got the greddy 15g kit + JRC FMIC (see all upgrades on sig). i've recently upped the boost to ~8.5psi. when i get on it, the revs get up to about 4500, then this strange performance hicup... the boost dies a little, the hp dies a little, and the revs jump a little... it seems as though it looses some compression... like there's some kinda disconnect of the power train.

am i reaching the limitations of the auto tranny? could it be the torque converter's going bad? could it be head gasket (i haven't seen any signes of leakage)? charge coupler(s) leaking? vtec cam overlap causing some blow-thru? valve-train doing something funny? back-up in the exhaust? anyone know how to diagnose this?

i'd give more info, but i'm not sure what else to give... i'm open to suggestions.

 

i should add:

running uber w/ no probs. i swear by it. the AFR is dialed in nicely - no problems there. the ignition retards 0.75 degress per pound of boost...

i don't think it's creep. i keep a good eye on the boost gauge when it happens... no spikes.

 

 

what are you running for a plug gap?

checked your cap and rotor?

you have a wideband I'm guessing? any change at all in the afrs when this hiccup happens?

 

warrick-
thanks for the response - i'd love to be able to figure this crap out on my own. answering your Qs:

not sure on the plug gap... i checked it a while ago... i think it's around 0.45.

cap & rotor has been replaced recently.

i do have a WB & datalog via uberdata. the AFRs don't do anything funny... i've checked, checked, and checked them...

i probably need to install my 370cc FIs, as i'm still running the stock 240s. but, i have the B&M fuel pressure modifier...

 

What is happening is the common "blowing out of the flame kernal" scenario.

By "0.45" I assume you mean 0.045" of gap. That's too much for a turbo. Decrease the gap to 0.030", then report back.

 

beepy:
you're right - 0.045". i'll drop the gap down to 0.03" and report back on my findings...

question though: i will have to buy the tool, and i don't want to buy the wrong POS, just because it's conveniently right down the street. it would be nice to have some confidence on the accuracy of precision parallel gaps throughout all the plugs... any suggestions on the tool? (i'll start searching)

 

yeah, your concrete floor and $5 feeler gauge set

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cree &raquo;</TD></TR><TR><TD CLASS="quote">beepy:
you're right - 0.045". i'll drop the gap down to 0.03" and report back on my findings...

question though: i will have to buy the tool, and i don't want to buy the wrong POS, just because it's conveniently right down the street. it would be nice to have some confidence on the accuracy of precision parallel gaps throughout all the plugs... any suggestions on the tool? (i'll start searching)</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dennis &raquo;</TD></TR><TR><TD CLASS="quote">yeah, your concrete floor and $5 feeler gauge set

</TD></TR></TABLE>******' A...

seems ghetto to me. are you the guy that uses his fingertip as a feeler gauge too? JK

 

no, I'm the guy who built my motor from the ground up, swapped it in, cut fabbed and welded all my charge pipes and downpipe, modded my ecu and tuned my car to run perfectly.

Edit: and yes, I used this method to gap my plugs to about .030 - no issues whatsoever

 

anyways.... i'll let you guys know how it turns out. thanks for the advice

 

well, i'm happy to report changing the gap fixed the problem...

THANKS GUYS!

...& dennis:
you'll be happy to know i used a feeler gauge and the concrete floor.
peace,
-c-

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cree &raquo;</TD></TR><TR><TD CLASS="quote">well, i'm happy to report changing the gap fixed the problem...

THANKS GUYS!

...& dennis:
you'll be happy to know i used a feeler gauge and the concrete floor.
peace,
-c-</TD></TR></TABLE>

Hehe, sweet! Glad it worked for you!