in every gear around 5800rpms i get a wicked series of backfires and extreme power loss with a random cloud of smoke any ideas mods are a k and n intake and zzp catless downpipe on the stock tune

 

that may be your problem

 

unplug your battery for a little bit then try it out. after i put my downpipe out my **** was going crazy haha, then the next start up it was fine.

 

i had the same mods on stock tune and that didnt happen to me. but yeah you should get tuned at some time.

 

A tune with any mods will most likely prevent stuff like that from happening.

 

Have you checked your plugs? Is your sig correct, you drive an '07 SC?

 

r u sure its not at rev limiter? cause it will do that when u hit it

 

Whats stock rev limiter 6500? N I just put in new plugs

 

your hitting your rev limiter.

 

Yes 6500. Unless urs somehow moved lol

 

negative.

Although running with a catless is going to make the backfire and gurgle more pronounced, this isn't going to happen just from running a stock tune.

 

limiter is 6300 for stock lnf and 6500 for stock lsj.. Like a few have already said, it sounds like you're hitting the limiter

 

no. 6300rpm stock. Rev was increased with gmstage 1 is 6500rpm.

 

but he said stock tune and im pretty sure LNF stock rev limiter is either 6200rpm or 6250rpm

Either way, its known that the tach cant keep up with the engine speed lol.

Edit: im going with 6250rpm and thats my final answer! I remember it being alittle wierd for a factor RPM limit.



Also anyone saying you hit your rev limiter knows that thats whats going on because we've done it lol. And that is exactly what happens when you redline it at WOT. Part of the NLS parameter to cut fuel for a a second but it makes a series of pops if WOT too long.

 

it's 6300 damnit!! lol

 

6350 lsj
bad plugs maybe?

 

Why do people keep referring to the lnf ,this is a LSJ nothing a like

 

Really? For which year? I have a couple 06 and 07 stock files that all show a 6500rpm limiter. I've never really seen a 6350 limiter on an LSJ but I could definitely be wrong..

::shrugs shoulders::

I attached a screen shot for an 06 and 07 stock rev limiter..

 

never-mind I'm confused now. Your sig says 07 so did you lnf swap?

 

Assuming you have an LNF your best bet is stock plugs at .035. If that's what you're using then idk.

 

Did you read the title or what group it is posted in? Says LNF.....

 

Everyone with experience with a LNF, knows you gotta shift when you see your tach hit about 5800rpm to not f the shift up when nls or shifting very fast and wot

 

Yeah I agree with most. You must be hitting the limiter. If not that then maybe the plugs are gapped too wide. I think .035 is the stock setting but many people also use .032. A FEW may use .030 as well.

Assuming that it's an LNF. I'm a bit confused myself.

 

yea its gotta be the plugs fix em before you need new ones or one melts into the block. my lnf ate up brand new NGK 1 step colders that way. Rapid Backfires in the 5500-6000 RPM range, i never felt power loss but it just knew it wasnt right. Kept me from NLS a bit till i got a Subaru exhaust note cause one was melted in the motor almost.

 

I have the annunciator light on my interceptor set to light up for shifts at 5900rpm