On Sat, 18 Sep 1999 18:42:29 -0400
Joseph J Burlein <tr6guy@juno.com>
Wrote: Re: "not sporty at all" ??? was TR4 Made by Honda?
How the heck are you getting 175bhp?!!!!!!
Joe Burlein
72 TR-6
Melbourne, FL
Joe,
It's all very simple and straightforward textbook tuning...
Re-bored 1998cc +60 thou'
note that the 1998cc engine as found in the Vitesse (HC-engine prefix)
is more freely revving than the comparatively long-stroke TR6 unit.
Next in order of importance is breathing,
both in and out.
Properly Gas-flowed Cylinder Head with stainless steel big valves,
balanced combustion chambers and phosphor bronze valve guides.
Up the compression ratio some, (I think it is at 9.5:1), but not too much or
Octane problems may occur on street gas.
Really well designed Exhaust Manifolding/Headers is most important...
mine is a 'one-off' 6 into 3 into one, big pipe heavy grade mild-steel design
by Mike-The-Pipe (Randall) of Wallington, England, this runs back to a
'full-sports' big bore Stainless pipe and 'straight-through' twin boxes made
by Bells of Swindon and marketed through the TSSC.
(The header design is almost the same as the tubular design favoured by the
guys who tune their TR6-PI's over here).
Inlet manifolds are Triumph Tune/Moss GT6 for the Weber 40 DCOE's that I have
fitted, with K&N filters.
Gas is supplied by Twin Facet Red-Top electric pumps in the trunk, from twin
fuel tanks, and a Jaguar changeover switch on the dash.
The Camshaft is a BL Special Tuning USA S2 Camshaft,
(I think Ted Schumacher can get those now?)
Fully balanced and tufrided crankshaft, c/w a lightened flywheel...remove
about 7lb.
not much more or smooth idle is compromised.
My rocker gear is at the moment fairly standard, but the arms have been
lightened and balanced and have oilite phosphor bronze bushes fitted.
I hope to replace this with roller rockers idc.
I have a duplex timing gear fitted for reliability.
The distributor balance springs and weights were chosen by a specialist,
(Microdynamics, now defunct), who also built the Lucas distributor and
supplied the 8mm spark plug HT leads and the NGK spark plugs.
Microdynamics also supplied their F1 Ignition pack.
(which I can bypass if needs be).
The water radiator is uprated to triple-core specification, as you need to
keep that hard-working engine as cool as possible, and an electric fan is
fitted.
The clutch is a TR6 white-spring cover, with a TR6 bonded friction plate.
It's a bit heavy, but I hope to one day fit a co-axial clutch release
mechanism.
The Gearbox is basically TR6 with J-type Overdrive and Dolomite Sprint Close
Ratio gearing.
The Differential is a Quaif 3.63:1 ratio 'LSD' and drives through modified
(narrowed) TR6 sliding splines, with are a very great improvement on the
original rubber doughnuts.
Brakes at the front are AP Racing 'small' mag-alloy 4-piston callipers and AP
Racing Ventilated front discs, servo assisted.
Wheels are minilite replicas, from the TSSC shod with modern Avon tyres in
175x70x13.
Next on the modification trail will be the coil-over rear damper conversion,
retaining the main spring of the transverse leaf spring for location purposes
with Koni dampers, and replacement of the standard rear drum brakes with
discs and callipers.
(I will tell the list idc, how that goes on...sometime over this winter)
There are literally dozens on minor mods on my car, but mostly they don't
directly add to the power output, so I won't mention them here.
So basically, there you have it.
Maximise the (cool) air going into the engine, maximise the air going out of
the engine, (aka noise!!!), supply the engine with lots and lots of (cool)
fuel/gas.
Ensure that the engine has the right camshaft fitted for your application,
(driving style/road/race whatever), build-in as much reliability as possible.
Ensure that big fat sparks hit the air/fuel mixture at exactly the right
moment, with a half decent distributor, (ie: one that has done less than
50,000 miles from new!),and finally make sure that all that power is usable,
and is actually transmitted to the road surface, otherwise it's all a bit of
a waste of time really!
Spinning tyres achieves very little!
I could have gone much further, but I didn't want to compromise the
driveability of my road car, and money is always a concern for most of us.
However, selective modifications go on and there is always a new project to
improve my car in some way in the background.
ie: a more modern alternator to replace that Lucas unit!!!, and the
replacement of many heavy items with lightweight alloy items. (see the
Racestorations or Cambridge Motorsport Catalogues for inspiration/lots of new
and interesting ways to use up all your 'spare' money ;-)
You might also talk with Ted Schumacher of Richard Good of Goodparts, on your
side of the pond ?
Perhaps you can apply some of these ideas to your TR6 ?
Best Regards
Léon
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