96ekdowork

hey guys looking to turbo my stock F20B this winter... i have been collecting parts for a little while now and i was just wondering, what would be the limit for the stock bottom end... i see the b18's make anwhere from 300-350-400+ on the stock bottom end.

now i know that 400+ wont last as long on a bone stock bottom end as 300 would, but just looking for some good information on what this F20B motor is good for, shoot me down if you must but im looking for about 350 to the wheels, on stock 11.1 compression!

96ekdowork

i recently just picked up a brand new custom made turbo manifold by John Pham, and a brand new turbosmart ultra gate 38mm wastegate... im not cheaping out on anything with this build so as long as it takes me to get quality parts thats when i will begin putting parts on the car

bigsnorlax

If you've got the money, why not sleeve it and go with forged internals? Any reason why you want to keep it stock? Set a record etc? If you wanna buy top of the line parts, you might as well beef up the lower end.

96ekdowork

well i am in the process of talking to eagle to see if i can send them a spare set of f20b rods i have here and have them duplicate them into an H beam, other than that, bore it over 1mm and run the k20a3 piston on it and give me right around 9.0 c/r and the iron sleeves would be great for boost...

but this will all be on the spare block i have, right now just looking to have a little fun with the 11.1

i know i can use b16 rod bearings and f23 mains, so if eagle can put together a rod for me then i think we might have something to work with for some more power.

96ekdowork

thats a no go on eagle rods.... not sure why??? they can duplicate h22 rods, and b18 rods, but they said they dont do custom rods lol, i asked them to make me a stronger factory rod lol

bigsnorlax

Why not just run an H22 rod? Its about ~2mm shorter than the F20B, which makes it longer than the H23's/F rods so its your next best bet.

My "intarweb," calculator looks like it should put you around 9:1 static compression ratio with the H22 rods which is perfect IMO for a street car w/ pump gas. Your already "ideal," R/S ratio for that F20B also looks like it wont be affected much by running H22 rods.

Im no expert but that seems like the easiest/best plan B move instead of getting custom rods.

96ekdowork

only problem with that is the f20b crank uses different size rod journals. probably going to bore it out and run k20a3 pistons. that would also put me around 9:1 c/r

hoon22

Not in fact challenging your statement above, I would want to learn it for my understanding. F20B is 85x87 and 11:1 CR whereas K20A3 is 86x86 and 9.8:1 CR. So, boring the F20B's sleeves by 1mm to put K20A3's 9.8:1 pistons would also take these pistons to stroke 1mm higher. In this case, on what calculations would you assume this combo's CR putting you around 9 to 1?

Well, if so, I'd love to do so on my F20B, too! Just intend to be sure of it...