my 3L dyno
12-11-2015, 08:46 PM
#91
Drifting
Well if the 968 turbo was at 20 psi it would see the same power but it runs 1 bar of boost so it's at 335 or 350hp.
How's that possible without larger injectors, fuel requirements, and tuning? Running a stock 951 or 968 Turbo RS using stock EM at 20 psi is likely a short lived EXPENSIVE mistake.
G
How's that possible without larger injectors, fuel requirements, and tuning? Running a stock 951 or 968 Turbo RS using stock EM at 20 psi is likely a short lived EXPENSIVE mistake.
G
12-11-2015, 09:16 PM
#92
Rennlist Member
Well if the 968 turbo was at 20 psi it would see the same power but it runs 1 bar of boost so it's at 335 or 350hp. And I thought it was a 2.7 head used. I have yet to see any prof otherwise beside people saying its a 951 head that's modified. Since there's only four 968 turbo rs engines made its not easy for me to find the owners and ask them to look at the PN on their 968 turbo rs cylinder head. The engine biuld sheets I have seen on the web only states it's "similar" to the turbo head. As I see it the 2.7 cylinder head is "similar" so I guess that's how I came to that conclusion. And it fits the big block as if it was disigned to be the turbo head to be used on the big block. There is absolutely NO information on the web for a part number for the 968 turbo rs cylinder head. All the information states it's similar eveywhere I've looked on the web. Perhaps you could provide the 968 turbo rs engine biuld sheet and the PN on the head. I would like to know and so would others. Thanks.
Cue Raj in 5...4...3...
In the meantime, here's an interesting tid bit it took me a long time to figure out. Cast aluminum parts on these cars don't always bear their Porsche part number. Often, the number is a casting number that is similar, but not the same, as the number in the parts catalog.
At any rate, my money is still on the turbo being a little too big for that power level. Otherwise, the output looks just about right to me for the reasons I said above. And as George said, it would take more than an extra 5.5 psi to get a 968 turbo rs up to that power level. The head, as Raj will soon belabor, was designed to keep peak power down within racing limits, and it did its job well.
12-11-2015, 09:32 PM
#93
Rainman
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Well if the 968 turbo was at 20 psi it would see the same power but it runs 1 bar of boost so it's at 335 or 350hp. And I thought it was a 2.7 head used. I have yet to see any prof otherwise beside people saying its a 951 head that's modified. Since there's only four 968 turbo rs engines made its not easy for me to find the owners and ask them to look at the PN on their 968 turbo rs cylinder head. The engine biuld sheets I have seen on the web only states it's "similar" to the turbo head. As I see it the 2.7 cylinder head is "similar" so I guess that's how I came to that conclusion. And it fits the big block as if it was disigned to be the turbo head to be used on the big block. There is absolutely NO information on the web for a part number for the 968 turbo rs cylinder head. All the information states it's similar eveywhere I've looked on the web. Perhaps you could provide the 968 turbo rs engine biuld sheet and the PN on the head. I would like to know and so would others. Thanks.
12-11-2015, 09:34 PM
#94
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Originally Posted by Tom M'Guinn
Cue Raj in 5...4...3...
In the meantime, here's an interesting tid bit it took me a long time to figure out. Cast aluminum parts on these cars don't always bear their Porsche part number. Often, the number is a casting number that is similar, but not the same, as the number in the parts catalog.
At any rate, my money is still on the turbo being a little too big for that power level. Otherwise, the output looks just about right to me for the reasons I said above. And as George said, it would take more than an extra 5.5 psi to get a 968 turbo rs up to that power level. The head, as Raj will soon belabor, was designed to keep peak power down within racing limits, and it did its job well.
12-11-2015, 09:55 PM
#95
Drifting
I hope Raj shows to provide more information. But I've been getting schooled so far which is a good thing!
Also Mr Brown, do you have an exhaust back pressure gauge installed? Seems a few people are telling you not to turn up your boost because your disappointed in the power output. A while back when I was talking to Mike Lindsey about "boost" he told me it's wise to install an exhaust back pressure gauge, so I did. He said to not have the exhaust back pressure in the crossover be greater then the intake boost pressure due to reversion that will happen and will blow just the head gasket if lucky. He said the exhaust and intake pressure gauges will pretty much match in PSI when at max boost on the setup used, and when the exhaust psi starts to overcome the intake boost turn it back down to where there equal psi and that's the max boost level. He said don't go past were they match at max boost levels, Mile was very certain about that so that's why I stated it again. He said an example is if 18 psi of boost is in the intake and 19,20,21 or more on exhaust then turn it down till they are the same psi weather it be 15,16,17 psi more or less being the max boost. And once the exhaust psi ecceeds the intake psi then it adds more and more exhaust psi over one psi intake boost increment. So if they were even at 16 psi, and then at 17 intake psi the exhaust goes to 19 psi (guesstimate) and if you go 18 psi intake then exhaust would be 25 ps (real rough guess)i, like it multiplies the exaust psi when the intake is turned up just one psi past the equal boost level. I guess what I'm asking is do you have an exhaust back pressure gauge so you can monitor the engine and not overboost the engine. Anyways that's my two cents that I'm passing on that I did myself. Hope I'm not wrong, but if so please correct me.
Also Mr Brown, do you have an exhaust back pressure gauge installed? Seems a few people are telling you not to turn up your boost because your disappointed in the power output. A while back when I was talking to Mike Lindsey about "boost" he told me it's wise to install an exhaust back pressure gauge, so I did. He said to not have the exhaust back pressure in the crossover be greater then the intake boost pressure due to reversion that will happen and will blow just the head gasket if lucky. He said the exhaust and intake pressure gauges will pretty much match in PSI when at max boost on the setup used, and when the exhaust psi starts to overcome the intake boost turn it back down to where there equal psi and that's the max boost level. He said don't go past were they match at max boost levels, Mile was very certain about that so that's why I stated it again. He said an example is if 18 psi of boost is in the intake and 19,20,21 or more on exhaust then turn it down till they are the same psi weather it be 15,16,17 psi more or less being the max boost. And once the exhaust psi ecceeds the intake psi then it adds more and more exhaust psi over one psi intake boost increment. So if they were even at 16 psi, and then at 17 intake psi the exhaust goes to 19 psi (guesstimate) and if you go 18 psi intake then exhaust would be 25 ps (real rough guess)i, like it multiplies the exaust psi when the intake is turned up just one psi past the equal boost level. I guess what I'm asking is do you have an exhaust back pressure gauge so you can monitor the engine and not overboost the engine. Anyways that's my two cents that I'm passing on that I did myself. Hope I'm not wrong, but if so please correct me.
12-11-2015, 10:08 PM
#97
Drifting
12-11-2015, 10:17 PM
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Originally Posted by Humboldtgrin
I hope Raj shows to provide more information. But I've been getting schooled so far which is a good thing!
Also Mr Brown, do you have an exhaust back pressure gauge installed? Seems a few people are telling you not to turn up your boost because your disappointed in the power output. A while back when I was talking to Mike Lindsey about "boost" he told me it's wise to install an exhaust back pressure gauge, so I did. He said to not have the exhaust back pressure in the crossover be greater then the intake boost pressure due to reversion that will happen and will blow just the head gasket if lucky. He said the exhaust and intake pressure gauges will pretty much match in PSI when at max boost on the setup used, and when the exhaust psi starts to overcome the intake boost turn it back down to where there equal psi and that's the max boost level. He said don't go past were they match at max boost levels, Mile was very certain about that so that's why I stated it again. He said an example is if 18 psi of boost is in the intake and 19,20,21 or more on exhaust then turn it down till they are the same psi weather it be 15,16,17 psi more or less being the max boost. And once the exhaust psi ecceeds the intake psi then it adds more and more exhaust psi over one psi intake boost increment. So if they were even at 16 psi, and then at 17 intake psi the exhaust goes to 19 psi (guesstimate) and if you go 18 psi intake then exhaust would be 25 ps (real rough guess)i, like it multiplies the exaust psi when the intake is turned up just one psi past the equal boost level. I guess what I'm asking is do you have an exhaust back pressure gauge so you can monitor the engine and not overboost the engine. Anyways that's my two cents that I'm passing on that I did myself. Hope I'm not wrong, but if so please correct me.
Also Mr Brown, do you have an exhaust back pressure gauge installed? Seems a few people are telling you not to turn up your boost because your disappointed in the power output. A while back when I was talking to Mike Lindsey about "boost" he told me it's wise to install an exhaust back pressure gauge, so I did. He said to not have the exhaust back pressure in the crossover be greater then the intake boost pressure due to reversion that will happen and will blow just the head gasket if lucky. He said the exhaust and intake pressure gauges will pretty much match in PSI when at max boost on the setup used, and when the exhaust psi starts to overcome the intake boost turn it back down to where there equal psi and that's the max boost level. He said don't go past were they match at max boost levels, Mile was very certain about that so that's why I stated it again. He said an example is if 18 psi of boost is in the intake and 19,20,21 or more on exhaust then turn it down till they are the same psi weather it be 15,16,17 psi more or less being the max boost. And once the exhaust psi ecceeds the intake psi then it adds more and more exhaust psi over one psi intake boost increment. So if they were even at 16 psi, and then at 17 intake psi the exhaust goes to 19 psi (guesstimate) and if you go 18 psi intake then exhaust would be 25 ps (real rough guess)i, like it multiplies the exaust psi when the intake is turned up just one psi past the equal boost level. I guess what I'm asking is do you have an exhaust back pressure gauge so you can monitor the engine and not overboost the engine. Anyways that's my two cents that I'm passing on that I did myself. Hope I'm not wrong, but if so please correct me.
12-11-2015, 10:23 PM
#100
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Well if the 968 turbo was at 20 psi it would see the same power but it runs 1 bar of boost so it's at 335 or 350hp. And I thought it was a 2.7 head used. I have yet to see any prof otherwise beside people saying its a 951 head that's modified. Since there's only four 968 turbo rs engines made its not easy for me to find the owners and ask them to look at the PN on their 968 turbo rs cylinder head. The engine biuld sheets I have seen on the web only states it's "similar" to the turbo head. As I see it the 2.7 cylinder head is "similar" so I guess that's how I came to that conclusion. And it fits the big block as if it was disigned to be the turbo head to be used on the big block. There is absolutely NO information on the web for a part number for the 968 turbo rs cylinder head. All the information states it's similar eveywhere I've looked on the web. Perhaps you could provide the 968 turbo rs engine biuld sheet and the PN on the head. I would like to know and so would others. Thanks.
For what its worth, I am by no means an expert - and Raj has a huge amount of time and experience researching information related to the 968 Turbo models.
There was a post here years back regarding 968 Turbo S and RS items used. From my notes, here are the part numbers for the cylinder heads:
Turbo S = 951-104-303-30
Turbo RS = 951-104-303-31
Not off the shelf items by any means. The 2.7 head matches up with minimal effort, but as previously pointed out the original head had different features - and the entire powerplant was restricted to allow running in a specific series race group. Never mind that the 911 could not be dethroned as the King of the Hill from a power output perspective.
Regardless, there is information out there...but one has to look long and far to find the pieces and put them together. It ain't easy...but then again, if it were - well, it'd be like owning a Chebby.
As always, YMMV.
12-11-2015, 10:32 PM
#101
?????????? Who told you the 3 inch exhaust can only go to 300hp?????????
12-11-2015, 10:41 PM
#102
Rennlist Member
Seriously? Does Lindsey fill its mufflers with concrete? And if it's limited to 300hp, why did it make 405?
12-11-2015, 11:36 PM
#103
Rainman
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the king has spoken 
Raj, where can you get valve guides for that head? They are 7mm stem, no? Same OD as the regular 944 stuff or different altogether? 45 or 48mm (or other) intake valve?
also...would you mind measuring the port diameters? or are they the same size as 944T?
Raj, where can you get valve guides for that head? They are 7mm stem, no? Same OD as the regular 944 stuff or different altogether? 45 or 48mm (or other) intake valve?
also...would you mind measuring the port diameters? or are they the same size as 944T?
12-12-2015, 01:42 AM
#104
Rennlist Member
3L Turbo
Wow.... interesting thread; lots of emotion, a ton of input, some good information, and some mis-information. Here's my .02, some of which has been mentioned, but bears repeating.
First, heat and humidity have a significant impact on power (reduced), and a 'corrected' output will not only provide more accurate and comparable data, but puts the number much closer to what JBrown is expecting.
Second, with that big turbo and a "race" cam, there is no way the engine has peaked at 6000. By extrapolating the graph, it's VERY likely this engine will make around 450 at 6500, and perhaps a bunch more at 7000.
Now, with temp/humidity corrected data, AND a pull to 7000, you may well have exceeded your expectations! Perhaps you can arrange one more pull? It seems like they'd get some positive exposure with the more accurate/higher output. I'd ask them to add some fuel to the WOT map, however. It's a bit lean.
I wouldn't touch anything (other than the fuel at WOT). You're where you wanted to be. I hope you enjoy it.
First, heat and humidity have a significant impact on power (reduced), and a 'corrected' output will not only provide more accurate and comparable data, but puts the number much closer to what JBrown is expecting.
Second, with that big turbo and a "race" cam, there is no way the engine has peaked at 6000. By extrapolating the graph, it's VERY likely this engine will make around 450 at 6500, and perhaps a bunch more at 7000.
Now, with temp/humidity corrected data, AND a pull to 7000, you may well have exceeded your expectations! Perhaps you can arrange one more pull? It seems like they'd get some positive exposure with the more accurate/higher output. I'd ask them to add some fuel to the WOT map, however. It's a bit lean.
I wouldn't touch anything (other than the fuel at WOT). You're where you wanted to be. I hope you enjoy it.
12-12-2015, 04:54 AM
#105
Three Wheelin'
Devon, I have to agree with all the wait and see advice. Your car should be awesome and so you are putting the horse before the cart. You don't even know if you have a problem, so no point trying to fix it yet. Its wasted energy.
As for Alberts behaviour on social media, personally I think it is incredibly unprofessional and says more about his nature and how he chooses to run his business, than it does about *the bad customer*. It certainly doesn't make me want to use his services, regardless of his alleged expertise and skill. If Albert is so swamped with work he doesn't have time to communicate directly with his customers, then it makes no sense that he can spend so much time and effort on social media talking about it all, airing his dirty laundry.
I can only think if Albert put the same effort he did into putting down a paying customer, on social media, into actually communicating with the customer in the first place, maybe this whole incident could have been avoided. Yes some customers need to be reassured and want constant updates, and that may not be easy or convienent but when a customer hands over their pride and joy and a large chuck of cash, then why wouldn't you do whats required to keep them updated and happy ? The customer isn't always right but he is always helping you to make a living, and putting food on your table. If it had been kept private and direct, it could have easily have been a far better outcome for both parties imo.
As for Alberts behaviour on social media, personally I think it is incredibly unprofessional and says more about his nature and how he chooses to run his business, than it does about *the bad customer*. It certainly doesn't make me want to use his services, regardless of his alleged expertise and skill. If Albert is so swamped with work he doesn't have time to communicate directly with his customers, then it makes no sense that he can spend so much time and effort on social media talking about it all, airing his dirty laundry.
I can only think if Albert put the same effort he did into putting down a paying customer, on social media, into actually communicating with the customer in the first place, maybe this whole incident could have been avoided. Yes some customers need to be reassured and want constant updates, and that may not be easy or convienent but when a customer hands over their pride and joy and a large chuck of cash, then why wouldn't you do whats required to keep them updated and happy ? The customer isn't always right but he is always helping you to make a living, and putting food on your table. If it had been kept private and direct, it could have easily have been a far better outcome for both parties imo.