2006 997.1 Carrera S going in for trans rebuild - do I bother with IMS upgrade?
07-22-2015 | 12:39 PM
#31
Former Vendor
Joined: Nov 2010
Posts: 6,968
Likes: 2,295
From: Cleveland Georgia
^ Mr. Raby has some experience to conclude that is a bad idea ...
http://www.flat6innovations.com/index.php/broken-crank
http://www.flat6innovations.com/index.php/broken-crank
07-22-2015 | 12:39 PM
#32
Rennlist Member
Joined: Sep 2014
Posts: 1,652
Likes: 13
From: Sherman Oaks, CA
Hi all.
I just picked up a 2006 Carrera S with a manual (of course) and it turns out my first gear is bad, either chipped or cracked based on the clackity noise in first gear and the metal in the gear oil when I had it drained.
Anyway, while the transmission is out and being rebuilt along with a wavetrac LSD install (by BMCG-Gearbox), would you recommend that I do an IMS upgrade? I was surprised to find the cost of $800 for the parts from LN and Tuners Motorsports DOF system. Car has 82K miles and will see weekend and track usage, though not a dedicated track car. Are either of these systems preferable over the other?
First hand experience appreciated, but all input welcomed.
Thanks,
Jason
I just picked up a 2006 Carrera S with a manual (of course) and it turns out my first gear is bad, either chipped or cracked based on the clackity noise in first gear and the metal in the gear oil when I had it drained.
Anyway, while the transmission is out and being rebuilt along with a wavetrac LSD install (by BMCG-Gearbox), would you recommend that I do an IMS upgrade? I was surprised to find the cost of $800 for the parts from LN and Tuners Motorsports DOF system. Car has 82K miles and will see weekend and track usage, though not a dedicated track car. Are either of these systems preferable over the other?
First hand experience appreciated, but all input welcomed.
Thanks,
Jason
07-22-2015 | 01:13 PM
#33
Burning Brakes
Joined: Feb 2015
Posts: 974
Likes: 4
From: The Windy City
I wish somebody would make a lightened dual-mass flywheel for our cars like Porsche did for the Cayman GT4.
I did a lightweight aluminum flywheel on my Talon and my MINI and dropped 15 and 25 lbs, respectively. Made a big difference in response.
But it's not worth a two-piece crankshaft!
I did a lightweight aluminum flywheel on my Talon and my MINI and dropped 15 and 25 lbs, respectively. Made a big difference in response.
But it's not worth a two-piece crankshaft!
07-22-2015 | 04:33 PM
#34
Burning Brakes
Joined: Apr 2015
Posts: 1,124
Likes: 365
From: Central California Coast
The 6305 bearing radius is about .295 inches more than that for the 6204 bearing, so unless the factory increased the IMSB access bore diameter and the reinforced shoulder and area around it for the IMS bearing retainer, that is a lot of machining, into the existing M96/M97 bell housing mounting lip.
Could it not be that Porsche already saw the dimensional limits of the block in this area and couldn't provide the bore diameter to make it removable ?
07-23-2015 | 06:36 PM
#35
Former Vendor
Joined: Nov 2010
Posts: 6,968
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From: Cleveland Georgia
Makes zero sense to me... Plus, how about the debris generated? The 06+ IMSB has proven to be a solid performer, we don't see them fail unless they are on the track; even then they hold up pretty well. Use good oil and drive it, don't worry about crazy procedures that bring more variables into the equation that can CAUSE issues..
a decade into the M97 IMSB we have only seen 1/2 dozen total failures. Thats nothing.
a decade into the M97 IMSB we have only seen 1/2 dozen total failures. Thats nothing.
07-24-2015 | 05:24 PM
#36
Rennlist Member
Joined: Jul 2009
Posts: 5,902
Likes: 23
From: MA
Makes zero sense to me... Plus, how about the debris generated? The 06+ IMSB has proven to be a solid performer, we don't see them fail unless they are on the track; even then they hold up pretty well. Use good oil and drive it, don't worry about crazy procedures that bring more variables into the equation that can CAUSE issues..
a decade into the M97 IMSB we have only seen 1/2 dozen total failures. Thats nothing.
a decade into the M97 IMSB we have only seen 1/2 dozen total failures. Thats nothing.
07-25-2015 | 11:42 AM
#37
Three Wheelin'
Joined: Feb 2006
Posts: 1,412
Likes: 4
Who is they ?
The 6305 bearing radius is about .295 inches more than that for the 6204 bearing, so unless the factory increased the IMSB access bore diameter and the reinforced shoulder and area around it for the IMS bearing retainer, that is a lot of machining, into the existing M96/M97 bell housing mounting lip.
Could it not be that Porsche already saw the dimensional limits of the block in this area and couldn't provide the bore diameter to make it removable ?
The 6305 bearing radius is about .295 inches more than that for the 6204 bearing, so unless the factory increased the IMSB access bore diameter and the reinforced shoulder and area around it for the IMS bearing retainer, that is a lot of machining, into the existing M96/M97 bell housing mounting lip.
Could it not be that Porsche already saw the dimensional limits of the block in this area and couldn't provide the bore diameter to make it removable ?
Best advise is leave it alone but there is ims anxiety created on this and like sites and there is money to be made. As an expert in the matter, Jack Raby is to be commended for his honest statement here. Thank you Sir.
07-25-2015 | 12:08 PM
#38
Former Vendor
Joined: Nov 2010
Posts: 6,968
Likes: 2,295
From: Cleveland Georgia
I have a directive about seal removal on the M97 IMSB cars. Yes, I do believe it is a good idea, IF you already HAVE to go in to change a clutch. If you don't fit that description, just drive it.
Don't do anything except more frequent oil services, every 6 months of 5K miles, and don't use an oil thats filled with chlorinated paraffin, despite what Porsche may tell you.
Do that, and live happily ever after.
Don't do anything except more frequent oil services, every 6 months of 5K miles, and don't use an oil thats filled with chlorinated paraffin, despite what Porsche may tell you.
Do that, and live happily ever after.
07-25-2015 | 12:37 PM
#39
Three Wheelin'
Joined: Feb 2006
Posts: 1,412
Likes: 4
Board Administrator
I have a directive about seal removal on the M97 IMSB cars. Yes, I do believe it is a good idea, IF you already HAVE to go in to change a clutch. If you don't fit that description, just drive it.
Don't do anything except more frequent oil services, every 6 months of 5K miles, and don't use an oil thats filled with chlorinated paraffin, despite what Porsche may tell you.
Do that, and live happily ever after.
Don't do anything except more frequent oil services, every 6 months of 5K miles, and don't use an oil thats filled with chlorinated paraffin, despite what Porsche may tell you.
Do that, and live happily ever after.
07-25-2015 | 02:39 PM
#40
Former Vendor
Joined: Nov 2010
Posts: 6,968
Likes: 2,295
From: Cleveland Georgia
It took me 10 years to gather the trend data to make this statement. Things are much different than they were 10 years into the M96 engine.
BUT everything changes if you track the car. What Porsche did to strengthen the bearing, and remove load on the street increased surface speed. This worked great on the street, but moved failures from the street (M96) to the track (M97).
BUT everything changes if you track the car. What Porsche did to strengthen the bearing, and remove load on the street increased surface speed. This worked great on the street, but moved failures from the street (M96) to the track (M97).
08-04-2015 | 09:02 AM
#41
Rennlist Member
Joined: Sep 2009
Posts: 677
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2006 997.1 Carrera S going in for trans rebuild - do I bother with IMS upgrade?
I won't say which race team because I don't have their permission, but I spoke to a team that races a lot of IMSB Caymans and has several IMSB 997.1 customer race cars and some of their own and they have not had any failures due to IMSB. Not saying I disagree with flat6, just saying even if you track, the car it is still very solid.
08-04-2015 | 09:26 AM
#42
Former Vendor
Joined: Nov 2010
Posts: 6,968
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From: Cleveland Georgia
It all boils down to luck with this.
The M97.21 engine (06-08 Cayman S) isn't known for IMSB issues. They are known for rod and main bearing clearances being too tight, and causing a host of issues on the track.
Some people never have an issue, others have had 3-4 engines in 5-6 years.
The M97.21 engine (06-08 Cayman S) isn't known for IMSB issues. They are known for rod and main bearing clearances being too tight, and causing a host of issues on the track.
Some people never have an issue, others have had 3-4 engines in 5-6 years.
08-04-2015 | 01:26 PM
#43
Three Wheelin'
Joined: Feb 2006
Posts: 1,412
Likes: 4
It all boils down to luck with this.
The M97.21 engine (06-08 Cayman S) isn't known for IMSB issues. They are known for rod and main bearing clearances being too tight, and causing a host of issues on the track.
Some people never have an issue, others have had 3-4 engines in 5-6 years.
The M97.21 engine (06-08 Cayman S) isn't known for IMSB issues. They are known for rod and main bearing clearances being too tight, and causing a host of issues on the track.
Some people never have an issue, others have had 3-4 engines in 5-6 years.
How should one proceed in this scenario to identify what is happening?
TIA.
08-04-2015 | 07:01 PM
#45
Three Wheelin'
Joined: May 2013
Posts: 1,428
Likes: 471
From: North/Central, NJ
Comeon Jake -you know better. Some M96s have the larger revised bearing as well. Mine is a base 2005 997, build date 03/05, M96 with the bigger bearing - based on visual inspection with myself and Indy.