Performance Rebuild for Turbo Car // Track & Street Use
 

I'm in the midst of a resurrecting my turbo setup to utilize new EFR glory. Long term, I plan to convert to an exocet for mostly AutoX and Track fun while occasionally driving to car meets and work. I will be getting any and all bugs worked out while the car is still a Miata, and then swapping to the EXxo. It sounds like the current weak link will be the trans/diff somewhere north of 300whp. I will be putting in a 6spd/3.9 and would love 350-400whp on e85, but don't want to replace the trans and diff regularly. Maybe the reduced weight of the Exo will counteract this to some degree.

Some help from those who have had more experience with the rebuild side would be largely appreciated.

Plans:
* Keep the '95 Block
* ST Forged Pistons
* Manley Forged Rods
* Stock Crank
* ARP Fasteners
* ACL Bearings
* '99 or VVT head
* Custom Turbo Mani, DP and IC Routing
* e85 Compatible Fuel System (DW300 and 1000cc ID's)
* BE Oil Pump and Gears
* ACT HD PP and 6-Puck Clutch
* MS ECU
* Fancy Crank Damper

Questions:
* What Size and CR Pistons?
* I'm gathering VVT > '99 > everything else. If its worth going to the VVT head over the '99, what would be advisable to upgrade in the head?
* Custom Intake Mani or just get a '99? Larger TB?
* Is the ATI Damper worth the extra chedda over the SuperMiata?
* Do I need to worry about the fuel filter or fuel lines running e85?

8.6:1 supertechs, I think they only come in one size
VVT head is probably going to be cheaper and easier to get than a 99 head
99 or flat top mani, get the skunk 2 if you plan on reving higher than stock
the supermiata damper is better than the ati one
should be fine, might need to replace the filter after the tank of e85

Thanks Leafy. I'm still in process of sourcing the head and intake, but I'll keep your thoughts in mind.

The 8.6 pistons show to be available in 83.5 and 84mm. But moving up to the 9.0 pistons gives the additional 85 and 85.5mm sizes available. I'm not sure if the additional displacement is worth the extra trouble or not.

Why is the super miata better then ATI damper??

The BHJ designed 949 damper is a rubber spring mass damper designed for the frequencies actually measured on the BP engine. The ATI damper is a viscoelastic (read silicone fluid) damper which is designed to damp most frequencies. Think of it like putting a custo tuned length header on the engine that was tuned on a dyno to make optimal power vs just putting on a racing beat.

Thanks leafy.

Good analogy. FWIW, the RB was systematically designed an optimized on a dyno. Folks assume they are not optimized because they are inexpensive. We have tested many headers here and I have yet to see anything outperform an RB. This on 135whp stock N/A all the way to 350whp S/C builds.

Standing offer for any custom header. Ship it here and I'll A/B/A it with an RB for free.

/drift

Stick with 84mm pistons. Clearances between cylinders becomes a problem when going bigger then that.

I would go 83.5mm unless you need to bigger. That way you get another rebuild out of the block.

All I really want to see now is an RB with the collector cutoff and replaced with a burns collector and converging diverging megaphone.

I share that suspicion. The RB is right, but with an inexpensive straight collector. We have a new Maruha VP in the shop to A/B with. It won't get tested until mid September though. At some point, I might have my exhaust fab guy (Hytech) add a venturi to an RB to test.

So from the culmination of knowledge thus far from this thread and the other current E85 thread:
91 and E85 - 83.5 or 84mm 8.6:1
E85 Only - 83.5 or 84mm 11:1

So if I chose to keep the option of running pump gas, I'm going to be significantly belittling some of the advantages that E85 provides. Am I interpreting correctly?

Thanks again for the ATI vs 949 damper explanation. I'm sure Emilio will be getting a fair amount of my monies soon.

Is my above interpretation correct? I know that the high boost/lower comp vs low boost/high comp is commonly debated. I just want to build this once and do it right.

My only hesitation for designing for strictly e85 is that it is still a relatively new product. If they choose to shut off the supply at some point in the future, I don't want to be stuck with running race gas only.

Its not like you cant brew your own E100 if they ever shut down production. It doesnt sound particularly difficult.

Interesting thread, I am also making a shopping list of parts to rebuild my engine for my sprint/track Familia gtx.
I am going for cp pistons 9-1 (reccomended by my tuner) decent rods,acl bearings,arp bolts for the block.
I've managed to get hold of a bp4w head but I'm not sure what cams to run?
I'm not after pub talk massive bhp just want early good boost up to the redline,the holy grail I guess
I already use aem ems 4 engine management.
I suppose I should start a thread of my own though!.