Manual
GFB EX50 Wastegate
Packing list: 
•  Assembled EX50 50mm wastegate, fitted with: 
o  1 x 13psi spring (60mm O.D.) 
o  2 x V-band clamps 
o  1 x outlet weld-on flange (part # 7041) 
o  1 x inlet weld-on flange (part # 7051) 
o  Valve seat 
Included in box: 
•  2 x banjo hose connectors & 1/8” BSP bolts 
Installation 
Install the boost nipples using a 5mm hex key, making sure that the head of 
the banjo bolt sits into the large tapered seat on the banjo as shown. Position 
the  nipples  in the best orientation  for  the  installation.    The thread  is  1/8” 
BSP,  which is a commonly  available thread should  you  wish to  use a 
different type of hose fitting. 
Weld-on fittings: 
Already  fitted to  the EX50  you  will find  two 
stainless  steel  fittings,  which  need  to  be  welded  onto  your  turbo  exhaust 
manifold and exhaust system, onto which the EX50 is mounted using the 
supplied v-band clamps.  The inlet and outlet weld-on fittings are both 
different, having been designed for the  pipe that  is most suitable for  each 
purpose. 
The inlet fitting, which is welded to the exhaust manifold and supports the weight of the wastegate, is best suited to 1.5” 
(48mm) nominal bore Schedule 10 or 40 pipe – a commonly available heavy-walled pipe. The outlet fitting is designed 
to  accept  2”  (50mm) O.D.  thin-walled  pipe,  which  is  commonly  used  for  exhaust systems and  screamer pipes.   Of 
course, it is possible to use different size and wall-thickness pipes than those recommended, provided a suitable weld 
can be achieved. The weld-on fittings are available separately from GFB if required. 
The inlet fitting should be welded to the exhaust 
manifold  after  all  the  exhaust  runners  have 
merged, and in a position that promotes smooth 
flow to the wastegate – fast-moving exhaust gas 
is  reluctant  to  make  sharp  turns,  which 
significantly  reduces  the  flow  potential  through 
the wastegate.   The diagram opposite shows  a 
suggested installation location. 
On  any  street-driven  car,  the  wastegate  outlet 
MUST  be  connected  to  the  vehicle’s  exhaust 
system  (before  any  catalytic  converters  and 
mufflers),  and  should  be  done  in  a  way  that 
allows the  gases  to merge smoothly. On  race 
cars  where  regulations  allow,  the  outlet  can  be 
routed out of the engine bay to atmosphere. 
Setting up the EX50 
Use the following guide to help set up your EX50.  You should determine the minimum and maximum boost pressure 
that you want to run (if you are not planning to vary the boost, then the minimum and maximum are the same), and your 
control method. 
Care should be taken when selecting boost pressures, and it is always best initially to err on the conservative side, until 
the engine can be run on a dynamometer to ensure safety. Always consult an expert when making boost changes, and it 
is recommended that the car be checked on a dyno, as high boost and/or lean air/fuel mixtures can cause engine damage 
or worse, total failure. 




