That doesn't matter much. Did we see a significant jump in compression ratio when direct injection was introduced in petrol roadcar engines? No we didn't. Comparing Diesel and Petrol is like comparing Apple and Oranges.rscsr wrote: ↑01 Sep 2018, 13:53But not exceptionally high for a direct injection engine. Most Diesel engines are using in excess of 18:1. Of course you can get away with such a high compression when the fuel burns slower, hence limiting the temperatures. And it is also well known that higher compression improves efficiency. Even the old V8 in F1 used compression ratios of about 16:1 (only limited due to the short stroke used)
Here's how I think the bleeding air from the compressor could work. Just to note, I don't think they are doing it for a power advantage but more for an aerodynamic advantage. Having a low speed aero advantage would allow greater acceleration and therefore maximize its benefit on the straight. Let me explain.ringo wrote: ↑01 Sep 2018, 03:57
Regarding bleeding air into the turbine from the compressor, i don't think that would be very helpful and doesn't have anything to do with acceleration since the MGUK can only output 120kW.
It is possible to get more power from the turbine by dropping the pressure at its outlet, and in turn harvest more or increase boost pressure, but why dump boost to make boost?
Are you familiar with spark plug non-foulers?saviour stivala wrote: ↑01 Sep 2018, 16:36In my opinion the TJI combustion system is not compatible with formula 1 direct injection rules, not even when inverted on its side to meet exhaust side entry injection because it still injects and ignites in a pre-combustion chamber.
Since TJI is a Mahle system an they are a big Ferrari partner would you say that the Ferrari combustion system is illegal ?saviour stivala wrote: ↑01 Sep 2018, 16:36In my opinion the TJI combustion system is not compatible with formula 1 direct injection rules, not even when inverted on its side to meet exhaust side entry injection because it still injects and ignites in a pre-combustion chamber.
Yes I am, in fact in the height of their popularity (side-valve/flat-head) era I use to make them on my lathe for others to save them having to re-bore their engine, that was a time when a re-bore was regarded as a swear word.godlameroso wrote: ↑03 Sep 2018, 14:34Are you familiar with spark plug non-foulers?saviour stivala wrote: ↑01 Sep 2018, 16:36In my opinion the TJI combustion system is not compatible with formula 1 direct injection rules, not even when inverted on its side to meet exhaust side entry injection because it still injects and ignites in a pre-combustion chamber.
Sorry, but:saviour stivala wrote: ↑03 Sep 2018, 23:14Malhe TJI combustion system is not compatible with the FIA direct injection rules. Because it injects and ignites in a pre-combustion chamber.
Because Malhe is a FERRARI partner it doesn’t mean FERRARI are using Malhe TJI combustion system.
doesn't prohibit a TJI system like the one from Mahle at all. "Direct Injection" isn't even particularly stated in the rules. The fuel injection must happen somewhere between the inlet and exhaust valves, that's all the FIA wants.5.10.2 There may only be one fuel injector per cylinder and no fuel injectors are permitted upstream of the intake valves or downstream of the exhaust valves. Only approved parts may be used and the list of parts approved by the FIA, and the approval procedure, may be found in the Appendix to the Technical Regulations.
So is this a hint that the combustion process is conventional?saviour stivala wrote: ↑04 Sep 2018, 07:36“there has been lots of discussion of this (Malhe TJI combustion system) here in various threads”. Yes there was, and also elsewhere where the speculation started about what the formula one engine combustion chamber is like and or the process is like.
“the intents and benefits of ‘TJI’ could be achieved by a single direct injector spraying towards the exterior of the ‘prechamber’ (containg the spark-plug)” so the formula one engine uses a ‘pre-combustion chamber’. That is the original rubber band like reasoning to justify his claims, by the original discoverer of what goes on inside the FI engine combustion and or what the combustion chamber is like. This after the original discoverer inside a week's time had changed his mind from manufacturers (are using HCCI) to manufacturers (are using Malhe TJI).
For some very old history....godlameroso wrote: ↑04 Sep 2018, 13:13
So is this a hint that the combustion process is conventional?