Running too lean
12-03-2009, 04:04 AM
#1
Administrator
Thread Starter
Running too lean
I already have a CAI, test pipes and a true dual catback. That's a lot more flow than OEM, I am also planning on getting some long tube headers sometime soon. My fear is that my engine might start running too lean which from what I read, know isn't good (can cause detonation??).
How lean can I go before I start getting worried? Do I NEED a tune?
How lean can I go before I start getting worried? Do I NEED a tune?
12-03-2009, 05:38 AM
#3
Administrator
Thread Starter
Are you saying the engine would react by adjusting timing IF it senses too lean a mixture?
12-03-2009, 08:58 AM
#5
Administrator
Thread Starter
Yeah, CAI & Catback are ok.. but once you get test pipes numbers will start becoming scary.. let alone long tube headers.
12-03-2009, 01:34 PM
#7
With the G3 Intake, TPs, and catback exhaust, you are running lean at low rpm and rich at high rpm. Don't you have a Cobb AP yet? You can see the A/F
It runs 13 at low rpm and it goes down to 10 at high rpm.
But, it also depends on a car.
The only way is to get a dyno again.
It runs 13 at low rpm and it goes down to 10 at high rpm.
But, it also depends on a car.
The only way is to get a dyno again.
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12-03-2009, 01:44 PM
#8
Administrator
Thread Starter
Cobb wouldn't work on gulf spec cars
But I'm definitely getting on a dyno the second I install the long tube headers
But I'm definitely getting on a dyno the second I install the long tube headers
12-03-2009, 01:58 PM
#9
Registered User
best thing to do Sam is to get her on the rollers and plug a sniffer on her...
of course don't you guys use magic gasoline where you have 98 octane? you have nothing to worry about. lol...i kid!
why don't you check your plugs?
12-03-2009, 02:09 PM
#10
Administrator
Thread Starter
yes. i was running 14.2s across the range with just exhaust, headers, plenum, intake. everytime at WOT it would pull but then hesitate and fall in its face. Tadashi from technosquare pulled my plugs and found aluminum shavings on my plugs...my car was detonating because it was pulling fuel. So all Tadashi did was richen her up to get the a/f ratio to an acceptable range (around upper 12s lower 13s). this is of course with my 350Z DE engine...i have no idea what the VHR reacts to mods like yours as i have stayed out of the modding scene when i got my G.
best thing to do Sam is to get her on the rollers and plug a sniffer on her...
of course don't you guys use magic gasoline where you have 98 octane? you have nothing to worry about. lol...i kid!
why don't you check your plugs?
why don't you check your plugs?
12-03-2009, 02:32 PM
#11
Registered User
In simplistic explinations this is how it usually goes:
1) Factory tunes ECU pig rich for saftey and fuel economy and not at the optimum A/F ratio for best performance.
2) Tuner leans the ECU with basic breathhing mods to extact the last 10whp from the car via intake and cat back.
3) Tuner gets 'tuner crazy' and thinks the more breathing mods the more power...leans the crap out of his car to the point where it's out of the optimum a/f range and heading toward detonation city
4) Tuner then flashes his ecu or gets a reliable piggy to richen the a/f back to safe yet optimum levels through hours of dyno tuning
5) Tuner then realizes that with all the n/a mods he's put in he would have been half way toward a good FI kit...LOL. Tuner's pecker then shrinks at his palty 30whp gain compared to TT set ups that triple the power at the same cost / hp ratio
...not that I speak from experience of course...LOL
but seriously Sam...all this is just talk unless you know she is indeed running lean.
1) Factory tunes ECU pig rich for saftey and fuel economy and not at the optimum A/F ratio for best performance.
2) Tuner leans the ECU with basic breathhing mods to extact the last 10whp from the car via intake and cat back.
3) Tuner gets 'tuner crazy' and thinks the more breathing mods the more power...leans the crap out of his car to the point where it's out of the optimum a/f range and heading toward detonation city
4) Tuner then flashes his ecu or gets a reliable piggy to richen the a/f back to safe yet optimum levels through hours of dyno tuning
5) Tuner then realizes that with all the n/a mods he's put in he would have been half way toward a good FI kit...LOL. Tuner's pecker then shrinks at his palty 30whp gain compared to TT set ups that triple the power at the same cost / hp ratio
...not that I speak from experience of course...LOL
but seriously Sam...all this is just talk unless you know she is indeed running lean.
12-03-2009, 02:46 PM
#13
Sam, maybe you can send in your ECU to Tadashi if someone has done a dyno tune there with similar setup already.
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Last edited by ucla bruin; 12-03-2009 at 05:00 PM.
12-03-2009, 04:07 PM
#14
Registered User
12-03-2009, 04:15 PM
#15
This is at WOT correct? Cause when I dont hit the gas, it says I am like 14.4. At WOT, I am at mid 12s to low 13s and then back to high 12s.
Sam you should definitely get a tune with the LTH.
Sam you should definitely get a tune with the LTH.