Building NA H6 for 220+kW

[666]

Can anyone produce an actual dyno sheet with 180kw at wheels for a h6?
Not a virtual dyno, not a calculation based on G/S.


I like the h6, but some of these power claims are getting up there.

Don't make me wheel out the stupid bets again.

My two cents worth.

I have extensive ATW dyno charts for my H6 going back 8 years, usually on a Dyno Dynamics machine and can say that 180kw ATW for an NA H6 is somewhat fictional. I really think that the ceiling for these engines in NA form even on E85 and the usual intake/exhaust mods to be around 160-170kw on a good day and a reliable AWD dyno.

The only way you can ever get into the 200kw ATW and above is to use some form of forced induction.

Currently with Raptor intake, headers, rear mufflers and 98RON Matt tune it posted 145.2Kw

Chasing NA gains is hard work, much easier to bolt a supercharger or turbo on them.

Rob.

[west_minist]

To achieve that power, you going to have to add boosted pressure or perform all of the following for NA power:

1) Increase cams duration and lift
2) Better flow heads - minor port and polish with 1mm oversize valves
3) High compression pistons
4) E85 or race gas like vp ms109

[dr20t]

This is why you shouldn't build a street engine to a power figure but rather a driving experience/style. Power figures are arbitrary at best as mentioned above. Setting out to build and targeting some figure from a forum isn't necessarily going to get you the engine you want especially if you try to cheap out. If you do your research, plan a budget, and make mods to suit you driving style you should then see usable increases. As most people have found these engines respond best to a good tune with the bolt-ons being supporting players. To really get it singing you are going to delve deep into both the engine and your wallet and a lot of unnecessary expense if basing a power figure.

Spot on as always, Adrian

I also hear of these big power n/a H6's and think where is the logic.

Maths and Phsyics don't lie - to produce 180awkw from a n/a H6 is at the very very least 210kw at the flywheel - that's assuming a manual trans and 30kw drivetrain loss (or 14.2% which is less than the general rule of 17-20% drivetrain loss - mind you I also don't agree with a flat percentage as power loss is not generally linear but that's another discussion).

So lets assume 210kw at the fly. To make this power, the engine needs to ingest a peak of about 240 grams per second of air.

With a n/a 3.0 litre, that's a hell of a lot of air to flow.

240 g / second of air is approx 31lb/ min

Assuming 14.7psi atmospheric density, and static intake temp, that's about 418cfm of peak airflow.

Hear me out for a second - but some conservative assumptions I have made for the below calculation are

Bring back peak cfm to 400 to allow for conversion errors
3.0 litre is 180 cubic inches.
Peak power at 7000 (conservative as I've yet to see an unported / cammed h6 make power this high up in the rev range)

Using calculator of VE = (3456 x CFM) / (CID x RPM)

VE = (3456 x 400) / (180 x 7000rpm)

= 1.097 or 110% VE

Generally, unless its a full time race engine, an n/a engine won't go over 100% VE and even then, that's pushing assuming everything is absolutely pristine and on the ragged edge.

180awkw out of an n/a 3.0 litre is not happening without bottom end work to support higher revs, massive cams, extreme headwork and an absolutely spot on tune.

Mick

[west_minist]

You have basically said the same thing I wrote.

[dr20t]

Agree - wanted to verify it with maths

[west_minist]

[dr20t]

Nice curve - but how stock is that setup?

And as we know, unless maf scaling / calibration is spot on, calculated VE will always be out. Ie - when you change maf pipe diameter / resolution, it impacts the actual airflow reading in g/ second. With the calculator relying on input from the maf in g/s, this can change the calculated VE

I just don't want the kiddies thinking its easy to make 300hp out of their 3.0 litre H6.

110% VE is no joke.

Mick

[west_minist]

Usually just under 100-105 in top range.

Yes maf scale to match fuel table.

Point is as we stated, 300whp is not easy.

[JBM3.0NZ]

Yes funny how you go to the Raptor website they show a 20atw kw increase just from their headers and tune ? so 180kw stock motor in the H6 + headers tune should =200kw atm ++++(plus another 7-10kw from raptor intake ??)

was hoping to get 210-220kw at the fly (150-160atw kw) ....from the raptor mods on 95-98 fuel + free flowing exhuast ....but seems unlikely going from this thread

[west_minist]

Thats possible on gas and may not even need headers. Raptor headers are prefect. Tim have done a fantastic job with them. If the based run is 200, you can see raptor doing 220+
The higher the based power, the better the gains.

[JBM3.0NZ]

right prob have to run with a 95 fuel tune from kido ....Raptor headers -x-force exhaust ....hopefully least 200kw atm ....(not sure on the intake advantages worth spending $$$ on raptor CAI)

also where I live we get some nice cold weather so should help reach decent numbers

[west_minist]

Sounds good.

[666]

Yes funny how you go to the Raptor website they show a 20atw kw increase just from their headers and tune ? so 180kw stock motor in the H6 + headers tune should =200kw atm ++++(plus another 7-10kw from raptor intake ??)

was hoping to get 210-220kw at the fly (150-160atw kw) ....from the raptor mods on 95-98 fuel + free flowing exhuast ....but seems unlikely going from this thread

You should have no problems getting around 145 - 150kw ATW on 95 RON with the headers, exhaust and a decent tune. An intake will yield a few more kw's and better throttle response. Remember with NA engines a little gain here or there is all you can expect and they do add up in the end.

Rob

[JBM3.0NZ]

Yes so true guess this shows how well the Subaru motor technicians have done ..3000cc = 185kw stock (going from this online manual http://www.legacyiv.webspace.virginmedi ... F/2008.pdf

?? 180 or 184 ...185 seen all three printed as fact ..most likely at what rpms the higher given at 7300rpm etc


gaining 30kw atw is well worth the money IMHO ...(220kw+ power plant)

[KiDo_Tuning]

Just like to point out that the NA EZ30 motor is quoted at 180Kw at 6600rpm, with peak torque of 297Nm/219FtLbs at 4200pm

For every person who has ever driven them, torque starts at 3500rpm and drops off above 5500rpm to the point, the factory tune makes 190Nm at 6600rpm which is why it noticeably falls over so quickly above 5500rpm
Is 297Nm/219FtLbs or 15% gain in high rpm torque so hard to believe? If so, your at 291Hp or over 215Kw... You gain in peak power is from higher rpm and more torque

Anyone ever bothered to setup an EZ30 on an engine dyno? I know someone who has, resulted in 18 extra non-public tables being found from cylinder fill rates to Engine Torque limiters etc...

Also, with the chemical nature of E85 allowing more oxygen molecules squirted into the engine without having to have it sucked in, it circumvents the airflow issue. Guess that will have no difference on adding torque towards redline