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hotrodding the 4.3 V6 (tips & tricks)

198332 Views 190 Replies 52 Participants Last post by  sixsix
G'day, mates!

For those of you who have the venerable 4.3 v6, but want more power as well as throttle response this post is for you.

First off, I know how frustrating it is to have to work with all of the limitations built into the Astro engine: the small choked up t.b.i., or the weirdo c.p.i. "spider" intake manifold, mild cams, and weak ignitions, etc. :crying: There isn't one day that goes by that I don't think about how can I make my engine PERFORM better.

I will admit, a v-8 option SHOULD have been offered. As well as a turbo (look at the syclone/typhoon), or at LEAST take the tuned port intake (instead of cpi) and chop two ports off of it and tune it! (Would make an awesome project). But, since I rent an apartment, most projects HAVE to be done within a day or two.

So, most of these tips are Very doable with minimal downtime. šŸŒ Also, throwing big money at hipo parts doesn't always pay off. (Not in this day and age, anyways) Only the parts that are reasonably priced will be mentioned.......

1. Ram-air: bringing in COOLER air makes it easier for the engine to make power. (Try driving your van without a/c with the windows up on a 90 degree day, your engine is in the same scenario ) This can be made at home with dryer ducting with an aluminum sheets and some clamps. Cheap Cheap! :dance:

2. K&N filter: (8-10 horsepower). If you are in a dusty area, add a foam filter as a buffer. Paper filters restrict your airflow and most people forget about them and they get progressively dirty.

3. Morosso or Proform Air cleaner base: smooths out the airflow and allows removal of the stock "restricter" ring underneath it. This thing is TERRIBLE for performance.

0000tbi choker.jpg

4. Raise the TBI injector pod: this allows more air to get in past the injectors. Turbo city has some goodies. View attachment 4 This spacer/gasket raises the injector pod 1/4". I raised mine to 1". :layrubber:

5. Adjustable fuel pressure regulator: Add more air, add more fuel. Raising your fuel pressure on late models is akin to changing jets on a carb.

0 1000 cfm adjregulator.jpg

6. Fuel pressure gauge: for proper fuel pressure tuning. I set mine to 15 psi. these are fairly cheap.

7. Throttle spring modification: Removal of the stock throttle spring, and replacing it with a SOFTER old-style return spring(s) will increase the opening speed and improve overall throttle response.

8. Throttle enhancer: Casper electronics has a piggyback sensor that when the throttle is at 70% open, it tricks the computer into thinking it's at 100% open, increasing throttle response. (This product DOES work very well, I have one on my Fiero as well)

0 1000 tps enhancer.jpg

9. Bigger TBI: Stick with the stock one...UNLESS you add an edelbrock aluminum intake with a 7.4 liter TBI with the 2" bores. ( This is just a backburner idea at most)

10.1" Throttlebody spacer : (fits under TBI) will add torque by increasing the intake volume. Swirl-type spacers also help mix the fuel and additional air before it's combusted. Unfortunately, swirl types don't work on CPIs....they're port-injected already. I currently have the helix 1 1" spacer. I thought I remembered seeing a 2" trandapt spacer years ago but, I think they discontinued it. Just a while ago, found out CFM technologies has a spacer that's supposed to allow the engine to pull air/fuel from either tbi bore (if it's a duel-plane), offering a more balanced air/fuel mix resulting in more power. Not sure if ours is a dual or single plane, but it's worth mentioning.

0 1000 supersucker.jpg

Most of these parts , together as a whole and with tuning, should net 20+ horsepower. :rockon:

This concludes part ONE for now..........stay tuned for more.

Thank you


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Get yourself an "okayish" obd2 Bluetooth module (elm327, vicar, obdlink) and using either a laptop or a desktop with a hella long usb extension you can connect to and pull a copy of your PCM's OS using PCMhammer. From there just download and install tuner pro, then head over to the TunerPro OBDII forums, and find the XDF that matches your OS. In my case I ditched the stock OS and /changed to the 'universal 12212156 os (only OS that will work for any gm v6/v8 platform) and simply copied my stock tables into a 'lean burn' 12212156 copy I had from an s10.

2156 is a nice version to use since that one has the best XDFs available (the most adjustable parameters) not to mention a user on the pcmhacking forums released a patch for it that gives you 2 step launch control (with optional boost building timing retard) up to a 3 bar MAP table among a few other things.

The best part is that the only barrier to entry is a ~$20 obd scanner (I recommend the obdlink lx or mx), anything with an 0411 512k p01/p59 1mb PCM (or one that has been swapped in, it's really not that hard) and some form of a pc/laptop with bluetooth. Everything is essentially open-source and is simple to use once you get the hang of it. Nothing sweeter than perminately disabling a nuisance SEL code, and lowering trans temps with no more than 5 mins of dicking about.

It's one thing to throw on a better flowing intake and exhaust, along with some better injectors, it's another thing entirely once you've adjusted the tune to take advantage of them. I managed to make a ~400hp 4.3l s10 out of maybe 500 in parts and most of that was spent on stuff I didn't use/need. All thanks to open source tuning (and amazon warehouse discounts <3 my pair of GM8 turbos I got for ~75 each).

i was working on making a wiring pin chart for swapping an "0411" PCM into a '99 van but had to take a break because i couldn't see what i was doing 'cause of cataracts.

couldn't see the numbers on the connectors to continue :
Electrical wiring Rope Electrical supply Wood Wire

now that i can see! what i'm doing i'll be getting after it again. i see! that you have swapped an 0411 into your 2002 - do you have a finished swap chart???
here's the link for the thread i was posting on to show where i got to :
changing 1999 "black box" VCM to 2002...
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