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Performance mods to MGBs

To: british-cars@autox.team.net
Subject: Performance mods to MGBs
From: garyb@iotek.ns.ca (Gary Burrell)
Date: Fri, 29 Apr 1994 10:56:12 -0400
I got a neat catalog from MOSS U.K. the other day and figure folks on the list
might be interested in it.  Anyway it's sort of a cross between a catalog and
a special tuning manual.  Its called performance MGB and contains about 20 pages
on modifying street based MGB's for performance without loosing drivability.
(As opposed to their special tuning catalog which is more race car oriented)
The catalog is mostly comentary on why the particular options where choosen,
and what effect they would have, with test data given for modified cars at the
end.


Anyway they present 3 levels of performance tuning stage 1 (Bolt on additions
only), 2 (minor engine mods)  and 3 (overbored engine).

Suspension Mods: All stages

  Uprated front roll bar
  Urethane shackle bushings
  Uprated lever arm or tube shock conversion
  1" Lowered front and rear springs
  Front springs are "mildly stiffer"
  Rear springs are stock re-arched
  
  Alternately they suggest their coil over spring front conversion.  I've seen
  stuff on this before and it looks good altough at 300 U.K.pounds it should 
  be.  (L. Porter highly recomends this in his DIY restoration book)
  
Braking Mods
        All Stages: Stainless Steel Hoses
        Stage 1: Uprated Pads
        Stage 2: Vented Disks and 2 pot calipers
        Stage 3: Vented Disks and 4 pot calipers

Engine Mods:
        Stage 1: K&N Filter and LCB header
        Stage 2: Stage 1 + polished head, high lift street cam, tailored 
                 Distributer, and either Weber or HS6 carbs
        Stage 3: 1950 cc Engine with Weber carb, and mild cam

Clutch Mods:  (Recomended only)
        All Stages: Fast Road clutch with roller release bearing
        
Anyway they did rolling road test on all the cars and got the following
performance figures:

Stock MG (1974 80,000 miles on engine never rebuilt)  74.1 bhp @ 4508 rpm
Stage 1: (Same car as stock) 80.7 bhp @ 4380 rpm
Stage 2: (Say 1980 but in description refer to it as CB so am not sure
          engine rebuilt 15,000 miles ago)
          SU HS6 97.7 bhp @ 4858 rpm  Weber 45 DCOE 100.3 @ 4773 rpm
Stage 3: (1980)  SU HS6 104.5 bhp @ 4711 rpm  Weber 110.8 @ 4528 rpm

These figures are given as bhp at the flywheel

Note they said they could get 15-20 more bhp on the 1950 cc by uprating the
cam but the object was to make a car that was drivable under all road conditions
Hence the perfomance figure, are not that much improved from stage 2.

Anyway I found it interesting.  Note the difference between the measured bhp
and the 98 bhp quoted as standard.  They quote the bhp as being at the flywheel
although I would think with a rolling road it would be at the wheels.

                                Gary Burrell
                                





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