hey guys i just ordered my regular tube hytech replica for my jdm gsr engine and the guy told me he ran out and wants to send me the big tube... would i benefit from this or lose power?... im goin to xenocron in april for a tune to gain more but which would help me big tube or regular? i have 2.5 full invidia exhaust

 

without knowing anything about the rest of your engine setup im gonna say regular

 

i have 3 inch sort ram aem intake..2.5 full invidia exhaust on a jdm b18c w stage 1 clutch and a tune on neptune rtp as soon as header gets here... ill post the numbers for the difference on the 2 headers.. its only a couple mm

 

Standard/Regular Tube

Primary Tubes = 42.3mm to 44.3mm to 47.8 mm 4-2 collector = 47.8mm 2-1 collector = 50.8mm Outlet = 65mm (2.5inch)


Big Tube

Primary Tubes = 44.5mm to 48mm to 50.8 mm 4-2 collector = 50.8mm 2-1 collector = 54.0mm Outlet = 65mm (2.5inch)

 

stick with the regular unless you plan to dig into internals

 

gunna do furture upgrades but im saying for now ya know

 

there isnt that much of a difference on paper. few mm here few there

the smaller tube will give you better low end and the big tube will give you more top end.

i would get adjustable cam gears and tune them for the power band you plan on. either low or top end. the cam gears move you power band to left or right when you look at the graph. they might not add much power but it makes a huge difference on the street

also i have never saw anyone use a big tube on a stock internal jdm 10.6 to 1 b18c with bolt on....so you might break records for hp with a better flowing exhaust.

alot of n/a guys dont hit their goals because of small exhaust so i say go with big tube.

buy a new air filter before the tune too