Hey Chuck, I have the same problem. I tried some SU HIF6's and they worked
okay until something got caught in them. I then went to Z-S carbs. I took
the temperature compensations and screwed them all the way down and reshaped
the needles to a profile similar to a V12 E-type. They ran okay but you're
right about the difference from a set of Webers.
I was told the very best carbs out there for air flow (what you really want
as opposed to gas flow) are the early TR4 Z-S carbs. They're funny looking
and I think floats are hard to come by, but they flow much better on a flow
bench then the others.
I did fairly well with my early TR6 intake manifold by hogging it out and
removing most of a baffle in the way of I think the #2 & 5 runners.
I have a bunch of carbs I been playing around with and may not use them this
year. I'm trying to set up the PI on my 6, always an option for you to turn
your car into a TR5.
It seems to me the twin carbs gave you more low end torque and ran out of
high power. I haven't tried the early Z-S carbs yet, but might be the way
to go.
Charly
----- Original Message -----
From: "Chuck Arnold" <chuck.arnold@oracle.com>
To: "FOT" <fot@Autox.Team.Net>
Sent: Wednesday, January 19, 2005 5:50 PM
Subject: Carbs for Vintage Racing TR250
> I have been communicating with Joe Alexander regarding induction for my
> some-time to be TR250 vintage race car. I asked what would be
> preferred -- 2 SUs or 2 Strombergs.
> Here is his reply [maybe from a digest mode]
> "So the order of choice is 1 - late SU's, 2 - early SU's, 3 - Stroms
>
> Now the reason that nobody with a vintage TR6 uses any of the above is
> that the stock intake manifold absolutely kills intake flow. It is just
> awful. That's the reason everybody running TR6's use Webers. TR6 intake
> ports are very restrictive, and putting the stock manifold on it kills it.
>
> If Webers not a choice, I'd get the Richard Good three carb manifold
> without the Stroms he sells and put SU's on in their place. A few
> purists might wince, but nobody in a club like VSCDA would care. Just an
> opinion, but I think a TR6 with two carbs on a stock manifold would be
> beaten by every TR4 on the track. But if the owner can't afford Webers,
> go with it".
>
> Unfortunately, SOVERN, the vintage group whom I will be racing under
> requires the car to be setup to the 1969 SCCA regulations. According to
> their site, this means 1.75 Strombergs or SUs [no mention of PI, though
> Kas has related to me that that was the only way the factory raced
> them].
>
> So, to the collected group:
> What carbs give me the most gas? Is there anything [visibly legal] that
> can be done to improve the intake manifold's flow?
>
> Thanks,
> Chuck
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