last weekend I went to the Nuerburg-Ring, where we had some
on the old Nordschleife (that part, where Niki Lauda burned off).
Besides this I talked to one of our Autox's. He raced a TR4 on HS 6's.
What I found on his car was a little bit surprising for me:
He used the SU's on the (unflowed) pre TR4A manifold without Rampipes or filter
and he switched to this configuration, 'cos with the flowed later manifold he
found the (as I remember) plugs on 1 and 4 running lean. My first thought was
bridge between 2 and 3 manifold pipes, but this was closed by welding. Next
was a not centered wall inside the manifold, where the gas is splitted and on a
close look, this might be the point.
Additionly I was told, that the engine produces more power on the new setup
with the older manifold....
I took another close look into the SU's and found two things where I'm not
about, wheather it's good or not!
-the carb' input was widend up, it looked like it was done on a lathe.
-the edge at the bridge where the piston falls onto, was rounded.
I can't say anything about the first, but IMO and as far as I remember (can't
find anything written) the second might be worse, 'cos the edges, on the bottom
of the piston and the bridge should be sharp, in order to swirl the air quite a
What can be done to racetune SU's, instead of changing jet and needle ??
In the moment my favorite is switching to twin HS8's, although there are still
quad HS 6's in mind (it's not only you Nick).
Allright, now, it's your turn!
Peter Juergens -- - - / <> \ __,@_\____
PiJay@t-online.de - --- '--0--'~~'--0-----0->
´62 TR4 daily
>>>>>Only the fastest toy wins!<<<<<