Resources for NA high performance engine builds?

[Tor]

Thanks for all the replies. Ok, I found the thread from Celek. 2.3 liter is more like it. As far as I can tell he is not done with it yet?

I suppose a build like that is more like 10k+$ and an endless amount of time investment. Will be very curious to see what kind of power that can make.

Would a less extreme version be doable for normal human beings and on a more limited budget? Like sleeves to increase the volume but on stock crank and some head work to increase the rpm?

[wparsons]

Originally Posted by Tokay444

I'm holding out for 4Piston.com to start building long blocks for us. Or at the very least develop a killer head program. I can build my own short block.

I think heads/cams/intake manifold that make power north of 8000rpm (and rockers that don't blow apart) are the key to making big gains NA. The manifold gets interesting with runner lengths and the distance between heads.

[Kodename47]

Originally Posted by wparsons

The manifold gets interesting with runner lengths and the distance between heads.

....and bonnet clearance. @Tor the 250hp (crank) is more easily achievable without opening the engine, definitely if you have access to E85. These guys going for the mega builds are looking at attempting 250whp, near 300hp in our terms.

[Spartarus]

Intake runners are your obstacle for revs.

The head needs no work for a budget NA build.

The stock valvetrain will hold up reliably to right around 8k as long as it's not a '13 motor... Oh, and around 8,400 the oil pump gives up anyway.

Even with sleeves you're only getting .1 liters out of overboring. Not worth it without increasing the stroke.

JUN proved that simply shortening the runners at stock diameter carries the torque curve up by several hundred RPM, which reflects as a proportional increase in power. Something I have said for years.

If I was doing a budget NA build on an FA20, it would be ACE header, tuning & flexfuel, stock unopened motor, make (or have made) a custom aluminum intake manifold with shorter runners... Think 15mm shorter. A simple one with tubular runners, hand milled flanges, and a sheetmetal plenum.

Tuning on ECUTEK with a rev limit of 8000.

Throwing blind darts, I'd bet very safe money on 210 peak WHP on pump gas. 200 if you didn't touch the intake manifold... (But then you wouldn't raise the rev limit because there's no point doing that NA until the intake manifold is addressed. Moving an identical torque curve to the right is what makes the extra peak power.)

Oh, and it's worth mentioning I'm speaking in terms of repeatable, uncorrected dyno numbers on an accurate machine. E85 is getting into guesswork territory but I figure another 5-8%

...Any reasonable amount of extra money would buy you only disappointment.

Beyond that, the classic Subaru exhaust ports are going to be the choke point that becomes a hard limit.

Now here's the caveat. Find someone similarly knowledgeable who disagrees with me... And isn't trying to sell you a product.

[Icecreamtruk]

Originally Posted by Spartarus

Intake runners are your obstacle for revs.

The head needs no work for a budget NA build.

The stock valvetrain will hold up reliably to right around 8k as long as it's not a '13 motor... Oh, and around 8,400 the oil pump gives up anyway.

Even with sleeves you're only getting .1 liters out of overboring. Not worth it without increasing the stroke.

JUN proved that simply shortening the runners at stock diameter carries the powerband up by several hundred RPM. Something I have said for years.

If I was doing a budget NA build on an FA20, it would be ACE header, tuning & flexfuel, stock unopened motor, make (or have made) a custom aluminum intake manifold with shorter runners... Think 15mm shorter. A simple one with tubular runners, hand milled flanges, and a sheetmetal plenum.

Tuning on ECUTEK with a rev limit of 8000.

Throwing blind darts, I'd bet money on 210 peak WHP on pump gas. 200 if you didn't touch the intake manifold... (But then you wouldn't raise the rev limit because there's no point doing that NA until the intake manifold is addressed. Moving an identical torque curve to the right is what makes the extra peak power.)

...Any reasonable amount of extra money would buy you only disappointment.

Now here's the caveat. Find someone similarly knowledgeable who disagrees with me... And isn't trying to sell you something.

This sounds very interesting and actually doable with a budget similar to a basic FI setup, correct? Would you say that this setup would hold up to track usage better than a FI one or worse since we are upping the rpms?

[Spartarus]

Originally Posted by Icecreamtruk

This sounds very interesting and actually doable with a budget similar to a basic FI setup, correct? Would you say that this setup would hold up to track usage better than a FI one or worse since we are upping the rpms?

I'd say doable on the same budget as a basic NA build plus about 1000 for a good fab shop to make a well-built intake manifold for you.

That would put it between an NA build and a low-budget FI build... And between those two, I know which one I would be willing to thrash on a track without the constant fear of blowing it up.

Oil cooling is the only additional necessity for track use.

Buying the actual JUN manifold will set you back over 2k, and then we're getting into FI-money territory... But it makes power with proven theory that holds up in the real world, not smoke-and-mirror snake oil bullsh*t.

[celek]

Originally Posted by Tor

Thanks for all the replies. Ok, I found the thread from Celek. 2.3 liter is more like it. As far as I can tell he is not done with it yet?

I suppose a build like that is more like 10k+$ and an endless amount of time investment. Will be very curious to see what kind of power that can make.

Would a less extreme version be doable for normal human beings and on a more limited budget? Like sleeves to increase the volume but on stock crank and some head work to increase the rpm?

No I am not done yet.
But time and money are a constraint.
I have been working with a couple companies on being able to have them offer a kit at less of a cost. The issue is you have 1 set of rods/pistons made at a time the cost is 20% higher than having 5 sets made at once.
Keep your eye out on the market you may see a more affordable version of mine for around $3500 in parts to make a 2.3 liter

[Tokay444]

Originally Posted by wparsons

I think heads/cams/intake manifold that make power north of 8000rpm (and rockers that don't blow apart) are the key to making big gains NA. The manifold gets interesting with runner lengths and the distance between heads.

Kinsler needs to make a proper ITB setup.

[CounterSpace Garage]

Piper Cam installed.

[Tor]

Originally Posted by Spartarus

Intake runners are your obstacle for revs.

The head needs no work for a budget NA build.

The stock valvetrain will hold up reliably to right around 8k as long as it's not a '13 motor... Oh, and around 8,400 the oil pump gives up anyway.

So a spare engine wouldn't even be necessary. What about pistons, would there be any advantage with going with forged pistons in such a scenario.

And if having a 2013 engine (like I do) what needs to be changed?

JUN proved that simply shortening the runners at stock diameter carries the torque curve up by several hundred RPM, which reflects as a proportional increase in power. Something I have said for years.

Who is JUN?
*edit* Is it this you mean?
http://www.junauto.co.jp/products/su.../index.en.html

If I was doing a budget NA build on an FA20, it would be ACE header, tuning & flexfuel, stock unopened motor, make (or have made) a custom aluminum intake manifold with shorter runners... Think 15mm shorter. A simple one with tubular runners, hand milled flanges, and a sheetmetal plenum.

Tuning on ECUTEK with a rev limit of 8000.

Throwing blind darts, I'd bet very safe money on 210 peak WHP on pump gas. 200 if you didn't touch the intake manifold... (But then you wouldn't raise the rev limit because there's no point doing that NA until the intake manifold is addressed. Moving an identical torque curve to the right is what makes the extra peak power.)

Oh, and it's worth mentioning I'm speaking in terms of repeatable, uncorrected dyno numbers on an accurate machine. E85 is getting into guesswork territory but I figure another 5-8%

If not doing the intake and raising the rpm, and not using E85 (which I don't have available anyway), that leaves just the ACE header and a tune, or am I missing something? I think that would get 180-190whp at best?

[Tor]

Originally Posted by celek

No I am not done yet.
But time and money are a constraint.
I have been working with a couple companies on being able to have them offer a kit at less of a cost. The issue is you have 1 set of rods/pistons made at a time the cost is 20% higher than having 5 sets made at once.
Keep your eye out on the market you may see a more affordable version of mine for around $3500 in parts to make a 2.3 liter

That sounds interesting and an affordable price point that brings it into (or below) FA territory. I liked your FB page too. Looking forwards to updates and seeing it running!

[Spartarus]

Originally Posted by Tor

So a spare engine wouldn't even be necessary. What about pistons, would there be any advantage with going with forged pistons in such a scenario.

And if having a 2013 engine (like I do) what needs to be changed?

Who is JUN?
*edit* Is it this you mean?
http://www.junauto.co.jp/products/su.../index.en.html


If not doing the intake and raising the rpm, and not using E85 (which I don't have available anyway), that leaves just the ACE header and a tune, or am I missing something? I think that would get 180-190whp at best?

1. Rocker arm pivots. In short, your engine has 2 sets with 2 different part numbers. Half are a bad design. Also gives you a chance to check and make sure none of your roller pins are backing out due to poor swaging / poor QC. I'll have to go dig though old stuff to be more specific than that.

2. Yes, that's the JUN I'm talking about.

Here's a link to the original thread. The math in there explains why it works.

http://www.ft86club.com/forums/showthread.php?t=110517

3. Yep, leaves ACE and a tune, but it'll do better than you're guessing. Oh, and a drop-in filter if you care... 199 WHP can be done consistently on a normal dyno (not a hero-run on a dyno) on just that... With normal-people pump gas.

Every NA hp after that is an expensive diminishing return.

[Tor]

Originally Posted by Spartarus

1. Rocker arm pivots. In short, your engine has 2 sets with 2 different part numbers. Half are a bad design. Also gives you a chance to check and make sure none of your roller pins are backing out due to poor swaging / poor QC. I'll have to go dig though old stuff to be more specific than that.

2. Yes, that's the JUN I'm talking about.

Here's a link to the original thread. The math in there explains why it works.

http://www.ft86club.com/forums/showthread.php?t=110517

3. Yep, leaves ACE and a tune, but it'll do better than you're guessing. Oh, and a drop-in filter if you care... 199 WHP can be done consistently on a normal dyno (not a hero-run on a dyno) on just that... With normal-people pump gas.

Every NA hp after that is an expensive diminishing return.

Thanks for the link! What is the disadvantage? Why is no one else offering intakes like this at a more reasonable price? Seems like an obvious thing for someone like Racer X fabrication to get into ( @Jeff@Racer X Fab ).

I am skeptical about the 199whp on E0, of course, depends on the dyno and stock baseline. That's why I prefer crank hp for comparison. 230 crank with just an ACE header and tune I would suppose is the absolute maximum. 199whp in my baseline would equate to 250 crank.

[himbo]

All this NA talk makes me

I wonder how much capable the 17 motor is with the headwork, cams, and intake manifold from the factory is...