S2 Turbo Project
#31
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I've always believed that Porsche didn't use the 16 valve head in 968 turbos because 1) it was a lot cheaper to use the 951 stuff instead and 2) they got 300+hp 911-spanking performance anyway.
1981 944 GTP race car had a turbocharged 16-valve engine btw
Personally, I love the idea of a 3-liter 16v turbo engine. Too bad I'm not going to afford one in many years... but who knows, maybe some day!
1981 944 GTP race car had a turbocharged 16-valve engine btw
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Personally, I love the idea of a 3-liter 16v turbo engine. Too bad I'm not going to afford one in many years... but who knows, maybe some day!
#32
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Fen:
[QB]Porsche didn't use the 16V head on the 968 Turbo S. Now there must have been a reason for that because ALL 968's are 16V, therefore the head is not suitable for Turbocharging IMHO.
QB]</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">From what I have heard, the 16 valve head is not a problem for the turbocharging, it is the variocam that was in the 968's. The 16 valve head will also be able to breathe a lot better in the higher RPM's
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> The 8V head is not a straight swap onto the 3.0 block. There is a waterway mismatch at the front of the casting that needs modification that I know about already and could well be other problems. It can be done though and I would suggest is easier than trying to fit a Turbo to an S2.
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">The 8 valve head from the 89 2.7 NA is a direct bolt on for the 3.0 litre block. Some companies will also modify the regular NA head to attach to the 3.0 block for $300 or so.
[QB]Porsche didn't use the 16V head on the 968 Turbo S. Now there must have been a reason for that because ALL 968's are 16V, therefore the head is not suitable for Turbocharging IMHO.
QB]</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">From what I have heard, the 16 valve head is not a problem for the turbocharging, it is the variocam that was in the 968's. The 16 valve head will also be able to breathe a lot better in the higher RPM's
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> The 8V head is not a straight swap onto the 3.0 block. There is a waterway mismatch at the front of the casting that needs modification that I know about already and could well be other problems. It can be done though and I would suggest is easier than trying to fit a Turbo to an S2.
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">The 8 valve head from the 89 2.7 NA is a direct bolt on for the 3.0 litre block. Some companies will also modify the regular NA head to attach to the 3.0 block for $300 or so.
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Interesting about the 2.7 head (I'm thinking of doing a 3.0 litre conversion to my turbo as it's currently stripped down).
I believe I have heard the variocam being a problem, but then that's easily removed using S2 kit, so that shouldn't be a showstopper for Porsche. Agreed on the breathing, which makes it seem strange to me that they didn't use it unless there was a big problem.
I don't buy the 911 beating thing because the 968 Turbo S was such a specialised, rare car. Was the 968 Turbo RS 8 or 16 valve?
I believe I have heard the variocam being a problem, but then that's easily removed using S2 kit, so that shouldn't be a showstopper for Porsche. Agreed on the breathing, which makes it seem strange to me that they didn't use it unless there was a big problem.
I don't buy the 911 beating thing because the 968 Turbo S was such a specialised, rare car. Was the 968 Turbo RS 8 or 16 valve?
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968 Turbo RS used the 8 valve head as well.
I'd assume the biggest differences between a 968 Turbo S and Turbo RS weren't in the engine, but in the chassis setup - where the Turbo S was more of a street car, and the RS of course a full race car. Naturally I'm not an expert on these cars, so I'm just guessing...
<a href="http://vista.pca.org/stl/968t.htm" target="_blank">http://vista.pca.org/stl/968t.htm</a>
<a href="http://www.968turbo.homestead.com/" target="_blank">http://www.968turbo.homestead.com/</a>
<img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />
I'd assume the biggest differences between a 968 Turbo S and Turbo RS weren't in the engine, but in the chassis setup - where the Turbo S was more of a street car, and the RS of course a full race car. Naturally I'm not an expert on these cars, so I'm just guessing...
<a href="http://vista.pca.org/stl/968t.htm" target="_blank">http://vista.pca.org/stl/968t.htm</a>
<a href="http://www.968turbo.homestead.com/" target="_blank">http://www.968turbo.homestead.com/</a>
<img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />
#38
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I have a friend who worked over in Germany after high school for a year in Mercedes, Audi, and a couple other plants as part of a work program that he was in.
He told me after I bought the S2 that over there in a lot of the club racing the serious guys were having too many reliability issues with the 944 turbo, so they came up with a turbo kit for the S2 and ran those things flat out in 24 hour races all the time. I'm not sure what all is involved with the conversions they did but I doubt it was using all 944 turbo parts because they didn't use those cars for a reason.
So if they can do things like that, I think everyone who says the 16v head is too "fragile" is just speculating. There are plenty of turbo S2s/968s out there. The few you hear about on here are just a fraction. And how many heads have you heard of that have blown up? (Other than HGs which 951s lose all the time as well) So far I haven't heard of any, and I do try to follow these things as best I can because I plan to do it someday. Somebody please enlighten me on any extra info you may have.
The whole "The Porsche factory did it for a reason" thing I don't buy with this issue. Why wouldn't the factory make 300 whp out of the 951 then, since so many are doing it now with no issues? Because it would be better than the 911? They could easily have made the 911 turbo 450 hp in the 964 trim, plenty do it now with no issues. Porsche is one of very few car companies that I trust the judgement of. But it's been proven so many times that 16v 944 turbos DO work for everyone to be shooting it down all the time. YES it's more expensive than just working with a 951 motor, but what you get will be a much bigger powerhouse when you're done. With the NA guys you tell them they need new brakes, suspension, etc. The S2 already has all that, so then you go into the 16v head on these cars...please.
The 951 isn't the "perfect" 944. It's the easiest one to modify for extra power and it's slightly quicker in stock form than a stock S2. All money issues aside, once you modify a 951 at all you can't compare it anymore. BONE STOCK vs BONE STOCK the S2 is a better all around car than a 944 turbo (except Turbo S of course), it has nearly all the grunt, but constant power, no lag, better gas mileage...try taking a stock 951 against an S2 on a track without straights longer than a 1/4 mile...I've seen it in person the S2 will be quicker. Sure you can spend $300 and make the 951 slaughter it, but I said all money/modifying issues aside.
Now that I've said that, money issues still aside, you take a car very competitive with a stock 944 turbo in its NA form, turbo it, and what do you have? A car that will make more power running less boost and likely be as reliable. So those with the money to do this setup, why knock them for it? I'm not knocking 951s..I love them! But I think sometimes people get a little carried away here...
I think it's 3L/16 ventiler envy from the 951 guys.. <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />
P.S. I'm not claiming to know all here, I'm just stating my personal observations. I welcome everyone here to prove me wrong if you need to. I don't claim to have every bit of info, so please enlighten me if you know something I don't.
He told me after I bought the S2 that over there in a lot of the club racing the serious guys were having too many reliability issues with the 944 turbo, so they came up with a turbo kit for the S2 and ran those things flat out in 24 hour races all the time. I'm not sure what all is involved with the conversions they did but I doubt it was using all 944 turbo parts because they didn't use those cars for a reason.
So if they can do things like that, I think everyone who says the 16v head is too "fragile" is just speculating. There are plenty of turbo S2s/968s out there. The few you hear about on here are just a fraction. And how many heads have you heard of that have blown up? (Other than HGs which 951s lose all the time as well) So far I haven't heard of any, and I do try to follow these things as best I can because I plan to do it someday. Somebody please enlighten me on any extra info you may have.
The whole "The Porsche factory did it for a reason" thing I don't buy with this issue. Why wouldn't the factory make 300 whp out of the 951 then, since so many are doing it now with no issues? Because it would be better than the 911? They could easily have made the 911 turbo 450 hp in the 964 trim, plenty do it now with no issues. Porsche is one of very few car companies that I trust the judgement of. But it's been proven so many times that 16v 944 turbos DO work for everyone to be shooting it down all the time. YES it's more expensive than just working with a 951 motor, but what you get will be a much bigger powerhouse when you're done. With the NA guys you tell them they need new brakes, suspension, etc. The S2 already has all that, so then you go into the 16v head on these cars...please.
The 951 isn't the "perfect" 944. It's the easiest one to modify for extra power and it's slightly quicker in stock form than a stock S2. All money issues aside, once you modify a 951 at all you can't compare it anymore. BONE STOCK vs BONE STOCK the S2 is a better all around car than a 944 turbo (except Turbo S of course), it has nearly all the grunt, but constant power, no lag, better gas mileage...try taking a stock 951 against an S2 on a track without straights longer than a 1/4 mile...I've seen it in person the S2 will be quicker. Sure you can spend $300 and make the 951 slaughter it, but I said all money/modifying issues aside.
Now that I've said that, money issues still aside, you take a car very competitive with a stock 944 turbo in its NA form, turbo it, and what do you have? A car that will make more power running less boost and likely be as reliable. So those with the money to do this setup, why knock them for it? I'm not knocking 951s..I love them! But I think sometimes people get a little carried away here...
I think it's 3L/16 ventiler envy from the 951 guys.. <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />
P.S. I'm not claiming to know all here, I'm just stating my personal observations. I welcome everyone here to prove me wrong if you need to. I don't claim to have every bit of info, so please enlighten me if you know something I don't.
#40
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Peckster:
<strong> </font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by John Anderson:
<strong>Peckster,
Done what? Turbo'd an S2? Send me your email and I'll send you a tele number of man that has put about 15K miles on a turbo'd S2.
I repeat:
Send me your email, and I'll send you a tele number of a man that has put 20K miles on a turbo'd S2 (he drives fast...ok)
Take Care!</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica"></strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I'm not interested in talking to him personally, although others may be.
I guess that means there's no one on this forum who's actually done it, right?
Not saying it can't be done, just that I'm wondering whether you could achieve close to the same result for less money by buying a 951.
I prefer to keep my vehicles pretty close to stock most of the time, but that's just a personal preference. I know there are lots of guys out there that can't wait to start changing things on a car as soon as they get it.
<strong> </font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by John Anderson:
<strong>Peckster,
Done what? Turbo'd an S2? Send me your email and I'll send you a tele number of man that has put about 15K miles on a turbo'd S2.
I repeat:
Send me your email, and I'll send you a tele number of a man that has put 20K miles on a turbo'd S2 (he drives fast...ok)
Take Care!</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica"></strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I'm not interested in talking to him personally, although others may be.
I guess that means there's no one on this forum who's actually done it, right?
Not saying it can't be done, just that I'm wondering whether you could achieve close to the same result for less money by buying a 951.
I prefer to keep my vehicles pretty close to stock most of the time, but that's just a personal preference. I know there are lots of guys out there that can't wait to start changing things on a car as soon as they get it.
#41
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Haven't you all seen the long-**** thread about the guy at Pelican who turbo'd his S2?
<a href="http://forums.pelicanparts.com/showthread.php?s=89996970d95af9eee2600c72e877daa9&threadid=109647" target="_blank">clicky</a>
<a href="http://forums.pelicanparts.com/showthread.php?s=89996970d95af9eee2600c72e877daa9&threadid=109647" target="_blank">clicky</a>
#42
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Nabeel:
<strong>Haven't you all seen the long-**** thread about the guy at Pelican who turbo'd his S2?
<a href="http://forums.pelicanparts.com/showthread.php?s=89996970d95af9eee2600c72e877daa9&threadid=109647" target="_blank">clicky</a></strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I read that one. Wow, that guy is a real jerk. If the car is real it would be incredible. I just don't believe it exists.
<strong>Haven't you all seen the long-**** thread about the guy at Pelican who turbo'd his S2?
<a href="http://forums.pelicanparts.com/showthread.php?s=89996970d95af9eee2600c72e877daa9&threadid=109647" target="_blank">clicky</a></strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I read that one. Wow, that guy is a real jerk. If the car is real it would be incredible. I just don't believe it exists.
#44
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by 944pete:
<strong>I read that one. Wow, that guy is a real jerk. If the car is real it would be incredible. I just don't believe it exists.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">He posted a dyno chart..
SHAUN
<strong>I read that one. Wow, that guy is a real jerk. If the car is real it would be incredible. I just don't believe it exists.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">He posted a dyno chart..
SHAUN
#45
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I've no axe to grind - I have (effectively) a Turbo S and an S2. In fact I just want to know what the truth is, because my turbo is stripped just now and I am trying to decide what to put back in when it's rebuilt.
I just think that the 16V head would have been on the 968 turbos unless there was a reason not to, and I don't buy the 'too much competition for the 911' argument.
I too trust Porsche's decisions (although I think they err on the side of caution, like every other manufacturer, not just of cars), and I'd like to know why they stuck with 8V. Maybe it was just cost. For all the 968 turbos they built they may just have used some 951 heads they had lying around. Maybe the inherent loss of torque low down that 16V engines have over 8V complimented the turbo power delivery badly? I don't know, but there must have been some reason...
I don't know why the German racers would find the 2.5 turbo unreliable either - yes it eats head gaskets if it isn't set up right, but the 3.0 will be the same. Perhaps it's the extra knock sensor in the S2 block, perhaps they used 968 engines with the extra oil spray bar and modified oil galleries?
The Secretary of the 944 register of PCGB has just replaced his engine with another one because his 16V head cracked allowing water to contaminate the oil. Over time the thinned oil had caused excessive wear and damaged the Nikasil coating (I think number 3 bore). It could have been repaierd but he did not have enough time as he had commitments for the car. His S2 was stock.
I just think that the 16V head would have been on the 968 turbos unless there was a reason not to, and I don't buy the 'too much competition for the 911' argument.
I too trust Porsche's decisions (although I think they err on the side of caution, like every other manufacturer, not just of cars), and I'd like to know why they stuck with 8V. Maybe it was just cost. For all the 968 turbos they built they may just have used some 951 heads they had lying around. Maybe the inherent loss of torque low down that 16V engines have over 8V complimented the turbo power delivery badly? I don't know, but there must have been some reason...
I don't know why the German racers would find the 2.5 turbo unreliable either - yes it eats head gaskets if it isn't set up right, but the 3.0 will be the same. Perhaps it's the extra knock sensor in the S2 block, perhaps they used 968 engines with the extra oil spray bar and modified oil galleries?
The Secretary of the 944 register of PCGB has just replaced his engine with another one because his 16V head cracked allowing water to contaminate the oil. Over time the thinned oil had caused excessive wear and damaged the Nikasil coating (I think number 3 bore). It could have been repaierd but he did not have enough time as he had commitments for the car. His S2 was stock.