GTS crank in 5l engine..?
06-28-2010, 08:01 AM
#16
Rennlist Member
06-28-2010, 12:27 PM
#17
Racer
Join Date: Jul 2004
Posts: 409
Likes: 0
Received 0 Likes
on
0 Posts
I estimated the area of the triangular opening found on many (most? all besides gts? Ask Erkka) at 2033mm^2
Therefore you would have approximately a 28% increase in flow capabilities.
Is it worth it to retain this and try to save the block? I would say yes. Porsche would not have put these windows in without testing for a real benefit as it involves a significant change in the block and extra machining operations. OEM durability testing typically involves cycling an engine between peak torque and peak hp for hundreds of hours.
Good luck with whatever you decide to do.
06-28-2010, 02:37 PM
#18
Rennlist Member
anderson and fan have proved that the 6.5 liter is barely 420rwhp with this set up. I have all the below, but no 968 valves and tuning and at 370rwhp . sure, i sould be able to get near 400rwhp with tuning, but heck that is out of a 6.5 liter. I dont think 968 valves alone would give me 50hp, so you? tuning, even the miracle of Dennis and Morton, only gained about 12hp with tuning. 360 with no tuning, and a real peak HP of near 375rwhp after extensive tuning out of the 5 liter with some nice mods.
06-28-2010, 03:22 PM
#19
Nordschleife Master
devil in the details
The seemingly little things such as the exact valve event timing, the exact cam profile, appropriate valve springs, the exact exhaust configuration, exact tuning, etc. and how they fit together can make or break the end result.
(A digression. I am not even going to include head porting or valve jobs in that list -- when someone says they have a ported head and give no more detail I am not sure if that's a positive or negative sign in terms of power production! ;-) I myself will soon scratch an expensive head-porting lottery ticket soon, my head porting experience ended up being like a espionage fantasy movie, only party missing from the drama was the Mexican mafia. End of digression.)
It seems to me that we're seing 10-15% real (not dyno related) peak power differences between engines that have parts that look similar on paper. It just doesn't seem to be the case that any amateur like myself can slap together an engine and have it perform reliably let alone produce power close to its potential. The linear hp-from-parts formulas, such as x hp from GT cams and y hp from 968 intake valves, appear to have a really, really large error term.
This is by the way why this engine stuff is so fascinating.
(A digression. I am not even going to include head porting or valve jobs in that list -- when someone says they have a ported head and give no more detail I am not sure if that's a positive or negative sign in terms of power production! ;-) I myself will soon scratch an expensive head-porting lottery ticket soon, my head porting experience ended up being like a espionage fantasy movie, only party missing from the drama was the Mexican mafia. End of digression.)
It seems to me that we're seing 10-15% real (not dyno related) peak power differences between engines that have parts that look similar on paper. It just doesn't seem to be the case that any amateur like myself can slap together an engine and have it perform reliably let alone produce power close to its potential. The linear hp-from-parts formulas, such as x hp from GT cams and y hp from 968 intake valves, appear to have a really, really large error term.
This is by the way why this engine stuff is so fascinating.
06-28-2010, 03:39 PM
#20
Rennlist Member
we do have a lot of real data points now as far as hp to mod info.
anderson and fans were identical, even when mark did the porting, extrude honing, and drysumping vs fans (more like mine) near stock set up. 420rwhp with a 6.5 liter, better than GT cams and 968 valves. (1mm greater lift than the 85 or GT cams)
I bolted a known quantiy bottom end , 6.5 liter on the top end that was at the top of the heap, as far as GT peformance. 335rwhp at its best. it only went up less than 50hp for a stroker mod. sure, there is some gains for tuning there, but just bolting stuff on ,thats what happened. I dont think it would be a stretch for a 400rwhp estimation for some good tuning. But, i dont think that pulling out 1 liter of displacement could yeild the same power. dennis did 375rwp, but did it at in the RPM danger zone, so thats all about cams and tuning. what did it make at 6000rpm, not that spectacular.
I think we all know that going into the 6500rpm + range for our motors, is a no-no, until someone really solves the oiling issues at the high rpm levels (like 7000rpm, plus)
anderson and fans were identical, even when mark did the porting, extrude honing, and drysumping vs fans (more like mine) near stock set up. 420rwhp with a 6.5 liter, better than GT cams and 968 valves. (1mm greater lift than the 85 or GT cams)
I bolted a known quantiy bottom end , 6.5 liter on the top end that was at the top of the heap, as far as GT peformance. 335rwhp at its best. it only went up less than 50hp for a stroker mod. sure, there is some gains for tuning there, but just bolting stuff on ,thats what happened. I dont think it would be a stretch for a 400rwhp estimation for some good tuning. But, i dont think that pulling out 1 liter of displacement could yeild the same power. dennis did 375rwp, but did it at in the RPM danger zone, so thats all about cams and tuning. what did it make at 6000rpm, not that spectacular.
I think we all know that going into the 6500rpm + range for our motors, is a no-no, until someone really solves the oiling issues at the high rpm levels (like 7000rpm, plus)
The seemingly little things such as the exact valve event timing, the exact cam profile, appropriate valve springs, the exact exhaust configuration, exact tuning, etc. and how they fit together can make or break the end result.
(A digression. I am not even going to include head porting or valve jobs in that list -- when someone says they have a ported head and give no more detail I am not sure if that's a positive or negative sign in terms of power production! ;-) I myself will soon scratch an expensive head-porting lottery ticket soon, my head porting experience ended up being like a espionage fantasy movie, only party missing from the drama was the Mexican mafia. End of digression.)
It seems to me that we're seing 10-15% real (not dyno related) peak power differences between engines that have parts that look similar on paper. It just doesn't seem to be the case that any amateur like myself can slap together an engine and have it perform reliably let alone produce power close to its potential. The linear hp-from-parts formulas, such as x hp from GT cams and y hp from 968 intake valves, appear to have a really, really large error term.
This is by the way why this engine stuff is so fascinating.
(A digression. I am not even going to include head porting or valve jobs in that list -- when someone says they have a ported head and give no more detail I am not sure if that's a positive or negative sign in terms of power production! ;-) I myself will soon scratch an expensive head-porting lottery ticket soon, my head porting experience ended up being like a espionage fantasy movie, only party missing from the drama was the Mexican mafia. End of digression.)
It seems to me that we're seing 10-15% real (not dyno related) peak power differences between engines that have parts that look similar on paper. It just doesn't seem to be the case that any amateur like myself can slap together an engine and have it perform reliably let alone produce power close to its potential. The linear hp-from-parts formulas, such as x hp from GT cams and y hp from 968 intake valves, appear to have a really, really large error term.
This is by the way why this engine stuff is so fascinating.
06-28-2010, 06:01 PM
#22
Racer
Thread Starter
Join Date: Jan 2006
Location: Sweden, Norway and Beyond
Posts: 263
Received 0 Likes
on
0 Posts
Love this forum.
So tomorrow I will hear from the chaps in Upsala regarding my cranks condition.
If its a go, I will try to port the tops. Look into the cost of 968 Valves and assemble the engine ASAP.
I have a X pipe waiting. I will use the GTS R2 rods and pistons with new rings.
This is very exciting!
I wonder if I should use the GT ECU or a GTS ECU that I have lying around?
It will have GT cams...
Cheers.
So tomorrow I will hear from the chaps in Upsala regarding my cranks condition.
If its a go, I will try to port the tops. Look into the cost of 968 Valves and assemble the engine ASAP.
I have a X pipe waiting. I will use the GTS R2 rods and pistons with new rings.
This is very exciting!
I wonder if I should use the GT ECU or a GTS ECU that I have lying around?
It will have GT cams...
Cheers.
06-28-2010, 06:05 PM
#23
Racer
Thread Starter
Join Date: Jan 2006
Location: Sweden, Norway and Beyond
Posts: 263
Received 0 Likes
on
0 Posts
Regarding the headers...
Erkka mentioned MSDS.
I have 928 Motorsport headers on my race car project.
My mech nearly gave up fitting them...
More than 10 mm off in places.
So please tell me about the price and fit of the MSDS headers?
Is that a US company?
Cheers again.
Erkka mentioned MSDS.
I have 928 Motorsport headers on my race car project.
My mech nearly gave up fitting them...
More than 10 mm off in places.
So please tell me about the price and fit of the MSDS headers?
Is that a US company?
Cheers again.
06-28-2010, 07:22 PM
#25
Addict
Rennlist Member
Rennlist Member
928 Motorsports sells them so its likely they are same and you already have them.
06-28-2010, 08:38 PM
#26
Racer
Thread Starter
Join Date: Jan 2006
Location: Sweden, Norway and Beyond
Posts: 263
Received 0 Likes
on
0 Posts
They look familiar...!
At least Carl is off the hook if these guys make them.
Or maybe the early headers were rather inaccurate.
Anywhere in Europe we can get such Erkka?
At least Carl is off the hook if these guys make them.
Or maybe the early headers were rather inaccurate.
Anywhere in Europe we can get such Erkka?
06-29-2010, 07:31 AM
#28
Rennlist Member
anderson and fan have proved that the 6.5 liter is barely 420rwhp with this set up. I have all the below, but no 968 valves and tuning and at 370rwhp . sure, i sould be able to get near 400rwhp with tuning, but heck that is out of a 6.5 liter. I dont think 968 valves alone would give me 50hp, so you? tuning, even the miracle of Dennis and Morton, only gained about 12hp with tuning. 360 with no tuning, and a real peak HP of near 375rwhp after extensive tuning out of the 5 liter with some nice mods.
Mark, if you ever looked into the ignition maps for a S4 and even a GT, you would not believe how retarded, pun intended, they are. We were able to advance ignition by up to 12deg on my GT engine and 9deg on my GTS before we got any pinking at rpm where it really makes a difference. Trust me, there is a lot of power to be had with a ST Mk2 in hand. My engine is dry-sumped, thus I can actually use the upper rev range reasonably safe in the knowledge that I don't get any oil starvation.
P.S. It happens that over the last two weeks or so I have been driving my brother's Lorinser SL500, which is 5ltr V8 32v with 326bhp and 500Nm of torque (1991 California Car). It only needs 3 bar of oil pressure...
06-29-2010, 01:19 PM
#29
Rennlist Member
yep, as funny as that sounds, yes. by the way, so have anderson and fan for the longest time.
why? $$$$$$$$$.
I know its safe, as we have a lot of dyno time on the old and a little on the new, so the mixtures are rich, but safe. Im sure there is power there, but I am also running 91 octane pump gas too.
why? $$$$$$$$$.
I know its safe, as we have a lot of dyno time on the old and a little on the new, so the mixtures are rich, but safe. Im sure there is power there, but I am also running 91 octane pump gas too.
06-29-2010, 01:21 PM
#30
Nordschleife Master
Can you beg someone to help you for free with a Sharktuner? On your knees?
yep, as funny as that sounds, yes. by the way, so have anderson and fan for the longest time.
why? $$$$$$$$$.
I know its safe, as we have a lot of dyno time on the old and a little on the new, so the mixtures are rich, but safe. Im sure there is power there, but I am also running 91 octane pump gas too.
why? $$$$$$$$$.
I know its safe, as we have a lot of dyno time on the old and a little on the new, so the mixtures are rich, but safe. Im sure there is power there, but I am also running 91 octane pump gas too.