Thread: Using highport valve train for a lowport RR 01 SE

Like Vadim said, probably not worth the time effort and money to start swapping out too many things. If you are just going for a modest turbo setup, the stock RR low-port head with upgraded springs and retainers should be fine. Just keep in mind though that you will have to change the ECU anyway to compensate for the higher redline of the S3R cams. If you went with say a P10/P11 G20 ECU which redlines at 7500(depending on year), if i remember right, you could then tune your fuel maps with an SAFC or something better?? Unfortunately for the ECU change you either need to make a B15-->B14 step-down harness or change to a B14/P10/P11 engine harness. Us B15/P11 guys are a step behind the B13/14 guys. Too bad nobody cracked the B15 ECU for us.

Vadim knows a lot about this type of swapping and a ton about turbo so he could probably better direct you turbo-wise and as far as ECU and tuning options for turbo. I am a turbo virgin!

Oh your going turbo? (I honestly didn't read the first post just looked the recent posts about RR vs highport).

A turbo RR would be fun, you will definitely want to use a 16bit ECU, OBD1 if you can, but OBD2 would do. It would need to be a chipped ECU, Calum, Nistune, JWT, etc.

When you go to the old ECU, you can't use your B15 IACV valve, so you would need to convert to the old IACV, which would require the whole low port intake manifold.

Only real problem with the Roller Rocker motor is the weaker pistons. Other problems are not as big, ultra low oil pressure, 4cw crank, piston rods. You would need to get your tune spot on and fight back knock. Because those pistons will not tolerate any detonation.

You said your motor is on the stand, so I'm assuming your doing some level of rebuilding?

ive already built it about two years ago with cp 8:5:1 forged pistons and eagle rods but ive now just had the chance to get started on this thing.

I could do that but that seems just like a big PITA but idk. i really would just like to keep everything alone and do some type of piggyback but i know im not rly gonna get a getter gain without going to the b14 stepdown.

All you need to know if you are planning on keeping your current wiring harness: http://www.sr20-forum.com/howtos/47198-how-modify-00-p11-b15s-work-older-ecus.html

All you need to know if you get a 99 P11 harness: http://www.sr20-forum.com/ve/47166-howto-99-p11-engine-harness-into-00-p11-sr20ve.html

Thanks for all the detailed info..so whats the advantages? Higher redline and ecu upgrades?

A decently running car to a very crapily running car.

Piggy backs essentially lie to the ECU, ECU compensates, piggy back has to lie more. It's a never ending battle. You need to have your car running in peace and harmony. Do it right or not go turbo at all, otherwise you might be picking up pieces of your melted pistons from the oil pan.

Well i guess i dont want that to happen lol

Don't get me wrong, plenty of people run it with a piggy back, but I feel like it's a half-assed way to go.

non rr valves are longer than RR's.