4.3L HP upgrades

[L31MaxExpress]

E Fan will get you the most butt dyno feeling.

March Underdrive pulleys gave me a better butt dyno feel than electric fans. Electric fan was almost zero difference when it was freewheeling. The duramax fan blade only coupled when it was over 100°F and in long periods of idling in stop and go.

 

[1998_K1500_Sub]

I would tweak the ECU programming and consider changing the rear gear, as follows.

Tune (using whatever method... TunerCat on older ECUs, Jet Performance Dynamic Spectrum Tuner on newer, or whatever you choose):

- Power enrichment delay, change to 1s

- Power enrichment enable, change to enable based on MAP and configure so that enrichment comes in around 7" vacuum (~23" manifold pressure)

- Tweak the shift and lockup points to give yourself the best seat-of-the-pants experience and drivability, as you wish

- Play with disabling the EGR (I've seen this make a notable improvement in drivability on my own 1995 S10 Blazer VIN W)

- I don't mess with the fuel or spark tables; you can do what you wish


Rear gear: Change it to something that gives you 2500RPM (or higher, if you find it suitable) on the road at whatever speed you like to cruise (70MPH is what I use, YMMV) using the tires you prefer. If you've got a 4WD, the task is a bit more involved (front and rear diffs) but still tractable ($).

The above is my $0.02, based on the three V6 4.3s I've had (VIN Z 1995 S10 longbed 4L60E, VIN Z 1995 S10 ext cab 5spd manual, and VIN W 1995 Blazer 2dr, 4L60E), all RWD, as well as my 1998 K1500 Sub 5.7L 4L60E.

FYI the 4.3L "VIN Z" means they used throttle-body injection, the "VIN W" means the central port fuel injection (CPFI).

 

[Erik the Awful]

There are some AN fittings that are $30-45 each out there. Lord help ya if you can fab a fuel system without ever buying extra fittings, I know I never can. $1500 fuel system for what ends up being $1000 in what is actually used to plumb it, toss the $500 spare ones in for next project bin.

Truth. "I don't know what everybody's complaining about. AN fittings are fairly cheap, like $5 each." Two hundred fittings later, "Why am I broke?"

 

[HeavyAsAChevy]

Wouldn’t it be cheaper to buy a turbo kit from summit or a similar company?

 

[LC2NLS6]

Wouldn’t it be cheaper to buy a turbo kit from summit or a similar company?

You could boost it to the moon, add fuel, and maybe get 300 hp, meanwhile a bone stock 2002 4.8L W/T truck with 400k miles and a death wobble will be faster.

 

[HeavyAsAChevy]

Is there any OBD ll chips out there that have been known to work on these trucks?

 

[df2x4]

Is there any OBD ll chips out there that have been known to work on these trucks?

Every plug-in performance "chip" I've ever seen for an OBD2 vehicle is a complete scam. Most of them are just an LED stuck in a box.

 

[kennythewelder]

Is there any OBD ll chips out there that have been known to work on these trucks?

Chip, no, hand held flash runner, yes. Jet still offers a flash runner for these trucks. It does a decent job. It walks you through a few different menus. It also works as a code reader. It is effective, but not as effective as a Dyno tune and it's about $325. You could do a Dyno tune for ARO ng the same money. You could also do a mail in tune and that is also more effective than the jet programmer. The programmer will also let you adjust for tire size and gear ratio, so if the speed o is off, it can be fixed. It also adjust trans shift firmness, and shift points, and you can set things like top speed, and top RPMs.

 

[HeavyAsAChevy]

When I get to it I’ll just buy a PCM from somewhere like Black bear. I currently don’t have the funds though as I just spent a bunch on my steering. Replacing tie rods, idler w/ bracket, pitman.

 

[HeavyAsAChevy]

I was watching videos and saw that on the throttle body. That plate that rotates to let air in, has a metal shield type thing attached to it that restricts air flow. One guy got after it with a light grinder and a Dremel. Anyone tried this yet? I have the tools necessary to do this and considering it. But I’ve been swamped with work and school. If it works I’m going to do it. Thanks.