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

 

[AtomicHoe094]

****** headers are good headers. ceramic coated is the way to go or stainless.

 

[skyhighsami]

Finally got in touch with someone at Doug Thorley. They discontinued making headers for our trucks. He suggested Gibson but the first hand experience I've had with their products has always been less than stellar

Where would you rank ****** versus Pacesetter? When you mentioned stainless I'm down for that but I doubt it would from Stainless Works. I have their headers and ORY for my Camaro and had to fix some stuff on the ORY. I guess I will look tonight

 

[JennaBear]

AW bummer, we sell Doug Thorleys now- would have been happy to help.

I personally would not buy Flexalites, just get some OEMs from the junk yard. 05+ Tahoes.

 

[skyhighsami]

Do you sell the wiring to connect the fans? And if you can find someone better at DT to deal with than I could you might be able to find someone but I had to call I promise 6 times before I got someone. I will be getting with you to tune the truck hopefully in a couple days. I am trying to get everything together now as far as part numbers and exactly who I am ordering everything from. Since you would know, the factory ECU controls the rev limiter right? So I wouldn't need to get the MSD 6AL box that has a rev limiter built in would I? Or would the MSD 6A box be sufficient?

 

[JennaBear]

We do have the harness: Black BEar E-Fan harnesses

Do you have the part number you are looking for? DT is hard to get a hold of, that is actually why we just became dealers. Their middle man (BNR Performance) just screwed us out of $700 on headers for the Blazer. DT asked if we wanted to become dealers after they heard of our run around.

The PCM does control the rev limiter (to an extent), but I need to double check on your year. Can you shoot me an email ([email protected]) to remind me to check into the specs?

 

[skyhighsami]

And, Jenna when could you tune the ECU and have it shipped to me, how much would it be, would there be a core and how much is it? The truck is a 1996 Chevy Tahoe. I spoke with Nelson because I had forgotten about y'all and they said they would do it for $200. I have never had anything tuned by y'all before so I am willing to give it a shot

 

[JennaBear]

We charge $200 for the tune, and a $60 core charge (refundable).

 

[steamroller]

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

5600 RPM depending on how accurate the stock tach is. Factory programming has the trans shifting before then, not making any power that high with the stock cam anyways.

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

My experience is zero and zero, or so small I can't feel it. If it makes a difference it's because one of the components is worn out. Money is better spent on a cam instead of the MSD box, harness, distributor and coil.


I run the ****** 2462's-1 5/8" primaries, 2 1/2" collector.
****** has the 2806 w 1 3/4" primaries and a 3" collector.
Headman, Pacesetter, Stainless Works are other brands with longtubes that will work. Pacesetters are the only ones with EGR provisions and the Stainless Works primaries are too big for a stockish engine IMO.

 

[skyhighsami]

Awesome input. Since I live in Alabama I have no emissions testing so any and all emissions garbage will be removed. I wasn't going to replace the intake because on the newer style trucks I have had the stock intake was really good. Is that the case on this body style truck? This is my second one of these Tahoes but the first one I owned when I was much younger and I threw parts at it for the sake of modding it. I even spent money as I am sure that everyone on here has at one point or another on a throttle body spacer.

I don't remember if I asked it in here or not but since I have the catback exhaust from my Duramax dually I had I was thinking about using it to have the exhaust from the Y pipe built on this Tahoe. It is 3 1/2" or 3 3/4" in diameter which if I am correct would be equal to me running a set of dual 2 1/2" pipes which would be my plan B. However since I have this and it can be cut up and welded together I have a mandrel bent catback. Will it be too much for a 350 now and perhaps a 383 later when this motor goes boom? Again I don't remember asking it in this thread if so I am sorry. I have been working like a rented mule.

 

[steamroller]

On the intake manifold you be the judge, it's not designed for performance with all that stuff under the plenum.

Pics in this thread of the 1/2 ton exhaust like our SUVs have vs the 3/4 ton trucks, same 5.7 engine. Single 3.5" would be fine IMO. I run dual 2.5" (not mandrel bent though) which is almost the same if you calculate the area of the pipe.

http://duramaximizer.com/forum/viewtopic.php?p=89951&sid=d144acc124b325a28113d4abaa28d3f6