Exhaust for power gains??

[MaCe]

He guys,

Had my baby on the Dyno on the weekend (really happy!)
With 180 000kms on the clock and im racking up 247kw and 507Nm on the
wheels! (YEY)
Now i've got a question i have a Lehmann motor ECU upgade(i think)
and a 50mm decat powerflow freeflow with one box and was thinking of going bigger
Now the Question is HOW BIG??

I think the 50mm is way too small and was thinking of going 76mm with one box and a BMC airfilter to go with??
Any ideas?

(PS. remember guys i live in the southern most point of africa so cant
get hold of all parts and stuff like you guys can so ill be making everything up @ powerflow)

[VaudiGR]

are you sure you have a 50mm exhaust??? original one is 63mm from factory.MAybe you meant 70mm?

I have a 76mm downpipe and 70mm catback with 2 BNpipes racing cats and im about 400-420hp crank at the moment.A 76mm would be better but will be louder.Im planning on modifying the downpipe a bit to allow less restriction

What mods have you done besides the remap? 247Kw whp is 325whp which is more than 400hp crank.However the 507Nm doesnt really add up... For a 507Nm of torgue i would assume that you have about 350-380hp crank

[MaCe]

Look i'll post the dyno sheet up later this evening but as i said i measured 50mm in the middle of the system.
the original downpipe does look alot bigger and presume it is around 70 odd mm so thats why i was thinking 76mm.

I dont actually know whats been done to the car i only got it 3 months ago and the previous owner said that to his knowledge it was stock other than the exhaust! But in the engine bay i have a sticker on my airbox saying (Lehmann Motor) . He told me to phone the first owner to find out if he had done anything, but cant get hold of him.

the only other thing that i am doing is running octane booster NF Black and i got 247kw and 507Nm