ok so at the shootout what seems like ages ago Phil mentioned a completely wild alternative to a turbo swap... something dealing with 14:1 compression ratio and a turbo block
(I also remember people telling me not to listen to Phil when he starts talking about 14:1 compression ratios)
recently I got thinking, a very dangerous thing
If I could get a turbo block cheap and custom pistons from crawford (read higher compression) could I just put my NA heads and ECU on it and have a higher output N/A motor?
If it's a horrible idea blame Phil, it's his fault for creating such ideas.
I figure it's a little more involved in some ways than a turbo swap but it could also yield a different product. I don't think the idea has been discussed, or well maybe that's because it isn't really feasible.
A set of custom pistons and custom forged rods should do the trick. And of course, some ARP headstuds, to keep it all one peice.
You'll have to pull the heads anyway, so you could always port it out and get it to flow well, work the valve train, and you might be able to squeeze 8000 RPM's out of it.
The trick with high compression is detonation. I doubt the stock ECU could run at 14:1 without teetering on the brink of detonating 93 octane. You'd need some kind of management.
14:1 is pretty serious compression, but it'd be a hell of a build, and you could probably squeeze around 200 to 250 bhp out of a perfect setup. Unique, but not ideal for high HP.
I believe, however, that my original advice was 14:1 and quad throttles...
It's one throttle body per cyl. It's for throttle response. 14:1 is crazy high on pump gas. I doubt that forged internals and a turbo block are necessary, but i don't really know. MM would. Definately would want uprated valve springs, some porting and polishing, cams, and i would really want a more precise engine management, ie one that can take advantage of a wideband o2 sensor. Keep in mind that a civic or whatever idles just fine, whereas a non-ej257 subaru will kinda rattle and be pokey in low rpms.
I think if i wanted an engine like that, i'd bump up the cr to about 9-9.5:1, do some head work, and run low boost turbo.
[url=http://www.thawa.net/gallery/albums/album108/DSCF0330.jpg]90 legacy of awesomeness[/url]
so 14:1 pistons, engine manag... wait can I bypass the ignition except when cold i.e glowplugs?
oh man too many possibilities
so basically buy a built block with pistons from crawford, ship em my heads and let them go to town on them, get motec or some engine management, plug it all together, convert to catholicism and say many hail marys, turn key ???? profit?
You could try pseudodiesel. Put constant-duty glow plugs in where the spark plugs normally go. Then send the TPS signal to the ECU in place of the MAF signal.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
Vikash, what if I cannibalize some VW TDi ECU....
or not... diesels make torque at low rpms and generally don't run up to 6500 rpm so I think the engine would probably pull one of those oil commericials and jump out of my car if I were running at high RPMs
I wasn't really serious... pseudodiesel probably wouldn't be worth it anyway. But to continue the hypothetical discussion -- the reason diesel engines don't spin fast is primarily that they're made of heavier stuff that can't safely spin fast. So if you used 14:1 gasoline pistons it would probably be okay.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
A good diesel build would be very expensive and complicated (I'm talking direct injection and such). I don't think you could run 14:1 on pump gas. I'd go 11:1 and add some cams and head work.
Steve
Midnight in a Perfect World on Amazon or order anywhere. The first book in a quartet chronicling the rise of a man from angry criminal to philanthropist. Midnight... is a distopic noirish novel featuring 'Duchess', a modified 1990 Subaru Legacy wagon.
The reason most diesel engines don't rev high is because of the weight of the internals THAT CAN WITHSTAND THE ABUSE.
I don't see a 14:1 diesel running well (N/A)
I don't see why you think you need a turbo block, N/A blocks are much cheaper to replace when you blow the whole thing up.
I would spend the money on the heads for a N/A build. Bump up the compression but not to 14:1, get real. Might as well start with a 2.5 as well, better heads more cc's to work with...
I will also add my crazy idea to the mix. How much NOS could you run in a turbo engine with no boost??? I bet a lot
Since the turbo and na have the same conrods, and the conrods handle considerably more torque in some turbo motors, why are they a concern? Is n/a harder on rods per hp? That doesn't really make sense.
Same goes for the block. The n/a block should be just fine for 220 hp, and you'd be lucky to squeeze any more out of it. (sure, it wouldn't last forever, but you wouldnt expect a homebuilt high hp n/a engine to anyway)
[url=http://www.thawa.net/gallery/albums/album108/DSCF0330.jpg]90 legacy of awesomeness[/url]
"Conrod crunching" was an expression, often used to describe high stress situations. A Supra running 2bar making 1300whp, is conrod crunching boost. Me, running 16psi, is conrod crunching boost. Exceeding stock expectations of components would constitute, to me, a high stress situation. Sorry for using terminology that you aren't aware of.
I was also unaware that the durability of components was ALL subject to who did the work. If it's done right, does it really matter if it was done by a professional, or at home? As for the block, stiffer, beefier, and stronger is better when asking a lot from it. An N/A block wouldn't last forever, as you said, but a Turbo block would Surely be more capable of handling nearly 100hp over stock, wouldn't you agree?
I don't get it Scott, do you have some kind of problem with me? If so, I'd appreciate it if you would inform me of it, and get over it instead of trying to pick apart, and analyize every post I make, searching for a flaw to focus on and attack.
I was wondering about the differences in the stock to turbo rods. While I don't plan on doing any major drag runs since the clutch cant take it, I am planning on getting 200 whp or more out of my NA block. But.... can the rods handle it? We shall see. Just send your contributions to me!
Reddevil, Awaiting new heart, will it ever happen?
1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
1992 Touring wagon, should I keep it?
Neither Matt, nor myself, neither of the Jasons, or DZX, or any other of us well modded Turbo guys have had our rods snap that I know of, so I think they would probably be OK for the 200whp you plan on acheiving.
I won't be trusting the stock rods or stock pistons when I step it up though, that's for sure.
Once you start running a 14:1 CR it will be imperative for you to run race gas. I don't know of anyone that has that kinda compression and is on pump gas.
Secondly, to build a normally aspirated beast you'll need either:
1. displacement - that's not happening on a subaru
2. rpms
Does anyone know of any aftermarket cams that are efficient at higher rpms? Not sure about the R/S ratio on these engines. What's the bore and stroke for the EJ22t? For some reason, I don't think the EJ engine would be good for anything over 7500rpm... reliably anyway.
AWD... the bain of existence what talking about a car that in the end probably wouldn't have enough torque to move out of it's way in the low-mid range. You could do fwd, but then why are you working with a Subaru????
I totally disagree about the rpm capability. The crank is forged, has large mains and rod bearing surfaces, good journal overlap, is very short, and extremely stiffly suppoprted. The rods are also forged so the only thing I'd worry about bottom end wise would be the pistons' weight. This application would require custom pistons anyway. The block on the N/A may flex at these rpms, though. There are plenty of 2.0 WRX engines doing 8k from the factory. True they are smaller displacement, but I'll stand by 8500-9k rpm on the bottom end. The real concern, to me, would be getting air in and building the valve train to support those rpms. He could also go rwd, your valid point about it being a Subaru not withstanding.
Steve
Midnight in a Perfect World on Amazon or order anywhere. The first book in a quartet chronicling the rise of a man from angry criminal to philanthropist. Midnight... is a distopic noirish novel featuring 'Duchess', a modified 1990 Subaru Legacy wagon.
14:1 is about the highest you'll ever be able to run on unleaded fuel (100 octane). And even then your going to be on the KNIFE EDGE of detonation, a fly farts and you'll pull timing.
In all honesty, I was joking with that original recomendation, but I do think a super high compression, high revving car would be fun. I don't know if I'd do it in a Subaru, but I think it would be fun. I'd rather build the internals, run 9:1 and a few pounds of boost.
