Tony wrote:
>Hello all, I've got a '77 Spitfire 1500 with Weber DGV carb and headers on
>it, I was wondering about switching to dual Zenith Strombergs for more
>performance as it came out them with in England (or so I've been told
>anyhow). Dual Webers would be nice but I don't think I can swing the price.
>Any ideas on this subject or other ways to increase the Horsepower of my
>Spit?
You already have more carb than the 1500 can use. Indeed, enough that getting
the car to accept full throttle at low rpm is a problem. I am not saying the
DGV conversion is a *good* thing. The jetting as supplied and the manifold
design leave much to be desired. Truimphs with a DGV conversions tend to
stumble and bog, especially when cold or turning right. This is all due to
the cruddy semi-updraft manifold, and is usually amplified by people not
hooking up the token water heating built into it.
That said, you're not going to make any significant performance gains by
changing to a different carb set up. Changing to the twin SU/Stromberg or
a single sidedraft Weber/Mikuni/Dellorto may gain you something in drivability,
but not much in terms sof raw power. 70's cars were seriously detuned to meet
the dreadful smog laws. You're at the point that you have to undo the hard
part of this. You need to get the compression and valve timing up to "normal"
specs. First off I'd say 9.0 to 1 flat top pistons to get the compression
out of the lawnmower range. Then look at cams. And if you still want more,
more valve and porting. Once this has been done, the motor will be able to
use the carb you have, and changes there will start to have an effect.
Randy
randy@taylor.wyvern.com
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