Introducing Niels' GMC gasguzzler

[Nelis]

Hi all,

I'm Niels and I just moved from the Netherlands to Houston (TX) temporarily. I bought this van in good shape to commute and be able to do roadtrips, sleep in it and haul surfing gear at the same time. It will get further upgrades from the stock interior it has now, to better accomodate this.

The idea is to bring it back to the Netherlands at the end of the year. Fun facts (not fun) about the Netherlands:
-Fuel prices in NL are easily 3 times higher than in the US.
-There's a tax for owning a vehicle that's based on the fuel type and vehicle weight. Petrol being the normal rate, LPG gas a bit higher and diesel about twice the petrol rate. My BMW 1-series little diesel car was about 116eur a month, so these taxes are substantial. The roadtax in Texas in comparison for this van is a one-time 500usd.
-The idea is to convert and register this van as a campervan in the Netherlands, which cuts the tax down to a quarter of a normal van, to 53eur a month. This would involve installing a pop-top roof, among other things.
-It will be converted to a LPI direct injection LPG with a large tank.

Now to the Ecomodding part!

Offcourse the 5,7l Vortec engine with 4l60e slushbox and brick aero make this van terrible on economy. But that's exacly what brought me to this forum, and I feel there's some low-hanging fruits that can be adressed to make it better. Some mechanical things I will do while still in the US because of good part availability and knowledge on this model, and some stuff I will do once back home and have my garage at my disposal.

I'm completely new to this, but already did some research and came up with the following gameplan:
- Install TCI EZ-TCU (already bought it): In an effort to minimize losses in the gearbox, this unit should allow me to firm up shifts, alter shift points, and influence lockup behaviour of the torque converter. I am looking into a lower stall torque converter (Hughes Fuel Miser) as well, but will first see how this mod turns out.
- Reduce final drive ratio. I will first investigate how the current highway rpm's are, using the EZ-TCU dash, to see if that's worth the trouble. If I do this mod, I will probably install a Torsen diff at the same time because of my wintercamping plans in the Alps. So I'll need to save some serious money first.
- While checking out the harness install scope for the TCU, I noticed the ignition stuff looked old, and the coil wasn't even bolted to the bracket. I will possibly replace the coil, distributor and leads for upgraded parts with larger spark plug gaps. I read into LPG conversions, and it seems a strong and long spark is even more important there.
- Hydrau fan conversion to electric. In NL the weather is mostly cold enough the fan won't engage. Seems a common mod for this engine that's a sure improvement in MPG.
- For both aero and underbody protection from harsh environments, I am planning to do an underbelly, as large as possible, keeping the driveshaft and diff free. I looked underneath, and it looks like there's something to gain to say the least.
- I just read that the L31 Vortec engine had some sort of mechanical injectors, and that upgrading to electrical ones is easy and popular mod, so I might look into this further.

If anyone has comments on any mods above, I would love to hear your opinion, especially on the engine mods, as this is my first V8/Chevy car.

Best regards, Niels.

[oil pan 4]

The electric fan is a good idea.
It should be easy to adjust the final drive ratio while you are in the US. The rear axle on that van are common here and gear swaps are normal.

[Daox]

Welcome to the site Nelis.

[elhigh]

In addition to the lower axle ratio, while you're in there consider changing the differential to a limited slip model. I think your winters in the Netherlands get a lot more snow than Texas ever did, and the LSD will help keep you on the road and mobile.

With a lower axle ratio you might want to consider a new camshaft to move the torque peak further down the Rev range to complement the lower cruising revs.

Really interesting project.

[oil pan 4]

The stock cam puts just about all the torque possible down low.

[justadude]

Welcome to the site. Also, that's a pretty bold project. I hope you will successfully complete it! I can't wait to see some pictures of your progress, if you want to take some. Cheers and good luck!