Hi Dick,
Hmmm, interesting. The reason i asked was when I changed the exhaust on my
saloon car about two years ago to one with improved flow, I registered a
vacuum drop at idle from 9 in Hg to around 7 in Hg which made the car run a
little rich at idle.
I didn't realise the vacuum on the US spec cars was so high. Wow, mine
doesn't even get that high engine braking!!
I haven't read Kastner's book on tuning (perhaps I should) but although my
TR6 motor has been "warmed up", I intend to use it more for open road
cruising than a flat knacker race machine (the South Is of NZ is heaven -
open roads, no cops, fantastic scenery, fun corners, long straights, no
worries!).
Anyway, I had better go (my pen is running out of ink)
I'll post some pictures to Mike B for the EFI converstion when it is complete.
Cheers
Bernard
'71 2500 PI (soon to be EFI)
'73 TR6 PI (in disgrace for "failing to proceed" - bloody lucas coils!)
At 21:00 1/06/00 -0700, Sally or Dick Taylor wrote:
>Bernard---At the end of your interesting message on EFI's you asked if
>open exhausts change the vacuum signal by much. I have the option of
>running an open exhaust quickly, by opening a two bolt flanged cap,
>which then bi-passes the muffler. At idle, there is no indication of
>higher vacuum with the exhaust uncapped. (Mine's steady at 20 inches.)
>Perhaps if the muffler were more restrictive it might. The benefit, if
>any, would be at higher rpm's when back pressure might show up. I think
>the comfort level and what one likes to hear coming from the exhaust
>pipes should be given the most weight here. Kastner's comp prep book may
>confuse those who like the twin pipe theory. At least it did me.
>
>Dick T.
>
>
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