Hi,
A V2 compressor wheel
profile machined into the original comp cover will give you aprox 300 - 350 RWHP at 1 bar of
boost given fuel is aprox. 11.5 AFR
under load, exhaust 3", etc match. The wheel is heavily back-cut. (see pix on website) I use 2 springs on the
backplate to strengthen the thrust.
On a bench drill I just drill a large enough hole to still leave a
seat for the flapper to sit on, I also
keep drilling untill I drill through the
scroll in the centre of the housing. Using a porting tool I further
enlarge the hole until its as large as
possible but still retains a smallish seat. A
larger flapper "disc" can be welded on but I've found its not
necessary in most cases as the above
seems to fix the problem. There are other options for more power but the above will
adequately fill your requirements very
economically. If you find there is too much torque for your buggy you
could try a Series 5 turbine housing
which will transfer the power into the higher
rev range but most people seem to love the torque. The Series 5
housing has 2 flapper holes (Hitachi
realised they had a problem) & the mods are therefore not necessary to the flapper
hole, but the housing is more offset
& consequently your engine pipe etc will move to the side a bit.
You need to lay the 2 housings side by
side to see what I mean or if you can't email me back & I'll take a pix for you. I would
stick to the Sreies 4 & consider
trying the
Series 5 later if necessary.
I charge $630 (+ 10%
GST AU only) for the above including reconditioning the turbocharger but freight is obviously an
issue from here as they are quite
heavy. Hopefully someone nearby can help you at a reasonable cost.
I sometimes also get the comp cover
"power ported" or called "extrude honed"
in the States rather than change covers & backplates
which helps further increase air
flow & helps reduce inlet temperatures. Not so expensive here compared to the States I think, aprox. $180. You should also drill & tap a 1/8
Gas (NPT) thread hole into either the
turbine housing housing or exhaust manifold & test exhaustt
manifold pressure which should roughly
= boost pressure. You can put a 1/8 steel plug back in the hold after finished testing. If
you find exhaust manifold pressure is
too high (email me with results if you like) you can machine a bit of housing away around the turbine
outlet blades, try about a millimetre
to gauge the differance. Pressure drop across the intercooler
shouldn't be more than 2 psi, a simple
test & a permanent pyrometer is a good idea with the probe mounted about 2" behind the turbo
in the engine pipe as rotaries can
tend to run too hot. I don't like to see much more than 850c for reliability although many race at 950c. The
pyrometer can also be used to help you
tune the engine as we used to use pyro's for this years ago before Air Fuel Ratio Metres (AFR's) were
invented. Finally you'll notice
on the website pix I machine the exhaust housing outlet in a funnel shape (all above work
done on a lathe except drilling
flapper hole), to further help exit exhaust gas, the angle I use is
7 degrees which will still leave
enough room for the dump pipe to seal
although you may have to modify the gasket & dump pipe should you
find there diameters are small than the turbine outlet
diameter after modifying.
Hope this helps & if you have
any further questions please fell free to ask.
Regards
Max Heywood ATS/Turbonetics
20a Assembly Drive,
Tullamarine, Vic.,
Australia, 3043.
Phone- 613 93351254
Fax- 613 93351264
www.turbonetics.com.au
----- Original Message
-----
From: "Schemmel, Grant"
<Grant.Schemmel@Aeroflex.com>
To:
<sales@turbonetics.com.au>
Sent: Wednesday, May 19, 2004 3:30
AM
Subject: 13B turbo
modification
> Dear Sirs:
>
> I was referred to your website
from a rotary newsgroup. I have a '90 13b
turbo engine which I plan to
install in an off-road vehicle, that will see
sustained 5000 - 8000 rpm use, low
rpm operation will not be a factor. I'm
hoping to set up the engine up to
run at around 220 - 250 HP. I understand
from the newsgroup that the stock
factory turbo will have a tendency to over
boost or creep. I also see from
your website that you offer turbo
modifications to take care of
this.
>
> So, could you give me an idea
as to the pricing of your services on an
existing turbo?
>
> Thanks!
>
> Grant Schemmel
> Penrose, CO USA
>