I've done multiple searches on this forum and many other forums, and it seems eveyone has their own idea of what the problem is or what set up to do to fix my issues, so I have a couple of questions, that i figured I would just post and hopefully bringing all of you fellow FORCED induction junkies together in the same thread will help me get my issues straigtened out:

Fiirst: MY ISSUES:
My 1996 383 Procharged LT1 with 8 lbs of boost is having a misfire issue... Im hoping its not any of the MSD components, so I decided to start with the plugs. SOme people told me to gap them at 35-38, and I think they were getting "blown out". others told me to gap them at 20... and people are telling me thats to tight. I run one degree colder stock plugs. When idling there are NO signs of misfire, no Popping , no sputtering. But on the dyno, the car clearly shows a misfire around 4500-4800 rpms...Also when decelerating while in gear, an occasional POP can be clearly heard.

MAF sensor is being MAXED out.... or thats what Im told. I first tried tuning the car with the stock MAF, then I upgraded to a GRANITELLI MAF, which I bought used from a member of this board who was using it on a N/A application but I still dont think its enough and we are having tunning issues. I've heard that converting to an LS1 MAF will solve my issue due to their ability to read more... or something like that...

Help me please, Im ignorant and learning about the Forced induction world, Below I will paste my ENTIRE build, for refference. If anyone has had the same problems please tell me what you did to correct or better the issues, and if anyone has the parts or upgrades I need, let me know, and I will probably take that stuff off your hands....

THANKYOU IN ADVANCE FOR READING THIS ONG WINDED AND BORING POST, BUT I NEED TO GET MY CAR RUNNING RIGHT.... By the way LT1 EDIT software is being used for the cars tuning.

1996 Camaro Z28 M6NO SECRETS) 383 LT-1, PROCHARGED/INTERCOOLED with 448rwhp @ 8.2 lbs of BOOST
BUILD SHEET:
-PSC1 Procharger 8.2 lbs of boost-INTERCOOLER-MSD 6AL-MSD Blaster coil-MSD BILLET OPTI-60lb Motron injectors-4 bolt main corvette block-scat 4340 forged crankshaft-scat pro series I beam rods-srp forged pistons - 14cc inv. dome-clevite 77 H-series rod and main bearings-Total seal rings-rotating assembly balanced within .1 gram-melling hv oil pump-melling pick up screen-melling hardened oil pump driveshaft-SECRET SQUIRREL custom ground hyd. roller camshaft-comp cams roller lifters-comp cams hardened pushrods-aluminum full roller rocker arms=chrome valve covers-clevite 77 hp cam bearings-cloyes roller timing set-arp head studs - 12pt.-fully ported lt1 heads-2.02/1.6 valves-stainless steel valves-isky .600 lift springs-combustion chambers polished (will out perform lt4 heads)-fully ported lt1 intake-runners matched to heads-BBK 58mm throttle body-GRANITELLI MAF-Cat bypass-LT4 Knock module-Pacesetter long tubes-Magnaflow Muffler-Whalboro 255 HV in tank fuel pump with external helper pump-4.10 MOTIVE gears (in 10 bolt)-LS-1 Aluminum D/S-SLP Subframe connectors-TA dif cover with girdle-Rear seat deletes-tubular K-member-BMR 2"lowering springs-Drilled front rotors-Z06 wheels (275's up front,295's out back)

 

No matter what MAF you run it will be maxed out when under boost, you just have to tune the PE tables according to the A/F ratio on a wideband. Basically you will only be using the MAF for part throttle cruising. Hope that helps some :S, not sure what to tell you on the spark issue, I used the LTCC ignition on mine and havent had any spark issues at all.

 

Don't be afraid to try colder plugs and work your way hotter - thats the safe way to do it. So what if they foul - its better than having detonation.

 

First off you need the right heat range for the plugs. I am running .28 gap but even under extreme boost conditions .32 gap should be MORE than enough.

Granatelli MAF's are notorious for sending wrong signals to your computer. Sell it, and get a stock one back in there. De-screen the stock one, and get it re-tuned by a pro like Bryan Herter from PCM's for less. Most MAF's max out after just 5#'s and 450 RWHP or so. Bryan knows how to compensate for the maxed out MAF. Trust me, this is not an easy thing to do, but Bryan is a genious at it.

 

I'm appreciating all of ur advice.... thankyou... keep it comming and I'll keep printing them out and giving them to my tuner.....

As far as going back to the stock MAF..... what about the LS1 MAF swap???? anyone try that?

 

I never heard of it. I guess it may be possible, but even then, it will be maxed out as well, so I can't see how it would benefit you any. Just get a stock LT1 MAF and de-screen it.

 

When they refer to the "LS1" MAF sensor they are most likely talking about the 4inch z06 MAF IMO.

 

Both 94-97 LT1's and 98 - 02 LS1's came with GM part number 25179711 MAF sensors. So they must be talking about the Z06 one.

 

You definitely need to decrease the gap on the plugs. Try. .030 and use some TR6's if anything. Don't know much about the MAF's I prefer SD.

 

Thats exactly whats in mine, TR6's at .030

 

+1 on going back to stock MAF.

As far as spark issue...I'd check for a wounded or melted spark plug wire. It sounds simple, but I have had it cause mysterious up top misses similar to what you are seeing. And its simple/cheap to check. Otherwise, I once had a crane hi-6 ignition box go hay-wire, and cause a similar result...but I don't think that is nearly as common.

Just my $.02.

 

The only other MAF I would consider other than a stock one, would be this one from LPE> http://www.lingenfelter.com/store/l480000000.html

It's 100mm and doesn't max out until MUCH MUCH higher than the stock MAF does.

 

Can we see your dyno graph? Whats the a/f do when it cuts out?

 

or... you could pick up this

http://www.admperformance.com/adm/in...mart&Itemid=38

and then get the slot maf sensor from a colorado ...thats what the sensor in the LPE maf is..

 

The whole problem with swapping the MAF is getting the MAF table in the PCM right. Without some sofisticated equipment, you never will get it exactly right.

Your best bet with the stock pcm is gonna be a 2bar speed density tune, though you lose some resolution in all the MAP related tables.

As far as the miss... Describe your ignition setup, I just combated the crap outta this same issue and have solved it completely.

I am currently running a FAST XFI setup, but I AM still using the opti...
For me, a fresh opti, good coil, and new wires eventually solved my problem. I started with the wires, and it got a little better, then replaced the opti which didnt change a thing. The final straw was a MSD Blaster HVC II coil and a fresh MSD box. I dont know exactly which fixed it, as I put them both on at the same time... But my miss is completely gone.