THE 3.0 Liter Turbo Thread
03-20-2005 | 12:48 PM
#106
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From: Just CA Now :)
Originally Posted by Pauerman
The Mahle 16V turbo pistons can be seen here:
Go to Engine Components then to HMR 968 16V turbo pistons
www.heritagemotorcar.com/research/index.htm
Go to Engine Components then to HMR 968 16V turbo pistons
www.heritagemotorcar.com/research/index.htm
03-21-2005 | 10:11 AM
#107
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Joined: May 2001
Posts: 159
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From: Central Florida
Tom,
Jason Lee will certainly sell the radiator. Jason Judd has one in his turbocharged 968 track car. The pistons will probably depend on supply and demand. If he has more that he needs for the work he expects to do, then your chances are better. I am having HMR turbocharge my 968 and the radiator, Mahle/HMR pistons, and Arrow connecting rods are being used. The engine is being built now, installation in the car and tuning will occur in the May-July time frame. Give Jason Lee a call, I'm sure he would be happy to talk to you.
Jason Lee will certainly sell the radiator. Jason Judd has one in his turbocharged 968 track car. The pistons will probably depend on supply and demand. If he has more that he needs for the work he expects to do, then your chances are better. I am having HMR turbocharge my 968 and the radiator, Mahle/HMR pistons, and Arrow connecting rods are being used. The engine is being built now, installation in the car and tuning will occur in the May-July time frame. Give Jason Lee a call, I'm sure he would be happy to talk to you.
04-18-2005 | 02:11 PM
#108
Nordschleife Master
Joined: Feb 2003
Posts: 5,801
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From: Lebanon, OH
Originally Posted by Jay Wellwood
Thanks for the updated info Raj....got too damn busy at work today...another 'emergency' so I couldn't break away to chat. Promise to hide in a Closet Friday.
For those just joining....or seeking more info...Here's the deal. To be able to fully boost a 968 engine, you'll have to lower the compression to do (or limit your boost accordingly). To raise the boost - you'll need to lower the Compression Ratio - this helps to save the motor (or limit activation of the knock sensors) - and also helps to reap full advantage of the boost. That being said - follow below. Sorry for the confusion if it seems like I bounce back and forth...
For the 89 NA head...in as far as the head and water passage is concerned (or lack thereof)...sounds even more believable based on the PET info that I have. There is no difference on the part numbers between the the 89 NA and the 3.0l head gaskets...which tells me we're 'in the groove'. All I gotta do is match it up in the field to confirm...but I feel 100% confident that this is a non-issue.
What about the head studs...talkin' with Dave led me to believe that I'll need a custom length set...not a problem...but an unforeseen...anyone know for certain? If I have to go with different studs...Dave will sell 'em for a measely $370/set. Just need info to confirm. (another helpful note here).
Next...Pistons...or Rods...or how to lower the Compression ratio? I've got a line on both...but I also have a preference....
For those just joining....or seeking more info...Here's the deal. To be able to fully boost a 968 engine, you'll have to lower the compression to do (or limit your boost accordingly). To raise the boost - you'll need to lower the Compression Ratio - this helps to save the motor (or limit activation of the knock sensors) - and also helps to reap full advantage of the boost. That being said - follow below. Sorry for the confusion if it seems like I bounce back and forth...
For the 89 NA head...in as far as the head and water passage is concerned (or lack thereof)...sounds even more believable based on the PET info that I have. There is no difference on the part numbers between the the 89 NA and the 3.0l head gaskets...which tells me we're 'in the groove'. All I gotta do is match it up in the field to confirm...but I feel 100% confident that this is a non-issue.
What about the head studs...talkin' with Dave led me to believe that I'll need a custom length set...not a problem...but an unforeseen...anyone know for certain? If I have to go with different studs...Dave will sell 'em for a measely $370/set. Just need info to confirm. (another helpful note here).
Next...Pistons...or Rods...or how to lower the Compression ratio? I've got a line on both...but I also have a preference....
Why? can we not just make a thick headgasket? Its compleately possible and compleately proven to be a cheap way to turbo a High compression engine. While we might not see anything like 15psi I think that 10psi is compleately duable with a thicker headgasket. I know that the internals were not made to take the extra stress that turbocharger adds but there not exactly weak equipment eather. The internals are more then capable to handle a lower boost application. Many E36 M3 owners have been doing this trick for years on there M3's So why can we not do it on our S2's?. Many of them from companys as reputable as AA tuneing are doing this on M3's so what is stopping us? I have also read about melting pistons/combustion chamber heat issues?
05-01-2005 | 08:39 PM
#109
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Originally Posted by Fishey
Why? can we not just make a thick headgasket? Its compleately possible and compleately proven to be a cheap way to turbo a High compression engine. While we might not see anything like 15psi I think that 10psi is compleately duable with a thicker headgasket. I know that the internals were not made to take the extra stress that turbocharger adds but there not exactly weak equipment eather. The internals are more then capable to handle a lower boost application. Many E36 M3 owners have been doing this trick for years on there M3's So why can we not do it on our S2's?. Many of them from companys as reputable as AA tuneing are doing this on M3's so what is stopping us? I have also read about melting pistons/combustion chamber heat issues?
But then if you use a thicker head gasket spacer to lower compresion, what are the other so-called 968 tuners going to do? You know, the ones that charge $25k for a turbo kit.................They will be exposed as nothing but overpriced crooks.
They won't be able to sell their "special" $1800 pistons
They won't be able to sell their "special" $2200 rods
Hmmm.............$4000 for pistons and rods (and 15-20 hours of labor), or $250 for a head gasket spacer (and 6-8 hours of labor) to lower the compression.......
It makes no sense!!! The 968 has forged pistons, forged rods, and forged crank from the factory! And anyone who tells you otherwise, is FOS and simply trying to justify why you need to buy their pistons and rods!
And the "secret" will be out that you DON'T have to spend $25k to turbocharge a 968 (or 944S2). This is not a Murcielago we're talking about!
But some people feel more comfortable when they spend a LOT more $. It makes them feel better I guess........If so, go right ahead.
If I offended anyone here that did spend $25k + to turbocharge their 968, I apologize in advance, but it's just like spending $25k on turbocharging a E36 M3 instead of doing it for $7k.
Now that's a big TIP!!!
05-02-2005 | 01:45 AM
#110
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Joined: Sep 2003
Posts: 98
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From: Akron/Canton Ohio
This is what I learned from the conversion... I used the 2.7 89NA head. I chose to go this route for several reasons. The main being all of the 951 parts match up and the head is a perfect fit on the 3.0L block. The DME also works with a new burnt chip and works the existing 968 speedo. Using the 3.0L head has alot more custome work with adding a turbo and that turns out to alot more $$$. Anyone who has gotten to ride in a turbo 968 with the 2.7 head would agree its plenty fast to satisfy anyone. Mine has been done for about 1 year now and I have not had any complications. Everything works perfect..I guess there is somthing to be said for that. I plan to be at the DC celebration with my turbo cab and anyone is more than willing to go for a ride. You do not have to spend 25k to turbo a 968. I spent about 12k using the 2.7 head and 951 parts. Thats with lowering the compression (new pistons, rods and new studs). Just my opinion... a really affordable and reliable way to boost the 968. Kudos to you who have done it with the 16valve.
05-02-2005 | 05:21 AM
#111
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A lot more $ and a lot more custom work to use a 3.0 16v head?.........
WRONG! It's a lot LESS work, because all you buy extra is the head gasket spacer! $250, not $4000. Which is more expensive?
The 968 COMES FACTORY STOCK with a 3.0 16v head.
How is it a lot more money? .........
$4000 on a rigged-up combination of custom pistons and rods to lower compression
$500-$1000 on a 2.7 head
plus all the labor involved!!!
.......wow, that's just pure genius.
Not to mention that you need to run about 4 to 6 psi more boost if you use the 2.7 head to get the same output as you would get with the 3.0 16v head.
(Why not use an old 924 2.0 head and run 35 psi of boost? It would make just as much sense.)
2.7 8v head= a lot more work and $, and less HP potential
3.0 16v head=less work, a LOT less $, and more HP potential
If you wanna save even more $, and have a fast 968, here's the best way to go:
Sell the 968 engine (you'll get between $3000 and $4500 depending on condition and mileage).
Buy a 951 engine (from $1000-$2000)
Bolt on a Vitesse stage 3 kit ($3600, 440+whp)
$3000 for labor (if you don't do it yourself)
And you're DONE!
You'd have spent about $5000, and you'd have a 440+whp 968.
JM964CAB, how much HP does your 968 Turbo make?
WRONG! It's a lot LESS work, because all you buy extra is the head gasket spacer! $250, not $4000. Which is more expensive?
The 968 COMES FACTORY STOCK with a 3.0 16v head.
How is it a lot more money? .........
$4000 on a rigged-up combination of custom pistons and rods to lower compression
$500-$1000 on a 2.7 head
plus all the labor involved!!!
.......wow, that's just pure genius.
Not to mention that you need to run about 4 to 6 psi more boost if you use the 2.7 head to get the same output as you would get with the 3.0 16v head.
(Why not use an old 924 2.0 head and run 35 psi of boost? It would make just as much sense.)
2.7 8v head= a lot more work and $, and less HP potential
3.0 16v head=less work, a LOT less $, and more HP potential
If you wanna save even more $, and have a fast 968, here's the best way to go:
Sell the 968 engine (you'll get between $3000 and $4500 depending on condition and mileage).
Buy a 951 engine (from $1000-$2000)
Bolt on a Vitesse stage 3 kit ($3600, 440+whp)
$3000 for labor (if you don't do it yourself)
And you're DONE!
You'd have spent about $5000, and you'd have a 440+whp 968.
JM964CAB, how much HP does your 968 Turbo make?
05-02-2005 | 11:09 AM
#112
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Joined: Sep 2003
Posts: 98
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From: Akron/Canton Ohio
Where are you going to get the parts to actually make the turbo bolt on to the 16v head. Intake manifold, exhaust manifold, crossover pipe, exhaust with wastegate, ect... Thats the custom work I was talking about that adds up to extra money. Maybe I'm wrong I have never done a 16v turbo conversion. There is more work involved than just throwing on a head gasket spacer. someone with a 16v conversion can jump in and add their knowledge about it.
05-03-2005 | 01:25 AM
#114
Racer
Joined: Dec 2001
Posts: 412
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From: Montreal, Canada
The thicker head gasket approach has been discussed many times before and has been discarded largely because of heat related problems. Beyond the obvious change in combustion chamber design and geometry (all of which was carefully engineered and honed to perfection by highly skilled Porsche people), by fitting a thicker head gasket you are creating a bunch of exposed edges that can overheat and cause misfire.
Here's a better explanation, from thread no. 103043, by Chris White
Porsche has developed the 968TS engine based on a modified 2.7 head, they must have had good reasons to give preference to this more expensive route. And it worked quite well.
Another word of wisdom by member Chris White:
As you suggested then. However fitting the 2.5l engine and make everything work properly won't be a piece of cake. And it doesn't sound nearly as glamorous and mouth watering as 3.0l turbo, you must include this somewhere in your clever mathematical calculations.
Regards,
Chris
Here's a better explanation, from thread no. 103043, by Chris White
There are a couple of problems with the shimming method – not show stoppers but reasons to consider. – Either you will literally have to stack several head gaskets (which has several things going against it) or have a custom made shim gasket. Either one of these has some problems. If you stack gaskets you are making a weak sealing point and you are exposing many more hard corners to the combustion area – a bad thing to do. Any sharp edge that is exposed to the combustion area makes for a hot spot and this will add to preignition problems when under load.
Also – gaskets were designed to seal against the block or head, not against another gasket, could be a potential problem area, definitely not good for track use.
If you get a custom made shim then you are back to the sealing problem. Head gasket on either side of the shim? Lots of exposed corners!!
Also – gaskets were designed to seal against the block or head, not against another gasket, could be a potential problem area, definitely not good for track use.
If you get a custom made shim then you are back to the sealing problem. Head gasket on either side of the shim? Lots of exposed corners!!
Another word of wisdom by member Chris White:
With 370rwhp (reliable - sub 20 psi) available for the cost of a turbo, intercooler pipes and engine management what are you looking to get with the 3.0 set up?
Regards,
Chris
05-03-2005 | 07:59 AM
#115
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As you quoted:
"Porsche has developed the 968TS engine based on a modified 2.7 head, they must have had good reasons to give preference to this more expensive route. And it worked quite well."
YES, they did have a good reason why they used the 2.7 8v head!
Here's why:
They did not want to surpass the output of the 911 Turbo. I remember reading about this almost 15 years ago.
Does anybody ever wonder why a Boxster has less HP than a 911? It handles better than a 911, so obviously if it was also faster..........what would happen to the value and sales of the 911?
So, limit the HP potential as Porsche did, as not to surpass the poor old 911 Turbo ..............Hmmm.......(When NOT in Rome, DON'T do as the Romans do!)
This is getting ridiculous.
They should change the name of this thread to:
1. "limiting your HP when turbocharging a 968".
2. "reasons why you can't/shouldn't turbocharge a 968 unless it costs more than twice as much as the car".
3. "why turbocharging a 968 should be limited to the 2.7 head (be nice to those 911 Turbo owners)".
4. (answer to #3) "do not use a 16v head when turbocharging a 968, or you will make too much power and die!"
"Porsche has developed the 968TS engine based on a modified 2.7 head, they must have had good reasons to give preference to this more expensive route. And it worked quite well."
YES, they did have a good reason why they used the 2.7 8v head!
Here's why:
They did not want to surpass the output of the 911 Turbo. I remember reading about this almost 15 years ago.
Does anybody ever wonder why a Boxster has less HP than a 911? It handles better than a 911, so obviously if it was also faster..........what would happen to the value and sales of the 911?
So, limit the HP potential as Porsche did, as not to surpass the poor old 911 Turbo ..............Hmmm.......(When NOT in Rome, DON'T do as the Romans do!)
This is getting ridiculous.
They should change the name of this thread to:
1. "limiting your HP when turbocharging a 968".
2. "reasons why you can't/shouldn't turbocharge a 968 unless it costs more than twice as much as the car".
3. "why turbocharging a 968 should be limited to the 2.7 head (be nice to those 911 Turbo owners)".
4. (answer to #3) "do not use a 16v head when turbocharging a 968, or you will make too much power and die!"
05-03-2005 | 06:25 PM
#117
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Why bother with a 16V head when the 8V design has long been proven to be both reliable and cost effective ?
The first 16V head was successfully tested in Le Mans back in the early eighties even before Porsche announced the launch of the 944 turbo, and this head made with a "proper" design, without the poor cam chain design derived - for cost-cutting reasons - from the 928 S4.
If Porsche really had intended to launch a 16V turbocharged road car they would certainly have started working from this head.
In answer to d993 :
The factory did not produce the 16V turbocharged engine they tested not only because it would have destroyed the 911 turbo performance but also because the cars had become too expensive to produce ; 968 sales were so bad with regards to what they needed to sell it would just have proven even less financially viable than the original 968 TS was in the end. When new they cost almost the double of a late 944 turbo ; still today that sounds ridiculously high money for what's technically merely a "slight evolution".
edit :
Huh ... just noticed I had already posted in that thread ... sorry for repeating myself
The first 16V head was successfully tested in Le Mans back in the early eighties even before Porsche announced the launch of the 944 turbo, and this head made with a "proper" design, without the poor cam chain design derived - for cost-cutting reasons - from the 928 S4.
If Porsche really had intended to launch a 16V turbocharged road car they would certainly have started working from this head.
In answer to d993 :
The factory did not produce the 16V turbocharged engine they tested not only because it would have destroyed the 911 turbo performance but also because the cars had become too expensive to produce ; 968 sales were so bad with regards to what they needed to sell it would just have proven even less financially viable than the original 968 TS was in the end. When new they cost almost the double of a late 944 turbo ; still today that sounds ridiculously high money for what's technically merely a "slight evolution".
edit :
Huh ... just noticed I had already posted in that thread ... sorry for repeating myself
Last edited by Thom; 05-03-2005 at 06:45 PM.
05-03-2005 | 08:05 PM
#118
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From: Germany/Braunschweig
it is amazing how many "experts " we have here ;-)
so take now some facts.
Porsche did NOT use a modded 2.7L head in the 968 T S
The head is something between the 951 head the 2.7L head and some other stuff that you will not find in both of these heads.
It is the same thing if you say it was a modified 951 head. or a mix of 2.7 AND 951 and 30% new design.
BTW Porsche did not made an 16V head because it was not alowed to arce with this in ADAC GT cup.
they made the car just for racing and they needed a street model in order to homologate the car for racing.
Not clever to build an 4 valve if it is not alowed.
The 8V is fast enough and was faster in accelaration and top speed compared to the old 911 Turbo in 93.
only the 911 IMSA supercar with the 380 HP was faster.
if someone thinks it is easy to build an 16V Turbo then he must FIRST build it and then if it lasts he can talk about this.
Porsche already made some 16V engines but not for the production..
If someone wants an original 16V 968 Turbo head he can contact me. If you do not have the money not even bother to ask.
It is not dificcult for Porsche to do a 16V Turbo engine that last but it is difficult for someone who do not has the experience and the support.
so first try then talk and tell us what you find out. Probably the same that many here already knows ;-)
Konstantin
so take now some facts.
Porsche did NOT use a modded 2.7L head in the 968 T S
The head is something between the 951 head the 2.7L head and some other stuff that you will not find in both of these heads.
It is the same thing if you say it was a modified 951 head. or a mix of 2.7 AND 951 and 30% new design.
BTW Porsche did not made an 16V head because it was not alowed to arce with this in ADAC GT cup.
they made the car just for racing and they needed a street model in order to homologate the car for racing.
Not clever to build an 4 valve if it is not alowed.
The 8V is fast enough and was faster in accelaration and top speed compared to the old 911 Turbo in 93.
only the 911 IMSA supercar with the 380 HP was faster.
if someone thinks it is easy to build an 16V Turbo then he must FIRST build it and then if it lasts he can talk about this.
Porsche already made some 16V engines but not for the production..
If someone wants an original 16V 968 Turbo head he can contact me. If you do not have the money not even bother to ask.
It is not dificcult for Porsche to do a 16V Turbo engine that last but it is difficult for someone who do not has the experience and the support.
so first try then talk and tell us what you find out. Probably the same that many here already knows ;-)
Konstantin
05-04-2005 | 04:44 AM
#119
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Originally Posted by Konstantin
it is amazing how many "experts " we have here ;-)
Perhaps the less convincing "experts" are those who pretend to know better than others and use a tone accordingly expressive ;-)
05-04-2005 | 09:21 AM
#120
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Joined: Nov 2004
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Quote:
"If someone wants an original 16V 968 Turbo head he can contact me. If you do not have the money not even bother to ask." Oh, so there's an "original" 16V 968 Turbo head? (Those stupid people at Porsche! How could they?? I guess some people don't listen)
If I buy the 16V 968 Turbo head, can I have 1/2 of the cam lobes machined off so that it operates as a 8V engine? Will it work then? (Or would I still be making too much power)?
Well, guess what: NOT GONNA WORK.
You HAVE to use the 8v head. LMFAO!
5 years ago, a 951 with BOLT-ONS that made 450whp was a considered a fantasy....I was told that you have to change the rods and pistons if you go past 325whp.........to what? "Forged-ER"?
I live about 10 minutes away from AAP (home of some of the fasted turbocharged Supras, some with 1200hp), and I should suggest that they switch to 2V per cylinder heads..........What do you think?
Also, I have a '93 Audi S4, and I'm running 24psi of boost on the stock block, pistons, rods, etc.
Yes, it has a 4V per cylinder head.
Should I change to a 2V per cylinder head?
No, I'm not an "expert", but I don't believe in the BS "monkey-see, monkey-do" mentality that is enforced here. "Oh, so and so said it can't be done...........Porsche didn't use the 16V head.........
Leave it stock then! That type of mentality doesn't deserve more than 240hp anyway!
"If someone wants an original 16V 968 Turbo head he can contact me. If you do not have the money not even bother to ask." Oh, so there's an "original" 16V 968 Turbo head? (Those stupid people at Porsche! How could they?? I guess some people don't listen)
If I buy the 16V 968 Turbo head, can I have 1/2 of the cam lobes machined off so that it operates as a 8V engine? Will it work then? (Or would I still be making too much power)?
Well, guess what: NOT GONNA WORK.
You HAVE to use the 8v head. LMFAO!
5 years ago, a 951 with BOLT-ONS that made 450whp was a considered a fantasy....I was told that you have to change the rods and pistons if you go past 325whp.........to what? "Forged-ER"?
I live about 10 minutes away from AAP (home of some of the fasted turbocharged Supras, some with 1200hp), and I should suggest that they switch to 2V per cylinder heads..........What do you think?
Also, I have a '93 Audi S4, and I'm running 24psi of boost on the stock block, pistons, rods, etc.
Yes, it has a 4V per cylinder head.
Should I change to a 2V per cylinder head?
No, I'm not an "expert", but I don't believe in the BS "monkey-see, monkey-do" mentality that is enforced here. "Oh, so and so said it can't be done...........Porsche didn't use the 16V head.........
Leave it stock then! That type of mentality doesn't deserve more than 240hp anyway!