Chevy & GMC Vans

Overview:

Taken from http://en.wikipedia.org/wiki/GMC_Typhoon
The GMC Typhoon is a high-performance version of the GMC Jimmy SUV. Produced in 1992 and 1993, the Typhoon was based on the 1991 GMC Jimmy SUV.
Both the GMC Syclone and Typhoon (SyTy) trucks featured a Mitsubishi TD06-17C/8 cm2 turbocharger and Garrett Water/Air intercooler attached to a 4.3 L LB4 V6 intake manifolds, fuel system, exhaust manifolds, and a 48mm twin-bore throttle body from the 5.7 L GM Small-Block engine. All SyTy's had a GM 700R4 transmission (4L60) 4-speed automatic transmission and a BorgWarner 1372(Syclone)/4472(Typhoon) transfer case splitting torque with 35% forward and 65% to the rear wheels. Both trucks featured all-wheel drive, upgraded brakes, and sport modifications to the standard suspensions. Unlike the Syclone, the Typhoon featured an air-operated self-leveling rear suspension. Output was officially 280 hp (209 kW) and 360 ft·lbf (488 N·m), but some stock Typhoons have been measured at over 300 hp (224 kW) on a dynamometer.
The Typhoon was capable of accelerating from 0-60 mph in 5.3 seconds and could do a quarter-mile run in 14.1 seconds at 95 mph (153 km/h). Car and Driver was impressed, comparing the Syclone's performance favorably to the Ferrari 348ts, Chevrolet Corvette, and Nissan 300ZX Turbo. It cost US$29,970, though the magazine criticized the plasticy interior pieces.
All three trucks were built for GMC by Production Automotive Services of Troy, Michigan. Aside from a handful of prototypes, only 4,697 Typhoons were built by GMC: 2,497 in 1992, and 2,200 in 1993.

Parts:

http://www.ancc.cc/chris/Astro
I've taken the parts info from http://home.swbell.net/loeryder/partstext.html and preserved it on my Astro page ONLY because so much valuable info gets lost on the web when people don't pay the bills.

ECU:

Westers Garage http://westersgarage.eidnet.org/index2.htm

Where can I find a Syclone engine, how much will it cost, and how do I get it into my Astro??

timelessbeing wrote:Where can I find a Syclone engine, how much will it cost, and how do I get it into my Astro??

Thats the point. You have one for the most part in a stock Astro. Stock Astros have higher compression so just run less boost. Everyone installs the V8 including me....having done the v8 install twice, im thinking a turbo is a better option. No need for the Syclone intake, exhaust ect..

Look at how STS runs the turbos. They put the turbo inline with the exhaust, then feed the turbo via air intake, pump the air back to a intercooler, intercooler to the engine intake MAF (Mass Airflow sensor)
http://ststurbo.com/gm_suv_install_pics
Video
http://www.youtube.com/watch?v=3SN32K3KqUE

So, does that cut the life of the engine short as well?

Kind of still didn't answer my question.Was the turbo 4.3's over time found to have problems and is that why we don't see many of them around??.

When I had my turbo Corvair,I did follow oil changes more often.I don't think we knew about letting the car idle after driving to let the turbo cool like we now know to help prevent carbon build up on the turbo.That is something I found on the diesel turbos.The turbo on the Corvair did seize up eventually.

The Ty/Cy is a very niche market Gary. Very small pool of interested buyers. It was hard enough selling the special performance model of anything in the late 80's, early 90's nevermind one based on a boxy SUV.

My brothers tenant had a cyclone for a while that had the turbo turned up and some other mods to it. It had been sent to Japan as a left hand drive import. Then it hit them max age over there so he bought it for a deal and had it shipped here. The thing went like a bat out of hell. It seemed reliable when he had it. Someone offered him a giant wad of cash so he sold it. As stated they didn't sell many of them in the states never mind Canada that saw even less. The only way you will get hold of one is to find someone driving it and then wait till they die of old age and try and pry it from their cold dead hands. You would have a better chance of getting hold of a mint Buick Grandnational.

1Gary wrote:Kind of still didn't answer my question.Was the turbo 4.3's over time found to have problems and is that why we don't see many of them around??.

I think overall they were pretty reliable vehicles. BUT, a lot of owners hot rodded and beat on them. I was interested in buying one a few years back and in my search, I found two types. The ones the owners babied and only drove occasionally... and who wanted too much money for them; and the affordable, even cheap ones, but had a list of modifications a mile long and you got the feeling they were held together with bailing wire and bubble gum with the owners hoping they would last long enough to get the title transferred.

Back in '95, I took a used Syclone for a test drive that was sitting on a local car lot. All I can say is WOW! It would 'shit & git'. The reason I didn't buy it... I was concerned about reliability. I had an 80 mile roundtrip to work every day and this would be my only vehicle. I decided the year-old Mazda I'd bought new would be a safer bet then a several year old Syclone whose history I had no clue about!

1Gary wrote:Kind of still didn't answer my question.Was the turbo 4.3's over time found to have problems and is that why we don't see many of them around??.

The Sycone and Typhoon were pretty expensive. They changed the body style right after those trucks, too. They didn't seem of fly off the dealer lots at $25500 for the Syclone and $29000 for the Typhoon.

Right after that, the EPA started to clamp-down on emissions. Turbo cars had a hard time passing the test, because the turbo would prevent the cat-con from getting hot enough. No more Turbo Regal, Turbo Trans Am, or Turbo Sunbird... all of 'em... gone!

When I had my turbo Corvair,I did follow oil changes more often.I don't think we knew about letting the car idle after driving to let the turbo cool like we now know to help prevent carbon build up on the turbo.That is something I found on the diesel turbos.The turbo on the Corvair did seize up eventually.

Reliability doesn't appear to be a reason for why there are no more turbo cars out there. Go over to the Turbo Buick forums. There are many of them with 150,000+ miles still on the road. The Regal went FWD in 1988, so there was no platform for that beasty engine.

You don't see many turbo 4.3s on the road, because it's cheaper to build a big, bad SBC. There wasn't much aftermarket for the Syclone/Typhoon because they didn't make many. From 1984-1987, Buick pumped-out 50,000+ turbo Regals. That's enough to make any vendor say "hmmm"

I put a turbo on my Astro, but it didn't lower the compression ratio. I was only able to run about 10 psi of boost on pump gas. Actually the Vortec heads on the '96-up 4.3 breathe better than the heads on the Syclone/Typhoon

I still want to build one, or at least a semi-clone of one. If you start with an LB4, you need the nodular iron bearing caps, the pistons to lower compression (you can run less boost and use the stock NA LB4 pistons, but you'll have to pull the timing back too much), and the turbo, an L98 TB (add the airfoil), the turbo and intercooler and attendant radiator for the i/c. And a bucket of money and patience while you jam it all into too little space.

You see few sbc and mini sbc motors turbo'ed because of the plumbing problems. You either use a twin turbo setup, or use a crossover and lose the pulse energy in the exhaust flow from the offside, or use a rear mount turbo and lose the pulse from both sides plus have the lag of pressurizing that long column of air from turbo to TB.

There are not a lot of potential donor vehicles out there. Many met a tree or other solid object at speed.

As a general rule, you lose engine longevity with a turbo, how much depends on boost level used. At around 10psi, I figure you lose about 20% of engine life. Since a 4.3 properly maintained (if it was built right in the first place, a crap shoot) can easily hit 200k, even 300k, you are looking at losing 40 to 60k miles of engine life. It's just like the old saw about burning the candle at both ends: (Burn the candle at both ends, it makes a merry light, burn the candle at both ends, it will not last the night...). 300hp will assuage a lot of regret over the loss, however...

Turbo engines are usually quite durable if you build them right, oil them right, don't boost them to 20psi, and avoid detonation like the plague. I built a turbo 2.6 mitsubishi Montero, using mitsu starion parts, and raised the boost to 14psi. It ran like a train for 150k. Then I turned the boost up to 20 one day in a fit of madness, and it clanked it at wot at the torque peak in 3rd at about 90. I was on my way to a 12sec quarter mile time, too. Not too shabby in a 3500lb suv with a 159ci engine. I love boost...

JMO Vortec heads, the carbed intake for Vortecs converted to EFI, a cam (If you can find one the 4.3L "B" cam or the CPI cam would make lots of power) and something like a 60-1 or if you're feeling really squirrley a T70. I'd do pistons and at least the later L35 rods, the caps are nice but optional; Splayed 4 bolt if I was going to do them as you're going to the trouble for a line bore anyways you may as well go for the gold. Piston wise forged would be nice, but the originals just used Hypers in it. I've seen the Speed Pro/TRW hypers ran in some very powerful Buick turbo engines, so I wouldn't be altogether afraid of them. Just need wider ring gaps than N/A which seems to be the fatal flaw in most cases.

ED:Some Caprices also came with a tubular manifold. They should be thick walled too so if you can find a couple they would be great to fabricate something from. There are tons of single turbo systems that use a crossover including the Buick GN and the Syclone and they still make good power so even though it's a concern it's not altogether a huge one; it's not like you're seeing pulse tuning engineered into a T3 or mitsu based setup (which most production 4 cylinder cars came with) as there's not a split scroll anyways.