Ignition and ECU tune questions

[skyhighsami]

I have 1996 Chevrolet Tahoe 4wd and I'm having trouble with it starting. I've replaced a lot of the parts that could cause problems but none of them have fixed it. The code I'm getting is for a random misfire. Next up to replace is a distributor cap, rotor button, and coil. I want to upgrade the ignition while I'm at it. Several year ago I did an MSD box and an upgraded coil on a 4.3 and had good results. What coil and MSD box do I need for my Tahoe and what PN are y'all using?

Also what electric fans are y'all using and how are you controlling them? I've seen the sensors that go in the radiator hoses, how well do they work? I flushed the coolant completely after I bought it. I'm looking more to free up HP and economy.

Finally I want to replace the exhaust and remove the cats. Can Blackbear tune the ECU for this vehicle and turn the rear O2 sensors off?

 

[AtomicHoe094]

1) check out summitracing.com itll pull up everything you need. The iggy box, id just use a msd 6a box, no need to jump to the 6al unless you have a ton of mods and need a rev limiter. they have harness' as well for the coil to iggy box so its all plug and play. (dont know the vortec numbers off hand only tbi)

2) flexalite fan owner here. They have all the parts,thermostat and etc you need. never used one inside a radiator hose nor would I. Flex gives you a prob you stick threw the fins on the raditor. havnt had any problems and keeps it nice a cool.

3) yes they can..Check emissions before you pull the cats off tho

 

[SunlitComet]

I use the flexalite 280 setup every thing you need except split loom tubing or wire bundle clamps. $550 it has a variable speed controller with temp prob that fits in rad fins. No issues at all.

blackbear can tune out the rears normally. Just not sure about it on a '96 PCM may need to do 411 pcm swap first. As for ignition here ya go.

This is a complete setup. If you dizzy gear is still good forget the msd dizzy and just grab a cap&rotor and every thing else. Add some autolite 605, or 104 if you need one step colder, plain copper core plugs or acdelco equivalent gapped at.055". That will be the best ignition system you can get that is legal for the truck.

Ignition:
6425

Coil:
8231

Distributor: 5592




Spark Plug Wire Set:
32169

Harness:
8877

MSD IGNITION 8017 Cap & Rotor Kit



---------- Post added at 05:39 PM ---------- Previous post was at 05:30 PM ----------

I use the rev limiter one because I believe the pcm in 1996 does not have a rev limiter just vehicle speed limiter.

 

[skyhighsami]

How much power and economy do you think all that would gain me?

 

[AtomicHoe094]

probably nothing

 

[SunlitComet]

Hard to tell it has never really been dynoed before but you can expect to probably never drop a cylinder because of ignition system. Your emissions will be cleaner. you should expect a better throttle response and maybe some economy improvements. Just the way ignition upgrades are.

 

[skyhighsami]

Since the headers for my chassis are out of stock it said that these are the next closest thing http://www.summitracing.com/parts/DTE-300Y-S-C/Application/?prefilter=1 Will they fit my truck being a 4wd? I also have been doing a lot of reading about exhaust size. I have the exhaust from my Duramax dually left from when I pulled it off and went to a 4" Corsa. That piping is about a 3 1/2". If I get these Doug's headers, which have a 2 1/2" collector, built a 2 1/2" down past the transfer case and then merge into a nice 2 1/2" Y to 3 1/2" from there back into a nice long round or oval Magnaflow. Will this be too much or would I need to run a single 3"?

 

[SunlitComet]

Apparently they go to years up to late eighties with a floor shift manual so I say they won't fit.

 

[skyhighsami]

Wouldn't the 3 1/2" exhaust be comparable to running a dual 2 1/2"? I've noticed my torque seemed higher with a nice Y and high flowing single pipe. With dual exhaust it seemed to greatly help high end HP and the engine's ability to rev higher faster

 

[skyhighsami]

Getting the ECU tuned won't be a problem. Do I need the MSD 6A or 6AL? Doesn't the truck's ECU have a rev limiter? So why would I need a 6AL? That's the only difference between the two I've found.

Headers, what are y'all using? Ultimate plan would be 383 with the 350 gives up the ghost and it'd be built for torque not high horsepower. I was thinking to get the long tube tri Y Doug Thorley headers but it looks like they're out of stock and can't get anyone at Doug Thorley to answer. So what is a good plan B?

Finally, why in the hell are the Flex-a-Lite 280 fans so damn expensive? Is there not a junkyard option that will work? Almost $600 for some fans is about $250 more than I was expecting to pay. If there's another option or justification for the price please let me know