jc_oo5 0 Report post Posted August 27, 2018 Jas anyone ever wondered about how much horsepower the Yamaha 3.4 v8 can put out. What's the difference between the: 96 -99 sho v8 Yamaha 3.4l 235hp and naturally aspirated engine 05-10 volvo xc90 4.4l 288 -311hp naturally aspirated engine 09 up Nobel m600 4.4l twin turbo 450 550 650bhp 13 volvo polestar s60 5.0 620 - 640hp naturally aspirated All of the above motors are all based on the v8 Yamaha 3.4l blocks I believe bored out. The only difference I see is a 1l to 1.6l difference with or without a turbocharger. Is there a way we can mod a 3.4l sho motor so we can get better horsepower using the same or similar parts to at least get 350 hp. Share this post Link to post Share on other sites
zenriddles 142 Report post Posted August 28, 2018 The easiest mod that worked for several folks over the years is a nice shot of giggle-gas. A 75 shot of Nitrous is about max healthy level on a stock setup. Your tranny won't live long with ANY kind of serious boost in power. When I finished building SHO R T S (Eaton M90 @ 16psi boost) I already had a heavily built tranny and Tq Converter on a bench waiting to go in when the stock tranny failed. Stock tranny last 160 miles under boost. Any kind of forced induction would be whatever you can make yourself. I have done both Centrifugal and Roots superchargers on the 3.4 SHO. Looked into a rear turbo, which on hindsight probably would have been the easiest fabrication. Not as much up-front ummph, but probably less of a shock on the drivetrain. Share this post Link to post Share on other sites
Spridget 495 Report post Posted September 17, 2018 The 3.4L block uses the same diameter pistons (and rods) from the 2.5L Duratec. IIRC the SHO pistons are flat top whereas the Duratec pistons are dished. Since the rods are shared with the Duratec 2.5 and 3.0, I always thought it would be cool to bore and sleeve the 3.4L and use Duratec 3.0 pistons for a 4.0L SHO. Share this post Link to post Share on other sites
SHO-WGN 74 Report post Posted September 17, 2018 Here is my two cents worth. Officials of all three companies involved (Ford, Yamaha and Volvo) insist that the Volvo V8 is not related to the SHO engine. The Volvo V8 is a die-cast, open-deck aluminum block and is different from the sand-cast closed-deck aluminum SHO engine block. The interesting feature is the two engines share many common dimensions including bore centers, stroke, bearing journal diameters, and deck height. Check: http://en.wikipedia.org/wiki/Volvo_B8444S_engine Share this post Link to post Share on other sites
