10 degrees IF/WHEN I change the WG springs to bump the boost up towards 15 PSI.... And keep checking the logs for knock retard and pull a plug or two and check them....... This is starting to really come together for me.

Do you think 10 PSI of boost would be okay with low teens for spark advance in the boost area of the spark table while running 91 octane?????

I didn't even know you could log boost!!! I just keep learning....

And also ChopperDoc I didn't know that you could change the histograms to show in multiple decimal places.... Definitely cool to be able to more precisely dial in the VE and spark tables that way!!


And yes, something seems to be broken with the posting of and downloading of tunes on this site....

Lsxford

iTrader: (6)

I couldnt agree more with what doc and spider have said. BTW ElQueFør i couldnt open either of the first 2 tunes you posted either, it could 100% be my fault. What version of HPT are you running? Ill have to try your latest 1 in the am

Google hptuners boost pid and youll see how to set it up

ddnspider

iTrader: (26)

I'd set it at 12 degrees and see how the plugs look. Also if you put a fresh set of plugs in and make a pull and check the plugs again you can find your hottest plug. Then later on when you make changes you only have to check the hottest plug.

ElQueFør

Nah dude, something is screwed up on this site apparently because I can't even reopen my own tune file I posted

Version 3.6.6

Yep! I'm going to be looking into that!

ElQueFør

Thanks spider, going to do that! I'd guess the back two cylinders are going to be the hottest.

ddnspider

iTrader: (26)

Got a chance to look at the tune, some comments:

-Set 12315 and 12316 to 0.8. This should help with idle fueling being overly rich assuming the rest of your fuel tables are accurate.

-Your VE table is super jagged in the lower kPa. I would try to smooth that out and average between cells you didn't hit while logging.

-Your spark table has a weird drop to some low timing values at .08/.12 around idle RPM's. I'd make sure those cells match your idle timing tables.

-Looks like you have stock rev limit. I would drop timing to nothing and add fuel if you over rev and set the RPM rev limiter high. This will prevent blowing something up if you happen to bounce off the rev limiter.

-You pull several degrees of timing starting at 95* IAT's, this is overly conservative. Usually you would start pulling timing around 122*.

-I typically disable burst knock as this is theoretical, not actual knock and can screw with you during logging.

-I would increase the knock retard decay rate as this is when knock has stopped how quickly to ramp back in timing.

ChopperDoc

I saw that you still had burst knock enabled too, which reminds me I need to turn mine off. I must have missed that when I was changing my PCM. The tune file I sent you is not quite done, since the winter has made it hard to take the car out. And right now I have the trans out because my dumbass managed to snap off the back 2 studs on my oil pan, so my cam swap turned into replacing the rear cover, too.

Your spark table indeed needs some work. And from what I said last night, it only looks like you only changed idle and WOT. It's going to need some work in between. I would also smooth the transition into the decel area too, since you have that cliff there. Otherwise it looks completely stock up there. I usually pull a lot of that area down to keep it from knocking on the decel region, which seems to occur in the middle rpm areas under lighter loads, on sudden transitions. I had burst knock disabled on my old pcm, and I just did the same thing on a newer Camaro cam swap because it just had too much decel spark. Had to pull out about 5 degrees.

The only reason it does go so high is to keep the engine spinning when you chop the air off. With modified engines I've seen it cause knock. Mine I think maxes out around 35 or something. That's more than enough to keep it going, and won't affect power at all, because it's decel.

And of course you know that VE table needs work. This should get you going in the right direction. Try and nail down that VE before coming back to add spark. To be safe just set up a conservative spark table and get your VE squared away first.