Why dont more people just turbo the S2?
10-19-2007, 07:50 PM
#61
Racer
carbonrevo, I used the inserts from Jager Engineering in Canada, same link as aribop posted. They are some sort of silicon with an adhesive backing, good quality, about $40 and in different colours.
rgds
mike
rgds
mike
10-19-2007, 07:56 PM
#62
Racer
3.1 liter, darton sleeves, JE pistons, 8.9 static comp. ratio
Pauter rods, crank and head work by Brian Pauter, T04E with Garret hot side
Breathers run to cheap plastic cacth can AOS gone.
Pauter rods, crank and head work by Brian Pauter, T04E with Garret hot side
Breathers run to cheap plastic cacth can AOS gone.
10-20-2007, 02:30 AM
#63
Rennlist Member
I had a 3.0 liter 8v before I had my 16v built. For my experience, there was no comparison. My 16 valve is a much, much better motor. I really don't care about the hp numbers as much as the tq. I want to go as fast as possible with the biggest push in the back.
It also took a lot of modifying my 90'S2 block to make everything work together the way it has. My motor came with a warranty and is able to do back to back 30 minute sessions. It even came with a warranty. What I got was a 480 whp, 470tq motor on a load dyno dynamics dyno. IIRC it was 509whp without a load. It just cost an arm and a leg.
Now, I'm looking to upgrade with some bolt on parts and I hope it doesn't ruin the reliability of the motor.
On a side note, the tranny did not hold up. It was a newly rebuilt 89 Turbo S LSD. I broke second gear. Most of you know I have now bought a 968 six speed. Much stronger. Just trying to find gears for it now. (If anyone knows a good source for Audi gears, let me know. They are interchangeable and hopefully much cheaper)
It also took a lot of modifying my 90'S2 block to make everything work together the way it has. My motor came with a warranty and is able to do back to back 30 minute sessions. It even came with a warranty. What I got was a 480 whp, 470tq motor on a load dyno dynamics dyno. IIRC it was 509whp without a load. It just cost an arm and a leg.
Now, I'm looking to upgrade with some bolt on parts and I hope it doesn't ruin the reliability of the motor.
On a side note, the tranny did not hold up. It was a newly rebuilt 89 Turbo S LSD. I broke second gear. Most of you know I have now bought a 968 six speed. Much stronger. Just trying to find gears for it now. (If anyone knows a good source for Audi gears, let me know. They are interchangeable and hopefully much cheaper)
10-20-2007, 04:41 AM
#64
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How do we actually know which is stronger a 968 internal part (rod, piston, etc) or an S2, 951, 944na?
Is there some kind of scientific proof that has tested the strength of the parts? I ask because we have many people contradicting each other. One person says stock 968 parts are fine other say "no way... have to use 951 rods." It sounds like mostly rumors and hearsay.
Other builder charge thousands of dollars to knife edge and lighten everything inside their engines, then you have John Doe saying he's using all stock and getting 400-500whp.
I'd like to see some scientific strength testing, not just people guessing about the differences based on something they heard from someone else who saw some guy at a track who said his brother had 951 rods.
It also makes no sense that a 3.0 would be less responsive than a 2.5. I've heard you can get cams that put the powerband wherever you want.
Is there some kind of scientific proof that has tested the strength of the parts? I ask because we have many people contradicting each other. One person says stock 968 parts are fine other say "no way... have to use 951 rods." It sounds like mostly rumors and hearsay.
Other builder charge thousands of dollars to knife edge and lighten everything inside their engines, then you have John Doe saying he's using all stock and getting 400-500whp.
I'd like to see some scientific strength testing, not just people guessing about the differences based on something they heard from someone else who saw some guy at a track who said his brother had 951 rods.
It also makes no sense that a 3.0 would be less responsive than a 2.5. I've heard you can get cams that put the powerband wherever you want.
10-20-2007, 05:27 AM
#65
Rennlist Member
I'd also like this to be extended to the gearbox. You hear the same conjecture about the 5 speeds v's the 6 speeds.
10-20-2007, 07:15 AM
#66
Rocket Scientist
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AOS is gone as in you plugged the AOS holes in the block or welded them shut? And you only vent from the valve cover as seen in the pic? How long have you been running the motor? Is it dry sumped?
10-20-2007, 11:10 AM
#67
Rennlist Member
Are they wet or dry sleeves?
10-20-2007, 11:42 AM
#68
Racer
Bottom AOS port plugged, top port is another breather with same size hose as ones on valve cover. The sleeves are dry, not MID but they have a wide flange at the top, cylinder area of block is milled lower then deck, sleeves installed and then the whole thing re-decked. This was a pain as the #4 cylinder wall kept cracking when boring it out for the sleeve to be installed. Finally had a guy weld up the back of the block and the entire bore with material then re-bord #4I have been rinning it 3 or 4 weekends a year, I only run about .8 or .9 bar boost, made 426 at the wheels during tuning, I figured this was enough. The texas heat is not kind to turbo vehicles running hard on the track so kinda felt this was playing it safe
10-20-2007, 11:47 AM
#69
Racer
Oh ya, not dry sumped, I try to only spin it up to 6500 or so, maybe in the future but funds are tight right now, and this thing is expensive enough to run as it is. Thanks for all the interest, I dont post much, cant type, but I enjoy reading all you guys experiences.
10-22-2007, 01:24 PM
#72
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you hear some guys talking about 88 beings stronger in the trans or this year or that year not having a strong torque tube, but how does everyone really know this? I've heard of guys running na transmisions in their V8 ls1 944.
10-22-2007, 01:37 PM
#73
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I think a supercharger would be better than turbo.
You can still generate around 10-12 psi with a twin screw super charger and have much less lag. Your top end might not be as strong, but on the track (especially a tight one), it seems like a better choice - at least in my head it does. Super charging an N/A car is usually easier than turbo charging too.
As far as the logistics and reliability of the car afterwards, I have no clue. But, then again, how reliable is a highly modified 951? Probably not everyday driver, stop and go traffic, where 25 miles takes 1 hour kind of reliable... But we're not looking for that (at least I'm not) - that's what VWs, Hondas, Toyotas, Mini Coopers etc. etc. are for.
As for what it takes to make a turbo - it seems like you haven't seen the old 80's add by Porsche "What it takes to make a turbo." You'd most likely have to do some driveline/transmission upgrades to deal with all of that extra torque; modified 951s break that stuff already. You need a lot more than what you listed NZ951 - if you want it to last more than 500 miles and 3 clutch drops. And in the end, you just end up with a half-assed version of a 951 that's more expensive and less reliable.
Super charging seems like it would be more effective.
You can still generate around 10-12 psi with a twin screw super charger and have much less lag. Your top end might not be as strong, but on the track (especially a tight one), it seems like a better choice - at least in my head it does. Super charging an N/A car is usually easier than turbo charging too.
As far as the logistics and reliability of the car afterwards, I have no clue. But, then again, how reliable is a highly modified 951? Probably not everyday driver, stop and go traffic, where 25 miles takes 1 hour kind of reliable... But we're not looking for that (at least I'm not) - that's what VWs, Hondas, Toyotas, Mini Coopers etc. etc. are for.
As for what it takes to make a turbo - it seems like you haven't seen the old 80's add by Porsche "What it takes to make a turbo." You'd most likely have to do some driveline/transmission upgrades to deal with all of that extra torque; modified 951s break that stuff already. You need a lot more than what you listed NZ951 - if you want it to last more than 500 miles and 3 clutch drops. And in the end, you just end up with a half-assed version of a 951 that's more expensive and less reliable.
Super charging seems like it would be more effective.
10-22-2007, 01:56 PM
#74
Racer
FWIW I 've been running a stock 968 6 speed for the last three years.
I always thought I drove pretty agressively but more than one person riding along have that I am easy on that part of the equipment, and these guys were hard core racers, been doing a lot longer than I have.
I always thought I drove pretty agressively but more than one person riding along have that I am easy on that part of the equipment, and these guys were hard core racers, been doing a lot longer than I have.
10-22-2007, 02:26 PM
#75
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It's a proven point already that thicker headgasket mod works with 3.0 engines allowing decent boost (up to 18-20 psi) and spectacular power numbers. Markus951 968 engine was STOCK sans Cometic headgasket and 951 rods and made 567 hp @ 1.35 bar.
Markus changed the rods. This is not a stock S2 motor. With a piston change he would basically have a 3.0 like what I'm talking about in the first place. If Markus changed the rods he pulled the motor and went through everything but the pistons. Because he used the stock pistons, he had to lower the compression using a thicker headgask. This motor is basically a 3.0 conversion tubo motor, sans the piston.
I'm assuming that the original intent of this post was to not have to pull the motor and basically do a rebuild.
George
Markus changed the rods. This is not a stock S2 motor. With a piston change he would basically have a 3.0 like what I'm talking about in the first place. If Markus changed the rods he pulled the motor and went through everything but the pistons. Because he used the stock pistons, he had to lower the compression using a thicker headgask. This motor is basically a 3.0 conversion tubo motor, sans the piston.
I'm assuming that the original intent of this post was to not have to pull the motor and basically do a rebuild.
George