Hey guys! I've been lurking on this thread for a while now and am finally starting to make some progress on my build. I bought a cosmetically nearly perfect 1997 Volvo 850R Estate with a blown head gasket a while back to eventually make into my DD, so I will be setting it up for optimized fuel economy at roughly stock power output (250 bhp and 258 lb/ft torque) while still looking stock. It is a 2319cc 5 cylinder with a high pressure turbo, so fuel economy is surprisingly good in these cars even out of the box, as long as you stay out of the boost. Performance is on the same level as an E36 BMW M3, but with better fuel economy, more luxury, and much rarer (Volvo only built about 13,000 or so 850Rs), so it's really hard to beat if you want a collectible high performance car that can get decent fuel economy on a moderate budget. Plus it can tow 4,000 lbs
Goal is to get 40 mpg cruising @ 65 mph. I'd like to see 25 urban and 30-35 suburban, but, being a 3,300 lb car with a turbo, I'll probably have to take whatever I can get. I do have very light feet (unless I am on a short entrance ramp, of which there are many in Boston, or a fun road, of which there are none in Boston), so staying out of the boost shouldn't bee too hard most of the time.
What mods do I have planned?
Manual swap!! The 850R only came with an automatic in the US. It seems dumb for a high performance car and I'm sure it cost them a lot of sales to BMW, and is even dumber for a fuel efficient car. It has an Asin Warner AW50-42LE, which was high-tech in the '80s. Most people average about 22/28 with the factory automatic setup. I will be using a M66D 6-speed manual from a European market 2006 V70 D5 (diesel) as it has a much longer 6th gear than the transmissions for gas cars that I could get out of my local JYs.
ENGINE: The 850 came out in 1991 and was the first car to use the Volvo "whiteblock" 5 cylinder engine. 25 years later,t is still a fantastic engine and is still in production today in its basic form, but with several improvements, some of which I will be incorporating into this project. In 2002, the pistons and crankshaft were lightened and the connecting rods lengthened, reducing friction and reciprocating mass by nearly 10 lbs. I am hoping to replace my rods/crank/pistons with these. In 1999, VVT was added, so I am hoping to also replace my head with a VVT head.
TUNING: These cars came with Motronic 4.3, which is not a very good EMS for fuel economy. Luckily, upgrading to Motronic 4.4 is nearly plug and play, which will improve fuel economy considerably. Although neither of these systems really have a way of controlling the VVT that I hope to add, I plan on working with one of the leading tuners for M4.3/4.4 based Volvos on this project, and he has come up with a way to gain at least some control over the VVT. He also can lean out my AFRs considerably under light load.
That is what I'm focused on for now, but, once all that is all set, I'll be moving on to some aero. This being a high performance car, it is already lowered about 1½" compared to a normal 850 and also comes with a much lower front air dam/spoiler, so Volvo already did some of the work for me, but I believe there are still some considerable gains to be had on the underbody. The exhaust system on these cars is a bit unusual and may limit some of what I can do (the muffler is in the middle of the car under the floor, not at the back like normal), but I'm hoping I can at least find a way to clean up the flow under the engine bay and add a rear diffuser.
Here are some pictures of what it looked like when it was delivered to my house last year:
The odometer works. Gear was replaced by the original owner at the dealer. Dealer pulled the mileage from the computer when they did this.
And this is where I am at currently:
Today
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