Back Pressure. Backbox

[brian]

Does anyone know is there a big difference in the backpresure allowed from a 1L or 1.2 backbox up to a GSi/GTE backbox.
On the Valver last year i had a GSi system. the backbox blew and had a 1L or 1.2 one so fitted it, welded a more respectable pipe off it and it was nice and quiet but blew it open twice!!
I welded it up very good the second time and that back box is now on a GSi system on a standard GSi engine. its runin ok but i feel its a little down on power from past 1600 GSi/GTE's i've owned. im just wondering is there a difference in back presure in all these boxes and should i use a GSi box?
Up until this i presumed they were pretty similar.

[mowgli]

I once ran a 1600gte lump in a mk1 astra on a complete 1300 manifold & system, it went very well. I stuck the engine in a nova and fitted a proper gte system & I personally didn't think that it ran as well. the std gte back box is not very free flowing.

[locky]

I can see straight thru my new backbox!
Is that good or bad lol

[Mark]

Bad if the cars running :lol: :lol: :lol:

[burgo]

is it glass or somefing then locky??

[locky]

:lol: no stainless but if i look down 1 end i can c str8 thru 2 the other!

[rgv_stu]

my jetex is like that

[Ste_Nova]

i had my 2.0 16v on a 1.2i system..... still made 163bhp on the rollers