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Re: Honda Power Unit
Posted: 06 Aug 2015, 17:27
by Brian Coat
That is quite interesting. Thanks.
I should have read the 'however' bit more closely!
They are already OK to use (say) bio isooctane based on bio isobutanol a la Gevo/Total as part of the 5.75%
Re: Honda Power Unit
Posted: 06 Aug 2015, 21:57
by PlatinumZealot
trinidefender wrote:Here is a question for those more versed in the chemistry side of fuel than me.
We are talking about stoichiometric and trying to figure out the most efficient a:f ratio. For normal road car petrol I know stoichiometry to be about 14.5:1 - 14.7:1. How much can the change in chemistry of these fuels affect stoichiometry. What I mean by that is what if the stoichiometric ratio for these fuels is 15.5:1.
If that were to be the case then the engines would be running more rich (or maybe less lean) than we thought. The opposite being true if the stoichiometric a:f ratio is lower than that of regular road car petrol.
Is not a chemistry problem though... it is a mechanical problem. It's a temperature problem and 3 dimensional fluids dynamics problem. With the whole stratified injection thing - and God knows whatever pockets they put in the pistons... you could have multiple local AFRs at different times. Far from a chemistry problem. We here working these one dimesional A:F numbers does not add up to much.
Re: Honda Power Unit
Posted: 06 Aug 2015, 22:32
by trinidefender
PlatinumZealot wrote:trinidefender wrote:Here is a question for those more versed in the chemistry side of fuel than me.
We are talking about stoichiometric and trying to figure out the most efficient a:f ratio. For normal road car petrol I know stoichiometry to be about 14.5:1 - 14.7:1. How much can the change in chemistry of these fuels affect stoichiometry. What I mean by that is what if the stoichiometric ratio for these fuels is 15.5:1.
If that were to be the case then the engines would be running more rich (or maybe less lean) than we thought. The opposite being true if the stoichiometric a:f ratio is lower than that of regular road car petrol.
Is not a chemistry problem though... it is a mechanical problem. It's a temperature problem and 3 dimensional fluids dynamics problem. With the whole stratified injection thing - and God knows whatever pockets they put in the pistons... you could have multiple local AFRs at different times. Far from a chemistry problem. We here working these one dimesional A:F numbers does not add up to much.
It is a chemistry problem because different fuels will themselves have different stoichiometric values. Therefore it is just one more variable that people would have to include into their equations when trying to work out if these ICE units are running lean, rich or at stoichiometric.
It is also a chemistry problem because I was specifically asking those with knowledge of the fuel rules, what is the range for different stoichiometric ratios among different fuels used by different PU manufacturers.
Re: Honda Power Unit
Posted: 12 Aug 2015, 14:44
by Abarth
http://en.f1i.com/news/21205-honda-prep ... n-spa.html
If he talks about that much increase that it could potentially cause reliability and even powertrain problems, he's not talking about 2%, methinks.
The strange part is when he talks about gearing:
“Also the chassis side - in order to increase the power we have to change the set-up, especially the traction with the tyres and the gearing. It’s very important in order to be able to increase the power.”
AFAIK a gearing change is not allowed now...
Re: Honda Power Unit
Posted: 12 Aug 2015, 17:47
by godlameroso
No but you can control the power delivery, delaying full boost at low wheel speeds to prevent slip etc.
Re: Honda Power Unit
Posted: 13 Aug 2015, 23:24
by PlatinumZealot
Abarth wrote:http://en.f1i.com/news/21205-honda-prep ... n-spa.html
If he talks about that much increase that it could potentially cause reliability and even powertrain problems, he's not talking about 2%, methinks.
The strange part is when he talks about gearing:
“Also the chassis side - in order to increase the power we have to change the set-up, especially the traction with the tyres and the gearing. It’s very important in order to be able to increase the power.”
AFAIK a gearing change is not allowed now...
They might** be allowed a gearing change since their engine is new. Just was not publicized perhaps.
Re: Honda Power Unit
Posted: 14 Aug 2015, 05:50
by Sixbarboost
How can Honda be so down on power, don't they know how to build a 1.6 lightly boosted V6?
Re: Honda Power Unit
Posted: 14 Aug 2015, 06:44
by pgfpro
Sixbarboost wrote:How can Honda be so down on power, don't they know how to build a 1.6 lightly boosted V6?
I think it might be a little more complicated then that?
Re: Honda Power Unit
Posted: 14 Aug 2015, 07:27
by gruntguru
Agreed. Go and read
http://www.f1technical.net/forum/viewto ... f=4&t=9259 - or at least the last 100 pages or so.
Re: Honda Power Unit
Posted: 15 Aug 2015, 15:37
by GoranF1
Intersting insight from a memeber of forum over at Mclaren team tread.
@Wazari;
All I know is that he is working on the combustion chamber design with special emphasis on the exhaust volume and flow into the turbo. That's all he'll say except that there is a major change upcoming on the port and chamber design.
Re: Honda Power Unit
Posted: 15 Aug 2015, 23:03
by PlatinumZealot
Too high back pressure it seems they underestimated the back pressure sensitivity in an engine with mguh. The backpressure must swing massively when you try to take over with the mguh. There might be some resonance happenng too from the pressure swings pumping back hot gases into the chambers.
Re: Honda Power Unit
Posted: 16 Aug 2015, 20:04
by ringo
I think their design is too compact.
Added to that the hidden detail they have with their turbine in the factory videos. They may have a a really compact wastegate/pressure relief system which is limiting their performance.
Re: Honda Power Unit
Posted: 16 Aug 2015, 20:07
by godlameroso
Then how would changing port, or chamber geometry be a workaround for their congested pressure relief system?
Re: Honda Power Unit
Posted: 17 Aug 2015, 10:47
by Sixbarboost
pgfpro wrote:Sixbarboost wrote:How can Honda be so down on power, don't they know how to build a 1.6 lightly boosted V6?
I think it might be a little more complicated then that?
Don't get me wrong, I get that part, but with a fixed MGU-K power, I fid it odd that a power deficit from the ICE would be as much as 120 Hp according to Boullier. Honda is not exactly rookies with turbo engines?
Re: Honda Power Unit
Posted: 17 Aug 2015, 11:51
by Abarth
Well, the fixed 120 kW of the MGU-H is not really THAT fixed.
Perhaps they could not use it continuously because of overheating? Or the ES and/or corresponding power electronics was the limit when massive charge / discharge situations were asked for?
And, as mentioned in several threads, you cannot look at the isolated ICE. It's always a "compound" with MGU-H and MGU-K when running in a self sustained mode (i.e. without using kinetic recovered energy).
So, doing several things "wrong" may well lead to a substantially underpowered unit (although I do not believe it's 120BHP, when did Boullier say so?).