max "potential" NA power.

[StormTrooper]

There is something about the immediate throttle response from na you can't get from FI.

Plus if your talking bolts ons itll be nearly as reliable as stock... Not so much with a turbo kit.

[humfrz]

Originally Posted by diss7

Perhaps I was a bit harsh earlier, sorry. We certainly want to seen as welcoming to new people. No hard feelings.

Too many people are jumping into FI because there are some easy options there, and that's cool. I was FI and have gone back to NA.

It's slowler on the street. But I enjoy it more at the track.

Well, I can identfy with that.

I can also identify with @archer in his quest to investigate the potential of the engine non-FI.

How can an old coot like me identify .. ??

Story time ....

Back in the day, mid 50s, among us "hot rodders", it was a common practice to slip a small block chevy V-8 (265 or 283 cu in) into the body of a 1940s car.

Of course, one could slap a couple of 4 bbl carbs on top or slip a "blower" between the carbs and the heads (making it totally undriveable on the street).

I decided to see how much I could get out of my old "stovebolt" 6. I started with a 216 cu in 6 and ask my uncle (who owned a machine shop) to bore it out to 235 cu in. I acquired a set of pistons and a head off of a wrecked GMC truck (bigger valves), from another uncles chevrolet dealership.

I had the head milled and put on a thinner head gasket. Also, I ported and polished the intakes and exhaust in the head.

Topped with 3 single barrel carbs and a homemade header, she was ready .....

After I slipped that puppy into my 1948 coupe; ..... I was ready to hunt for, and blow away, all domestic sixes and flathead V-8s on the street .....

Thanks for bearing with me ...... you too will get old...

humfrz

[Deep Six]

Originally Posted by diss7

Perhaps I was a bit harsh earlier, sorry. We certainly want to seen as welcoming to new people. No hard feelings.

Too many people are jumping into FI because there are some easy options there, and that's cool. I was FI and have gone back to NA.

It's slowler on the street. But I enjoy it more at the track.

Interesting that you went back to NA. I have planned all along to end up with forced induction for my car which is semi daily driven but will see track duty every couple of months. I bought the car used in May and did a track weekend right away to baseline the stock setup. My car is being modified in phases with the first phase focused on braking and handling. Track results were impressive but passing could be a challenge even though the car was much faster than the other as long as you had momentum. The latest phase was for cooling (Robispec) and power. The car made over 200whp with E85 which will be a track only fuel for me. I was astounded at the difference the additional power made, passing was a non issue and gear selection changed for certain turns.

I was certain that eventually the horsepower cravings would dictate a move to the next level but it may be a while since the car is very competitive and loads of fun in its current configuration.

[archer]

Originally Posted by diss7

Perhaps I was a bit harsh earlier, sorry. We certainly want to seen as welcoming to new people. No hard feelings.

Too many people are jumping into FI because there are some easy options there, and that's cool. I was FI and have gone back to NA.

It's slowler on the street. But I enjoy it more at the track.

all's cool.

[archer]

Originally Posted by InvalidJohnny5

I honestly don't think this engine was built to be an NA engine, it just reacts too well to any properly installed/tuned FI system. I mean it is a Subaru engine after all. How many fast 2.0 NA boxers do you see with high HP? Porsche have high NA hp due to their displacement and obvious price. It's a pipe dream to build an NA FA20 with 240rwhp on pump gas. FI systems can produce it easy on 91oct, you might as well have bought a Cayman at that point :p.

I dont know if this is true or not but i heard before that this car was actually developed to have a turbo originally but they dropped the turbo to keep the car more affordable. If this is true, then your spot on saying this engine wasn't built to be NA.

[Ice]

Originally Posted by archer

So iv been searching around online for quite a while before joining the forum and from what iv gather the peak HP for a NA is around the 200 mark with bolt on's and a tune. I have seen some place's where people have even directly said the peak power is 200 ish with bolt on's and a tune. But i'm curious, once we have more part's on the market such as camshaft's, piston's, rod's, valve's, valve spring's, lifter's, throttle body's and so on. what do you think this engine is capable of. I understand there's no way of knowing anything until the parts are actually here, just curious about idea's on max power once there's more then just bolt on part's.

Also, i understand that the stock throttle body and camshaft are great to begin with but somewhere down the road better one's will be out there.

I think the key question is under what parameters? Are we talking a dyno queen NA engien, track engine or your every day dd/street engine.

I personally have your typical shopping car econobox engine that will put out near 180whp on pump gas. With E85 it should hit around 200hp maybe. *shrug* The thing is to get to that point on a econobox engine that factory put out 140hp at the fly, the point is to get to this state sacrifices have had to be made. For instance it's not an engine that your mum could get in and drive or joe bloe without a little practice.

What sacrifices are people willing to make to, get lots of NA hp?

Originally Posted by Captain Snooze

Honda S2000 (1st gen) 119 hp/litre @ 8,300 rpm
Ferrari 458 Speciale 132 hp/litre @ 9000 rpm
Caparo T1 159.3 hp/litre @ 10,500 rpm
How much money do you want to spend?

Fair point.

Originally Posted by dabocx

Your going to have to wait for Cams , ITBs, and a stroker kit to see what this car can really do N/A. Very expensive

All depends on how the extra stroke is gained. IF they've shortened the rods (as I suspect they have) to make way for the increased stroke teh crank offers then what your effectively doing is hampering the possability of max peak horse power.

If they've decreased the compression height (distance between wrist pin and the top of the piston) by pushing the wrist pin higher on the piston then it could offset some of the loss that a highly strung NA build will have down low.

Originally Posted by moto-mike

Frankly I think past 200 on pump gas is definitely optimistic. We hit an honest 205 or so on E85 with Simmons' car last year (now Derek's) and I doubt you'll see too much higher. It is > 100hp/liter, to the wheels, which is damn impressive. While we could get more creative with some dyno work (such as arbitrary dynojet conversions on other dynos...) I think there's just a limit to what a 2.0l will do with stock compression--which is already a ludicrous (for an OEM) 12.5:1.

I doubt you'll see too much with cams; the stock setup is already pretty aggressive. If it weren't you wouldn't get the torque dip nor spin to nearly 8k without a massive tq drop. Thankfully the dual VVT keeps things at bay. I'd say no more than 10 hp from cams alone. Compression wise there isn't too much room if you plan on doing many miles.

ITBs sound nice, and make for great response. But the stock plenum ain't half bad for flow. Larger throttle body(ies) might make more HP but I've not seen anyone prove this just yet.

My gut tells me Subaru/Toyota are not making this one easy for the NA aftermarket. Though they certainly did for FI, given the punishment these motors are taking.

I disagree with this. People always assume that because the static compression is high that there isn't much left before the engine goes bang. The reality is that it's the final figure after cam bleed off, engine age etc that determine whether the static compression ratio works. (My engine for instance starts of with 12.4:1 static, its dynamic is about 10.3:1).

The stock setup is not agressive when you compare it with the cams utilised by some of the KA20 or B18 guys.

It's been a while since ive read into Throttle bodies so someone feel free to correct me, but by enlargening the Throttle body. You would be reducing the velocity of the air entering the manifold. This would affect your low end.

Originally Posted by troek

what witchcraft are those honda engines using?!? lol

Honda (cept there current stuff isnt awesome) with the exception of yamaha make some of the best heads available on the market IMO. They just have incredible flow and with utilising different cam profiles they are able to use heads that would otherwise not be acceptable for alot of there intended audience.

Originally Posted by InvalidJohnny5

I honestly don't think this engine was built to be an NA engine, it just reacts too well to any properly installed/tuned FI system. I mean it is a Subaru engine after all. How many fast 2.0 NA boxers do you see with high HP? Porsche have high NA hp due to their displacement and obvious price. It's a pipe dream to build an NA FA20 with 240rwhp on pump gas. FI systems can produce it easy on 91oct, you might as well have bought a Cayman at that point :p.

Any well made engine will react well to boost. That's the definition of a good engine

Originally Posted by Deep Six

Interesting that you went back to NA. I have planned all along to end up with forced induction for my car which is semi daily driven but will see track duty every couple of months. I bought the car used in May and did a track weekend right away to baseline the stock setup. My car is being modified in phases with the first phase focused on braking and handling. Track results were impressive but passing could be a challenge even though the car was much faster than the other as long as you had momentum. The latest phase was for cooling (Robispec) and power. The car made over 200whp with E85 which will be a track only fuel for me. I was astounded at the difference the additional power made, passing was a non issue and gear selection changed for certain turns.

I was certain that eventually the horsepower cravings would dictate a move to the next level but it may be a while since the car is very competitive and loads of fun in its current configuration.

Turbo isn't for everyone.

People tend to chase down turbo builds because it offers attractive gains for little money in comparison to NA.

The reality is that turbo and NA benefit difference driving styles, at least that's what I've found.

Anways. My 2 cents.

[350matt]

you make a valid point

there's a definite focus on this forum towards the peak number in FI and NA formats

and thats never the whole story, if you could put together a pack of parts that gives a solid mid-range gain of 15 bhp but only gained 10 bhp on peak or have one that gave 5 bhp mid range but 15 on peak which would you rather have?

believe me the 1st case would be the quicker car and more satisfying

[arghx7]

Originally Posted by InvalidJohnny5

I honestly don't think this engine was built to be an NA engine, it just reacts too well to any properly installed/tuned FI system.

Originally Posted by archer

I dont know if this is true or not but i heard before that this car was actually developed to have a turbo originally but they dropped the turbo to keep the car more affordable. If this is true, then your spot on saying this engine wasn't built to be NA.

It's a happy accident that the engine doesn't tend to blow up when you boost it. There was a significant safety margin in the stock components, and the ECU/control system is forgiving. The heads and cams certainly were not designed for boost.

[QUOTE=Ice;1406884]I disagree with this. People always assume that because the static compression is high that there isn't much left before the engine goes bang. The reality is that it's the final figure after cam bleed off, engine age etc that determine whether the static compression ratio works. (My engine for instance starts of with 12.4:1 static, its dynamic is about 10.3:1).[quote]

I've never seen specs on the stock intake intake cams. When do the intake valves close at full retarded cam phasing, at say 1mm lift?

There are two factors at work. One is based on simple geometry, and one is based on airflow. First is the effective volume at intake closing timing. Once you close past about 10-20 degrees after bottom dead center, your effective compression ratio decreases in the geometric sense. Your AVCS tuning changes your dynamic compression ratio in that way.

The other factor is filling efficiency. This is based on the closing timing, engine speed, and pressure drop across the intake valve. This exact relationship is unique to every engine, but basically at higher speeds you get better cylinder filling at later intake valve closing. This is due to the inertia of the air. Beyond that there is also dynamic effects of the intake manifold.

Don't forget too that there is compression ratio, and there is expansion ratio. The actual compression ratio is going to be determined by geometry and intake valve closing timing, and the expansion timing is determined by the exhaust valve opening timing. Retarded exhaust valve opening gives a greater expansion ratio and thermal efficiency, but it also requires more pumping work because of a weaker blowdown pulse.

Part of the reason why this geometric compression ratio debate isn't so important is because most of the builds we're talking about here are running E85 and thus knock resistance is not a big deal.

[86-tundra]

Originally Posted by arghx7

It's a happy accident that the engine doesn't tend to blow up when you boost it. There was a significant safety margin in the stock components, and the ECU/control system is forgiving. The heads and cams certainly were not designed for boost.

People really believe that they designed this car with a turbo and then ripped it off last second? did you guys even watch the videos? check my sig

[diss7]

Best and most true signature ever

[jamesm]

this particular engine was obviously not designed for boost. it has 12.5:1 compression.

however it's a subaru engine, and they don't make new ones very often. i'm sure it was well understood during development that in some applications this engine would be boosted. of course now this has happened. i'm sure they made changes to accomodate this. it probably no longer has 12.5:1 compression, for instance.

that doesn't mean the engine doesn't accomodate boost well in na form, though. it has dual vvt, direct injection, great modern combustion chamber design, and lots of other stuff that make it a great engine. i think it's awesome that people are driving around on 400whp boosted fa20's without issues, even if it's only for a while. people who want more will build their engines, but if you're going that far you're probably building an engine regardless of what you start with.

[Captain Snooze]

Originally Posted by trevorovert

did you guys even watch the videos? check my sig

My comments are not directed to anyone side of this discussion but those two video clips were released by the marketing department. They only show/say things that reinforce the image they are trying to sell. I don't think they offer much value for showing the whole design process.

[Ice]

Originally Posted by arghx7

I've never seen specs on the stock intake intake cams. When do the intake valves close at full retarded cam phasing, at say 1mm lift?

There are two factors at work. One is based on simple geometry, and one is based on airflow. First is the effective volume at intake closing timing. Once you close past about 10-20 degrees after bottom dead center, your effective compression ratio decreases in the geometric sense. Your AVCS tuning changes your dynamic compression ratio in that way.

The other factor is filling efficiency. This is based on the closing timing, engine speed, and pressure drop across the intake valve. This exact relationship is unique to every engine, but basically at higher speeds you get better cylinder filling at later intake valve closing. This is due to the inertia of the air. Beyond that there is also dynamic effects of the intake manifold.

Don't forget too that there is compression ratio, and there is expansion ratio. The actual compression ratio is going to be determined by geometry and intake valve closing timing, and the expansion timing is determined by the exhaust valve opening timing. Retarded exhaust valve opening gives a greater expansion ratio and thermal efficiency, but it also requires more pumping work because of a weaker blowdown pulse.

Part of the reason why this geometric compression ratio debate isn't so important is because most of the builds we're talking about here are running E85 and thus knock resistance is not a big deal.

I havnt seen any official looking paper with the specs but remember reading somewhere that they were 255 degrees, no idea what they were measured at.

However this doesn't unrealistic either.

Be nice to see a cam with more duration and lift. How far can AVCS move the cams? Just wondering what sort of overlap numbers are possible stock.

Iam aware of the factors you mentioned was just trying to not make it too technical. Wasnt sure how technical peeps get

[s0sl0w]

Originally Posted by diss7

Wants max NA hp, but is butt hurt at the cost of replacement throttle body?

Any one uber serious about crazy NA setup, I'll slip you some info. You know those v8s they made out of two hayabusa engines, well there's a version in New Zealand called the synergy V8. It's a custom block with Kawasaki heads I believe.

They've had a wrecked 86 for 12 months now. They've also partnered up with the electronic guys who did all the work on the TR86s for Toyota racing.

Their plan is to offer it as a turn key street package. I know a lot of details about it as getting one is still what's hanging me up on doing a custom turbo setup.
Here's some details.
Motor is 2400cc, but can be 3000cc
Runs on pump gas, but can run on race gas
2400cc on pump makes 350hp @10,500 rpm . The 3000cc on race gas was closer to 500. (off the top of my head, I have the dynos at work)
It's dry sump
It has ITBs
It will work seemlessly with all the stock electronics
It is lighter than the fa20
It has been mounted 86mm (lol) further back than stock, but I believe a custom DS is a part of the package
It has a CRAZY light flywheel/clutch. (They should us weight : pictures in the NZ owners club on fb) I could find that pic next time I'm on my PC, don't mind sharing that one as they've already shared it.

Um, thats probably all I can say. I've seen pictures of it in the bay, now other details about inclusions, price etc. Let's just say the motor on its own is $40kNZD.

Reason I like it, it's an extremely understated supercars. If I buy a porsche / Ferrari, next thing my staff/customers/family think I'm making too much money. Have something like this, it's easier to get away with.

Go google synergy v8 and watch the YouTube videos. Get some tissues ready, either for tears or for baby batter.

I want to know more about the progress they're making on the 86