Volvo did produce a tune-up kit for B230F engine. The kit includes a 531
cylinder head, VX cam and 60mm exhaust (same size as Turbo / 16V I assume).
In the Volvo accessories brochure, it claims that you can achieve 136hp
(100kW). The brochure also includes power and torque graph before and after
the tune-up kit. I haven't checked the cost or availability of this kit at
a Volvo dealer, but I've head that it cost around USD$2000 and they stopped
marketing them about a year ago.
So far what I've done to my 740 is almost the same as the kit, except I got
my 531 cylinder head and VX3 cam (VX3 is VX retarded 3 degrees to improve
low end and driveability) used at a wrecking yard and had it reconditioned
before I installed it. All up including labour and the gaskets I've spent a
bit over AU$1200 (USD$900). I haven't done my exhaust yet and I'm
estimating my engine output to be 130hp (96kW), which is the output Volvo
publishes for the B230FB engine, as my upgrade effectively converts my
engine from a B230F to B230FB.
You're right about the K&N filter, coil, plugs, wires and distributor cap
giving you a very small power gain, if at all. But if they are a bit old
and haven't been changed for a while, you might actually have lost 1 or 2hp
there, so changing them allows you to regain the power you've lost and
freshen up your engine. That's what I was trying to suggest.
Different market have different emission equipments and thus different power
output rating. Take the B230F engine for example, the American brochure
says 114hp, the Japanese brochure says 115hp, the UK brochure (and my
owner's manual) says 116hp. Also there's the difference of SAE vs. DIN, SAE
(American standard) measures power at the flywheel and allows ancillaries
(alternator, power steering pump etc.) to be disconnected, while DIN (German
standard) measures power at the rear wheels and all engine ancillaries has
to be connected. The B30E engine in my 164E for example is rated at 175hp
SAE and 160hp DIN, exact same engine. For fairness, I got all my
performance data out of a '91 Japanese catalogue, which has specs on B230F,
B230FB, B234F and other engines such as B230FT and B280F. All the power
rating in that catalogue is in DIN, except the 16 Valve B234F's power is
given as 150hp (SAE), so really the true DIN rating of the B234F is LESS
than 150hp.
Here's a link to a website that produces ECU / chip upgrades.
http://www.powerchipgroup.com/
I don't have any dyno'd proof as I've only done the cylinder head and cam.
I can however scan you the torque and power graph from the accessories
brochure, which includes the upgraded 60mm exhaust as well (only 3 pieces -
the bend over the rear axle, rear muffler and tailpipe). But given that you
can easily gain 20hp with the tune-up kit and reach 136hp, I think it won't
be hard to gain another 14hp to reach 150hp if you do a more comprehensive
upgrade of the exhaust (doing the header and cat section as well), port and
polish your intake manifold, ECU upgrade or even a hotter cam. The VX cam
which I've been referring to so far is NOT a performance cam, it is a mild
cam designed to boost mainly the mid range and slight gain on top end
without too much compromise at the low end, and still allow you to pass
emissions. If you're more interested in high end performance and increasing
your HP rating, try A cam or V cam. I decided to stick with VX because my
car's automatic and I don't want to loose my low end too much otherwise
driveability will be affected.
_________________
Will
'90 Volvo 744 GLT
B230F converted to B230FB (531 Head & VX3 Cam)