7 replies to this topic

[zebidee]

Ive got a 1275 carb engine, pretty standard, with an LCB manifold. At the moment it has a 2'' sportex exhaust, anyone know how much bhp this is losing me over a 1 3/4''? I wanted to change it to a standard bore maniflow, but since a 2'' link pipe fits straight on the y-piece, would just the y-piece need changing or would i need to change the whole manifold?

[taffy1967]

Is the LCB and Y piece also Maniflow products?

I doubt you'd have to change the whole manifold and chances are the 1 3/4'' exhaust pipe will fit inside the Y piece as opposed to around it?

I'd imagine you'd have to get it on the rollers to compare performance, but 2" is too large a bore for a standard 1275.

[kitroxin]

Is the LCB and Y piece also Maniflow products?

I doubt you'd have to change the whole manifold and chances are the 1 3/4'' exhaust pipe will fit inside the Y piece as opposed to around it?

I'd imagine you'd have to get it on the rollers to compare performance, but 2" is too large a bore for a standard 1275.

what about a 1275 with a stage 3 head?

[philc]

you may find having a larger bore exhaust you will loose torque at low end and top end, I have since changed mine to 1 3/4 and has made a huge difference in pick up and top end

[zebidee]

I cant tell if it is maniflow manifold or y-piece, they were originally fitted to the car and are looking pretty rough now! PhilC, did you just pop the new system straight on the y-piece you had?

[philc]

I cant tell if it is maniflow manifold or y-piece, they were originally fitted to the car and are looking pretty rough now! PhilC, did you just pop the new system straight on the y-piece you had?

yep,your 2" centre pipe fits over the piece as the 1 3/4 fit in the y piece, buy a maniflow or rc40, if you want a lcb manifold try millenium, i have watched a few bench tests and this came out top.

[zebidee]

I cant tell if it is maniflow manifold or y-piece, they were originally fitted to the car and are looking pretty rough now! PhilC, did you just pop the new system straight on the y-piece you had?

yep,your 2" centre pipe fits over the piece as the 1 3/4 fit in the y piece, buy a maniflow or rc40, if you want a lcb manifold try millenium, i have watched a few bench tests and this came out top.

Thanks for the help bud

[Pauly]

Sorry to hijack but is the LCB the same bore as a freeflow manifold?

Also I thought 1" 7/8 where a good bore for 1275's?

Paul.