Honda Power Unit Hardware & Software

[dren]

What's a good reason for running four pipes to six cylinders?

My guess is they are the intake runners for cylinders 2,3,5,6, 1&4 being entirely inside the plenum. The runners are not symmetrical. Runner indicated 4 in the picture seems to have the tightest radius and may feed cyl 2, runner 1 is the next tightest radius and i guess that would feed cylinder 5. Runners indicated 2&3 feeding 6&3 respectively due to 3 being slightly further forward.

It's hard to tell if there are two more under those four that we cannot see. I'm guessing the variable runners are inside the large manifold.

[63l8qrrfy6]

At "low rpm" when coming back on throttle they will use the MGUK for torque fill and also use the MGUH to keep the turbo spooled.
Glorious.

That's pretty much a given, the K filling torque. Just curious as to where the low RPM torque boost the size of a small car Honda was claiming came from.

I might have missed that claim... link?

It is pretty well known. There is a rule however that forbids K torque fill under a certain speed (100 kph I think?).

[dren]

At "low rpm" when coming back on throttle they will use the MGUK for torque fill and also use the MGUH to keep the turbo spooled.
Glorious.

That's pretty much a given, the K filling torque. Just curious as to where the low RPM torque boost the size of a small car Honda was claiming came from.

I might have missed that claim... link?

Let me do some digging. It was a while back; a translated interview. If anyone else remembers, please help out.

[63l8qrrfy6]

What's a good reason for running four pipes to six cylinders?

My guess is they are the intake runners for cylinders 2,3,5,6, 1&4 being entirely inside the plenum. The runners are not symmetrical. Runner indicated 4 in the picture seems to have the tightest radius and may feed cyl 2, runner 1 is the next tightest radius and i guess that would feed cylinder 5. Runners indicated 2&3 feeding 6&3 respectively due to 3 being slightly further forward.

It's hard to tell if there are two more under those four that we cannot see. I'm guessing the variable runners are inside the large manifold.

Yes there's a couple more underneath and yes the trumpets are in the plenums.

[dren]

That's pretty much a given, the K filling torque. Just curious as to where the low RPM torque boost the size of a small car Honda was claiming came from.

I might have missed that claim... link?

It is pretty well known. There is a rule however that forbids K torque fill under a certain speed (100 kph I think?).

Yeah, I think there is a formula dictating torque up to a certain RPM, too.

[PhillipM]

HCCI with spark is not an HCCI anymore. Clearly TJI have an advantage here compared to low speed compression engine. As far as i know HCCI cannot be utilized at high load and high rpm because of fuel need to be ionized and reacted with O2 first and it takes time. No injector could handle very large amount of fuel with super short time at TDC at high speed. Even if there is, will classified as diesel and not as efficient as HCCI. For f1 engine, HCCI is a wet dream TBH

That's what is being talked about. HCCI mode in rpm range where it can operate, then it turns into spark ignition in the higher rpm range. It's still an HCCI engine in a given rev range where it actually operates as HCCI.

HCCI is essentially useless then, unless you're cruising, which F1 cars don't do much of. What is being done is stratified combustion, a small easily ignitable flame ignites a larger less reactive flame. The beauty of RCI is that it's a universal concept, and you don't need two fuels to do it, but it certainly helps. Using a pre-chamber or TJI is still reactivity controlled ignition, in that an area with a rich mixture(higher reactivity) is igniting an area with a lean mixture(lower reactivity). It's all about controlling the reactivity of the fuel to optimize it's burn characteristics, it's also where your CFD makes or breaks you.

No, that's not what the Mazda spark ignited engine does, it does use a spark yes, in a small, rich prechamber - but the main charge isn't set off by the flame front, but rather by a shaped shockwave from the prechamber to set off compression-ignition in the main chamber. So you have a mix of both, with no sudden change from one to the other, now, obviously engine speeds and fuel injection time change through the rpms, so you end up with more compression ignition at low rpms and light loads and vice versa, but it still is HCCI, just a blend of that and SI, rather than pure.

[PlatinumZealot]

The key benefit of HCCI is rapid combustion with completion very close to TDC.

By how it works combustion is rapid as i have said above, zguru but rapid cobustion is different from the timing of that combustion. TJI will beat it in that regard. How does one time HCCI anyway?

Isn't HCCI compression ignition of a petrol fueled engine? So the timing would largely be like a Diesel.

Which restricts how fast the engine can operate in that mode.

My understanding of HCCI engines is that they can convert to spark ignition at high rpm.

Ah yes, I know. It was rhetorical question for Guru. But I want to hear why he thinks the HCCI won't be speed limited. Formula 1 engines have a relatively narrow operating band and the lower edge of that band is so high above any Diesel or HCCI engine has reached.. like 8000 rpms.. I can't see why Honda would shoot them self in the foot by not using the more applicable technology which is TJI.

[MrPotatoHead]

That's pretty much a given, the K filling torque. Just curious as to where the low RPM torque boost the size of a small car Honda was claiming came from.

I might have missed that claim... link?

It is pretty well known. There is a rule however that forbids K torque fill under a certain speed (100 kph I think?).

Correct.

[MrPotatoHead]

Alonso on Honda:

"The good thing is I think together with the Japanese mentality, no one gave up, they're still always working."

"Even if you are out of Q1 the engineers spend 20 hours in front of the computer to keep improving."

"We didn't improve the situation much, but it was not because we lacked time of working."

[bigblue]

That's pretty much a given, the K filling torque. Just curious as to where the low RPM torque boost the size of a small car Honda was claiming came from.

I might have missed that claim... link?

Let me do some digging. It was a while back; a translated interview. If anyone else remembers, please help out.

My notes :
Spec 3.5 was penalty-free induction (bbc (http://www.bbc.co.uk/sport/formula1/41039407)) / exhaust changes mostly aimed at boosting low-end torque (via rudex, translation of yahoo.co.jp, post 5#2937 (http://forums.autosport.com/topic/20652 ... ?p=8071160) & 5#2942), Hasegawa estimates ~0.1s a lap (via Taylo207, translation of sportiva.shueisha.co.jp, post 5#3779).

See post #2942 :
"The improvement of this time raised the torque in the low speed range, the power of one mini vehicle is raised in terms of low speed torque," Yusuke Hasegawa chief manager Honda F1 says

P.S. nice to see muramasa posting again, and making the traditional trip to the GP !

[dren]

My notes :
Spec 3.5 was penalty-free induction (bbc (http://www.bbc.co.uk/sport/formula1/41039407)) / exhaust changes mostly aimed at boosting low-end torque (via rudex, translation of yahoo.co.jp, post 5#2937 (http://forums.autosport.com/topic/20652 ... ?p=8071160) & 5#2942), Hasegawa estimates ~0.1s a lap (via Taylo207, translation of sportiva.shueisha.co.jp, post 5#3779).

See post #2942 :
"The improvement of this time raised the torque in the low speed range, the power of one mini vehicle is raised in terms of low speed torque," Yusuke Hasegawa chief manager Honda F1 says

P.S. nice to see muramasa posting again, and making the traditional trip to the GP !

Excellent, thanks bigblue! So, it was exhaust changes, cam and/or headers.

[MrPotatoHead]

I might have missed that claim... link?

Let me do some digging. It was a while back; a translated interview. If anyone else remembers, please help out.

My notes :
Spec 3.5 was penalty-free induction (bbc (http://www.bbc.co.uk/sport/formula1/41039407)) / exhaust changes mostly aimed at boosting low-end torque (via rudex, translation of yahoo.co.jp, post 5#2937 (http://forums.autosport.com/topic/20652 ... ?p=8071160) & 5#2942), Hasegawa estimates ~0.1s a lap (via Taylo207, translation of sportiva.shueisha.co.jp, post 5#3779).

See post #2942 :
"The improvement of this time raised the torque in the low speed range, the power of one mini vehicle is raised in terms of low speed torque," Yusuke Hasegawa chief manager Honda F1 says

P.S. nice to see muramasa posting again, and making the traditional trip to the GP !

Ah yeas thanks. I remember that quote now.

[MrPotatoHead]

Hopefully my next trip to Japan will be at the time of the Grand Prix. I have been to Suzuka though when I was over there working on a project with Honda R&D - but sadly not at the right time of year. I would love to spend hours looking at that engine on display.

[godlameroso]

They wouldn't be able to stop me from taking a spanner to it and tearing it apart just to put it back together. I'm grateful for the pictures but sad I can't see in more detail. That they're showing the power unit like this, I imagine it's this engine's last time out.

Honest question, had the engine in the car for this weekend been in the car at the beginning of the season, would there have been more points on the board?

[ArcticWolfie]

I really hope to see a spec 4.0 engine tomorrow, but chances are low it seems...