I have a eprom tuned for a 11.7 with 91 oct and don't get any knock so am I ok as long as there is no knock? Can I go leaner? How lean is too lean? My side mount is starting to become warmer the leaner I go. My only restriction

wow, i wouldnt go that lean. How much timing advance do you get? How much boost are you running? What kind of turbo. Meth/ h2o injection?

I dont like to go any leaner than 11:1 a/f ratio on 91 pump because i like to run more timing. Im running a 16g though, so my car blows hot air at higher boost. If you arent knocking then you arent knocking so things cant be getting too messed up.

11.7 is ok, but you shoudnt go any higher than that to be safe.
If you don't have any knock, then you're doing good.

11.7 is pushing it. Are you doing back to back pulls when you tune? Its really hard to believe you are getting no knock with a sidemount and that afr.

I am only running 15psi. My mods are 2.5" full exhaust, 2.5" o2, ported everything including head, 2g mass, cyclone intake ported and short runners set to 4100, small 16g ported, 2.5" uicp, 2" j pipe, pte 580s dialed in at 535cc and walbro 190. Timing is pretty low peak is 22* by 6500. idc is a peak of 71% in 3rd and stock fpr at 38psi unless it is overuning it. highest hz on last run was 1730 hz at 6750rpm Also, this is just a good street tune. I have sence advanced my exhaust cam 2* and was now starting to see knock in 3rd. So I am at a 11.5-11.6 a/f right now also I am getting way better timing advance. Thanks for help.

Once you start to turn up the boost, being that lean will start to cause problems.

Going from 11:1-12:1 on pump gas isn't worth that much power...

How do you know it is really pushing 11.7:1??

ok either im seriously confused our your all seriously confused. first off.... the lower the number goes the richer your running not leaner. this i know so if u try to argue that your wrong! so now the question becomes where is the limit. correct me if im crazy but isnt 14.7:1 the ideal stoich mixture? how are you people so much lower than that? the proper way to tune is to start rich and turn up the A/F ratio until you start seeing knock. more knock = less timing HOWEVER more boost provides a bit more power over more timing, so its really upto you on how much knock u wanna see. most people say stop when u see anything but i think its ok to have some knock.

hmmmm,
14.7:1 is ideal under cruising or part throttle/engine load..........

It's a totally different story when you're at WOT and full load.......
Our cars seem to make the most power safely anywhere between 9:5-10.5:1
Some people can get away with leaner A/F's without knock or timing problems, but I wouldn't go any leaner than 11.0:1.......

That depends on what you tune for and if you have timing control.

If you are moving alot of air and trying to run stock timing numbers... its not going to be able to run that lean because the timing is to aggressive.

If you have full control like with standalone, a reflash, or dsm link you can easily tune for 11.7 if you can reduce your timing.

I run mine at ~11.3:1 on pisswater 91 octane @ 27psi with my 50trim. I have to run a good amount less timing in my maps to do that without knock.


BTW, your intercooler temp have nothing to do with how lean your tune is. That is dependant on the efficency of your turbo, intercooler and ambient airtemps. If its heat soaking you need a better intercooler.

Car Cannibal said:

How do you know it is really pushing 11.7:1??

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Edit: I just realized this wasn't directed at me.

Don't get me wrong, if you can get away with it good. But I would be doing everything like back to back to back to back pulls to make sure it isn't going to knock. I would rather run more boost and timing over a leaner afr. Though I did try an 11.5:1 pump gas tune on my car. I didn't mind it but it was really prone to knock with the onset of boost during shift recovery. I suppose I could have backed off the timing a little in that area and ramped it up after that.

As for who said having knock isn't a bad thing, good luck

sbiggi said:

That depends on what you tune for and if you have timing control.

If you are moving alot of air and trying to run stock timing numbers... its not going to be able to run that lean because the timing is to aggressive.

If you have full control like with standalone, a reflash, or dsm link you can easily tune for 11.7 if you can reduce your timing.

I run mine at ~11.3:1 on pisswater 91 octane @ 27psi with my 50trim. I have to run a good amount less timing in my maps to do that without knock.


BTW, your intercooler temp have nothing to do with how lean your tune is. That is dependant on the efficency of your turbo, intercooler and ambient airtemps. If its heat soaking you need a better intercooler.

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My car really enjoyed being around 11.3:1 too. Though the 16g did't really like being past 21psi on pump gas

The reason I was able to get away with running a 11.7 is because my timming was very low. After I raised the timing where I want it at about 22* and higher before the turbo spools I had to go richer. This is how my curve looks
11.7 until turbo spools at 3000 and 11.5 until 6000, then 11.6 up to redline with 0 knock. Now granted if I turn the boost up to 20psi I will probably want change to a 11.3 or 11.1 but this is a good street tune. I am burning a different chip for the track.

gdmbat85 said:

ok either im seriously confused our your all seriously confused. first off.... the lower the number goes the richer your running not leaner. this i know so if u try to argue that your wrong! so now the question becomes where is the limit. correct me if im crazy but isnt 14.7:1 the ideal stoich mixture? how are you people so much lower than that? the proper way to tune is to start rich and turn up the A/F ratio until you start seeing knock. more knock = less timing HOWEVER more boost provides a bit more power over more timing, so its really upto you on how much knock u wanna see. most people say stop when u see anything but i think its ok to have some knock.

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, you got dude. Tune your car for 14.7 on WOT then buy a Honda when it blows up.
Yes the lower the number the richer you are, I dont think anyone in this thread will find this as new info.

Sounds like a nice set-up you have there and it seems to be tuned well. That car must haul ass for a 16g setup (what my car should be doing shortly!)

If you can go 11.6:1 a/f and get 22 degrees timing on anything over 15psi then you are doing good my friend. Out of preference, I just like to tune for 10.8-11.1/1 a/f ratio. My car seems to knock and pull timing anything over that, but im still on my 450's i gotta put my 660's back in this weekend. I guess its probably due to higher compression pistons.


Good luck with the tune bro, you seem to have your methods down!

92tsifwd said:

The reason I was able to get away with running a 11.7 is because my timming was very low. After I raised the timing where I want it at about 22* and higher before the turbo spools I had to go richer. This is how my curve looks
11.7 until turbo spools at 3000 and 11.5 until 6000, then 11.6 up to redline with 0 knock. Now granted if I turn the boost up to 20psi I will probably want change to a 11.3 or 11.1 but this is a good street tune. I am burning a different chip for the track.

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Well at least you know how to be cautious

2gAWDTalon said:

, you got dude. Tune your car for 14.7 on WOT then buy a Honda when it blows up.
Yes the lower the number the richer you are, I dont think anyone in this thread will find this as new info.

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Once you turn up that boost to where it should be you'll probably find you have to richen that up abit. Most like the 11 to 1 range on pump. I like to tune for 10.5-11 to 1 on pump as I would rather run more timing then a slightly leaner air/fuel. Before cams I was able to run up to 22 psi on pump 94 with this setup with my evoIII & add a few deg of timing in the upper rpms without knock. When I added cams it looks like the increase in VE just made the little evoIII work to hard & throw it way out of its effiency range. I could then only run 18 psi on the same tune without knock, but did still see the same amount of airflow as the higher boost pre cams. If I wanted to raise the boost I would have to run low 10's air/fuel. Hopefully the new turbo will cure this not running enough boost problem Im having

daren_p said:

Once you turn up that boost to where it should be you'll probably find you have to richen that up abit. Most like the 11 to 1 range on pump. I like to tune for 10.5-11 to 1 on pump as I would rather run more timing then a slightly leaner air/fuel. Before cams I was able to run up to 22 psi on pump 94 with this setup with my evoIII & add a few deg of timing in the upper rpms without knock. When I added cams it looks like the increase in VE just made the little evoIII work to hard & throw it way out of its effiency range. I could then only run 18 psi on the same tune without knock, but did still see the same amount of airflow as the higher boost pre cams. If I wanted to raise the boost I would have to run low 10's air/fuel. Hopefully the new turbo will cure this not running enough boost problem Im having

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I think everyone suffers from that problem

I am curious after I install my meathanal injection kit with a upgrade side mount what I will be able to run for boost timing and a/f? I would like to run 22-24 psi and a 11.1 a/f on a small 16g. Anybody else have a similer setup and could share some info?

I seem to remember a thread that was a few pages long.. (understatement) Well everyone in there eventually agreed theres really not any more power to be made past 11.3:1 Once you have that AFR you should play with your timeing if you want more. Or just crank up the boost.

Corse every car is diferent.

92tsifwd said:

I am curious after I install my meathanal injection kit with a upgrade side mount what I will be able to run for boost timing and a/f? I would like to run 22-24 psi and a 11.1 a/f on a small 16g. Anybody else have a similer setup and could share some info?

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With meth injection I have seen some very impressive results. 22-24 psi range shouldn't be to hard to do. I know a local guy that was able to do 27 psi on his 16g (can't remember which version) on pump & meth injection. I don't know if there would be any benefit to running a 16g sized turbo at that high of boost & you won't be able to hold it to redline anyways but you should defently see nice results in the 22-24 range .

daren_p said:

With meth injection I have seen some very impressive results. 22-24 psi range shouldn't be to hard to do. I know a local guy that was able to do 27 psi on his 16g (can't remember which version) on pump & meth injection. I don't know if there would be any benefit to running a 16g sized turbo at that high of boost & you won't be able to hold it to redline anyways but you should defently see nice results in the 22-24 range .

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The amount of tq you make by maxing out the turbo running that high give nice benefits Mine would always settle around 24psi after the initial hit.

Some of you guys run a lot of timing when ## on boost. Im running an fp3565 at 23psi on pumpgas and it runs at around 11.4-11.6 a/f with about 16 degrees of timing

16gkid said:

Some of you guys run a lot of timing when ## on boost. Im running an fp3565 at 23psi on pumpgas and it runs at around 11.4-11.6 a/f with about 16 degrees of timing

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Try a little richer with a little more timing though if you have that setup I would expect you have already been out playing and seeing what the car likes

I like running right around 11:1. Right now I'm running 11.3:1 going to 11.4:1 at 7000 rpm because I'm trying to get more out of my stock injectors. The leanest I'd ever run on pump is around 11.8:1 but I see no point in it. I was running 21 degrees of timing up top on the 14b, 11.3:1 and 20 psi but that tune was too aggressive for the 16g. I'm going to drop timing to a peak of 16 degrees, keep the AFR where it's at for IDC, then turn the boost up until my IDCs hit 95 percent. Then I'll bump the timing until I start to get knock. My priorities in tuning are 1. AFR ~11:1 2. Timing low (16 peak in this case) 3. Start bumping boost until you hit a nice level based on efficiency of the turbo (25 psi on my friend's SCM61, 22 psi on my Evo 16g) 4. Bump timing until you hit knock and back it down