Hi guys, Can anybody let me know with a custom plenium i have seen some with the small trumpets inside and some without. Do they really make a difference?? And if so what would be the approximate increase over the ones without horsepower wise. I have a custom without them but iam wondering if i would really notice the difference. I currently have 293rwhp at 9lbs of boost as it is still being run in this was all done in second gear as my gear shifter got stuck. Looking at running around 20lbs max its a fully forged motor,motec 700hp turbo big cam etc. Could i get some info please,and what do you guys recommend?? Thanks jetstream see you NSW guys at WSID real soon!!!

if your plenum has square edges where the runners start take it off , throw it in the bin and buy one that is designed by someone that knows what they are making. its costing you power and drivability bigtime

why dont u see if u need 1 first mate ? if ur not chasing under 10's dont go there spend money elsewhere i say !

They look kool and they do make a big difference so y not spend the money?

I have bought a JD custom plenium with the xf trottle body but it has the standard na runners with it will this make a difference i did not realise until i got it home.???

N/A runners will be fine, Rajab use them with their Plenums, I used them on my JD as have others, JETR31 made over 450rwkw with a JD on N/A runners.

sounds good to me!!! Thanks For the advice. I Have built a fairly healthy engine to give the NSW boys a run I have a turbo on it t3/t4 hybrid but the front housing has been polished so i cannot tell what it is any ideas on how to find this out??? Also a recommendation on a turbo?? I want 400+ rwhp Iam pretty confident i will make it with my set up at 20lbs boost.but what might be an alternative. You can see my turbo in the photo. Thanks for everybodys help so far!!