New suspension bits
06-18-2014 | 11:10 PM
#46
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Audi - turn in is affected by many things - the basic alignment can make a huge difference.
Pete:
The rake is really a measure of the body height - front vs rear (pretty much what affects the CG) , not the subframe height. By lowering the body (motor, tranny, etc) by 20mm, you are effectively removing ~20mm of rake.
WRT the Cup and street cars - the suspensions are essentially the same - uprights, side members, cross members are all the same - can be verified with part numbers. Biggest differences would be springs & shocks - which are different.
WRT ground clearance - 80mm is a bit low - lower than the RSR numbers
WRT springs: I had convinced myself that the 1000/1200 springs were far to much and wanted to install 700/900 or 750/950. I put ~320 miles on the car at WGI 1.5 weeks ago - and was starting to get a good feel to the point where I was starting to play with moving it around in the corners - a bit of a sphincter tighter event given the speeds, but things felt really good. So for now I will leave the springs as they are. I go LCMT in 3 weeks - another high speed track, I should have more information then.
The ABS will tolerate a 10-15% differential in circumference (I think) - I would keep it as close as possible.
245's will fit easily in the front, 255/265 perhaps - depending on the rim, and the camber, and if you have installed the RSR flairs :-)
I will get pictures shortly - been fixing/building rims this week - cracked a BBS center section at WGI...
Ray
Pete:
Ray,
the chassis is 20mm lower compared to the rear subframe, but the hieght of the car at rear is measured from the subframe. So the rake looks out slightly different with our side members. What I have not yet measure is how body is positioned compared to the ground. Ideal would be level or rear slightly higher. With my flat bottom it's easy to measure if the surface is level. (Not the case in my garage bacause of drainage well in the middle.)
Anyway street GT3s and CUPs run almost equal rakes, but one has to keep in mind the tire size issue affecting it, which I did not yet do... Back to the drawing board.
I also may go lower, but need to still maintain 80 mm ground clearance at minimum.
the chassis is 20mm lower compared to the rear subframe, but the hieght of the car at rear is measured from the subframe. So the rake looks out slightly different with our side members. What I have not yet measure is how body is positioned compared to the ground. Ideal would be level or rear slightly higher. With my flat bottom it's easy to measure if the surface is level. (Not the case in my garage bacause of drainage well in the middle.)
Anyway street GT3s and CUPs run almost equal rakes, but one has to keep in mind the tire size issue affecting it, which I did not yet do... Back to the drawing board.
I also may go lower, but need to still maintain 80 mm ground clearance at minimum.
WRT the Cup and street cars - the suspensions are essentially the same - uprights, side members, cross members are all the same - can be verified with part numbers. Biggest differences would be springs & shocks - which are different.
WRT ground clearance - 80mm is a bit low - lower than the RSR numbers
WRT springs: I had convinced myself that the 1000/1200 springs were far to much and wanted to install 700/900 or 750/950. I put ~320 miles on the car at WGI 1.5 weeks ago - and was starting to get a good feel to the point where I was starting to play with moving it around in the corners - a bit of a sphincter tighter event given the speeds, but things felt really good. So for now I will leave the springs as they are. I go LCMT in 3 weeks - another high speed track, I should have more information then.
The ABS will tolerate a 10-15% differential in circumference (I think) - I would keep it as close as possible.
245's will fit easily in the front, 255/265 perhaps - depending on the rim, and the camber, and if you have installed the RSR flairs :-)
I will get pictures shortly - been fixing/building rims this week - cracked a BBS center section at WGI...
Ray
06-19-2014 | 03:59 AM
#48
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From: fortistuning.fi
Now it would be nice to get an explanation from vehicle dynamics expert if there's any difference when the rake is done by suspension setting (GT3), previous plus tire size (CUP) or both previous plus subframes (RSR). There are differences in aerodynamics and CG, but how they actually show up.
WRT the Cup and street cars - the suspensions are essentially the same - uprights, side members, cross members are all the same - can be verified with part numbers. Biggest differences would be springs & shocks - which are different.
WRT ground clearance - 80mm is a bit low - lower than the RSR numbers
WRT ground clearance - 80mm is a bit low - lower than the RSR numbers
With 80mm ground clearance I mean splitter and undrfloor panel heights.
I'd like to keep it a real NB, so no flares for me, thanks. (At least now...)
06-19-2014 | 09:25 AM
#49
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From: fortistuning.fi
Fault code 5500
Wheel speed monitoring
Diagnostic conditions
• The fault is stored if the average speed of one wheel is at least 5
% greater than the speed of the other wheels for longer than 20
s.
5% in speed means about 25-30 mm bigger tire in diameter, depending on the starting point (18" wheel & tire).
Wheel speed monitoring
Diagnostic conditions
• The fault is stored if the average speed of one wheel is at least 5
% greater than the speed of the other wheels for longer than 20
s.
5% in speed means about 25-30 mm bigger tire in diameter, depending on the starting point (18" wheel & tire).
06-23-2014 | 11:28 PM
#51
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From: Carlisle, MA
Hi Folks,
Pete - you had asked for pictures - this is before that wash and wax on Sunday...
Been (perhaps not so slowly) combining the best of the Cup & RSR where affordable and reasonable.
I am starting to think that the next BIG project will be to pull the motor & go through it. Might consider changing the heads for 997 heads to get a bit better breathing...
The way I look at it is that there must be another whole pile of tools that I don't have :-)
Some obvious bits include E88 rims, MS Centerlock, vented front with cup car splitter, CF/Kevlar cup car rear bumper cover, quiet cup car exhaust - probably ~98db instead of the 110 db. This came off a European cup car, Grand AM wing, lid, uprights
Ray
Pete - you had asked for pictures - this is before that wash and wax on Sunday...
Been (perhaps not so slowly) combining the best of the Cup & RSR where affordable and reasonable.
I am starting to think that the next BIG project will be to pull the motor & go through it. Might consider changing the heads for 997 heads to get a bit better breathing...
The way I look at it is that there must be another whole pile of tools that I don't have :-)
Some obvious bits include E88 rims, MS Centerlock, vented front with cup car splitter, CF/Kevlar cup car rear bumper cover, quiet cup car exhaust - probably ~98db instead of the 110 db. This came off a European cup car, Grand AM wing, lid, uprights
Ray
06-25-2014 | 03:49 PM
#53
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From: Carlisle, MA
The wing/uprights are Porsche Grand AM bits I managed to scrounge.
The rims are the standard E88 cup rims - 18x9/11 - I forget offset - fronts use a 5mm spacer - not sure it is necessary for these rims.
The tires are 235/40, 315/30 18's (it might be 235/45) - anyway the circumference is the same...
Ray
The rims are the standard E88 cup rims - 18x9/11 - I forget offset - fronts use a 5mm spacer - not sure it is necessary for these rims.
The tires are 235/40, 315/30 18's (it might be 235/45) - anyway the circumference is the same...
Ray
06-25-2014 | 10:00 PM
#54
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From: Grand Rapids, MI
The wing/uprights are Porsche Grand AM bits I managed to scrounge.
The rims are the standard E88 cup rims - 18x9/11 - I forget offset - fronts use a 5mm spacer - not sure it is necessary for these rims.
The tires are 235/40, 315/30 18's (it might be 235/45) - anyway the circumference is the same...
Ray
The rims are the standard E88 cup rims - 18x9/11 - I forget offset - fronts use a 5mm spacer - not sure it is necessary for these rims.
The tires are 235/40, 315/30 18's (it might be 235/45) - anyway the circumference is the same...
Ray
06-25-2014 | 10:29 PM
#55
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From: Carlisle, MA
Andrew,
I would NEVER think of trying to improve on this great marque
Actually the Cup car spec on the rims are 46 & 59mm (front/rear).
The front tire are 235/40's
I actually did nothing to these rims...
WRT the rake - Pete one think I forgot to mention is that the RSR motor sits ~ 15mm LOWER than the stock GT3/Cup car. They use different motor mounts. The solid mounts from Rennsport are copies of the RSR parts. I have these installed, but needed to raise the motor ~ 7 mm for clearance issue
Ray
I would NEVER think of trying to improve on this great marque
Actually the Cup car spec on the rims are 46 & 59mm (front/rear).
The front tire are 235/40's
I actually did nothing to these rims...
WRT the rake - Pete one think I forgot to mention is that the RSR motor sits ~ 15mm LOWER than the stock GT3/Cup car. They use different motor mounts. The solid mounts from Rennsport are copies of the RSR parts. I have these installed, but needed to raise the motor ~ 7 mm for clearance issue
Ray
Last edited by rbahr; 06-25-2014 at 11:31 PM.
06-28-2014 | 09:18 AM
#58
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07-04-2014 | 05:56 PM
#60
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From: fortistuning.fi
Hello, and sorry about slow reply, it's been a busy week. about underlining numbers, see attached copy of PDF PET's page, they're all in there. Parts 1, 3, 4 L&R, 5, 7, 14 L&R. Then you'll need few extra #2, 8, 9's too.
996 doesn't have #4 L&R, so attaching those you must add some rivets with threads. I got them from my local Porsche maintenace. 5 / side, 10 altogether. You will find out positions for these rivets by installing #4 L&R from their inner points (which are the same than #3's), mark, drill and pull the rivets. Nothing there to be afraid of, you will not hit anything significant...
You may need to trim some outer front corners of 4 L&R and outer rear corners of #5. I solved the latter part by trimming edges of side skirts which happened to be in rather sad shape anyway.
Do a test fitting, think twice and drill once, I used also some zip ties in installing #7.
#14's are air ducts for rear brakes.
I hope this helps!
996 doesn't have #4 L&R, so attaching those you must add some rivets with threads. I got them from my local Porsche maintenace. 5 / side, 10 altogether. You will find out positions for these rivets by installing #4 L&R from their inner points (which are the same than #3's), mark, drill and pull the rivets. Nothing there to be afraid of, you will not hit anything significant...
You may need to trim some outer front corners of 4 L&R and outer rear corners of #5. I solved the latter part by trimming edges of side skirts which happened to be in rather sad shape anyway. Do a test fitting, think twice and drill once, I used also some zip ties in installing #7.
#14's are air ducts for rear brakes.
I hope this helps!