Todd Mullins wrote:
>
> Gary Burrell writes:
>
> > First Off I highly recomend the pamplet "Performance MGB"
> > by Moss UK.
>
> Hadn't heard of this one. What's the best way for a North American to
> obtain this?
>
I don't know I order some parts from MOSS UK and they sent it to
me. Maybe just call them and ask for it. (I'm in NA to0)
> > A note on performance the first 10 % increase is easy to get
> > the cost/ease of obtaining gets increasinly difficult/expensive.
> > Also as you get more perfomance don't forget to address
> > braking, handling etc.
>
> One distinction which I feel needs to be made here, and for some of you
> it may fall into the realm of nitpicking, but I'll make it anyway:
> Brake performance has nothing to do with engine performance. Sure, it's
> The only case in which an engine upgrade necessitates a brake upgrade is
> top speed. If you increase your top speed, then braking FROM THAT TOP
> SPEED will require more energy dissipation. But it takes a whole lot of
> horsepower to overcome the aerodynamics involved.
.... Much deleted
>
> Please note that this is explicitly NOT a suggestion to take a cavalier
> attitude regarding brake performance. You can never have too much
> brakes, no matter how powerful your engine is or how fast you go. My
> point is simply that there is no direct causal relationship between
> motor and brakes.
>
I beg to differ here. A higher performance car will get you to
a higher speed faster, thus giving you less time to brake, hence
the need for better brakes. Illistaration 2 cars at a stop light
1 low power, 1 high power. Some distance down the road is a
obstruction which can be see from X yard away. Both cars leave
the light but don't have a chance to get to top speed before reaching
braking point, high power car would be going faster hence need better
brakes than low power car.
That being said I haven't reached the point where I have to address
my braking, although next time I do a brake job I may add up rated
pads
> > 3) Competition Style exhaust with Long Center branch Header
> Actually, the dual-carb factory exhaust manifold is pretty darned good.
> Does anybody have any hard numbers on the performance gain that a LCB
> header nets?
>
Yup, see below
> > 5) Electronic Ignition kit. I used the crane/allison kit
> > but the new in the distribuiter type looks nice too.
> > (cost $100) I also used a sport coil ($40)
> > (More power to sparkplugs)
>
> All the electronic ignition really gives you is reliability and
> stability. It doesn't actually make any more power. The Sport Coil may
> allow you to open up your spark plug gap, which will make power, but not
> a whole lot (again - anybody have any hard data, so I can quit making
> such qualitative musings?).
>
Well no quanitiative data but qualitative data. Sport coil allows
higher voltage at plugs. Electronic Iginition also supplies more
power to plugs than points, Also at high RPM (5500) points suffer
from point bounce) A quote from "Performance MGB" about the
Newtronic (Pirhana) Electronic Ignition: "We ran a rolling road
comparison test against conventional points. The resultant power
curves prove the Newtronic Ingintion system offered greater power"
My results on my car (qualitative) support this.
> > After you've done this you probably want to change the carb
> > needles on your SU's to something slightly richer
>
> I've never quite understood this thinking. If you need a richer
> mixture, why not simply turn the jet screw a few flats?
This only serves to richen the mixture at Idle not accross the
entire power band. Selecting a new slightly richer needle
helps get more power.
O.K. Now for Some real # from MOSS UK "Performance MGB"
3 cars
Stage 1: K&N Filters, LCB Manifold
Stage 2: LCB Manifold, Modified Cam, tailor distributer,
polished head with large inlet valves. using ether
HS6 or Weber 45 DCOE with K&N filters
Stage 3: Stage 2 above 1950 CC engine different Cam
polished head large inlet and outlet. And a bunch
of other stuff
And now the numbers measured on a dyno
Stock: 74.1 bhp 105 ft/lbs
Stage 1: 80.7 bhp 110 ft/lbs
Stage 2 SU: 97.7 bhp 130 ft/lbs
Stage 2 Weber: 100.3 bhp 130 ft/lbs
Stage 3 SU: 104.5 bhp 150 ft/lbs
Stage 3 Weber: 110.8 bhp 150 ft/lbs
My obsevations 9% more power just by adding K&N and LCB header
At stage 2 not a whole lot of difference between SUs and Webers
but SU's a whole lot simpler to set up. (Webers really need
a roling road)
Stage 3 much $$$$$$ for that last 10 %
My car is a stage 1.5+ I have the polished head but not the
larger inlet, but I also have a large bore compition style
exhaust. With absolutly nothing to back this up I put my
car in the 85+ bhp ballpark.
As I said before YMMV
Gary
--
Gary Burrell
Design Engineer
Pentek Inc. One Park Way, Upper Saddle River NJ 07458
Phone: (201)818-5900 Fax: (201)818-5941 Email:garyb@pentek.com
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