Intake runner size for boost?
Intake runner size for boost? I was wondering what intake runner size all of the FI guys are running? I have been looking at alot of peoples sigs and seeing that alot of guys are either running a 215 or a 225. Should or can you have a bigger runner on a stock cubed motor? I know usually that the bigger cubed guys run bigger runners but, since its FI can you have like a 235/245 runner on a stock cubed motor? Any advice would be a help considering im looking to buy some heads.
It depends on your plans for your car,more street or more race? You can get good results with big heads on small cube motors,but any thing you do like that,bigger heads or bigger cam will take away from your bottom end and torque.Obviously it will add power higher in the rpm range.Nearly all setups have to compromise somewhat if its a street car,less so if its a race car.The good thing about a turbo car is it makes so much power you can make up some what for lower torque at the bottom but you still move the power up the r.p.m. scale with bigger heads or cam especially with smaller cubes.Its all a balanceing act with your combo to try and get the end results you want.
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From: Norn Iron
You will find, that the larger heads, tend to be setup with large diam chambers, so they naturally suit larger bore motors, otherwise the chamber will overlap the bore a little.
So that is a factor when choosing, and is why sub225 is more common.
Plus anything bigger is generally considered more a race head...and tend to be more expensive.
You can make huge power on 215 and 225....so it isnt always essential to go bigger. Just choose the best flowing head for its size.
So that is a factor when choosing, and is why sub225 is more common.
Plus anything bigger is generally considered more a race head...and tend to be more expensive.
You can make huge power on 215 and 225....so it isnt always essential to go bigger. Just choose the best flowing head for its size.
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From: Norn Iron
More recently...Ive opted for 225cc Trickflows.....although Im only on 3.905 bores, so the 215cc would have suited better.
But I'll upgrade to either an LS2 or LSx block next year with a 4.0" bore.
But I'll upgrade to either an LS2 or LSx block next year with a 4.0" bore.
