Hey guys,

I logged my car the other day to help a buddy on here troubleshoot some boost issues hes been having... only to find out my "working" car has up to 6* of knock and whacked fuel trims (STFT from + / - 10, LTFT at like +7). WTF... i thought the K&N SRI was supposed to be really good about not affecting trims? also my car is GMS1 so its lean to begin with however in the mid range (3-4k RMP where i get all my knock)its un godly lean ... like 14.5 - 15.5 with dips sometimes to 16... wtf is going on here that seems way too lean, even for DFI... is it all intake related or would someone suspect something else? i have 0 "flutter" from my BPV and no real symptons of a boost leak. First step obv is to take the intake off and re data log but seriously ... wtf...

 

You can rotate the filter to affect the fuel trims, but you really should be tuned for your specific application. If you decide you want to go the route of Trifecta, PM me and I can get you set up. Otherwise, just try rotating the filter and see if it helps any. Also check to make sure there is no excess oil on the filter, or anything else that could affect airflow over the MAF.

 

I have tried to tell people that the K&N is off more than 7%. I have tuned 2 LNFs with K&N SRIs and they needed up to 12% adjustments to get them back into line. Not that they are a bad intake they just require MAF tuning like 99.9% of all intakes for this car.

 

exactly! you cant go moding after being tuned even if its the gms1 tune....new mod = new tune

 

perfect (not what i wanted to hear but makes sense), I trust your opinion over most on this site, I'll take the intake off as i was planning, it's almost winter n e ways and I'll be probably tuning in the spring along with some other goodies (may PM you sometime soon to see what you do for tuning others and what not, not sure i wanna go trifecta, i have a guy local to me with HPT and spare creds so that is certainly the most appealing option right now )

 

i realize this however when the K&N first came out there were 2 mammoth threads (if not more) with people testing these intakes and logging them (un tuned) and seeing good trims, that's why i originally got this intake because i thought / was led to believe that it would be fine. NBD just means it comes off the car for a month or 2 then it goes up for the winter n e ways I'll more than likely be tuned right out of storage next year, so the intake will go on then

 

rotating the filter will affect the trims. Rotate it slightly and log it, see where it has the least affect on trims. To get it good or near perfect you will need to tune for it. Cudajoe has logged his and found a position for the filter to not whack it out too much...soo its trial and error.

rotate the filter and log to find the best position.

 

nice thats a good idea, yea but remember when these people log the k&n sri it was done on stock cars, not tuned ones...it does make a difference, but tuning after storage will be nice, ull get to open her up after awhile lol

 

yeah im pumped haha i have a wedding to pay off first in feb (to another member on here actually! MissyMac) but after that all funds are going into the car I'd be shot dead if i tried to do things the other way around ,

I have played with the filter position but frankly it'll be easier to wait i don't wanna monopolize this guys time that has HPT. it'll be easier to wait it out til spring. I'll swap to the stock air box if my trims / knock is still really badIi'll have to dig deeper... (correction the dealer will have to dig deeper. )

 

Wait...so your GMS1 with Intake needs a tune? Crazy..

 

whoda thunk it... smart ass but yeah in all seriousness, if u go off the 2 threads about the K&N when it first came out u can easily see how i came to the conclusion (and im sure plenty others have as well) that the K&N shouldn't skew trims (or at least didn't for a few select users) with the cars otherwise stock.

 

Better to be a smart ass right? LOL! Glad you have a good sense of humor, it's just jokes

 

i know a lot of people take **** too personally on here i listen to people that obv. know more than me about these cars (with reason, they certainly break more than any other car i have seen!) but yes i agree better to be a smart ass at least ur smart about something

 

no one said they didnt skew the trims...they just showed well from a couple peoples logs they were not as bad as other intakes trims......

 

Let me know what you want to do. I am always willing to help.

 

thanks

As a follow up. Last night i re data logged with the stock air box setup on. my knock was down to 4* (which I am told is normal for GMS1) as well my LTFT stayed 0.0 after a 20 ish minute drive . Afterwards just for confirmation we re-installed the K&N and drove the exact same route as before when we got back the LTFT was at 6.3. I probably could have spent time adjusting the filter and what not but seems like more effort than its worth where I'll be tuned in the spring. Just a heads up for all out there the K&N DOES skew fuel trims... in my case roughly 6%.

 

If you have 91 octane gas up to 4-5* of knock retard is normal on the stage 1 and even the regular GM tunes. My car knocked on the dyno on the stock tune and 93 octane but it did not knock on the street. Not that any knock is a good thing but it is normal unfortunately but it is easily fixed through tuning.

 

did you pull the battery after install? also it will take several key relearns to really break in.

 

yes i pulled the battery after each run and after original install to reset the trims