I was send an email at jenvey help for mechanical questions for which throttle bodie is the best for xe in general use and this was the reply who give me.
I am running the Vauxhall engine in my Golf GTi and went for the weber
style manifold with TB throttle bodies. The advantages of this is that
they are cheaper, give very good road driveability and unlike the SBD
and QED parts I didnt have to cut a hole in the bonnet as the throttle
bodies are horizontal not at an angle like the other two.
So if I was you I would use the TB Throttle bodies
Which throttle bodies and inlet manifold does he mean?
Does anyone has a link to see it?
Kind of an odd reply, as SBD do those very bodies as well as their tapers, and no-one has had to cut their bonnet when their in an astra!
check out http://www.sbdev.co.uk look at the multi-throttle kits, you're looking for the MT196 kit, which uses a set of parallels, they fit on a std DCOE manifold, so they are more popular as they are not engine specific.
I read the sbd site and i noticed that the multi throttle bodies if the performance diagramms is right that you have the 90% of all the power from 5500 rpm up to 7000 rpm which is the edge (196 bhp) and the power continues to exist up to 7750rpm which is the rev limiter.
In regard of taper tb's the multi tb's is more powerfull in larger rpm range and have the same torque with taper kit. The taper kit is more powerfull only from 7000rpm to 7750rpm.
From my opinion with the multi throttle kit you have the advantage to put the rev limiter to 7000-7200 rpm (if you want) because the max power is here and you don't have to worried for the durability of the engine componets to works all the time to the max rpm range to give the desirible horsepower.
Of course you loose from sbd 12 bhp.
But i think for the most people wants a powerfull car not only to the max rpm's but in larger rev range to go faster not only to a strait line but everywhere.
But all of this if the diagramms are correct.
And you save and money.
But all the things have always and a disadvantage.
Does anyone know what is it?
most of the time i change at 7k or so to get back into the torque band
there is power everywhere tho, but for what i am running i get much better torque below 7k, so when i change into 4th say the car surges forward it aint shy
the limiter is still at 7750 cos i cant be arsed changing it, but i am hankering after some cams which give a nice increase in power from 6k right thro to 7750 and no loss in power below 6k either best of both worlds
the tapered kit is better looking, but my mt196 is producing a fair amount of power, i dont think i am missing out all that much at the mod stage i am at.