empty first cat (1bar)

[Rinus]

Hi,

 

I emptied my first original cat.,

I already had fitted 2nd decat,

and hks catback,

greddy-bcc...

walbro

and of course the 1.2bar restrictor ring...

 

-->boost 0.8bar, thats to low..

 

Lets try it carefull without the rest-ring,

1,05bar at full boost

 

*I think for now the power on 1 bar is fine, and it doesn't

kill my turbo's so quickly...

 

But is the empty first cat even now a bit restrictive,

cause of the "box" model, compared to a 1st jspec decat??

[Rinus]

anybody an idea?

normally with 1st and 2nd decat,

the turbo's should spin up to 1.6bar without a restrictor ring...

[jevansio]

I have no idea what you're on about?

[colsoop]

Which HKS exhaust is it ?

[DannyB]

id say the shape of an empty cat would be a bit more restrictive then a decat pipe itself yes

[Rinus]

its a hks power exhaust (4inch I thought)

 

what I mean is;

if you normally put a full decat exhaust on a j-spec car,

the turboos will spin up to 1.6 bar,

cause of the smaller wastegate than a uk-spec car...

and then the turbo's wil die cause they can handle max 1.2 bar,

then you can put a 1.2 bar restrictor ring in it and it stays niceley

on 1.2 bar

now I did the same on my car, but the only difference is

that I used the original first cat and took al the stuff whats in there out, and whitout the ring I boost 1,05 bar max,

with the ring 0,8 bar...

this means that with an aftermarket 1st decat whitout ring--> 1.6bar

and original empty first cat without ring--> 1,05 bar

 

I can't believe that this makes a 0.6 bar difference...

[miko_supra]

id say the shape of an empty cat would be a bit more restrictive then a decat pipe itself yes

 

Yes exsactly that. Unless you weld in a piece of pipe in the empty cat casing it there will be allot of disturbed exhaust flow being caused.

[Rinus]

ok thanx,

at least we know now that it gives j/spec suup 1 bar this way...