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sn00k
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« Reply #30 on: June 27, 2012, 05:46:33 PM »
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i have to say i like this discussion..  well.. ill add this.. try to think outside the box for once..  im going to state that you can build an engine which is allmost impossible to make detonate, due to homogenization of the air/fuel mixture.. which would run a timing close to TDC and still get ~170% more then a conventional engines power converted from fuel to mechanical energy within the first 14 degrees of crankshaft movement(which is vital.. to those who dont know this.. after 14 degrees allmost everything is wasted in heat and not converted into mechanical energy) also, this can be done in a very lean environment, close to 22:1 to one, on normal pump gas. so, beeing hang up on older techs and "facts" doesnt really get you anywhere.. fresch thinking does.. i dare you to build your own concepts.. and yeah, i will be aiming for 400hp+/litre with this thing.. its not like thats something new around here. //Sn00b |
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ibizacupra
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« Reply #31 on: June 28, 2012, 01:11:56 AM »
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well, the question was formulated as in topic, what to use for a given power.. ofc these engines are made to run on pump gas, so no e85 fueling needs to be discoussed here.
(sure, you can raise the VE even more with race fuel, vp, e85, methanol etc etc..)
and im pretty confident the RS4 MAF will be too small for this.. and will not need to be able to calculate this flow accurately.. unless MANY hours is spent calibrating one and fabricating new tracts, air straighteners etc.
this engine will be running on pump gas, 98.4 oct, with a boost of ~43.5psi, and the VE will be very high.. so ive decided to find me one of those Pro-M 92:s.. with a 30 point transfersheet made and calibrated in flowbench.. which should be perfect for this build.
What displacement/engine is this going into? |
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lulu2003
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« Reply #32 on: June 28, 2012, 01:44:59 AM »
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23 degrees at 6000 rpm is naturally aspirated engine or VERY low boost engine timing in context of pump fuel.
I talked about 6500rpm all the time. exactly 12 hours ago I had a car on the dyno, rpm 6500: Lambda >0.85 and Ingition >20 and boost at 2300mbar, pump fuel. now what? |
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prj
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« Reply #33 on: June 28, 2012, 03:33:56 AM »
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I talked about 6500rpm all the time.
exactly 12 hours ago I had a car on the dyno, rpm 6500: Lambda >0.85 and Ingition >20 and boost at 2300mbar, pump fuel.
now what? 2300mbar absolute pressure or boost pressure? What compression ratio? If it's absolute pressure and 1.3 bar boost - then you are probably below 200hp/liter... We are talking about 300hp/liter engines here. We are also talking about port injected engines. With direct injection things are different. Also, I don't know what engine you are talking about. I just stated what timing my RS4 does, and what timing 600hp engines that I tune do before knock comes in. The 250+ hp/liter engines all run over 2 bar peak boost. |
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« Last Edit: June 28, 2012, 03:36:23 AM by prj »
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lulu2003
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« Reply #34 on: June 29, 2012, 03:24:08 AM »
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1,3 bar boost, compression ratio 9:1, slightly below 180PS/liter, classic port fuel injection. very similar to the RS4. On pump fuel a B5 RS4 can only run about 10-12 degrees timing at 6000 rpm with 19 psi boost on K04's.
And that only makes 450hp. so about 170 hp per liter what is your RS4 doing at 6500? to come to an end: let's state that HFM Sizing depends a lot on Mean effective pressure and that below 200 HP/Liter there are very good rule of thumbs as I said and extreme tunings above 2+ bar boost can vary a lot with ignition optimizing and fuel. But for both cases you can estimate a HFM size that will always be enough for xy HP or even more. |
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ibizacupra
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« Reply #35 on: June 29, 2012, 03:24:56 AM »
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seeing as the op has'nt confirmed what displacement he's referring to.. and I guess its 4cyl...
I have run 33degrees advance previously.. pump fuel, with 50/50 wmi, 1900cc 20v, 35psi boost, 9000rpm
zero det.. pump fuel shell vpower
however...
It lifted the head.. lol..
cylinder pressures is all I will say
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sn00k
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« Reply #36 on: June 29, 2012, 05:39:40 AM »
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a few posts back i wrote 1.8l base engine, and ofc a 4cyl 20v.. static compression 8.8:1.. and yeah.. VVT and custom control for dynamic compression, etc.
if your engine lifted the head id call that no more then a contruction and tuning mistake.. and yeah, extreme cylinder pressures is what im after.. but at the right time.. ~8-14degrees on the crank, after tdc.
timing is NOT one of those things where MORE is better, and id imagine that is why its called timing..
running too much advance and reaching peak expansion/pressure before the piston reaches TDC wouldnt be benificial to anyone.. and as the piston closes in on TDC it would most certainly be able to lift the head/blow the gasket.. normally it would detonate way before that.. but water/meth can supress detonation extremely well.
ive ran 38psi boost in an 1.8l 4cyl 8v engine, at 8:1 static compression and pump fuel, v-power, with good timing.. and id imagine this engine with way better combustion chambers, 5-valve tech, VVT, custom highpressure fuelsystem etc would coop real well at these pressures, should be no problems at all.
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prj
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« Reply #37 on: June 30, 2012, 01:05:49 AM »
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1,3 bar boost, compression ratio 9:1, slightly below 180PS/liter, classic port fuel injection. Yeah, exactly. 180 PS/Liter... Add 100 PS/liter, and you will see what I am talking about. Also, if you use big hotsides, with slow spoolup, you can also run more timing - but it makes the dynamics of the car bad. As for my timing, have a look... One thing is funny, that people say "pump fuel" when they are running meth injection. Meth injection is NOT pump fuel, it's like running race fuel all the time. When one says pump fuel, it means straight pump. No water/meth injection of any kind whatsoever. As for MAF sizing, I know for a fact, that my RS4, which probably makes around 440 PS right now, would make 500PS with meth injection. And if you notice, this thread was from the start talking about 300hp+ liter engines, that's why I said that it is nigh impossible to size the MAF without knowing more details about the engine or match it up to horsepower. The only thing you can say is a conservative estimate for how much horsepower it will 100% be enough in these cases and estimating horsepower from mass flow won't work. |
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« Last Edit: June 30, 2012, 01:10:24 AM by prj »
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ibizacupra
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« Reply #38 on: July 01, 2012, 07:21:09 AM »
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a few posts back i wrote 1.8l base engine, and ofc a 4cyl 20v.. static compression 8.8:1.. and yeah.. VVT and custom control for dynamic compression, etc.
if your engine lifted the head id call that no more then a contruction and tuning mistake.. and yeah, extreme cylinder pressures is what im after.. but at the right time.. ~8-14degrees on the crank, after tdc.
timing is NOT one of those things where MORE is better, and id imagine that is why its called timing..
running too much advance and reaching peak expansion/pressure before the piston reaches TDC wouldnt be benificial to anyone.. and as the piston closes in on TDC it would most certainly be able to lift the head/blow the gasket.. normally it would detonate way before that.. but water/meth can supress detonation extremely well.
ive ran 38psi boost in an 1.8l 4cyl 8v engine, at 8:1 static compression and pump fuel, v-power, with good timing.. and id imagine this engine with way better combustion chambers, 5-valve tech, VVT, custom highpressure fuelsystem etc would coop real well at these pressures, should be no problems at all.
Hmmm. you will have to consider cylinder pressures, as your power goals (unrealistic imho) from the spec tou elude to, are not going to be fulfilled.. Det threshold was no indication of the pressures being produced, and despite tensile head studs being in place the engine whilst fine when being tuned on the dyno, over many runs, it did let go when on track on its higher boost. You will have fun getting to your goals. I suspect you wont get close however. and as for trying to use a MAF on this project, and scale a maf, whilst the rest of the me7 will be blind to boost levels etc..... you are asking a lot. good luck  |
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« Last Edit: July 01, 2012, 07:24:21 AM by ibizacupra »
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sn00k
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« Reply #39 on: July 01, 2012, 03:24:16 PM »
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regarding MAF, yeah, me7 uses this as primary source for measuring airflow, which is 110% vital, and then MAP for diagnostics and reference. so it doesnt matter if the map cannot register over 2550mbar. ofc i know that i will have to run open loop based on flow and n75 dutycycle after 1.5bar boost, that isnt asking alot, that is childsplay, and yeah, i sure will be using MAF.. removing this vital part would make the me7 truly blind. i suspect you dont have a clue as to what the specs are of this engine, and id imagine from your replies that you wouldnt understand half of whats going into it, as you havent ever ran a compound setup and definitely not designed your own system, with variable valvetiming, custom grind camshafts and a custom designed fueling system for extreme atomization etc.. or have you?  not trying to be rude, just trying to state that this is NOT a tuned oem engine where you would hook up a big turbo and boost the crap out of things till its blown to pieces. high cylinder pressures at the right timing in the otto-cycle = power. running these boostlevels you would look to o-ring+copper gasket or even labyrinth seal the head to the block. an interesting fact is that bmw once used a compound setup in an old f1 engine.. which produced 1400hp in an 1.5litre engine at 3.9bar boost. good luck thanks |
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professor
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« Reply #40 on: July 02, 2012, 02:39:40 AM »
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Good luck from me too looking fw to read news on this topic |
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Seat Ibiza MK4 Cupra 1.8t 20V, stg3.
"Those 1.8T 20V machines are really tough" ©
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ibizacupra
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« Reply #41 on: July 26, 2012, 09:41:41 AM »
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regarding MAF, yeah, me7 uses this as primary source for measuring airflow, which is 110% vital, and then MAP for diagnostics and reference. so it doesnt matter if the map cannot register over 2550mbar. ofc i know that i will have to run open loop based on flow and n75 dutycycle after 1.5bar boost, that isnt asking alot, that is childsplay, and yeah, i sure will be using MAF.. removing this vital part would make the me7 truly blind. i suspect you dont have a clue as to what the specs are of this engine, and id imagine from your replies that you wouldnt understand half of whats going into it, as you havent ever ran a compound setup and definitely not designed your own system, with variable valvetiming, custom grind camshafts and a custom designed fueling system for extreme atomization etc.. or have you? not trying to be rude, just trying to state that this is NOT a tuned oem engine where you would hook up a big turbo and boost the crap out of things till its blown to pieces. high cylinder pressures at the right timing in the otto-cycle = power. running these boostlevels you would look to o-ring+copper gasket or even labyrinth seal the head to the block. an interesting fact is that bmw once used a compound setup in an old f1 engine.. which produced 1400hp in an 1.5litre engine at 3.9bar boost. thanks as for specs.. not a clue.. as you have'nt mentioned them.. and I am not a mind reader I am well aware what old F1 turbo motors did.. ...and as for what I know and do, and have done, you are equally as ignorent.. hope your project goes well. maybe you will share the results if they happen. |
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s5fourdoor
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« Reply #42 on: July 26, 2012, 11:34:06 AM »
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i have to say i like this discussion.. well.. ill add this.. try to think outside the box for once.. im going to state that you can build an engine which is allmost impossible to make detonate, due to homogenization of the air/fuel mixture.. which would run a timing close to TDC and still get ~170% more then a conventional engines power converted from fuel to mechanical energy within the first 14 degrees of crankshaft movement(which is vital.. to those who dont know this.. after 14 degrees allmost everything is wasted in heat and not converted into mechanical energy) also, this can be done in a very lean environment, close to 22:1 to one, on normal pump gas. so, beeing hang up on older techs and "facts" doesnt really get you anywhere.. fresch thinking does.. i dare you to build your own concepts.. and yeah, i will be aiming for 400hp+/litre with this thing.. its not like thats something new around here. //Sn00b no offense man but you are trolling your own thread with parts of this response. however you definitely get credit for how awesome a read this thread has been. fresh thinking is what's up, hells yeah. |
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