[bluecollar8]

Very interesting thread.Some of these tips will help me out a lot for what I want to do.I'm in the middle of swapping the 4.3 in my 90 Astro.My friends try to talk me into the V8 swap but I already have a 91 engine that I had put in an 87 Astro I had and it was a good runner but being an every day driver I want a few more ponies and a little more mpg.The throttle body info in here was a real eye opener.I had already thought about the exhaust and electric fans.My 90 came from Georgia and I live in the Buffalo Western New York area so running around in a 90 Astro is rare now days.They love to dump the salt when it snows.They changed the emission laws here so I try to stay before the 1996 vehicles to stay away from the sniffer hook up for inspections.Gained a lot of info here and although I don't plan on doing any drag racing I'd like to thank everyone for their input.I now have a better idea of how I can steal a few more ponies out of the 4.3 without going overboard on the fun tickets.Although I'm an old MOPAR guy I've always loved my Astros.I like the simplicity of my TBI V6 and I'm not spending a ton of money on the basic wear and tear parts.Probably the cheapest vehicle I've owned as far as replacing exhaust and brakes on.Mine is a rear wheel drive shorty so about the only gripe I've ever had is that I have to run the studded snows and add some weight in the back for the winter.I don't even think about removing the back seat for space in the winter so I have a nice little trailer I built to drag behind it.Once again thanks for the info guys.Awesome thread.

 

[Y2KSAFARI]

This thread has been a great read and surprising to me as a new-to-4.3L owner. I'm surprised that so many options exist for these engines which are so tightly controlled by sensors and a computer.

Having this wide scope of info available in a single thread allowed me to absorb a lot of actual applied experience without a multitude of searches.

Modifications and home shop hotrodding improvements continue on from the days of flathead engine technology.

snippage
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 its combusted. Unfortunately, swirl types dont work on cpi' s....they 're port injected already. I currently have the helix 1
1" spacer. I thought i remember seeing a 2" trandapt spacer years ago but, i think they discontinued it. Just a while ago, found out CFM technologies has a spacer thats supposed to allow the engine to pull air/fuel from either tbi bore( if its a duel-plane), offering a more balanced air/fuel mix resulting in more power. Not sure if ours is dual or single plane, but its worth mentioning. 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[/quote]

 

[tab1977]

tell me about the hyprtech chip.
I'm thinking about the stage one chip to cure drivability issues on my z code 1987 van. Tech bulitin from Chevy says z code vans have prom issue that causes,off idle hesitation for first five minutes after cold start,and surging at 30 to 40 mph .(MINE HAS THOSE EXACT PROBLEMS AND IS Z CODE )To fix problem gm says
Change out the prom per list I have after scaning for prom code.
the hypertech performance chip sounds like it will do the same.
factory chip makes z code motor run to rich. (also roten egg smell per Gm )I saw your comment"stupid hypertech chip"and would like to get your thoughts.

 

[pharside]

Fantastic post guys! I don't remember the last time I found so much useful info in a single thread.

 

[90safari]

Let me try this again. There's a lot of good info in this thread. Some of it I've already tried on a buddies 91 pickup truck, like the TBI mods. The MSD billet distributor though, I wouldn't waste my time with, as the wires to the pick up coil are smaller than the GM unit, and do fail (left my buddy stranded on a boat ramp when 1 of them broke). The MSD coil is a good buy, and does play nice with the stock system (just use a good cap and rotor).

That said, knowing what I do now, I'd just V8 it (no replacement for displacement). I only say that, as my 1st Astro was an 85 Cargo van that I bought without an engine or trans, that I installed a 350 and 700R4 trans (with a B&M shift kit) into. That swap was probably one of the easiest swaps I've ever done (try doing a V8 Monza or Vega on for size). I had a little over 2K into it totally with everything I did (cost of the van, engine, trans, tires and wheels, touch up paint), it also helps knowing people in the salvage yards for getting a good deal. But, rust was something that had a large foothold on it, and after 3 years I needed to replace it (too far gone to save, and it's replacement I picked up cheap).
The replacement for the 85 was an 88 Astro CL window van, that I still have (got it in 03).

I drove the 88 for 5 years (3 seasons per year), and while it was down in 08 (for the winter), I had the entire bottom sealed and painted, along with the outside, as the paint finish on the outside was getting tired, but also knowing GM doesn't really paint the bottom of these trucks. My plan this spring is to do an engine swap in it and drive it again, as I picked up a rusty 92 S-10 that's got a low mileage (20K) rebuilt engine in it (.060 over pistons, RV style cam, roller lifters, double roller chain and gear, hi volume oil pump, heads completely gone thru, and all the TBI mods mentioned in the thread, along with getting sealed up with Felpro gaskets). I know the guy who rebuilt it too, and after buying a long block for my wife's old rusty 86 Astro, I figured it was a steal buying the entire truck just for the engine. That long block went into her 90 Safari, as we bought with a rod knock (had 98K on it). Yes, we have 2 of these vans here, as they're damn good people (or whatever) haulers. My plan is to sell my 97 S-10 (4.3 V6 in it too), as I really don't need it any more, and I prefer my Astro.

 

[rsisson]

We have the venerable 4.3.... love the Van overall, but it is a bit weak when trailering... (we have a 10' cargo trailer full of niceties)

Unfortunately, my wife is a bit leery of heavy Mods so I am limited to what is safe, easily reversible and inexpensive (ie, the low hanging fruit)

I found a local speed shop that is pretty good (I don't have my shop anymore so I can't do anything myself...)

What I have as a "Wife Safe" list is:

- Better cold-Air Intake
- K&N Style Filter
- Raise the injector Pod
- Raise the ThottleBod (is this separate from the injector pod?)
- Water Wetter (no mention of a cooler thermostat?)
- Plugs, Cap and Coil & Wires
----- pause
- Performance Chip

Is that the basic list for "wife safe" bolt-on mods?

Did I miss anything? If we could pickup 20+Hp, that's 10%, and a -lot- when you are starting with only 190.

New CAT...Maybe... Cat-Back exhaust, less likely but possible. Wife isn't opposed to a 'BIT' more noise if it will drive better...

We don't want a tire smoking monster, just something that will do a bit better on hills... We had the V8 before, but it ate tie rods like crazy, and when it was time to trade it in, there was only the V6. The V8 swap is harder in the AWD, and again, is not exactly wife-safe.

We just had the trans rebuilt when it started to really slip and the shop "tightened" it a LOT, is shifts fast and hard now, may need to soften it a bit as it is a bit TOO harsh for the wife...

We have the trailering package already, supposedly bigger radiator and oil-cooler...

Should I add an electric Radiator fan to the list as well??

thanks for any suggestions or ideas....

 

[jkellow0506]

I had to remove my catalytic converter due to it clogging up. I cut the flange off the converter and measured the inside diameter of the pipe and it was 2 3/4" diameter. 2.5" isntbthe correct size of exhaust on a 2005 gmc safari..

 

[90safari]

I had to remove my catalytic converter due to it clogging up. I cut the flange off the converter and measured the inside diameter of the pipe and it was 2 3/4" diameter. 2.5" isntbthe correct size of exhaust on a 2005 gmc safari..

I believe that the short pipe in front of the muffler is 3 inch pipe, or maybe 2 7/8ths depending on where you measure it.
Are you planning on replacing the cat with a "hi flow cat" from someone like Magnaflow? Or are you gutting it? Or are you looking at replacing it with a "test pipe"?
Keep in mind that unless your replacing it with another cat, you'll need some sort of spacer to lift the rear O2 sensor out of the pipe's air steam, or it will throw a code. What most people don't understand, is that the very rear or "3rd" O2 sensor just monitors the car. It doesn't do anything else, besides throw a code.

 

[Slime]

Good info and read. Once I start putting mine back together I'll add those to my build. Other than the usual rebuild stuff, I added a Comp Cam 260HR, Edelbrock intake ( has a chip available for the intake add ), head work, .030 Mahle pistons etc. It will be nice to see how well it works..

 

[DriveDog]

My two cents about headers: true, that the flow increase won't benefit a lot at low/mid rpm, but "tuned" really means the length of individual pipes, which can be tuned to assist scavenging in particular rpm ranges. I'd want more around 3000-4000, but some would rather have the benefits above 4000. My primary pipes would be longer. Shorter pipes correspond to resonances at higher frequencies. Also, what I recall years ago was that anti-reversion headers did benefit torque and hp at lower rpm. As to why manufacturers shy away from headers on production vehicles, they certainly do adopt low-cost approaches to hp and mpg, but sometimes they avoid features that make assembly more troublesome or expensive or, to avoid injury to reputation, features that are more likely to cause trouble or increase the cost and complexity of routine maintenance. Headers do all those things. I'm not ready to commit to installing headers on my van, but I applaud anyone that does and would love to see more photos of it.

STS turbo setup: with the plumbing and turbo mounted way back under the van-really cool packaging-wise-that sure has to result in a lot of turbo lag. There's just going to be so much air in those long pipes that the inertia of it alone is going to cost a second or two when you open the throttle.

Has anyone here tried supercharging? I need to look around and see... KAPOW!!!!!

 

[dcsleeper]

re: rear mount turbo
I built my own.
None of what you said is true. There is no lag.
17 psi on a stock Ford 2.9, been running it for years.

 

[EXTREMEODD]

With my 2000 AWD LT all it took was swapping to the 0411 pcm and a bit of transmission shift/lockup tweaking to make the van feel significantly faster along with netting an easy 2+ mpg. However, after doing a bed mounted turbo 4.3l s10, I'm not satisfied with where the van is and thankfully I have another brand new gm8 turbo on hand which will find home where the Astro's muffler currently resides. For the sake of reliability and ease, I'll probably run a maximum of 7psi of boost so I don't need to run an external fueling system (the ol dime had an injector preturbo that came on at 5psi spraying methanol. Felt like vtech kicking in when that happened). My only concern is where I'll put the turbo air intake as I'd rather not have it at the bottom of the van and risk hydrolocking during heavy rains.

 

[Doe_nStein]

With my 2000 AWD LT all it took was swapping to the 0411 pcm and a bit of transmission shift/lockup tweaking to make the van feel significantly faster along with netting an easy 2+ mpg. However, after doing a bed mounted turbo 4.3l s10, I'm not satisfied with where the van is and thankfully I have another brand new gm8 turbo on hand which will find home where the Astro's muffler currently resides. For the sake of reliability and ease, I'll probably run a maximum of 7psi of boost so I don't need to run an external fueling system (the ol dime had an injector preturbo that came on at 5psi spraying methanol. Felt like vtech kicking in when that happened). My only concern is where I'll put the turbo air intake as I'd rather not have it at the bottom of the van and risk hydrolocking during heavy rains.

So what just a better tune with the 411? Funny you mention this as I am planning this mod on my Cadillac LT1 and bought two 411s from the junkyard. So I could have one for the van too.

 

[sixsix]

Have you considered the area in the inner fender - where the OEM air intake resides...
- going to be quite the plumbing feat. "Laws of Subtraction" may come into affect.
I for one, am looking forward to any build info and or pics, etc.

Welcome to the forum - Fresh Blood always Welcome...!!

 

[MI_Ghost]

re: rear mount turbo
I built my own.
None of what you said is true. There is no lag.
17 psi on a stock Ford 2.9, been running it for years.

But what is the wastegate pressure? Pics or it isn't true!

 

[dcsleeper]

17 psi

MINE1

• dcsleeper
• Sep 4, 2021

rangerturbo

• dcsleeper
• Sep 4, 2021

 

[sixsix]

zat a Lincoln...lol ?

 

[sixsix]

LOL

sorry

 

[EXTREMEODD]

Have you considered the area in the inner fender - where the OEM air intake resides...
- going to be quite the plumbing feat. "Laws of Subtraction" may come into affect.
I for one, am looking forward to any build info and or pics, etc.

Welcome to the forum - Fresh Blood always Welcome...!!

Thanks for the warm welcome!

I'll need to make a point of trying to remember to take pictures while working on the van, it's something that I've always been bad about. So far all I've done is swapped in a DR44G 140+amp alternator (manually controlling the output via PWM signal generator), removed the factory pin stripes, removed the cracking black vinyl decals around the windows and am currently in the middle of replacing the body bushings/rebuilding a completely rotten lower radiator support. Since that part will be hidden I'm going to essentially copy what Chevymankevin did. Thankfully the metal donuts arent that rotten and have been coming out of the electrolytic rust removal cooler looking better than I expected.

I mention the body mounts as I am planning on gaining some much needed room for plumbing via a 2in (maybe 3in) body lift. Doing the s10 build I learned that a mere 2in ID pipe that was over 10ft long was more than enough to push 15-17 psi down a 4.3's throat. With that said, the turbo's intake was literally 6in long so I'm not sure how much a longer/more restrictive intake will change things.

So what just a better tune with the 411? Funny you mention this as I am planning this mod on my Cadillac LT1 and bought two 411s from the junkyard. So I could have one for the van too.

Basically I turned off any of the "abuse mode" items, reduced the torque management trans tables by 2/3rds (that is how much power via timing the computer pulls just before shifting), adjusted the TCC lockup pwm minimum to 90%, maximum to 100% (by design the TCC normally never fully locks and almost always will have a 30-50 rpm slip. Allowing it to fully locked dropped my trans temps quite a bit, especially combined with allowing lockup to occur as early as 15mph in 2nd. Other gains came from the 0411 having a high and low octane spark map table, leaning out the PE mode along with lowering the entry point from 90% throttle to 60%. If you use a 12212156 OS you can change the platform from van to holden to allow for activation of "lean cruise" which will pull fuel and add timing at highway speeds (or lower if you desire. Mine is set to activate at 40mph and deactivate below 30), at 50mph I'm crusing at 16.3:1 afr which makes a very noticeable difference in avg MPG. Once my coworker is done borrowing my laptop I'll be able to get some logs and hopefully make a slightly more aggressive lean cruise table.

With that said, I'm a complete amateur when it comes to tuning and have only been messing around with the 0411 pcms for about a year, 90% of which was on a 5 speed so figuring out the 4l60e stuff has been quite the adventure.

 

[dcsleeper]

Basically I turned off any of the "abuse mode" items, reduced the torque management trans tables by 2/3rds (that is how much power via timing the computer pulls just before shifting), adjusted the TCC lockup pwm minimum to 90%, maximum to 100% (by design the TCC normally never fully locks and almost always will have a 30-50 rpm slip. Allowing it to fully locked dropped my trans temps quite a bit, especially combined with allowing lockup to occur as early as 15mph in 2nd. Other gains came from the 0411 having a high and low octane spark map table, leaning out the PE mode along with lowering the entry point from 90% throttle to 60%. If you use a 12212156 OS you can change the platform from van to holden to allow for activation of "lean cruise" which will pull fuel and add timing at highway speeds (or lower if you desire. Mine is set to activate at 40mph and deactivate below 30), at 50mph I'm crusing at 16.3:1 afr which makes a very noticeable difference in avg MPG. Once my coworker is done borrowing my laptop I'll be able to get some logs and hopefully make a slightly more aggressive lean cruise table.

With that said, I'm a complete amateur when it comes to tuning and have only been messing around with the 0411 pcms for about a year, 90% of which was on a 5 speed so figuring out the 4l60e stuff has been quite the adventure.

Fascinating stuff there!

Go on.....