Ok folks, smoked my stock F20C. Getting all my ducks in a row for a full build. My goals are 500-550 RWHP. I have the turbo/fuel mods to support it. Here is my parts list so far
Sleeved block: Darton dry sleeves OR Benson sleeves
CP Pistons: 8.5:1, 9:1, 10:1.....NOT SURE!!!
Skunk2 or BC rods: think they're both identical actually
ACL race OR King Performance bearings
ARP head studs
Micro polished crank, decked head and block,
OEM: Oil pump, water pump, head gasket kit, oil pump chain, timing chain, lower gasket kit, thermostat, AP2 valve spring retainers and keepers, and valve stem seals.

Seeking advice on the following:
-what ratio Pistons are best for boost? I'm running a BW S366 with twin scroll log manifold.
-should I use stock piston gaps
-should I use stock piston ring gaps?
-anyone used king bearings yet?
-anything else anyone thinks I'm missing or advice is very welcome!!!

 

IP is building my engine similar to what Carey Bales uses although I'm going with 11:1 CR and will be on C85 or E85. I'm going with 11:1 for off boost driveability and response and to help spool the turbo a bit quicker hopefully. If you go with IP, they take all the guess work out of what all you'll need. Unless you are planning on doing the build yourself, most shops like IP do this.

 

I'm taking a guess your going to build it yourself? You are on the right path. As far as compression pistons, stick with 10:1 and Skunk rods. Spend a few bucks more and go with ACL bearings too. We use Inlinepro for all our machine work and block sleeving. If you need a quote message us as were direct vendors for ILP. Also, I would use the Supertecth steel retainers.

 

Thanks for the advise guys. Does anyone have an opinion on ring gaps. Should I use stock gaps or something a little slacker. Also can anyone chime in on the advantages and disadvantages of higher CR on boosted engines. If seen reputable builders use 9.0:1, 10.0:1 and 11.0:1.

 

I can tell you about higher CR but not sure on the ring gaps. The higher CR will have better off boost drive-ability much like stock and should create a faster spool up on the turbo, probably something like 500 rpm quicker between 9:1 and 11:1. This should also create a bit more low end torque.

 

Thanks....so what's the downfall? Seems all positive. Less boost? Less power?

 

You can run a bit less boost and get the same output as running a bit higher boost with lower CR. I'm a big fan of running the highest and safest static CR you can since it's just a better well rounded car to drive. The only downfall would be the tighter tuning window with higher static CR but if your tuner is good and knows his shit, you'll be fine. I ran my stock engine at the stock 11:1 CR and made around 800 whp on e85 with no issues at all. That's why I decided to keep it at that CR with the build I'm doing with IP and going for 1000+ whp.

 

^^^^^ great answer. Just ensure you have a good set of headstuds too. Get them before there backordered again.

 

Hurry up and finish your build i want to see this thing already geez lol

 

This spring it will be out and about. Ill get a thread up soon on this build since its been a while from the last build.