Originally Posted by
escortkid Thanks,
Have visited various forums on this topic and there seem to be pro's and con's regarding the 5 progression holes.
Some say even with 5 holes the carbs still don't run as they should with a Zetec even after hours spent on a dyno.
Most say the car has to be present to precisely drill the holes in the correct position, then its trial and error plugging and redrilling till the correct position is found also with the hole dia. As no 2 Zetec's perform in the same way with air flows on each carb.
theres no reason zetecs would not react in a similar manner to my knowledge, its massed produced to close tolerances after all ? and the carbs dont have room to drill and plug, an expert will know where to drill when tuning it
As for TB's most suggest using a ST170 lower manifold on bike TB's or a GBS single pendulum manifold with a ST170 throttle body.
a single body will tune easily but cost power , the lower st manifold is a cheap bodge and will never flow correctly due to miss matched shapes -not required really as t/b's are cheaper these days . gsxr bodies are good as the early ones split , i cant imagine the re shaping working well tbh.
Most seem to use GSXR 600-1000 TB's with the ST manifold and use injectors in the ST manifold.
Some use a adaptor tube between TB's (round) and manifold (oval), others use a heat gun and reshape the ST manifold from Oval to Round eliminating the adaptor tube.
And some say the latter is Plug and Play, where various maps could be stored and used accordingly where only the Ign map could be stored with Carbs also strip and change jets etc.
none are plug n play without spending a lot. and since the suggestion is that maps can be stored and used in different engines ( which i agree with to a degree) then that makes nonsense of the suggestion earlier that all the engines are different ?
From this I am leaning to bike TB's and ST 170 manifold where it would easier to set-up having maps for Track days and maps for Road use.
thats a home brew lash up to be honest and not the way to go for " plug n play " reliability , and if its mapped correctly you only need one map ? unless using different fuel or intake etc.....
thanks again.
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