I figured I'd start a thread on my upcoming engine build and standalone tuning. I REALLY appreciate any input along the way. Hoping to also hear from those who have boosted their 3.2.
First,
HERE's the car, and
HERE is the rust work that I need to finish before I do the fun stuff (engine build).
Build goals:
- Modest power goals (320hp crank)
- Highly responsive, boost should come on at ~3,250rpm...hopefully
- Reliable and drivable. Not trying to smoke everyone on the road. I just want my version of a 930.
Engine rebuild plan:
- Rebuild the 3.2 and (hopefully) keep the existing pistons and cylinders
- Shave off a small amount of the piston dome to get down to 9:1 compression (need to remove 3.5cc fo aluminum)
- ARP connecting rod bolts and head studs (bought already)
- Rebuild cylinder heads, twin spark
- Grind cams to 964 spec? Worth it?
- Thought about building the heads to redline at 7k rpm but it just doesn't seem needed.
Boost:
- Retain factory headers and heat
- Turbo: Garrett G30-660. Any ideas on turbine AR? 0.62?
- 46mm Precision wastegate
- Side mount turbo on drivers side. I just seems like this is a better spot for the turbo, but I need to CAD it all up and make sure I'm right.
- Turbo oil drain into lower cam cover. Hopefully I can get the turbo high enough for this to work. Not water cooling the turbo.
- Water to air intercooler. Intercooler from a BMW M3. It's compact and it's performance is known. Pretty good little unit.
- Various 3D printed parts to make it as factory looking as possible.
Management/Fuel:
- ECUMaster EMU Black (I used this this in a fully built Audi URS6. Great ECU.)
- DBW throttle body
- 60-2 crank sensor (Either on a new flywheel or a pulley mounted wheel. Not sure yet.)
- Clewett cam sensor
- Injectors? I've used ID1000's before. They are great but very expensive and overkill for this build. Will run a Walbro 255 external fuel pump.
- Flex fuel sensor and all fuel lines to support E85. I'll mostly run pump gas but it's nice to tune on E85 before going to gas.
- Coil on plug ignition
Trans:
- Rebuild 915 with factory LSD. I'll tune the boost curve to keep torque under 300ftlb through the rev range. That means something like 6 psi max at 4000 rpm. Do the billet diff covers actually help?
- Clutch? Sachs Power Clutch? How much torque can these handle. I'm not launching this car so I don't need anything crazy.
There's a few reasons for the water to air intercooler. I'm not running a whale tail and I don't really like the look of the intercooler covering the engine. I can remove the end tanks on this intercooler and and build custom 3D printed end tanks to integrate it into the overall setup. I should fit mostly out of sight in the engine bay.
What am I missing? Open to any input and criticism too!
