997 GT3.mk1 PASM re-valve begins
08-02-2011, 09:45 PM
#46
Drifting
Thread Starter
Mini update
Car will be ready tomorrow.
Re-valved shocks arrived today as did the Swift springs.
The 228mm springs are almost exact size of stock OE 223mm - mechanic eyeballing thought they were exact - car will be corner balanced, aligned etc to correct everything.
Springs are a pretty powder blue for the interior decorating crowd.
All the RSS parts (rear upper control arms and new 2 piece rear lower control arms with mono ***** and solid caster pucks) installed without issue.
Road and track feedback will be a few days / weeks until I have time.
Does anyone know of an easy solution for a rear upper shock hat that would make trying a 60mm spring a reasonably simple task? I would like to try a 700-750# spring with the stock rear shock first without re-valving.
Car will be ready tomorrow.
Re-valved shocks arrived today as did the Swift springs.
The 228mm springs are almost exact size of stock OE 223mm - mechanic eyeballing thought they were exact - car will be corner balanced, aligned etc to correct everything.
Springs are a pretty powder blue for the interior decorating crowd.
All the RSS parts (rear upper control arms and new 2 piece rear lower control arms with mono ***** and solid caster pucks) installed without issue.
Road and track feedback will be a few days / weeks until I have time.
Does anyone know of an easy solution for a rear upper shock hat that would make trying a 60mm spring a reasonably simple task? I would like to try a 700-750# spring with the stock rear shock first without re-valving.
08-03-2011, 02:31 PM
#47
Drifting
Thread Starter
Another update,
Somewhat stupid me, the spring length works, but a better spring length would have been the 1inch shorter Swift spring - ie the 203mm spring, not the 228mm I ordered - factory front is 223mm. Why? Well because the spring I used, a 450# (80N/mm), of course doesn't compress as much as the factory 228# spring (insert Homer Simpson sound). At my spring choice of 450#s, the spring compresses approx 1.5 inches less than softer factory spring.
For anyone else contemplating this, the factory ride height leaves an approx equal number of threads either side of the stock position - or just less than about 2 inches in either direction. So, an 8 inch spring is about perfect for 450-500 pounds. At around 700#s you will want to go with a 7 inch spring.
As NJGT pointed out, you can do zero rate tenders and spring hats - I'm just adding that you have to keep the entire thing, to be safe, within +or- 1.25 inches of a 223mm stock OE spring whose spec is 228#s and given factory ride height / rake, compresses about 3 inches under the car's front weight.
Previously I have been running my front strut tops in the non-turned OE position and have just used shims to get to my desired camber. I decided to have them turned to bring caster down slightly as I'm running for street a 245/35/19 PSS tire that runs a tiny bit taller than spec and I noticed rubbed once street driving when I have never rubbed on previous tires. I can now see how if you really wanted to with the perfect offset and running a slightly short tire with a stiffer front spring you could wedge in a pretty big front tire.
Somewhat stupid me, the spring length works, but a better spring length would have been the 1inch shorter Swift spring - ie the 203mm spring, not the 228mm I ordered - factory front is 223mm. Why? Well because the spring I used, a 450# (80N/mm), of course doesn't compress as much as the factory 228# spring (insert Homer Simpson sound). At my spring choice of 450#s, the spring compresses approx 1.5 inches less than softer factory spring.
For anyone else contemplating this, the factory ride height leaves an approx equal number of threads either side of the stock position - or just less than about 2 inches in either direction. So, an 8 inch spring is about perfect for 450-500 pounds. At around 700#s you will want to go with a 7 inch spring.
As NJGT pointed out, you can do zero rate tenders and spring hats - I'm just adding that you have to keep the entire thing, to be safe, within +or- 1.25 inches of a 223mm stock OE spring whose spec is 228#s and given factory ride height / rake, compresses about 3 inches under the car's front weight.
Previously I have been running my front strut tops in the non-turned OE position and have just used shims to get to my desired camber. I decided to have them turned to bring caster down slightly as I'm running for street a 245/35/19 PSS tire that runs a tiny bit taller than spec and I noticed rubbed once street driving when I have never rubbed on previous tires. I can now see how if you really wanted to with the perfect offset and running a slightly short tire with a stiffer front spring you could wedge in a pretty big front tire.
08-03-2011, 02:58 PM
#48
Rennlist Member
when i was deciding about my build i was told by my mechanic who works on gt3 and cup cars that lowest rate worth doing was 600/700 and that was setup i went with. as of re-valving stock shocks, whole point of changing setup was to gain custom adjustability, imho if you go down this route there is littelr eason to stop mid-way. jrz rs or jrz pro (if car gets mostly track time only) is the way to do it.
springs are cheap, i bet you`ll find your ideal rate. i find 600/700 to work great for AX, street and track. for track only car i would do 700/900 based on what i know of my car now. i was also told against zero rate helpers, he used 150lbs ones and they work great.
450 spring in front is very low. be careful with dropping ride height too low, you need to preserve proper right angle between front arms or you will need to put on cup car uprights and change way more parts. plus put on bump steer rear arms which is not easy. it is overall simpler to maintain acceptable ride height rather than to go 'cup car' style low.
springs are cheap, i bet you`ll find your ideal rate. i find 600/700 to work great for AX, street and track. for track only car i would do 700/900 based on what i know of my car now. i was also told against zero rate helpers, he used 150lbs ones and they work great.
450 spring in front is very low. be careful with dropping ride height too low, you need to preserve proper right angle between front arms or you will need to put on cup car uprights and change way more parts. plus put on bump steer rear arms which is not easy. it is overall simpler to maintain acceptable ride height rather than to go 'cup car' style low.
08-03-2011, 04:30 PM
#49
Drifting
Thread Starter
If you think 450 is low, then I'm not sure what you'd think of the factory 228 front spring. This started as an experiment to see if I could fix the major issue that i have with the OE suspension for the track - not enough front spring.
Ride height is factory.
If you look at the KW Clubsport kit that many 911s use in Germany at the NRing, approximately (400f,950r), then my 450 front isn't very soft, it just isn't a full track setup.
Given the guys at Bilstein said my re-valved shock can easily handle up to 15% more spring, I may end up at 500/700 550/700 550/750 once I figure out the rear spring hat to remove the funky rear progressive / coilbinded / linear spring and replace it with a more standard setup.
Ride height is factory.
If you look at the KW Clubsport kit that many 911s use in Germany at the NRing, approximately (400f,950r), then my 450 front isn't very soft, it just isn't a full track setup.
Given the guys at Bilstein said my re-valved shock can easily handle up to 15% more spring, I may end up at 500/700 550/700 550/750 once I figure out the rear spring hat to remove the funky rear progressive / coilbinded / linear spring and replace it with a more standard setup.
08-03-2011, 04:53 PM
#50
Rennlist Member
i spoke to several people here and 3 shops in MA about all this... I know some people go for a real crazy big split between front/rear springs - like 400 front 1000+lbs rear. none of local people i spoke to advcated for such split. my mechanic praises his approach he does to 997 and 996 NB gt3 cars that run on dot r-comps and DOT hoosiers - he uses only 100lbs split, like 600/700 or 700/800. he says 200lbs split was somewhat typical for 993 cars and got inherited into 996 world but 100lbs works better. I can only take his word on this matter, i did not try any alternative setups.
cup cars get done differently, as slicks setups are different, ride height is different and pretty much all the rest is different, so it is irrelevant for our goals to look there much.
as of 'default' street KW or PSS10 kits I was told if I decide to get them I will have to replace springs and send shocks to be re-valved and total price would equal to price of JRZ RS so I went with JRZ RS setup (which is not a true monotube but still quite good) and for my DE/AX pursposes it works very well.
i also understood from my humble research you kinda want front springs to be at least close to weight you have at that front corner, but not much less. rear springs are all about required mid-turn balance and amount of oversteer you want to have at base. my corner balance on left side is 670/1075 lbs, right side is 634/1002. so I could use any springs in 600-800lbs range for front and 700-1100 rear springs. so far i see no real need to stifffen up rear end as sway bar adjustments seem to work fine in combination with shocks adjustments and I think I can control oversteer to required amount. Still it is very difficult to speculate of what should be best/optimal mid-turn grip on this car. None of that is static.
I think if you try next setup at 550/750 it should give pretty good feedback compared to what you have now. from other side - if you have 450/600 setup now it may feel quite close with sway bars at full stiff to 550/750 with bars set to softest end. like i said earlier - none of this stuff is static. my goal was to prevent A6 hoosiers from getting outer edge chopped and 600lbs springs do it nicely. if you will run on current setup and your tires will heat up equally and grip will be satisfactory good - then it may be not worth doing any more, unless you curious. I am very curious myself and most mods i do are just to satisfy this 'what if' feel i have all the time.
only too bad it costs more than I would like it to be.
cup cars get done differently, as slicks setups are different, ride height is different and pretty much all the rest is different, so it is irrelevant for our goals to look there much.
as of 'default' street KW or PSS10 kits I was told if I decide to get them I will have to replace springs and send shocks to be re-valved and total price would equal to price of JRZ RS so I went with JRZ RS setup (which is not a true monotube but still quite good) and for my DE/AX pursposes it works very well.
i also understood from my humble research you kinda want front springs to be at least close to weight you have at that front corner, but not much less. rear springs are all about required mid-turn balance and amount of oversteer you want to have at base. my corner balance on left side is 670/1075 lbs, right side is 634/1002. so I could use any springs in 600-800lbs range for front and 700-1100 rear springs. so far i see no real need to stifffen up rear end as sway bar adjustments seem to work fine in combination with shocks adjustments and I think I can control oversteer to required amount. Still it is very difficult to speculate of what should be best/optimal mid-turn grip on this car. None of that is static.
I think if you try next setup at 550/750 it should give pretty good feedback compared to what you have now. from other side - if you have 450/600 setup now it may feel quite close with sway bars at full stiff to 550/750 with bars set to softest end. like i said earlier - none of this stuff is static. my goal was to prevent A6 hoosiers from getting outer edge chopped and 600lbs springs do it nicely. if you will run on current setup and your tires will heat up equally and grip will be satisfactory good - then it may be not worth doing any more, unless you curious. I am very curious myself and most mods i do are just to satisfy this 'what if' feel i have all the time.
only too bad it costs more than I would like it to be.
08-03-2011, 05:06 PM
#51
Rennlist Member
Another update,
Somewhat stupid me, the spring length works, but a better spring length would have been the 1inch shorter Swift spring - ie the 203mm spring, not the 228mm I ordered - factory front is 223mm. Why? Well because the spring I used, a 450# (80N/mm), of course doesn't compress as much as the factory 228# spring (insert Homer Simpson sound). At my spring choice of 450#s, the spring compresses approx 1.5 inches less than softer factory spring.
For anyone else contemplating this, the factory ride height leaves an approx equal number of threads either side of the stock position - or just less than about 2 inches in either direction. So, an 8 inch spring is about perfect for 450-500 pounds. At around 700#s you will want to go with a 7 inch spring.
As NJGT pointed out, you can do zero rate tenders and spring hats - I'm just adding that you have to keep the entire thing, to be safe, within +or- 1.25 inches of a 223mm stock OE spring whose spec is 228#s and given factory ride height / rake, compresses about 3 inches under the car's front weight.
Previously I have been running my front strut tops in the non-turned OE position and have just used shims to get to my desired camber. I decided to have them turned to bring caster down slightly as I'm running for street a 245/35/19 PSS tire that runs a tiny bit taller than spec and I noticed rubbed once street driving when I have never rubbed on previous tires. I can now see how if you really wanted to with the perfect offset and running a slightly short tire with a stiffer front spring you could wedge in a pretty big front tire.
Somewhat stupid me, the spring length works, but a better spring length would have been the 1inch shorter Swift spring - ie the 203mm spring, not the 228mm I ordered - factory front is 223mm. Why? Well because the spring I used, a 450# (80N/mm), of course doesn't compress as much as the factory 228# spring (insert Homer Simpson sound). At my spring choice of 450#s, the spring compresses approx 1.5 inches less than softer factory spring.
For anyone else contemplating this, the factory ride height leaves an approx equal number of threads either side of the stock position - or just less than about 2 inches in either direction. So, an 8 inch spring is about perfect for 450-500 pounds. At around 700#s you will want to go with a 7 inch spring.
As NJGT pointed out, you can do zero rate tenders and spring hats - I'm just adding that you have to keep the entire thing, to be safe, within +or- 1.25 inches of a 223mm stock OE spring whose spec is 228#s and given factory ride height / rake, compresses about 3 inches under the car's front weight.
Previously I have been running my front strut tops in the non-turned OE position and have just used shims to get to my desired camber. I decided to have them turned to bring caster down slightly as I'm running for street a 245/35/19 PSS tire that runs a tiny bit taller than spec and I noticed rubbed once street driving when I have never rubbed on previous tires. I can now see how if you really wanted to with the perfect offset and running a slightly short tire with a stiffer front spring you could wedge in a pretty big front tire.
08-03-2011, 08:29 PM
#52
Drifting
Thread Starter
I have a call into Bilstein for help but I figure someone might have figured out an easy solution already.
As an aside, I did an inspection while the car was getting it's alignment and under load, the length of the rear compressed spring is about 8 inches. Now, the first approx 3.5 inches is a coil bounded progressive rate spring. The next 4.5 inches is a 600# spring under 1100 pounds so uncompressed it would be about 6 inches. Thus my guess is a linear 9-10 inch 600# spring would leave the adjustment perches in the same condition.
There is much more treads on the rear spring than the fronts so somewhere between a 6-9 inch 700-900# spring would be a perfect fit assuming you can get a top spring hat to fit.
08-03-2011, 08:53 PM
#53
Admin
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Another update,
Somewhat stupid me, the spring length works, but a better spring length would have been the 1inch shorter Swift spring - ie the 203mm spring, not the 228mm I ordered - factory front is 223mm. Why? Well because the spring I used, a 450# (80N/mm), of course doesn't compress as much as the factory 228# spring (insert Homer Simpson sound). At my spring choice of 450#s, the spring compresses approx 1.5 inches less than softer factory spring.
For anyone else contemplating this, the factory ride height leaves an approx equal number of threads either side of the stock position - or just less than about 2 inches in either direction. So, an 8 inch spring is about perfect for 450-500 pounds. At around 700#s you will want to go with a 7 inch spring.
Somewhat stupid me, the spring length works, but a better spring length would have been the 1inch shorter Swift spring - ie the 203mm spring, not the 228mm I ordered - factory front is 223mm. Why? Well because the spring I used, a 450# (80N/mm), of course doesn't compress as much as the factory 228# spring (insert Homer Simpson sound). At my spring choice of 450#s, the spring compresses approx 1.5 inches less than softer factory spring.
For anyone else contemplating this, the factory ride height leaves an approx equal number of threads either side of the stock position - or just less than about 2 inches in either direction. So, an 8 inch spring is about perfect for 450-500 pounds. At around 700#s you will want to go with a 7 inch spring.
Had the same issue, when I installed the front lift system.
The springs became longer as the height of the lift's base was added.
Combined with the lowered front height I was running.
I had no adjustability left and more importantly no droop travel.
So instead of buying new shorter springs, I modified the collars.
08-04-2011, 04:09 PM
#54
Drifting
Thread Starter
Update
Few topics to discuss
The revalve by Bilstein
I think they did an incredible job matching my 450# spring request. I drove the car as did my mechanic (ex race car driver), and we were both very surprised that the valving seemed perfect. When I first entered the car, I was a bit nervous, as in did I just screw the car up by attempting this - was it going to be too harsh, would they get the valving correct? etc. All I can say is wow. Car actually seem better than stock in terms of soaking up the bumps / not being harsh for the street - A+ for Bilstein on the revalve.
How does it feel different?
Definitely more spring holding up the front of the car but still extremely streetable. Less dive under braking for sure but spring is only a 450 versus stock 228 so it is way better but it isn't a race car - so this is what I wanted.
Biggest Difference
My mechanic drove the car before I got there to feel it out. We always talk in terms of corners at Mosport and how the car will act - and many times how we don't want the car to act as basically an off at Mosport is almost always very bad. His comment was, "if you come into a turn and lift off the gas, the front just grabs and turns in - you will have to be careful if you do that in Turn 8". So I went out and did as best as I could to enter an offramp in 3rd gear, under throttle but only mid rpm to keep it legal, and then mid turn lifted - sure enough the nose gets a super planted feel and just grabs the road - wow! - about a 200% better feel response than the car as stock. This makes a lot of sense when you think about it but when you make a change you never really know until you drive the car. The stock rear springs at 600#s have about 1100#s over them and when you snap off the throttle, something we all learn not to do on the track, the back of the car lifts about 1 inch and transfers that energy forwards - well now the car is meeting that force with more spring and appropriate damping and everything happens quicker - it sorta feels immediate versus the stock setup - the nose just plants and 'turns-in'. This is actually how I like the car, lift and the nose tucks in versus lift and counter steer. My mechanic's comment about Turn 8 at Mosport is that it is a very fast turn and if you lifted and the nose turned-in quickly the rear may want to follow. He did also say, and I also tried to provoke the rear, that the rear end did not feel nervous at all and in any way feel like it was coming around, it is just that the front feels unworldly in that it just turns-in.
Next Step
I'm hooked - I really can't believe that the car feels as good as it does - absolutely no downside (so far), from a street ability perspective ( I think the revalving is actually better than stock). I have gone ahead and ordered from Bilstein today, the parts off of the B16 Damptronics, the spring top hat, helper spring, spring isolator and bottom spring perches. This is so I can convert the stock rear spring monstrosity to a more standard liner spring / helper spring setup - but I'm going to not use the Damptronics 570# main 60mm ID spring but going to pick my own rate - yet to be determined. Why? Because having seem what is possible on the front, I think better matching it to an improved rear is only going to make the car even better and yet still be streetable. As discussed, there are 2 tuning approaches, big front rear split like OE and KW approach or 100-200 spring f/r difference. I'm going to have to think about this a bit and drive the car on track a bit to get a feel what approach I want to take.
Overall
I'm glad I did this. The shocks, PASM and all, definitely are worth trying to optimize for those that want to experiment. I see no reason why those that want a more track setup can't pick your spring rate approach, put the car on a hoist in the offseason, send them off to Bilstein for a re-valve and then go give it a try.
More comments later when I learn more about the subtleties of what I have done.
Paul
Few topics to discuss
The revalve by Bilstein
I think they did an incredible job matching my 450# spring request. I drove the car as did my mechanic (ex race car driver), and we were both very surprised that the valving seemed perfect. When I first entered the car, I was a bit nervous, as in did I just screw the car up by attempting this - was it going to be too harsh, would they get the valving correct? etc. All I can say is wow. Car actually seem better than stock in terms of soaking up the bumps / not being harsh for the street - A+ for Bilstein on the revalve.
How does it feel different?
Definitely more spring holding up the front of the car but still extremely streetable. Less dive under braking for sure but spring is only a 450 versus stock 228 so it is way better but it isn't a race car - so this is what I wanted.
Biggest Difference
My mechanic drove the car before I got there to feel it out. We always talk in terms of corners at Mosport and how the car will act - and many times how we don't want the car to act as basically an off at Mosport is almost always very bad. His comment was, "if you come into a turn and lift off the gas, the front just grabs and turns in - you will have to be careful if you do that in Turn 8". So I went out and did as best as I could to enter an offramp in 3rd gear, under throttle but only mid rpm to keep it legal, and then mid turn lifted - sure enough the nose gets a super planted feel and just grabs the road - wow! - about a 200% better feel response than the car as stock. This makes a lot of sense when you think about it but when you make a change you never really know until you drive the car. The stock rear springs at 600#s have about 1100#s over them and when you snap off the throttle, something we all learn not to do on the track, the back of the car lifts about 1 inch and transfers that energy forwards - well now the car is meeting that force with more spring and appropriate damping and everything happens quicker - it sorta feels immediate versus the stock setup - the nose just plants and 'turns-in'. This is actually how I like the car, lift and the nose tucks in versus lift and counter steer. My mechanic's comment about Turn 8 at Mosport is that it is a very fast turn and if you lifted and the nose turned-in quickly the rear may want to follow. He did also say, and I also tried to provoke the rear, that the rear end did not feel nervous at all and in any way feel like it was coming around, it is just that the front feels unworldly in that it just turns-in.
Next Step
I'm hooked - I really can't believe that the car feels as good as it does - absolutely no downside (so far), from a street ability perspective ( I think the revalving is actually better than stock). I have gone ahead and ordered from Bilstein today, the parts off of the B16 Damptronics, the spring top hat, helper spring, spring isolator and bottom spring perches. This is so I can convert the stock rear spring monstrosity to a more standard liner spring / helper spring setup - but I'm going to not use the Damptronics 570# main 60mm ID spring but going to pick my own rate - yet to be determined. Why? Because having seem what is possible on the front, I think better matching it to an improved rear is only going to make the car even better and yet still be streetable. As discussed, there are 2 tuning approaches, big front rear split like OE and KW approach or 100-200 spring f/r difference. I'm going to have to think about this a bit and drive the car on track a bit to get a feel what approach I want to take.
Overall
I'm glad I did this. The shocks, PASM and all, definitely are worth trying to optimize for those that want to experiment. I see no reason why those that want a more track setup can't pick your spring rate approach, put the car on a hoist in the offseason, send them off to Bilstein for a re-valve and then go give it a try.
More comments later when I learn more about the subtleties of what I have done.
Paul
08-04-2011, 04:43 PM
#55
Rennlist Member
that's great. Can you PM me the part #'s you ordered from Bilstein for the rear shocks ? I am going to do the rear conversion myself as well. I think I'm going to try the 672#rear spring to start, since I am not revalving anything. I agree that there is plenty of tuning available with the stock PASM shocks. Great posts!
08-04-2011, 04:55 PM
#56
Drifting
Thread Starter
Upper Spring Seat e4-ft3-z038a00
Isolator e4-xk6-z00za00
Spring Seat e4-ft4-z016a01
Adapter Ring e4-r04-z048a01
The Upper Spring Seat is only available by order from Germany so if you hurry up and call, ask for Wes Welch, tell him you got this stuff from me (Paul O'Neil) and want to place an order as well, the orders will be placed together.
Ph# 1.800.370.9522
Isolator e4-xk6-z00za00
Spring Seat e4-ft4-z016a01
Adapter Ring e4-r04-z048a01
The Upper Spring Seat is only available by order from Germany so if you hurry up and call, ask for Wes Welch, tell him you got this stuff from me (Paul O'Neil) and want to place an order as well, the orders will be placed together.
Ph# 1.800.370.9522
08-04-2011, 05:03 PM
#57
Rennlist Member
if you got 600# springs in rear and they do fit fronts you can try put 700# or 750# springs in rear and move 600# in front. more springs you get - faster reaction you get to your steering inputs and less weight transfer. and in case if you will not like it you can always revert it back to 450/600.
did your shop do corner balance after springs install?
did your shop do corner balance after springs install?
08-04-2011, 05:36 PM
#58
Rennlist Member
Thanks. What spring length are you going with in the rear? 6" , 7", or 8" ?? I guess we could use the same length that the Damptronics uses...
Upper Spring Seat e4-ft3-z038a00
Isolator e4-xk6-z00za00
Spring Seat e4-ft4-z016a01
Adapter Ring e4-r04-z048a01
The Upper Spring Seat is only available by order from Germany so if you hurry up and call, ask for Wes Welch, tell him you got this stuff from me (Paul O'Neil) and want to place an order as well, the orders will be placed together.
Ph# 1.800.370.9522
Isolator e4-xk6-z00za00
Spring Seat e4-ft4-z016a01
Adapter Ring e4-r04-z048a01
The Upper Spring Seat is only available by order from Germany so if you hurry up and call, ask for Wes Welch, tell him you got this stuff from me (Paul O'Neil) and want to place an order as well, the orders will be placed together.
Ph# 1.800.370.9522
08-04-2011, 05:51 PM
#59
Drifting
Thread Starter
if you got 600# springs in rear and they do fit fronts you can try put 700# or 750# springs in rear and move 600# in front. more springs you get - faster reaction you get to your steering inputs and less weight transfer. and in case if you will not like it you can always revert it back to 450/600.
did your shop do corner balance after springs install?
did your shop do corner balance after springs install?
The stock rear spring is a monstrosity - 1/3rd some progressive spring rate that is permanently coil binded and that takes a custom top hat as it is oversized and then it tapers some amount to a linear rate spring that is suppose to be 600#s - the bottom section width looks wider than 60mm ID but I have no idea exactly what it is - it is basically a spring abortion.
I know I'm going to up the rear, I just haven't decided what approach I'm going to try. I just re-looked at the 997 chassis KW clubsport setup and it is 400/1085 (this is the double everything approach) - their 996 chassis approach was 350/950 fwiw.
I appreciate your feedback from your local shops in terms of the 100-200 split for 996/997 chassis.
I really like the 450 as is. I'm sure, given what I felt today, that 500-600 is likely the upper limit to keep that streetabilty but that this would also work as you have said - without an issue.
I don't think I'd bother if I was just going to go from stock 600 to 700 so I'm likely thinking 800-900 with a re-valve so the valving can also better match the fronts. I guess this is kind of a hybrid approach as personally that is what in think the car needs from my perspective - ie at least double what the OE front rate was (I really like 450, I'm sure 500-550 would also work), and now, to match the front, re-valve and add a little spring - maybe end at 500/800.
If I actually do nothing else, to me the car is still better than it was - but I need to test it on the track before I'm ready to say this definitively.
08-04-2011, 05:54 PM
#60
Drifting
Thread Starter
I don't know that answer yet as Udo at Bilstein is to find out that answer for me - the rear Damptronic spring length - my guess is 6-7 inches so that is what I will use. There is lots of shock thread to use a shorter spring so shorter is lighter is better I would say.