The most NA power achievable?

[truupR]

I'm sure it's probably something that gets asked a lot, however I'm struggling to find the specifics (mod/parts list etc.)

So as the title suggests - what is the most realistic power achievable without boost

I'm really not too keen on boosting the DC5 as now looking at honda's new direction to go turbo. I feel like the DC5 and FD2 are the last of the NA screamers. Something which I personally feel is going to be sought after in years to come when every company is making turbo only sports cars (and perhaps for good reason?)

I understand the usual NA tuning route that most people go when asking for more power out of the K20. Better breathing mods, inlet manifold, exhaust manifold, aftermarket exhaust, decat, kpro etc. etc.. Now I've not yet gone this route myself, but it would get me nearer the 240/250bhp mark with increased mid range response and more torque(?)

What's the possibilities beyond this? A funny thing a guy at a garage said to me whilst having my FRSU done a few months ago was, 'why don't you just engine swap a k24 into it?'. Not sure how sound his logic was but after a bit of ol' googling, the k20 can be sort of frankenstein'd with other bits of honda engines?

I know next to nothing about engines, so I've no clue how realistic this sort of stuff. I say realistic in terms of money. I'm sure the sky's the limit if I had an endless bank account In comparison, supercharging the teg would set me back somewhere between £6k to £8k?

So what could push a k20 close to or even over the 300bhp mark whilst remaining NA? What sort of costs are involved? And would it even be drive-able as a daily car for commuting?

 

[coyote_dc5]

General rule of thumb

Boost - fairly low cost route to power with bolt on components and a remap

NA - expensive bhp gains by really improving head flow, increasing rpm and sometimes increasing displacement and compression. It ends up being more expensive as it generally involves major engine work internally as opposed to just bolt ons which is why most stop at 250 using bolt ons and remap as beyond here involves big money and engine overhauls

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[coyote_dc5]

For example my motor has new cams and valve springs. Forged rods and oversized pistons with increased displacement and compression to get me close to 270 mark. To go beyond here, I'd be looking at increasing intake and exhaust flow some more, increasing rpm again, more aggressive cams and blue printing internals. The further you go with it mind you, you end up sacrificing longevity

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[CaLi]

if you want near 300bhp then your gonna have to throw alot of money into it.

2050 K20 engine.bored and plateau honed, HC pistons,balanced crank assy,faced block,faced head, buddyclub stainless forged valves,buddyclub Spec3 cams,Buddyclub cam Pully,Buddyclub springs,
Buddyclub header.
RC Injectors.
Fuel pressure reg.
SPD one off induction system.
SPD 70mm TB,
Modified RBC bored out and ported.

also appears to be fine as a daily

 

[beppe786]

There a guy i know whos spent 10k on the engine k24 NA.. hes around 350bhp

 

[coyote_dc5]

YouTube channel and vid links?

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[truupR]

Reading what you just said Coyote, was what I was worried about. I was sort of aware that boost is the most realistic option, given bang for buck, boost is just miles cheaper. I've just been curious more than anything to see if anyone has seriously gone down the NA tuning route, what sort of bhp they're at, and how much of a dent it's put in their wallet.

What's the benefit of having the K24 engine vs the K20? I've read on some other forums people have put a k24 bottom end with k20... headers? No clue if I've even said that right, all that kind of stuff is way way over my head.

Is there more power to be gained from doing something like rebuilding using part of the K24 motor?

 

[coyote_dc5]

It's popular because it marries a 2.4ltr bottom end which Is fairly cheap to source with your k20 head which combined produces great power because of the 2.4 torque. Unless you uprate rods though your going to be limited to rpm and power which change the characteristic we're all hooked on

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[dave c]

K24 will give better torque because of the increased displacement

think of your K20 being 2L of milk and the K24 being 2.4L of milk - put very very simply, more is better!


They use the K20 head as i understand it flows the air in and out better so is therefore more efficient.


Hence the term K24 frank, as its a combination of a K20 and a K24

Traditionally the K20 head matched with the K24 bottom end

So the benefits are increased displacement and improved flow.

The downsides are they because of the length of the stroke i don't think you can rev the K24 as high out of the box

You could argue if you are going all out a K20 with oversized pistons and rebored to suit would be better but then its probably swings and roundabouts.

Not easy to explain in text if you are a novice in engines as there are so many factors to consider but this should give you a little hint at what and why

HTH's

 

[dave c]

to answer your first question i think 300bhp is probably the limit before things start to have a very short shelf life but if mapped well (Paul @ Tdi for example) then there isn't any reason why it couldn't be a daily however the engine wouldn't be as smooth around town as a stock motor.

you're more likely to experience a lumpy idol from the cams, a jerky throttle from the oversized intake and its gonna have to be hellish loud to make that power N/A as it will need at least a 3inch system

 

[beppe786]

YouTube channel and vid links?
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The Guys coming to the 10k racing dyno day in lesta next month.. ill post up a video.. also keep eye on my personal fb page your see some secret na vs boost.. lol

 

[p1tse]

if you want near 300bhp then your gonna have to throw alot of money into it.

2050 K20 engine.bored and plateau honed, HC pistons,balanced crank assy,faced block,faced head, buddyclub stainless forged valves,buddyclub Spec3 cams,Buddyclub cam Pully,Buddyclub springs,
Buddyclub header.
RC Injectors.
Fuel pressure reg.
SPD one off induction system.
SPD 70mm TB,
Modified RBC bored out and ported.

also appears to be fine as a daily

Is this yours, looks awesome and liking the photo upon drive thru

 

[CaLi]

Is this yours, looks awesome and liking the photo upon drive thru

No, its Pauls buddyclub demo car

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[p1tse]

No, its Pauls buddyclub demo car

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Ah right

Good link though

 

[Chewy]

That.is.PERFECTION.

 

[C&S Evo7]

400 is doable for $12K you can get a crate 400 hp motor,

this one is supposed to be closer to 500hp.

check out 4 Piston Racing

 

[dave c]

400 is doable for $12K you can get a crate 400 hp motor,

this one is supposed to be closer to 500hp.

check out 4 Piston Racing

:xaiweb6: AWESOME! Wonder what the spec is?

 

[jrscho]

If you want a high NA build I hope you have deep pockets...

A guy I know has recently went down the k24 route. had his k24 engine built from USA which was afew grand itself, not sure what cams etc or what internal parts he used but I know in total he spent over £7k just on the engine, not to mention exhaust etc on top. His made 300bhp! Sounds mental with his 3" exhaust!

 

[tricker_luke]

For reference, a 2.2l k20a, i.e. pistons rebored to 90mm and then fully forged and refeshed cost around £6.5k. That was before the exhaust, intake etc, but produced 280hp and 200lb torque.

 

[ljcharm]

Im currently running my DC5 at 252bhp with the following mods:

- K100
- Tegiwa M intake
- Tegiwa 421 Manifold
- Skunk2 Inlet 70mm
- Skunk2 TB
- 3" TDi North Exhaust

Im thinking about some TDi north drop in cams for £1500... anyone have any experience with these and how much gain realistically would I be expected to get? And importantly are they worth it!!?