E92 M3 Engine
- Thread starter Physicist
- Start date
Re: E92 M3 Engine
That is right my man..
The CS enjoyed the following main benefits ( Absolutely None in the weight savings dept ) :
1. CSL brakes
2. Quicker steering ratio and not exactly the CSL either one either
3. M-mode => semi DSC which allows the electronics to intervene less..great for track use. The non CS either had DSC off OR on ONLY.
MRacer77;205069 said:
That is right my man..
The CS enjoyed the following main benefits ( Absolutely None in the weight savings dept ) :
1. CSL brakes
2. Quicker steering ratio and not exactly the CSL either one either
3. M-mode => semi DSC which allows the electronics to intervene less..great for track use. The non CS either had DSC off OR on ONLY.
Re: E92 M3 Engine
isnt that like LanPar and ParLan?
Ok u win, u see I only PSLE nia
Physicist;205062 said:Beng,
Its Isle of Man. Man of Isle and Isle of Man are 2 totally different things!
isnt that like LanPar and ParLan?
Ok u win, u see I only PSLE nia
centurion
Well-Known Member
Re: E92 M3 Engine
OK OK I'm confusing between what I'd buy and what's my dream. The best is of course CSL, but the CS addressed the worst issues in the M3 (the stupid stock brakes) and was comfortable and most important of all, CHEAPER BY FAR compared to CSL. Makes the CS what the base M3 should have been.TripleM;205091 said:
Re: E92 M3 Engine
Yeah but a godzilla size piston..
Actually for those who want to track occasionally, the stock brakes can work but must change to race pads , ss brake lines, higher temp brake fluid..It should work pretty well...seriously.
But I know you will want big bak kua.
Azrielsc;205169 said:Well, the new E92 M3 will STILL be having single piston capliers
Yeah but a godzilla size piston..
Actually for those who want to track occasionally, the stock brakes can work but must change to race pads , ss brake lines, higher temp brake fluid..It should work pretty well...seriously.
But I know you will want big bak kua.
Re: E92 M3 Engine
What abt structural efficiency and purpose of those hollow torsion bars? Do they in any way impede the purpose of such equipment?
Shaun;205218 said:
What abt structural efficiency and purpose of those hollow torsion bars? Do they in any way impede the purpose of such equipment?
Re: E92 M3 Engine
Welbo, sorry didn't see earlier question. Re: RS4 V8, I dunno, haven't come across any tech writeups or photos, so no opinion.
Caysman, I don't understand the points you make on DI heat reduction and relation to 12:1 CR. Also about DI 8000 RPM consistency and reliability.
Welbo, sorry didn't see earlier question. Re: RS4 V8, I dunno, haven't come across any tech writeups or photos, so no opinion.
Caysman, I don't understand the points you make on DI heat reduction and relation to 12:1 CR. Also about DI 8000 RPM consistency and reliability.
Re: E92 M3 Engine
So am i right to say that hollow torsion bars are only good if they are rated to take a certain threshold as oppsed to normal torsion bars?
Shaun;205236 said:
So am i right to say that hollow torsion bars are only good if they are rated to take a certain threshold as oppsed to normal torsion bars?
Azrielsc
Core Group Members
Re: E92 M3 Engine
Waiting to get off my ass to custom fit the APs...
TripleM;205222 said:Yeah but a godzilla size piston..
Actually for those who want to track occasionally, the stock brakes can work but must change to race pads , ss brake lines, higher temp brake fluid..It should work pretty well...seriously.
But I know you will want big bak kua.
Waiting to get off my ass to custom fit the APs...
Re: E92 M3 Engine
Noted.
Shaun;205251 said:
Noted.
centurion
Well-Known Member
Re: E92 M3 Engine
The DI heat reduction point is related to a previous discussion on DI which you also contributed
On the 8000rpm DI injector reliability, I've read magazine rags and webtalk stating that the DI injector cannot cost efficiently retain reliability at high RPM. Is this true?
Shaun;205232 said:
The DI heat reduction point is related to a previous discussion on DI which you also contributed
On the 8000rpm DI injector reliability, I've read magazine rags and webtalk stating that the DI injector cannot cost efficiently retain reliability at high RPM. Is this true?
Re: E92 M3 Engine
And continuing from the original heat reduction discussion, I still don't see it as raising knock threshold thermally. I guess we have to agree to disagree.
I don't know if it is true. What are the listed challenges in getting DI to higher engine speeds? Large power draw from having to open quickly against very high rail pressures? I have read of limitations at very high engine speeds from lack of time for vapourization. Doesn't the R8 streetcar exceed 8000 RPM with DI?
And continuing from the original heat reduction discussion, I still don't see it as raising knock threshold thermally. I guess we have to agree to disagree.
I don't know if it is true. What are the listed challenges in getting DI to higher engine speeds? Large power draw from having to open quickly against very high rail pressures? I have read of limitations at very high engine speeds from lack of time for vapourization. Doesn't the R8 streetcar exceed 8000 RPM with DI?
centurion
Well-Known Member
Re: E92 M3 Engine
One last try at heat reduction characteristic of DI giving the possibility of increasing compression ratio without knock:
AutoZine Technical School - Engine
[FONT=Arial,Helvetica][SIZE=-1]Mitsubishi GDI engine has an extraordinarily high compression ratio of 12.5 : 1, this is perhaps the highest record for production petrol engine. The result is higher power output.[/SIZE][/FONT]
[FONT=Arial,Helvetica][SIZE=-1]How can it prevent combustion knock under such pressure ? The secret is the pre-injection process. During compression, the heated air is cooled by the fuel spray, thus knocking becomes less easy to occur.[/SIZE][/FONT]
[FONT=Arial,Helvetica][SIZE=-1]Renault: Gain in performance is due to the increase of compression ratio to an unusually high 11.5 : 1 (GDI is even at 12.5 : 1). Like the Mitsubishi, a pre-injection in prior to the normal injection helps cooling the combustion chamber, thus raising knock resistance and enables a higher compression ratio.[/SIZE][/FONT]
Member News and Activities
[FONT=ARIAL,HELVETICA][SIZE=-1]The distinct advantage of this point is the charge cooling effect, which results from injecting the fuel directly into the cylinder. This uses the same principal of latent heat as with air conditioning refrigerant. Because the fuel changes its state from liquid to gas inside the cylinder it absorbs a large amount of heat and thus reduces the in cylinder temperature sufficiently to reduce engine detonation. The compression ratio of the engine as a result can be increased to improve the engines thermal efficiency and fuel economy.[/SIZE][/FONT]
Audi Q7
[FONT=verdana, arial, geneva][SIZE=-1]Like the engine in the RS 4, the V8 in the Audi Q7 uses FSI petrol direct injection technology. Here the petrol is not delivered to the intake manifold but injected directly into the combustion chamber, where an even air/fuel mixture to the value of lambda 1 is produced. Thanks to the cooling effect of the directly injected fuel, Audi’s development engineers have at the same time been able to increase the engine’s compression ratio.
Green Car Congress: Engines
[/SIZE][/FONT]
Direct injection delivers precisely metered and timed fuel directly to the combustion chamber, enabling a more precise mixture formation. This also has a cooling effect in the chamber, enabling a higher compression ratio, and improving engine efficiency. Less fuel is required to produce the equivalent horsepower of a conventional port injection combustion system.
AutoSpeed - Bosch DI-Motronic Gasoline Direct Injection
The DI-Motronic system calculates the amount of fuel to be injected from the drawn-in air mass and performs an additional correction via Lambda control (using the wideband oxy sensor). In this mode of operation, a torque increase of up to five percent is possible. Both the thermodynamic cooling effect of the fuel vaporizing directly in the combustion chamber, and the higher compression of the engine, play roles in this.
[FONT=Arial,Helvetica][SIZE=-1]as for the reliability of the injectors at high rpm, it's not the time required for vaporization which affects the reliability, but the high pressure mode of the DI requires very expensive precision. The R8 presumably can afford the cost but the M3 cannot? I don't know. I'll do research on this when I feel the severe itch.
[/SIZE][/FONT]
There's lots of literature regarding the cooling effect of DI increasing knock treshold. Most of it is written by Liberal Arts majors aka journalists. If you have any material rebutting them, you have succeeded in uncovering one of the biggest automobile technology misunderstandings in history.Shaun;205319 said:
One last try at heat reduction characteristic of DI giving the possibility of increasing compression ratio without knock:
AutoZine Technical School - Engine
[FONT=Arial,Helvetica][SIZE=-1]Mitsubishi GDI engine has an extraordinarily high compression ratio of 12.5 : 1, this is perhaps the highest record for production petrol engine. The result is higher power output.[/SIZE][/FONT]
[FONT=Arial,Helvetica][SIZE=-1]How can it prevent combustion knock under such pressure ? The secret is the pre-injection process. During compression, the heated air is cooled by the fuel spray, thus knocking becomes less easy to occur.[/SIZE][/FONT]
[FONT=Arial,Helvetica][SIZE=-1]Renault: Gain in performance is due to the increase of compression ratio to an unusually high 11.5 : 1 (GDI is even at 12.5 : 1). Like the Mitsubishi, a pre-injection in prior to the normal injection helps cooling the combustion chamber, thus raising knock resistance and enables a higher compression ratio.[/SIZE][/FONT]
Member News and Activities
[FONT=ARIAL,HELVETICA][SIZE=-1]The distinct advantage of this point is the charge cooling effect, which results from injecting the fuel directly into the cylinder. This uses the same principal of latent heat as with air conditioning refrigerant. Because the fuel changes its state from liquid to gas inside the cylinder it absorbs a large amount of heat and thus reduces the in cylinder temperature sufficiently to reduce engine detonation. The compression ratio of the engine as a result can be increased to improve the engines thermal efficiency and fuel economy.[/SIZE][/FONT]
Audi Q7
[FONT=verdana, arial, geneva][SIZE=-1]Like the engine in the RS 4, the V8 in the Audi Q7 uses FSI petrol direct injection technology. Here the petrol is not delivered to the intake manifold but injected directly into the combustion chamber, where an even air/fuel mixture to the value of lambda 1 is produced. Thanks to the cooling effect of the directly injected fuel, Audi’s development engineers have at the same time been able to increase the engine’s compression ratio.
Green Car Congress: Engines
[/SIZE][/FONT]
Direct injection delivers precisely metered and timed fuel directly to the combustion chamber, enabling a more precise mixture formation. This also has a cooling effect in the chamber, enabling a higher compression ratio, and improving engine efficiency. Less fuel is required to produce the equivalent horsepower of a conventional port injection combustion system.
AutoSpeed - Bosch DI-Motronic Gasoline Direct Injection
The DI-Motronic system calculates the amount of fuel to be injected from the drawn-in air mass and performs an additional correction via Lambda control (using the wideband oxy sensor). In this mode of operation, a torque increase of up to five percent is possible. Both the thermodynamic cooling effect of the fuel vaporizing directly in the combustion chamber, and the higher compression of the engine, play roles in this.
[FONT=Arial,Helvetica][SIZE=-1]as for the reliability of the injectors at high rpm, it's not the time required for vaporization which affects the reliability, but the high pressure mode of the DI requires very expensive precision. The R8 presumably can afford the cost but the M3 cannot? I don't know. I'll do research on this when I feel the severe itch.
[/SIZE][/FONT]
Re: E92 M3 Engine
I can see how specific cooling in the cylinder can occur instead of the same mass of fuel being vapourized early on in the port all the way down to the back of the valve and in the cylinder. With reference to earlier thread, I don't see specific cooling of the cylinder head through DI, if anything port injection, especially high pressure port injection, cools the cylinder head more because of fuel time in contact with head and components. Standard injection IMO cools the piston top more IMO, not necessarily reducing knock threshold because upper layers are rich enough to combust.
So overall I see similar total heat reduction in good DI and good port injection, with DI focusing more of its reduction in the in-cylinder mix which seems like a good idea because that is exactly where detonation originates and that's where you stop it, instead of cooling surfaces to cool charge, to prevent knock.
Even then, I still see the major contributor to knock resistance as concentration of fuel around the plug, with mix temps distant second.
Re high speed limits, I didn't mean to suggest in upper street engine speeds that vapourization time was a limit, but that I knew of these limits in high 5 digit speeds way beyond 4 digit speeds, but that the Audi R8 even past 8000 didn't seem to have trouble.
I can see how specific cooling in the cylinder can occur instead of the same mass of fuel being vapourized early on in the port all the way down to the back of the valve and in the cylinder. With reference to earlier thread, I don't see specific cooling of the cylinder head through DI, if anything port injection, especially high pressure port injection, cools the cylinder head more because of fuel time in contact with head and components. Standard injection IMO cools the piston top more IMO, not necessarily reducing knock threshold because upper layers are rich enough to combust.
So overall I see similar total heat reduction in good DI and good port injection, with DI focusing more of its reduction in the in-cylinder mix which seems like a good idea because that is exactly where detonation originates and that's where you stop it, instead of cooling surfaces to cool charge, to prevent knock.
Even then, I still see the major contributor to knock resistance as concentration of fuel around the plug, with mix temps distant second.
Re high speed limits, I didn't mean to suggest in upper street engine speeds that vapourization time was a limit, but that I knew of these limits in high 5 digit speeds way beyond 4 digit speeds, but that the Audi R8 even past 8000 didn't seem to have trouble.
