i just finished installing an O2 housing and tubular manifold. in addition to the TBE (no cat) , cone filter and Greddy ebc that i already had. i also have a dynoflash reflash. now with the TBE boost controller, cone filter and flash i was running 10.9-11.3 AF up to 7800. with no other changes other than the manifold and o2 housing nothing was changed, same boost levels and same gas. now im running 10.9 at first and it keeps going up to 11.9 at 7800. im a little confused about it really. i know i should need another flash for the new mods, which i will get b ut i never heard of anything changing like that from those 2 mods. i have heard that some people have seen decreased knock with tubular manifolds and o2 housings. so the only thing i can think of is that im getting less knock so its adding timing and running leaner. im still concerned about it as leaner AF makes a hotter combustion and i dont want to burn a hole in one of my pistons. if Al or someone else could chime in with something i would apreciate it.

please no "why did you get a tubular manifold" or "you dont need that" crap. id like to keep this on topic. thanks.

nate

 

10.9 isnt really that bad. Its a safe afr to run even up to 7800rpm,s. 10.9-11.3 is fine. optimum afr would be between 11.3-11.5 so your really not to far off. 11.9 and your starting to go a little lean but not really into the danger zone. If you can get that 11.9 to around 11.5 you will be just about perfect.

 

it hasnt been doing it since i have driven the car a little bit. i think its ok now. i did see it as high at 12.2 a coupele times, but its down to 11.7 now.

 

funny this came up i was running 11.2 and the other night i notice 10.9..wondering y its running more rich now ?

 

Most tuners target 11.5:1 on pump gas. It sounds to me like you have a safe, conservative tune, even at 11.9 at 7800rpm. In theory you should rarely see 7800rpm since with the stock turbo you're just losing time by shifting above 7000.

 

i THINK, the colder the weather gets, the richer EVOs run with stock ecu.

 

stock fuel pump? if so, you might be moving more air with the new mods and the fuel pump isn't able to keep up anymore

 

might be the weather , i havent done any more mods since the tune . i got tune back in june and i only notice the 10.9 this weekend. its been getting cold out in the ny this week. ill do some data logging when i get a chance.