Running lean

by **Jackass-Jeff** » Mon May 30, 2005 3:07 pm

Just wondering...

Only having too much air intake would eventually push to the system running lean, correct? (aside from injector/fuel pump inefficiencies)

Would an exhaust make it run lean? I would think not... but you F/I guys obviously would know better than I do.

Thanks in advance,

Your local jackass.

by **Mandarinsolara** » Mon May 30, 2005 4:58 pm

theoretically (im NA), it should not. the factory ecu was setup to adjust itself to the supercharger. and the o2 sensors would just add more fuel anyways if it started to lean out.

by **Jackass-Jeff** » Mon May 30, 2005 7:19 pm

The 1MZ was designed so when the supercharger was added at stock levels (4 psi?) the injectors adjust enough... but, as you can see, once people added injen intakes, kn filters, etc... they began to hit the lean region and start to blow knock sensors

There obviously is a thresh-hold limit of the 1. injectors 2. fuel pump (solved via Jim's fuel track upgrade)

but I'm talking about adding a full exhaust system (exhaust manifold to muffler). No f/i, no intake, no nada. Only exhaust size increase, no intake increases except for a kN filter

by **i20solara02i** » Mon May 30, 2005 7:44 pm

adding exhaust, headers, intake leans out the car

by **lazyboyz69** » Mon May 30, 2005 10:24 pm

thats why i've haven't blown a knock senor yet.... no intake, no exhaust, no headers....

Website · by **Turbosolara** » Tue May 31, 2005 4:45 pm

I am not sure on this, i could be wrong but here is my logic

But i think what happen is when you have engine mods, they cause better flow inside the engine. For example, intake helped better flow into the intake maniford and the exhuast system help better flow out of exhaust system. Since solara (or most of car nowadays) has returnless fuel system, the fuel dilvery rate is very limited. Also, the factory ecu did not expect to have such big different occur and it cannot react to it. So that cause lean.

i remeber HKS had a A/F tunning controller (just like SAFC) that is for car that only has I/H/E that will allow you to tune your a/f ratio but not too much. It is not for force induction. i think it was like $150

if you have good tune, you should able to prevent blow knock sensors. My car is boosting 9psi and the knock sensor still good with 91 octane everyday.

by **Akfahad** » Wed Jun 01, 2005 7:13 am

Just adding on an exhaust will not lean out the car with no engine mods. That's what I did, had done nothing to the engine and put on my cat-back and it was fine.

The only time I got a lean signal was months after I had the supercharger installed and right after I had a shop put in my boost and EGT gauge. I don't know why putting in those two gauges set it off, but it did. (granted I do have the CAI installed, so that most likely added to the situation)Luckily, I already had the Walbro 190 pump and 318cc injectors, had a shop install that and that cleared the lean signal.

by **Jackass-Jeff** » Wed Jun 01, 2005 7:25 am

Akfahad wrote:Just adding on an exhaust will not lean out the car with no engine mods. That's what I did, had done nothing to the engine and put on my cat-back and it was fine.

The only time I got a lean signal was months after I had the supercharger installed and right after I had a shop put in my boost and EGT gauge. I don't know why putting in those two gauges set it off, but it did. (granted I do have the CAI installed, so that most likely added to the situation)Luckily, I already had the Walbro 190 pump and 318cc injectors, had a shop install that and that cleared the lean signal.

The answer I was looking for! Thanks

Maybe I'll get the Apex A/F controller too... just in case

by **Akfahad** » Thu Jun 02, 2005 11:56 am

Jackass-Jeff wrote:
Akfahad wrote:Just adding on an exhaust will not lean out the car with no engine mods. That's what I did, had done nothing to the engine and put on my cat-back and it was fine.

The only time I got a lean signal was months after I had the supercharger installed and right after I had a shop put in my boost and EGT gauge. I don't know why putting in those two gauges set it off, but it did. (granted I do have the CAI installed, so that most likely added to the situation)Luckily, I already had the Walbro 190 pump and 318cc injectors, had a shop install that and that cleared the lean signal.

The answer I was looking for! Thanks

Maybe I'll get the Apex A/F controller too... just in case

No need, in my opinion...

I just got mine a month ago, after I installed the supercharger, fuel, injectors, jim's fuel line upgrade, etc. I haven't even had the time to tune it yet, all it's been doing is monitoring and everything's been fine. Don't get me wrong though, as soon as I have the time, I'm definitely going to be tuning it to get the best performance out of everything.

by **Grnarowana** » Fri Jun 03, 2005 8:11 pm

In regards to mods, is putting a K & N filter a mod? I just din;t wanan keep onbuying air filtes for my car and went for the K & N filter. Leanign out the car? It does that if i Put a K & N air filter? WTF??? I htought it'll just save me GAS!!!

by **Akfahad** » Mon Jun 06, 2005 5:05 am

Just simply putting in a better air filter (K & N) in the stock airbox will not lean out the car. Your gonna get better airflow using a K & N and you'll feel a slight difference if any...but that's it. Nothing else will happen.

by **that1mexguy** » Mon Jun 06, 2005 6:00 am

Not sure if this helps, or maybe I'm overlooking something but I have full exhaust system, CAI, supercharger and still haven't blown anything.

Running lean

Running lean

K & N filter

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