IW STi Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
291 Posts
Discussion Starter · #1 ·
Have any of you guys run the cobb 100 octane map. While increasing the boost with either a boost controller or ecu tune. And see with a wideband how the air fuel ratios do. Reason I am asking is the 100oct map uses stock boost with more agressive timing. If you were to increasing the boost slowly while monitoring the air fuel,egt, and knock sensor, could you possibley run better than the stage 2 map. Or will running alttile higher boost on the 100oct map, make boom.
 

·
Registered
Joined
·
601 Posts
SubySteve said:
Have any of you guys run the cobb 100 octane map. While increasing the boost with either a boost controller or ecu tune. And see with a wideband how the air fuel ratios do. Reason I am asking is the 100oct map uses stock boost with more aggressive timing. If you were to increasing the boost slowly while monitoring the air fuel,egt, and knock sensor, could you possibley run better than the stage 2 map. Or will running alttile higher boost on the 100oct map, make boom.
I never tinkered with the cobb 100 map but I have made my own 100 octane map.. key points
  • I am using the cobb CATT downpipe and it seems to be restricting my air flow through engine (that will be fixed tonight with install of new non cat dp)
  • I use a helper spring on the wastegate.. my boost is 20psi from 3K to 5K then it drops to 16.2 by redline
  • I target 12 to 1 AFR (on 100 octane)
  • I target these timing advance numbers:
    • 18 from 3K to 4K
    • 21 from 4K to 6000
    • 26 from 6K to 6400
    • 32 from 6400 to redline
With this map, I ran best 1/4 mile time of 12.98 and best MPH of 106 with these mods: Cobb CAT DP, Stock intake, 3" Megan cat back, WG spring

I have since added a typhoon intake which increased my air flow. I also decided to go back to pump (93 octane) and fine tune my map. To date with the increased air flow from the typhoon I have run 13 flat best ET and 105.5 best MPH on 93 octane.

As mentioned above, I will install a Megan catt-less downpipe tonight along with a new boost controller (get rid of the spring:). My expectation / goal is to get the car into the mid 12's at 107 on 93 octane and then... create a 100 octane map and gain 20 to 30 WHP (low 12's ???)

Hope this info helps you out... take care

Jeff B
 

·
Registered
Joined
·
1,930 Posts
My 100 oct. maps runs 21 psi, 12:1 afr's, 20* at 4k 28* around 5500 and 32-33* at redline. You have to be real careful watching you wideband and timing b/c the type of gas it is, temps, etc. are all huge factors when running an aggressive map like that. My guess about Cobbs map is that it runs pretty aggressive timing and AVCS b/c it is using a lot less boost so I would not go straight to a high boost setting and test/tune from there. If you were going to approach tuning like that slowly raise boost very little at a time and see how afr's and the DA is doing before you go ahead and bump up boost some more.
 

·
Registered
Joined
·
601 Posts
crystal_Imprezav said:
My 100 oct. maps runs 21 psi, 12:1 afr's, 20* at 4k 28* around 5500 and 32-33* at redline. You have to be real careful watching you wideband and timing b/c the type of gas it is, temps, etc. are all huge factors when running an aggressive map like that. My guess about Cobbs map is that it runs pretty aggressive timing and AVCS b/c it is using a lot less boost so I would not go straight to a high boost setting and test/tune from there. If you were going to approach tuning like that slowly raise boost very little at a time and see how afr's and the DA is doing before you go ahead and bump up boost some more.
CI... is the 100 map you describe using alcohol injection? Also.. what is your best pass down the 1/4 mile using that map?

(I am still tuning with the 93 octane but hopefully within the next week or so I will make a new 100 map)

Thanks

jb
 

·
Registered
Joined
·
1,930 Posts
I just ran my alky tune last weekend and pulled a [email protected] mph which is on a different tune than my 100 tune. My best on my 100 oct. map was a [email protected] but I am sure I could have pulled a 12.4 with a better 60' time and some more aggressive tuning up top. I only ran it once before I got alky and started tuning it. Its amazing how much stronger and faster the car feels with it. I would recommend it instead of messing around with racegas. Cheaper and feels way faster, also I am going to try out meth in a couple of weeks and see which one allows me to tune more aggressivly. Just gotta find someone in the area that stocks it.
 

·
Registered
Joined
·
71 Posts
Hey CrystalImprezav,

Would you be willing to post your water injection map or maybe just a log. I have a fairly similar setup that I am starting to tune. It seems there are a few different schools of thought on tuning water/alky injection: Lean it out a little and advance timing a lot vs. Lean it out a lot and advance timing a little. I am interested in how you approached it. Your quarter mile times are pretty impressive.

Thanks,

Mike
 

·
Registered
Joined
·
1,930 Posts
When I get some time I will try. The problem with that is the way your system is dialed in makes a huge difference, if it is not on point to my calibrations then you run a huge risk of blowing up your motor. First off my fuel map is pretty ridiculous being that I have pulled as much fuel out as I can in the low-mid rpm range since my wideband reads pig rich upon VE and spool. You need to have a wideband to tune alky/meth no questions asked. If you would like you could send me you map or post it and I can take it look at it for you and give you some tips but you also need to get me all your parts and your WI settings. PM me and let me know.

I just looked at the cobb 100 oct. map and it is not that great of a place to start but ok. First off you would need to rescale the map b/c the loads are way too low for a stage 2 setup. After that the timing seems pretty typical for a stage2 tune nothing too aggressive imo. I havent had a chance to throughly look at the whole map but afr's could be leaned out quite a bit up top but mid-range seems ok, boost up a lot since it is running stock boost control for the class and timing touched last. First thing needed though is to rescale the load columns. The DAM needs to be upped to 1 too IMO. When I get some more time ill add some more input.
 

·
Registered
Joined
·
71 Posts
I wasn't planning to actually run your map, I just wanted to get an idea of how you approached the tuning. Now that I think about it, looking at one of your logs would probably be a bigger help so I could see your actual AFR's (from the wideband). I do have a wideband (LC-1) but I don't really have a map that I can send you yet. I have turned the boost up a little and leaned out my AFR's a little but the map is nowhere near being done.

Thanks,

Mike
 

·
Registered
Joined
·
1,930 Posts
Your in for some fun then, lol. Tuning the fuel is the hardest part IMO after getting the controller dialed in for the right psi's etc. Timing is easy to tune for the street but a track or dyno is needed to extract the true potential of the car. The thing is on alky/water it runs a bit better a little richer than racegas/meth as I observed when tuning with Doug on a local sz55 with WI on the dyno. I shoot for a consistent 11.1-11.3:1 across the board and the hardest part about that is with ST your can only pull so much fuel out with the stock ecu (14.7:1) which upon spool up still gives me a 10.9:1 afr leaned out to about 13.6:1 at redline which gives me a 11.1-11.2:1 afr. Posting a log wouldnt really help much considering it would only show you my actual afr's which is drastically different in the map. I got boost dialed in at about 21 psi on my DD map with a WGDC in the high 80's low 90's and my timing is only increased 1 degree down low and 2-3 up top to keep it safe incase anything happens. You are going to need to pull a lot more fuel out than you think to get it running right.
 
1 - 9 of 9 Posts
Top