997 GT3 Gen1 clubsport
Discussion
CK_N4S said:
Congrats on the car Steve
I'm sure you will come to enjoy it in time when you start sorting the small stuff.
I have not taken the greatest of steps in modifying mine - but some have been well chosen.
I have mine kept at the Nürburgring, and seen after by Tom Schirmer (Who most of you will probably know for his BMW work)
Currently I'm running endlass pads on the OEM discs by Toms recommendation. Can't tell you much about Wear on them, as I'm still on my first set (which has done more than 100 laps of the Ring this year)
It was fitted with a HR 997 cup racing suspension setup when I bought it - courtesy of the previous owner from Sweden and his racing team running in the Swedish Carrera Cup with another 997 Cup car. This setup was not road legal in Germany and was changed for a full Nitron adjustable coilover suspension with external reservoirs for the front dampers. The car was subsequently corner weighted and a full Geo was done for the Ring (and then raised by about 5 mm as the car was scraping quite a lot on the Ring
)
I'm sure the rear antiroll bar has been changed also, as I have never had any mentionable problems with understeer.
My thoughts on the next upgrades have been centered around weight saving by an Akrapovic exhaust and a light weight battery.
Looking forward to reading your Progress on the car and sharing experiences.
Mine is a keeper - and I wouldnt even change it for a 4.0 for fear of ruining my economy.
CK
Thank you for sharing details of your car with us. It sounds interesting and well judged for the ring. Thinking about the issues that I am looking to address it struck me that the standard car with just a passive set up will be a lovely option for the ring due to the fast flowing nature. Proportionately, there are not that many big and medium stops where a big trail is needed so bias and diff reliance is not as critical as it would be on a normal give and take circuit. Since these cars spend so much of their time at the ring during development, I can see why they have evolved in this way. I'm sure you will come to enjoy it in time when you start sorting the small stuff.
I have not taken the greatest of steps in modifying mine - but some have been well chosen.
I have mine kept at the Nürburgring, and seen after by Tom Schirmer (Who most of you will probably know for his BMW work)
Currently I'm running endlass pads on the OEM discs by Toms recommendation. Can't tell you much about Wear on them, as I'm still on my first set (which has done more than 100 laps of the Ring this year)
It was fitted with a HR 997 cup racing suspension setup when I bought it - courtesy of the previous owner from Sweden and his racing team running in the Swedish Carrera Cup with another 997 Cup car. This setup was not road legal in Germany and was changed for a full Nitron adjustable coilover suspension with external reservoirs for the front dampers. The car was subsequently corner weighted and a full Geo was done for the Ring (and then raised by about 5 mm as the car was scraping quite a lot on the Ring
) I'm sure the rear antiroll bar has been changed also, as I have never had any mentionable problems with understeer.
My thoughts on the next upgrades have been centered around weight saving by an Akrapovic exhaust and a light weight battery.
Looking forward to reading your Progress on the car and sharing experiences.
Mine is a keeper - and I wouldnt even change it for a 4.0 for fear of ruining my economy.
CK
All the Bosch literature I have seen suggests that its a feature within the ABS unit. Essentially its a program within the ABS ecu itself. Bosch literature also suggests that the TC stuff (fuel and spark cut off) are also controlled by the ABS unit again being a code within the ecu software.
The ABS monitors the wheel slip conditions at all speeds and decides what sort of intervention it should provide.
The ABS also controls bias and is really quite active on the proactive side. Most people only think ABS is reactive but it's come a long way. You will struggle to get bias moved back with the ABS on the car as it is. Your changes will just be offset by increased pressure reduction until a point is reached where the system reaches its limit and faults.
You will need to adapt your braking strategy to work with it or replace the ABS unit if you aren't happy with what that provides.
I don't have pin outs for the 997 ABS ecu. Do you have them? I would be interested to see if you could swap out the ecu from the 996.1 cars (any model) by just unplugging one and putting in the other. This doesn't have the code for the ABD or TC stuff and isn't as involved with regards to proactive brake interference strategies. Though with the systems all being interconnected this approach may just create other problems.
Some experimentation is needed
The ABS monitors the wheel slip conditions at all speeds and decides what sort of intervention it should provide.
The ABS also controls bias and is really quite active on the proactive side. Most people only think ABS is reactive but it's come a long way. You will struggle to get bias moved back with the ABS on the car as it is. Your changes will just be offset by increased pressure reduction until a point is reached where the system reaches its limit and faults.
You will need to adapt your braking strategy to work with it or replace the ABS unit if you aren't happy with what that provides.
I don't have pin outs for the 997 ABS ecu. Do you have them? I would be interested to see if you could swap out the ecu from the 996.1 cars (any model) by just unplugging one and putting in the other. This doesn't have the code for the ABD or TC stuff and isn't as involved with regards to proactive brake interference strategies. Though with the systems all being interconnected this approach may just create other problems.
Some experimentation is needed
Edited by fioran0 on Wednesday 24th December 14:53
Bugger. Thats the last thing that I want. If i'm going to go down the 996 abs route than a motorsport unit would be the route that I would take. But I'll only hybrid the car as a last resort. I may have to live with the moving bias thing and just learn how to make it work for me. The Beefy diff may help a lot.
Haven't picked the car up yet. Waiting for the V5 to come back - private plate retention.
Out of interest, how did you manage the brakes on your mad 996?
Haven't picked the car up yet. Waiting for the V5 to come back - private plate retention.
Out of interest, how did you manage the brakes on your mad 996?
Yeah, I agree. Let me have a look for the braking strategy seminars with Darrick Dong and send you the links. It will be worth a watch through in the context of the car and going forwards. May give you some food for thought.
I suspect that adapting strategy to maximise what you have will be a better option that changing parts out unless you are prepared to really start into it all in a big way. Something like the Bosch M4 would be ideal but it tends to run around 5 figures for an installed system.
Running a 996 Cup ABS brings its own challenges. You would need it reflashed to your tyre diameters as they are set for the Cup tyre sizes (with the large rear rubber). Im not 100% on how much control Motorsport have over doing this. These things aren't the easiest to get hold of either and they aren't that cheap. Last I checked there weren't any available from Motorsport though this may have changed since. If not you need to find one thats been removed from a Cup.
Finally, you get right back to the wiring issue. I don't know how compatible the pin outs etc on the later ABS units are. The 996 Cup uses the same pin outs as the early, pre 2000 ABS units used on the C2 and 996.1 GT3.
If the ABS units can just be swapped over, you would actually be better just grabbing a street car early type ABS unit to use. Its the same, primitive type of ABS thats actually perfect for track driving (i.e. it pretty much only does reactive ABS). The units that came after this took on more and more control until you end up where you are at now. The pre 2000 setup still used a mechanical proportioning valve.
I removed the Cup ABS system from my car and run the 997 CUP/RSR setup. Dual masters, no assist, no ABS etc though running the grand-am mod on the master cylinders to get a tad extra pedal travel to save leg fatigue. A big advantage is that I can run any tyre size I feel like since theres no electronic intervention on the braking at all. If it fits I can use it.
Edit: Just noticed the time. Merry Christmas
I suspect that adapting strategy to maximise what you have will be a better option that changing parts out unless you are prepared to really start into it all in a big way. Something like the Bosch M4 would be ideal but it tends to run around 5 figures for an installed system.
Running a 996 Cup ABS brings its own challenges. You would need it reflashed to your tyre diameters as they are set for the Cup tyre sizes (with the large rear rubber). Im not 100% on how much control Motorsport have over doing this. These things aren't the easiest to get hold of either and they aren't that cheap. Last I checked there weren't any available from Motorsport though this may have changed since. If not you need to find one thats been removed from a Cup.
Finally, you get right back to the wiring issue. I don't know how compatible the pin outs etc on the later ABS units are. The 996 Cup uses the same pin outs as the early, pre 2000 ABS units used on the C2 and 996.1 GT3.
If the ABS units can just be swapped over, you would actually be better just grabbing a street car early type ABS unit to use. Its the same, primitive type of ABS thats actually perfect for track driving (i.e. it pretty much only does reactive ABS). The units that came after this took on more and more control until you end up where you are at now. The pre 2000 setup still used a mechanical proportioning valve.
I removed the Cup ABS system from my car and run the 997 CUP/RSR setup. Dual masters, no assist, no ABS etc though running the grand-am mod on the master cylinders to get a tad extra pedal travel to save leg fatigue. A big advantage is that I can run any tyre size I feel like since theres no electronic intervention on the braking at all. If it fits I can use it.
Edit: Just noticed the time. Merry Christmas
And a belated Merry Christmas to you too Old Chap!
Thank you for taking the trouble yo share that information. Very useful. It's looking increasingly likely that - within the scope of the project brief - It will be easier to develop a strategy and driving style to make the best of the existing system.
Interesting that you have the 997 system on your car. Presumably you have the adjustable bias system on the dash?
Thank you for taking the trouble yo share that information. Very useful. It's looking increasingly likely that - within the scope of the project brief - It will be easier to develop a strategy and driving style to make the best of the existing system.
Interesting that you have the 997 system on your car. Presumably you have the adjustable bias system on the dash?
The aim is basically to unlock as much of the true dynamic potential of the car as possible with the minimum of modifications. It's looking like A stronger diff (which will want doing anyway), cup front discs and some passive. I'll drive around the moving bias. These mods will make it very easy to convert the car back to bog standard at any time.
Henry
Steve feels, as do I that the 997 can be much more than it shows as delivered. Not everyone does of course but he's putting his money on the table and having a go at getting it there. It's the way Porsche used to be which makes it interesting. I am biased of course but I enjoy seeing "air cooled" projects being carried out on the modern cars. Its a twinkle of the old days persisting in a modern Porsche scene that's much the worse for the lack of such owner engagement.
If one takes a GT3 and a Cup as being the two end points on a scale then Steves car needs to find itself a home somewhere between those limits.
Its easy to achieve the end points but less so to find the point in between that works according to whatever terms you choose to set. It's made worse that movement along the scale becomes increasingly one directional as you move towards the Cup side. By the time a car is at the point where the Cup sits, the effort required to move it towards the GT3 by even a tiny increment is huge. (Edit to add: Particularly on the 997)
I view this thread as an open conversation with Steve over what his terms are going to be and his thinking behind them. It's very interesting as a result and quite a brave decision on his part to lay bare the initial project process to the public domain. I use brave because its a frequently messy iterative thing.
Steve feels, as do I that the 997 can be much more than it shows as delivered. Not everyone does of course but he's putting his money on the table and having a go at getting it there. It's the way Porsche used to be which makes it interesting. I am biased of course but I enjoy seeing "air cooled" projects being carried out on the modern cars. Its a twinkle of the old days persisting in a modern Porsche scene that's much the worse for the lack of such owner engagement.
If one takes a GT3 and a Cup as being the two end points on a scale then Steves car needs to find itself a home somewhere between those limits.
Its easy to achieve the end points but less so to find the point in between that works according to whatever terms you choose to set. It's made worse that movement along the scale becomes increasingly one directional as you move towards the Cup side. By the time a car is at the point where the Cup sits, the effort required to move it towards the GT3 by even a tiny increment is huge. (Edit to add: Particularly on the 997)
I view this thread as an open conversation with Steve over what his terms are going to be and his thinking behind them. It's very interesting as a result and quite a brave decision on his part to lay bare the initial project process to the public domain. I use brave because its a frequently messy iterative thing.
Edited by fioran0 on Friday 26th December 13:56
I agree re braking strategy adaptation, though if the early ABS can be swapped out, in a plug and play fashion it MAY solve everything quite simply. I will try to get a street wiring schematic for the 997.1 and look through it with an eye to the physical connection aspect. That may kill it before it gets to stage 2.
Yeah, I have the cockpit mounted brake bias control.
Yeah, I have the cockpit mounted brake bias control.
Heres a relink to my post with the ABS braking strategy seminar with Darrick Dong.
http://www.pistonheads.com/gassing/topic.asp?t=141...
http://www.pistonheads.com/gassing/topic.asp?t=141...
I think that you have taken this a little out of context Henry. The engine, gearbox and chassis platforms are brilliant. It's just a case of working out what can be done simply to make the package better. If the abs bias can't be changed simply, it can't be changed. Any disadvantage can generally be turned into an advantage. If the abs bias is more rearward on initial braking there is more scope for front camber. Either way, these issues are not major stumbling blocks, they just make my world a little less ideal. As Neil says, it's just that I/we are sharing our thought processes on an open forum.
Hi Steve, I'm still awaiting the answer regarding the brake set-up on my car (x-mas break getting in the way of things) but here are a few pictures I took the other day of the BMC, ABS unit and the front & rear brake set-up. I was surprised to find a small run of Braided steel brake lines between the BMC and ABS unit. Also the cable loom going into the ABS unit also looks a little over exposed to me (maybe an indication of some splicing on wires). It would be great if anyone has any pictures of the stock set-up so that a comparison can be made. As soon as I know anymore I'll update.
Steve
I have all the tech info for all the ABS (and thus PSM,TC etc etc) on all the 996/997/CGT street cars. I will email you the summary of what's on the 997.1GT3, what the system does, parameters etc etc.
I'm not for getting in to it on a public board and the thread will turn into a clu$terf&c& if I do.
I have all the tech info for all the ABS (and thus PSM,TC etc etc) on all the 996/997/CGT street cars. I will email you the summary of what's on the 997.1GT3, what the system does, parameters etc etc.
I'm not for getting in to it on a public board and the thread will turn into a clu$terf&c& if I do.
Richie
Those brake lines are stock on LHD cars. Even the cayman has lines like that. I guess it makes parts fitment a little easier.
The loom is normal looking too.
You do have studs instead of bolts (make sure you check them for loosening) and obviously black calipers.
Those brake lines are stock on LHD cars. Even the cayman has lines like that. I guess it makes parts fitment a little easier.
The loom is normal looking too.
You do have studs instead of bolts (make sure you check them for loosening) and obviously black calipers.
Edited by fioran0 on Friday 26th December 21:48
keep it lit said:
Richie200 said:
keep it lit said:
nice mods on your car Richie... looks like your steering may have been uprated 
Thanks Keep it lit It's a CUP steering system.ttdan said:
keep it lit said:
Richie200 said:
keep it lit said:
nice mods on your car Richie... looks like your steering may have been uprated
Thanks Keep it lit It's a CUP steering system.Gassing Station | 911/Carrera GT | Top of Page | What's New | My Stuff