Phase 2: Looking for 380 N/A whp.
 

Maybe I've bitten off more than I can chew, but I'm somewhat confident that there's a lot more untapped N/A power left in the EG33, after hitting 221 AWD whp with the following:

'Bolt-ons'

*Used, stock longblock (block, heads, cams)
*Standalone Autronic ECU
* 1.75" custom headers/32" long primaries into 2.5" secondaries and merging into 3" main exhaust system with a single muffler
*Custom cold air box fed via WRX hood scoop
*MSD individual coils (6)
*STI injectors

I consider this to be basically a stock engine with bolt-ons, and a decent amount of tuning time invested.

'Phase 1' as I call it, was the increase in power to 292 AWD whp (about 375-380 crank hp w/ 24% driveline loss), with the addition of the following items to the previous combination:

*Cams send to Web Cams, welded and reground. Intake lift .444" (11.27 mm), exhaust lift .460" (11.68 mm). Duration @ .050" is 244° (IIRC stock is 198° for comparison). These are solid profiles, not hydraulic BTW.
*Stock heads were flow tested, results here.
*Heads were then ported mildly on the intake side. The straight exhaust ports were ported a bit more aggressively to try to balance the intake-to-exhaust proportion. The 'dogleg' ports were ported even more aggressively as they flowed worse than the straight ports. Again, this was in the quest for balance, rather than outright power.
*Heads were milled .040" (1mm) in an effort to increase compression.
*Supertech WRX valves, springs, and retainers were fitted, with the valves being .5 mm (.020") oversize in head diameter. The stock hydraulic buckets were gutted, and shims used under the buckets to establish valve clearance.
Valve clearance with the pistons with this engine is still .150"+.
Valve clearance at overlap/crossover (both intake and exhaust valves open the same amount) is getting tight though.



So now I am thinking about 'Phase 2'. This will be another engine for another car, not related to the Phase 1 engine at all. So it's a fresh sheet buildup, and the budget is appreciably larger. I like to think outside the box, but I have to deal with the contraints of an engine's original design restrictions.

For example, I have heard that the standard iron bore liners are not to be bored more than .5 mm oversized. Has anyone done otherwise and had their engine live? I'm thinking of enlarging the bore appreciably, as well as the stroke. It seems that anything from 3.4 litres to 3.6 litres is possible with minimal investment other than machine work and careful selection of parts, at least at first glance.

We've already surpassed the factory allowances for head milling, but I suspect that it primarily a cam phasing/emissions requirement more than anything else. Most OEM's request a limited amount of milling on their heads, but for the most part my experience is this can be largely ignored for racing purposes.

Anyway, a brief rundown on Phase 2 considerations includes the following:

*Standalone ECU of course, brand to be determined.
*Possibly larger displacement via overbore and offset-grinding the crankshaft
*Billet rods
*Forged pistons, at least 12:1 compression
*Extensively ported heads with an emphasis on improving exhaust flow further. I tentatively am considering +1 mm intake valves, and +2 mm exhaust valves. This depends on the engine's bore diameter (flow shrouding), as well as the overlap issues mentioned previously.
*Individual throttle bodies, so far Extrudabody is looking like my #1 choice. I've been in contact with them and they are willing to help develop whatever is needed to fit them. Their Porsche 911 kit will need minimal modifications to be adapted to an EG33. 45 mm TB's will meet our airflow requirements with ease.
*Custom equal length headers again, this time with more definitive merge collectors fabricated. I found off-the-shelf header flanges from Small Car Performance for far cheaper than I can hand make them. Probably thin-wall 316 stainless tubing to save some weight.
*Cams. Tough call here. I have no choice but to begin reducing the base circle diameter. In Phase 1, the lobes were welded up, and the stock base circle retained. The lobes were so tall they required that the areas to either side of the cam buckets be ground away for clearance, as well as the underside of the valve covers! So Phase 2 will mean the base circle needs to shrink to avoid further contact issues, or worse...the lobes digging into the edges of the buckets themselves. I'm thinking lift on the order of .480"-.500", and duration in the 250-252° @ .050" range. I don't think I can go much further on the duration/overlap without the valves striking each other.
*A serious diet. Any brackets that are iron will be made from scratch in aluminum. The heavy cast water crossover will be made from alloy tubing as well. If I can get the engine assembly to weigh the same as a turbo EJ25, I'll be very happy. Clutch will likely be a multiple plate 7.25" racing unit, which will again save weight.
*Oiling system upgrades. I have not ruled out a dry sump yet. Subarus have issues with crankcase pressures when they are pushed hard. Evacuating the crankcase is bound to free up some power. At the very least a custom oil pan with baffles will be fitted, and an Accusump added.

Target numbers are 380 whp, or about 500 hp at the crank. More would be better of course, but I have it under good authority that the first 350-375 crank hp is easy, the last 100 hp is a b***h!

As the project progresses I'll post updates here in this thread. Eventually I'll be able to post pics as well. I welcome any comments (good or bad) on this project as well, as long as they are constructive in nature.

:eek::eek:You sir, are my hero.

I wish you the best of luck, because those mods will hopefully be able to trickle down to us once perfected :)

admirable goal :D

That's my intent for posting it here to be honest. Not everyone wants, needs, or can afford to build for this kind of hp. But I figure parts of it can be detuned a bit and used on the street 'in moderation'. I really just love the way the engine sounds, that's my excuse for trying to get more hp!

I find your approach logical, devoid of confusion, and unfortunately, unique.;)

Good luck Bob, this does indeed sound incredible. Please keep us posted on what you have going as it interests us greatly. Also, if you need parts, engines, etc... give me a ring.

Tom

Thanks Tom. I will probably end up getting two core engines to speed development, so I will be contacting you. And whatever knowledge I glean from this project I'm more than willing to pass along.

Just like NASIOC, right?:rolleyes:

Bob,
Did you put the "worked over" heads on a SuperFlow? It would be nice to get a comparison with the flow numbers you got with the stock heads:cool:
-Bill

I did not. I wanted to, but by the time the car owner got the heads back from the machine shop and told me about it, they were literally already on the engine. As well, my flow bench, scales and other tools had already been moved out from XX Tuning's shop and into my new workshop I'm renting.

I did do some testing on the ported exhaust ports (w/o the oversized valves installed) while trying to balance the exhaust flow, but only jotted them on a scrap of paper. I never made a true 'flow chart' for my records, since we were pressed for time, and I wasn't trying for max flow, just balance between cylinders.

I will document every step of this new buildup with flow testing and photos. I find it's easier to forward such info to interested parties rather than have to write an essay every time I get asked 'how'd you do it?'.;)

Bob,
Understood. I've got a set of heads I've "worked over", but I haven't had the time to but them on my machinist's SuperFlow. I'm hoping to find a couple of days within the next 30 that I can play hookey from work and play in the shop:cool: Do you remember roughly what the flow rates you got on the exhaust ports?
Thanks.
-Bill

What He said!:D:cool:

I agree and am excited to see this progress.

This is quite possibly the most amazing thing I've ever heard. And it's just all the more believable since you've proven as fact that your engines did in fact put out about 275 and 375 bhp, respectively. I can't wait to hear about progress on this 500 bhp monster...

Are you planning on renaming it an EG36? :D