Chevy & GMC Vans

It's a nice kit, but, did you read the bottom line. It will take some serious fab skills to install it.

Yeah I seen that I was just checking to see if anyone had done it and what kind of improvements did it show over stock. I basically have to much time on my hands so I search for stuff lol.

Mr_Roboto has got yrs of research into turbo's for his 305 and I do remember one member that had a twin turbo Astro.

Twin turbo's would look cool but I was told a single turbo is actually faster due to less lag. Now I will be the first to admit I have no idea what that means though.

Guy's look threw the pick and pulls to find the smaller turbos and impellers.Actually is reduces the lag time.Lag time is the amount of time it takes from the power applied and the turbos spinning up.

I was thinking about looking in salvage yards to learn more about the turbo mechanics. I do know that a Turbo that goes on a carb or TBI is totally different and less powerful then other types of fuel injection/delivery.

If done right it does get involved.A overview is forced induction overcomes shortcomings a engine might have say in heads that don't flow well.


But is would have been ideal with a CPI

From what I have read the 95 4.3 heads are in fact of the vortec design and if someone is looking to build a 4.3 the 95 heads are better then the 94 and older heads but the 96 and up are better breathing due to the higher volume intake and exhaust ports. I have not removed the 95 heads to look at them though. if i decide to build the V6 verses going V8 in the future I will buy the components/tools to port and such then practice on some junky heads first. I am better at welding and fab then engine work but practice does make one better. My situation is this: if we buy the home in California the house in NH will be put on the market and until it sells my finances will be on a serious budget so I have tons of parts to install including the upgrade on brakes, tali light fillers, cady tail light install. rear bumper plate box to weld in, rear door swap with doors that I previously welded the license plate area in. (not totally finished) etc etc. I am still looking for 11 rear drum brake backing plates though too. If I stick with the V6 I can have a custom Y pipe made and depending on Cali laws I would like to have dual tail pipes. Anyway Y+This forum helps keep my brain centered on one project otherwise I would be divorced and have 5 vehiclas undone in the yard lol.

The early "High Swirl" heads flow awful just to try to meet emission standards. Even modern toilets don't swirl any more as it is SUCH an inefficient way to get product through a hole/port. 90 degree v6 engines are a bad idea anyway with a central induction system such as a carb or the early TBIs because 90 degree V6s have the flow in the intake manifold trying to do tricks to get to the cylinders. Now while air alone can get where its going at least ok with a big enough plenum, an air/fuel mix becomes a mess because the fuel has weight causing inertia to separate the air and fuel while it's changing directions due to the cylinders firing order leading to different cylinders getting different mixtures. GMs band-aid was the high swirl ports to try and remix the mixture as well as they could and HP by damned. Several accountant designs to help before getting to the current engineer designed multiple port injection system were just putting off doing it right.

Thank you for that honest, sobering look at our engines. It's too bad the Astro didn't get an LS1 or something more modern :(

Again Stan.The proof is the turbo forced induction systems forces the air/fuel mixture into the cylinders and within the parameters of the heads used helps negate the shortcomings of heads the don't flow well N/A.Does a turbo work better on a EFI or CPI system over a blow through carb??. You bet it does. It is mainly because of a better fuel management system.Each cylinder getting equal amounts of fuel and a CPI being a dry system all cylinders benefiting from the forced air of the turbo.A SFI would be even better.

One of the things turbos fall short on is it is a hot air forced induction system.The way to correct it is with a intercooler. These turbos rely heavily on good fresh oil.With the heat they operation in,they do have a tendency to create carbon build up and require oil changes more often.
Depending on the amount of boost,will dictate what octane gas is needed.It's the same thing as if you where running a high DCR.

Oh yeah................T/B