misfire or boost cut???
 

so finally i've got my brothers hatch running, we go for a drive. off the wg its boosting 3psi. well thats what the gauge says ^-^. But now we're looking to up the boost. Well i've got my ghetto boost controller hooked up. Everytime that thing seems to get at 8 psi. it just cuts out. feels like a boost cut, but i didnt put one on there. Although, the gauge may be off and im just maxing out the map sensor. No specific rpm. at about 8psi is where it cuts off. i have regapped the plugs and it helps a little bit. I just went and bought some bkr7e's but have yet to drive it. If someone know's whats up let me know. :)

setup
98 ls swap w/gsr tranny
log manifold
turbonetics t3/t4
running on crome. errr chrome the boost version ;)

Re: misfire or boost cut???
 

Same thing happened with my BKR7E's gapped at .030"

Gapped em at .028" and it helped a bunch.

Re: misfire or boost cut???
 

its raining right now so no time for a test drive :-\

Re: misfire or boost cut???
 

got the bkr7e's in. my brother said it still does it but not as early as it does. i think its probably just misfiring. going to regap them down to .028 :), they came pregapped at .030

Re: misfire or boost cut???
 

A hot plug is more likely to detonate than mis-fire. The mis-firing is more related to ignition system and plug gap. As boost goes up the ionization potential is reduced. This means you need more voltage at the plug for it to fire across the gap. You can decrease the gap but this will also reduce the spark duration.

Personally I would make sure your cap and rotor are in prime condition. Also make sure your wires are in good shape. On a stock ignition system that is working properly I`ve tuned them to 20 PSI of boost without misfiring. If you can pick up a cheap MSD system used that may help.

-Michael

Re: misfire or boost cut???
 

id prefer to use the stock ignition components over msd stuff. I'm going to regap the plugs and check the cap/rotor

Re: misfire or boost cut???
 

Make sure all grounds on the motor are GOOD. I ALWAYS gap the plugs to 18-20.. and a fresh cap/rotor/plug wires are always a must.. and you do have a wideband on the car right?

Re: misfire or boost cut???
 

I do have a wide band. 18-20 :o thats hella small. i think im going to try it :). also going to recheck the grounds. its fine at 3 lbs but what the hell is 3 lbs gonna do :D

Re: misfire or boost cut???
 

its a littie bit better but still cuts out. kinda feels like a boost cut but i didnt add one :-\

Re: misfire or boost cut???
 

I think i've got it figured out. well this is the only thing that kinda seems right to me. When i used xenocrons map as a base i didnt know how to scale it down to a stock map i just went through boost tools. But it just changed the values well as far as the bar's on top that show how much boost. but it didnt change the figures in the map ??? so if anyone knows how to scale down the entire map by changing the map sensor please let me know!! :) I cant try it out yet because my brother went to the gym ::)