A rev happy 16v with lots of power sounds even better... In fact that could be a more interesting prospect than a 20vt for the cordy
reducing capacity of 1.8T
- Thread starter RobT
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A rev happy 16v with lots of power sounds even better... In fact that could be a more interesting prospect than a 20vt for the cordy
PMSL - dont think this is right somehow but anyone spot where ?
I worked out that a well built competition spec (105% VE) 1400 turbo revving to 8000-10000rpm and between 1 and 2 bar boost would need 43-54 lb air / min
From what bill says, this seems about right
Now if combustion occurrs at the power friendly figure of 12.6:1, this will result in 3.41 - 4.28 lb petrol burned / min.
Petrol has a energy content of 48000 kJ/kg or in old money, 21778 kJ/lb
http://www.aidfueloils.co.uk/common/fueloils.htm
http://www.engineeringtoolbox.com/fuels-higher-calorific-values-d_169.html
So energy produced would be 74264 - 93212 kJ/min
Using this:
http://www.translatorscafe.com/cafe...sepower-[hp-to-kilojoule-per-minute-[kJ/min]/
I worked out hp - get this, 1659-2083 hp.
So either I have something very wrong or combustion is VERY inefficient.
I worked out that a well built competition spec (105% VE) 1400 turbo revving to 8000-10000rpm and between 1 and 2 bar boost would need 43-54 lb air / min
From what bill says, this seems about right
Now if combustion occurrs at the power friendly figure of 12.6:1, this will result in 3.41 - 4.28 lb petrol burned / min.
Petrol has a energy content of 48000 kJ/kg or in old money, 21778 kJ/lb
http://www.aidfueloils.co.uk/common/fueloils.htm
http://www.engineeringtoolbox.com/fuels-higher-calorific-values-d_169.html
So energy produced would be 74264 - 93212 kJ/min
Using this:
http://www.translatorscafe.com/cafe...sepower-[hp-to-kilojoule-per-minute-[kJ/min]/
I worked out hp - get this, 1659-2083 hp.
So either I have something very wrong or combustion is VERY inefficient.
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added:
http://ffden-2.phys.uaf.edu/102spri...tes/Zach's Web Project Folder/EICE - Main.htm
Thermal efficiency and mechanical efficeincy is about 20-34% it says - HOW CRAP IS THAT !
this gives hp of 331.8-416 to 564-708 (first at 20% and second at 34% efficiencies)
Not far off.....
just goes to show how much power we could get from making the engines more thermally efficient......
http://ffden-2.phys.uaf.edu/102spri...tes/Zach's Web Project Folder/EICE - Main.htm
Thermal efficiency and mechanical efficeincy is about 20-34% it says - HOW CRAP IS THAT !
this gives hp of 331.8-416 to 564-708 (first at 20% and second at 34% efficiencies)
Not far off.....
just goes to show how much power we could get from making the engines more thermally efficient......
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ceramic coated internals would assist in the products of combustion going to pushing pistons down and not heating everything.... more bang for buck so to speak.
interesting calcs
sorry i was well asleep there ffs - i meant the other way round, shorter throw crank and maybe longer rods help it rev higher like a motorbike style crank
mind you probably more chance of snapping one then but never seen a bike throw a rod yet but then they got less torque i suppose but sounds like you found one anyway
thermal efficency wise isnt pump fuel something daft like 1 in 5 or 6 parts is used the rest wasted or something like that - talking school notes now lol
jimmy8v
Guest
you mean a bit like this, without the supercharger...
http://www.vankronenburg.nl/PHP/page.php?page=projects_uk&pid=3&b=VAG
http://www.vankronenburg.nl/PHP/page.php?page=projects_uk&pid=3&b=VAG
VAG 1170cc 20V Turbo & Supercharger
Van Kronenburg Autosport wil launch a new concept in the 2000 cc class during 2006. A Audi 1800 cc 20V engine has been destroked to 1170 cc and is equipped with a Garrett turbo (GT series) and an Eaton supercharger. Due to its small cylinder displacement, the engine meets all FIA requirements for the 2000 cc atmospheric class(turbo factor of 1.7). The engine can be used in long distance races from 4 up to 24 hours. Dyno testing at our facility resulted in the following specifications: 385 HP @ 9400 rpm and 340 Nm @ 6000 rpm. Altough this may seem like a lot we believe that this concept has even bigger potential. More information be added soon.
![[B)]](/forums/styles/seatcupra/oldforumsmileys/shades.gif "Cool [B)]")
exactly like that! but just with a turbo and a bit more cc
equivalence for turbo in UK is generally 1.4 making a 1400cc T engine ok in upto 2000cc atmo classes
Equivalence in Euro / FIA is 1.7 which IMO is more even - 1,4 gives a massive advantage to a turbo lump hence me (and others) thinking of taking advantage of this
top find there for your first post Jimmy ! ta
equivalence for turbo in UK is generally 1.4 making a 1400cc T engine ok in upto 2000cc atmo classes
Equivalence in Euro / FIA is 1.7 which IMO is more even - 1,4 gives a massive advantage to a turbo lump hence me (and others) thinking of taking advantage of this
top find there for your first post Jimmy ! ta
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Not easy at all to work out - the higher the CR the better as this improves efficiency and gives less lag - just need to make sure detonation is managed but modern ECU's are good at this - more CR possible with better fuel - tough question.....
i suspect the biggest challenge, and also the key to releasing real power will to correct manage the combustion burn speed, remember 400bhp is 400bhp, no matter if it is nicely spread across 8 cyls of a 5.0 V8, or 4 tiny ones of 1.4l.
if you want to rev it hard, then you will have to burn 400bhp worth of air and fuel in very short period, and also, as the cylinders are so small (with a small surface area) the temp & pressure at the end of compression will be large, hence the engine will be very detonation prone, forcing you to retard the ignition, loosing power, and also, increasing the requirement for over fueling away from LBT to limit EGT's
On a turbo, the extra low lift valve curtain area advantage of a five valve layout is pointless, and burn rate will be crucial, so a high squish, high charge motion, high CR combustion system will be required. Also, due to the fact you will need a big turbo (in fact a 400bhp sized turbo, funny that) it won't spool till maybe 5krpm (small cc, big ports, long tuned exhaust manifold etc) which may actually help limit detonation as you won't be able to make big boost at low (<4k) rpm, where typically detonation is worst due to low charge motion and slow brn rate.
if you want to rev it hard, then you will have to burn 400bhp worth of air and fuel in very short period, and also, as the cylinders are so small (with a small surface area) the temp & pressure at the end of compression will be large, hence the engine will be very detonation prone, forcing you to retard the ignition, loosing power, and also, increasing the requirement for over fueling away from LBT to limit EGT's
On a turbo, the extra low lift valve curtain area advantage of a five valve layout is pointless, and burn rate will be crucial, so a high squish, high charge motion, high CR combustion system will be required. Also, due to the fact you will need a big turbo (in fact a 400bhp sized turbo, funny that) it won't spool till maybe 5krpm (small cc, big ports, long tuned exhaust manifold etc) which may actually help limit detonation as you won't be able to make big boost at low (<4k) rpm, where typically detonation is worst due to low charge motion and slow brn rate.
Some numbers for ya!
If you take:
engine Cap: 1400cc
Manifold Vol eff: 100%
Plenum Air temp: 35 DegC
Brake Specific Air Consumption: 3.70 Kg/kWHr (typical number for well developed "road engine")
Turbo Compressor efficiency: 73%
Ambient Air temp: 20 degC
AFR(): 12.5 to 1 (Lam 0.87)
MAF(Kg/s):0.309
Power(bhp):400
Tot Fuel Flow(kg/Hr):90
then for the flowing 5 cases of peak power at different revs:
case 1 case 2 case 3 case 4 case 5
peak power spd(rpm): 6500 7500 8500 9500 10500
MAP(kPa abs): 360 310 275 245 220
I/C heat rejection(kW): 53 45 40 34 29
I/C req'd effectiveness(%): 92 90 88 87 85
Torque(@ peak power rpm)(Nm): 442 380 337 300 270
BMEP(@ peak power rpm)(bar): 39.6 34 30 27 24
OR:
Spend a load of money, get Everything as optimised as possible, and get to the same BSAC as a WRC car (gonna be difficult as WRC's don't rev to 10k!) at 2.7Kg/kWHr and case 5 with 400 BHP becomes:
peak power spd(rpm): 10500
MAP(kPa abs): 162
MAF(Kg/s): 0.225
Tot Fuel Flow(kg/Hr): 65
I/C heat rejection(kW): 14
I/C req'd effectiveness(%): 77
OR:
get it horribly wrong, get a BSAC of 4.5Kg/kWHr (think V.poor road car)
and 400bhp @ 10.5krpm is:
peak power spd(rpm): 10500
MAP(kPa abs): 275
MAF(Kg/s): 0.375
Tot Fuel Flow(kg/Hr): 108
I/C heat rejection(kW): 47
I/C req'd effectiveness(%): 90
So hopefully, whats evident from those is that efficiency is everything!! lol
If you take:
engine Cap: 1400cc
Manifold Vol eff: 100%
Plenum Air temp: 35 DegC
Brake Specific Air Consumption: 3.70 Kg/kWHr (typical number for well developed "road engine")
Turbo Compressor efficiency: 73%
Ambient Air temp: 20 degC
AFR(): 12.5 to 1 (Lam 0.87)
MAF(Kg/s):0.309
Power(bhp):400
Tot Fuel Flow(kg/Hr):90
then for the flowing 5 cases of peak power at different revs:
case 1 case 2 case 3 case 4 case 5
peak power spd(rpm): 6500 7500 8500 9500 10500
MAP(kPa abs): 360 310 275 245 220
I/C heat rejection(kW): 53 45 40 34 29
I/C req'd effectiveness(%): 92 90 88 87 85
Torque(@ peak power rpm)(Nm): 442 380 337 300 270
BMEP(@ peak power rpm)(bar): 39.6 34 30 27 24
OR:
Spend a load of money, get Everything as optimised as possible, and get to the same BSAC as a WRC car (gonna be difficult as WRC's don't rev to 10k!) at 2.7Kg/kWHr and case 5 with 400 BHP becomes:
peak power spd(rpm): 10500
MAP(kPa abs): 162
MAF(Kg/s): 0.225
Tot Fuel Flow(kg/Hr): 65
I/C heat rejection(kW): 14
I/C req'd effectiveness(%): 77
OR:
get it horribly wrong, get a BSAC of 4.5Kg/kWHr (think V.poor road car)
and 400bhp @ 10.5krpm is:
peak power spd(rpm): 10500
MAP(kPa abs): 275
MAF(Kg/s): 0.375
Tot Fuel Flow(kg/Hr): 108
I/C heat rejection(kW): 47
I/C req'd effectiveness(%): 90
So hopefully, whats evident from those is that efficiency is everything!! lol
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