20v 5cyl turbo 944 project
01-31-2008, 10:21 PM
#61
Drifting
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Based on comment above - about intended to go sideways -
if this is a drifter car - that setup may be very good
over-sprung/over-valved rock hard rear with plenty of HP may lend itself well to drifting
if this is a drifter car - that setup may be very good
over-sprung/over-valved rock hard rear with plenty of HP may lend itself well to drifting
01-31-2008, 11:26 PM
#62
Formula One Spin Doctor
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Well the engine was porsches atempt to make it more of a porsche by useing an in house engine. As a result of not wanting to develop a full new engine they cut a v8 in half, this was also so that it would not compete in the same market segment as the the 6 cyl. 911s. The main problem with the engine is the head, I don't have a single posative thing to say about it. The other problem with the engine is is its lack of cylinders. It is to big to be a 4 cyl. so they had to use mitsubishi technology to fix this (balance shafts). Less cylenders means less valves, all ready a problem with this engine, and a very wide cylinder for the flame front to travel accross. Hello detonation. Oh and did i mention the turbo is in the wrong place, its like porsche went out of their way to make a ****ty engine. unless you want 1000 bhp , then both would not be my choice ...
The fix for all of this would have been the 20v 5 cyl. engine. lots of vlaves, smaller cylinders and a 5 cyl. engines have no vibration issues. It is super strong and its group B rally history speaks for its performance, also look into its upgrade path, Dahlback does great stuff with it.
What is wrong with the rest of the car? Nothing at all its great. I love the looks and handleing. I also like that it is not pure porsche and is a VW that Vw decided not to make so porsche had Audi make it for them. I come from an Audi back ground and like them alot, it is one of the things that led me buy the car. I just wish I had done better research on the engine.
The fix for all of this would have been the 20v 5 cyl. engine. lots of vlaves, smaller cylinders and a 5 cyl. engines have no vibration issues. It is super strong and its group B rally history speaks for its performance, also look into its upgrade path, Dahlback does great stuff with it.
What is wrong with the rest of the car? Nothing at all its great. I love the looks and handleing. I also like that it is not pure porsche and is a VW that Vw decided not to make so porsche had Audi make it for them. I come from an Audi back ground and like them alot, it is one of the things that led me buy the car. I just wish I had done better research on the engine.
I would have to disagree it is a ****ty engine based on the reasons you have given , the zo6 corvette has a side plug big bore engine also. Having worked with both Audi and 951 power plants , the 951 engine is unothrodox in a very porsche like manner, but a good power plant nonetheless,
The Audi being all steel bottom is a very stout item , but it came with a sideplug head just the same , that flowed way less than any 951. THe 951 is the better powerplant handsdown , if you are comparing 968 powerplant to s2 20V powerplant the audi head still does not flow as well as the 968 head.
Building a 1000 bhp behemoth might suite the audi steel platform vs the 951 open deck platform , but it does not make it a ****ty engine ..... i do like both powerplants, but If the goal is 1000 bhp , then both would not be my choice ...
What i was commenting on was RP very naive statement on suspension and weight balance. IN the Grandam series the mustangs are tube chassis carbon body V8 vs a tub chassis 6 cyl porsches, that is not comparing apples...
Put a ford v6 engine in a tub chassis mustang and beat a 996 cup and show me .... there is no comparison, a mustang is a outdated piece of crap period and uses superior engine capacity to make track time in series optimized for american crapoooola...........
RP,
You where the one that made the statements , regarding the outdated mustang crapooola i just reiniterated, based on the cut and paste distorted response that did not address the issues, i would say , Lawyer ....
01-31-2008, 11:31 PM
#63
Herr Unmöglich
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I am not reading 5 pages of comments to say that this as a frickin awesome project. This motor was dominant for the time and the fact that it can be built today to such massive horsepower and still maintain durability.... 
I am an Audi fan for sure, and really miss mine... the coupe Quattro was just the coolest, and the I5 turbo is one of my favorite motors of all time.
I don't care what anyone could say. Awesome.
I am an Audi fan for sure, and really miss mine... the coupe Quattro was just the coolest, and the I5 turbo is one of my favorite motors of all time.
I don't care what anyone could say. Awesome.
01-31-2008, 11:45 PM
#64
Three Wheelin'
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02-01-2008, 12:16 AM
#65
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Not to harp on for too long however, if what I believe is to be the case that the Audi has an iron/steel block v's alloy open deck design? Ok so what happens if we strengthen our block by pinning the girdle, installing steel sleeves, putting in a deckplate as in my avatar, larger headstuds, and either having a highflow 8v head or even going up to a 16v? Ok we can assume that apparently it's better to spin more pistons that are smaller than fewer that are larger, however if these Audis are getting a reputed 800hp+ why can't we get somewhere in the vicinity if we modify ours as mentioned above. Also if big pistons are meant to be more prone to pre-ignition, why aren't all these big block V8's hampered by this issue?
02-01-2008, 12:35 AM
#66
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big bore also means bigger valves
The v8s have less detonation / pre-ignition problems because they are not turbocharged.
(From what I have heard) The turbocharger and pump gas condition narrows the area between detonation and dangerously high egt's as boost pressure and and exhaust pressure increase. In other words, we are forced to run a certain amount of advance to keep from burning valves and frying turbos, and this amount becomes very close to the limit that our cylinders can handle without detonating as boost increases.
The v8s have less detonation / pre-ignition problems because they are not turbocharged.
(From what I have heard) The turbocharger and pump gas condition narrows the area between detonation and dangerously high egt's as boost pressure and and exhaust pressure increase. In other words, we are forced to run a certain amount of advance to keep from burning valves and frying turbos, and this amount becomes very close to the limit that our cylinders can handle without detonating as boost increases.
02-01-2008, 01:17 AM
#67
Drifting
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5 cylinder's believe it it or not has far better balance and less harmonics issues
all the fancy deck plates and stud girdles wont stop the crank case flexing .
i still think full length studs are the way forward for the 944 motor .
so the head studs tie into the crank case or main caps the way a bike or plane engine does .all big things do ping more remember to judge them considering specific power outputs (hp per litre) and with the same fuel .
I don't think the 944 it good beyond 600 hp
you could probably go as fast with the 600hp 3.0 as an 750hp 2.3 due to the power delivery
all the fancy deck plates and stud girdles wont stop the crank case flexing .
i still think full length studs are the way forward for the 944 motor .
so the head studs tie into the crank case or main caps the way a bike or plane engine does .all big things do ping more remember to judge them considering specific power outputs (hp per litre) and with the same fuel .
I don't think the 944 it good beyond 600 hp
you could probably go as fast with the 600hp 3.0 as an 750hp 2.3 due to the power delivery
02-01-2008, 01:22 AM
#68
Rennlist Member
big bore also means bigger valves
The v8s have less detonation / pre-ignition problems because they are not turbocharged.
(From what I have heard) The turbocharger and pump gas condition narrows the area between detonation and dangerously high egt's as boost pressure and and exhaust pressure increase. In other words, we are forced to run a certain amount of advance to keep from burning valves and frying turbos, and this amount becomes very close to the limit that our cylinders can handle without detonating as boost increases.
The v8s have less detonation / pre-ignition problems because they are not turbocharged.
(From what I have heard) The turbocharger and pump gas condition narrows the area between detonation and dangerously high egt's as boost pressure and and exhaust pressure increase. In other words, we are forced to run a certain amount of advance to keep from burning valves and frying turbos, and this amount becomes very close to the limit that our cylinders can handle without detonating as boost increases.
Ok let's assume that the V8s are twin turbocharged which is not uncommon. Also assume that the tuning is good.
Based on the narrow band between detonation and high egts also being present in these high hp 5 cylinder Audis. I guess I'm reaching for the age old question of why we lag so far behind on hp compared to many other motors. Just looking at the Audi block/head it seems redolent of ours too so it furthers my curiosity.
02-01-2008, 02:44 AM
#69
Formula One Spin Doctor
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Not to harp on for too long however, if what I believe is to be the case that the Audi has an iron/steel block v's alloy open deck design? Ok so what happens if we strengthen our block by pinning the girdle, installing steel sleeves, putting in a deckplate as in my avatar, larger headstuds, and either having a highflow 8v head or even going up to a 16v? Ok we can assume that apparently it's better to spin more pistons that are smaller than fewer that are larger, however if these Audis are getting a reputed 800hp+ why can't we get somewhere in the vicinity if we modify ours as mentioned above. Also if big pistons are meant to be more prone to pre-ignition, why aren't all these big block V8's hampered by this issue?
Assuming you mean Bigger valves are better...for higher hp applications?
Ok let's assume that the V8s are twin turbocharged which is not uncommon. Also assume that the tuning is good.
Based on the narrow band between detonation and high egts also being present in these high hp 5 cylinder Audis. I guess I'm reaching for the age old question of why we lag so far behind on hp compared to many other motors. Just looking at the Audi block/head it seems redolent of ours too so it furthers my curiosity.
Ok let's assume that the V8s are twin turbocharged which is not uncommon. Also assume that the tuning is good.
Based on the narrow band between detonation and high egts also being present in these high hp 5 cylinder Audis. I guess I'm reaching for the age old question of why we lag so far behind on hp compared to many other motors. Just looking at the Audi block/head it seems redolent of ours too so it furthers my curiosity.
Big bore short stroke engines are less detonation prone than small bore long stroke engines , Having a large bore will not cause more detonation.. the 944 issue is not the large bore , but from having a side plug head , this is not a problem in a 968 engine as it's centrally located spark plug and CC design does not make this an issue....
I know of no other 2 v 4 cylinder engine more potent than a 951 , regardless of it's idiosyncrasies ......Those big BHP audi factory engines share very little with there street counterpart and the Audi /VW heads in stock form flow less than the porsche head in stock form , but they do benefit from an all steel bottom end.
02-01-2008, 03:01 AM
#70
Rennlist Member
5 cylinder's believe it it or not has far better balance and less harmonics issues
all the fancy deck plates and stud girdles wont stop the crank case flexing .
i still think full length studs are the way forward for the 944 motor .
so the head studs tie into the crank case or main caps the way a bike or plane engine does .all big things do ping more remember to judge them considering specific power outputs (hp per litre) and with the same fuel .
I don't think the 944 it good beyond 600 hp
you could probably go as fast with the 600hp 3.0 as an 750hp 2.3 due to the power delivery
all the fancy deck plates and stud girdles wont stop the crank case flexing .
i still think full length studs are the way forward for the 944 motor .
so the head studs tie into the crank case or main caps the way a bike or plane engine does .all big things do ping more remember to judge them considering specific power outputs (hp per litre) and with the same fuel .
I don't think the 944 it good beyond 600 hp
you could probably go as fast with the 600hp 3.0 as an 750hp 2.3 due to the power delivery
I have heard of 951's with over 1000hp from Scott Gomes.
Depending on the circuit, yeah the 600hp 3.0L could easily beat the 750hp 2.3L.
02-01-2008, 03:02 AM
#71
Rennlist Member
Big bore short stroke engines are less detonation prone than small bore long stroke engines , Having a large bore will not cause more detonation.. the 944 issue is not the large bore , but from having a side plug head , this is not a problem in a 968 engine as it's centrally located spark plug and CC design does not make this an issue....
I know of no other 2 v 4 cylinder engine more potent than a 951 , regardless of it's idiosyncrasies ......Those big BHP audi factory engines share very little with there street counterpart and the Audi /VW heads in stock form flow less than the porsche head in stock form , but they do benefit from an all steel bottom end.
I know of no other 2 v 4 cylinder engine more potent than a 951 , regardless of it's idiosyncrasies ......Those big BHP audi factory engines share very little with there street counterpart and the Audi /VW heads in stock form flow less than the porsche head in stock form , but they do benefit from an all steel bottom end.
02-01-2008, 02:50 PM
#72
That car looks awesome. The 5 cyl. Audi engine looks like a great choice and a street version would be cool. I'd think you could tune it for a good combo of gas mileage and power. The quickest way to big power looks like the V8 Vette conversions but fuel economy would suffer. I had a 10th anniversary Trans Am with a 6.6L but when I drove it, I could almost see the gas gauge needle move. I'd love to have something like the Audi set-up for a daily driver.
The 951 engine is good with lots of potential. I'm working on a 6 cyl. project that should yield good power as well as gas mileage similar to the 951 since the ECM on this V6 has a lean cruise mode for the highway. Parts, maintenance and repairs should be easy. Having a timing chain is nice, too, but a timing chain can be fitted to the 951 engine with a good bit of modifying. Here's the progress on the 6 cyl. 944...
http://i145.photobucket.com/albums/r...w/IMG_0539.jpg
http://i145.photobucket.com/albums/r...w/IMG_0522.jpg
http://i145.photobucket.com/albums/r...w/IMG_0537.jpg
The 951 engine is good with lots of potential. I'm working on a 6 cyl. project that should yield good power as well as gas mileage similar to the 951 since the ECM on this V6 has a lean cruise mode for the highway. Parts, maintenance and repairs should be easy. Having a timing chain is nice, too, but a timing chain can be fitted to the 951 engine with a good bit of modifying. Here's the progress on the 6 cyl. 944...
http://i145.photobucket.com/albums/r...w/IMG_0539.jpg
http://i145.photobucket.com/albums/r...w/IMG_0522.jpg
http://i145.photobucket.com/albums/r...w/IMG_0537.jpg
02-01-2008, 03:22 PM
#74
Rennlist Member
What V6 is that? Fits in easily and looks shorter ie further back than even our i4.
Now if you just whack on a couple of VV turbos and then........
Now if you just whack on a couple of VV turbos and then........