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Setup is stated correctly and I'll add with slight toe out in front.
The factory suspension only permits -1.2 front camber or so hence the need for the adjustable LCAs.
There's more latitude in the rear stock suspension. I believe this is normal for 997 chassis other than GT3/2 cars.
Forget the inner monoballs. They will prematurely and unnecessarily wear the front suspension subframe compared to other bushingless parts. It's not going to crack it overnight of course but a few years of hard running will show signs of fatigue. I've seen it on 997.1s on the lift in my race shop. I was advised against them and don't see that I need for the type of tracking I do (DEs and open track only). The biggest upgrade was the front LCAs, solid pucks and adjustable sways. In that order. If I were to add monoballs that attach to the subframe anywhere it would be the front thrust arm to the subframe to reduce wander even more and next I'd remove the bushings between the rear subframe and the tub. Just one man's opinion but I don't have spare coin to be replacing an entire subframe every five years and the trade off is minimal.
Running spacers meant I needed longer bolts. Running different spacers F/R means I needed different length bolts F/R. Running different wheels at the track means I also needed to bring along my factory bolts AND the security socket.
So in addition to all my other tools I had to bring 20 extra bolts, a pair of wheel hangers and the security socket. When I switched wheels I had to keep track of the spacers and the different sized bolts. It was just an extra 20 or so pounds of gear and a headache I wanted to avoid.
Still running spacers I sourced 11x 82.5mm studs for the fronts w/ 8mm spacer and 11x 92.5mm studs for the rears w/ 15mm spacer along with 22x 'NASCAR style' (whatever that means) manganese coated nuts. All from Tarett. Always good to have an extra around if tracking. If I were tracking this car every week I would have enough spares for several wheels.
The formula for figuring out how much thread you need is 12mm for the hub + 7mm for the rotor hat + Xmm for any spacers +~8mm for your wheel hub (depends on the wheel) + 20mm for these nuts + 3mm for good measure (and extra thread after torquing0.
Now, I just have to store the spacers while on track and that's it.
It took about 15min per wheel to install and will save time and a headache at the track. I really recommend this mod for anyone tracking. It also saves your hubs from premature wear and possible crossthreading.
(sorry for the dirty wheel). Quick and dirty photo at Fuelfed this AM.
Forget the inner monoballs. They will prematurely and unnecessarily wear the front suspension subframe compared to other bushingless parts. It's not going to crack it overnight of course but a few years of hard running will show signs of fatigue. I've seen it on 997.1s on the lift in my race shop. I was advised against them and don't see that I need for the type of tracking I do (DEs and open track only). The biggest upgrade was the front LCAs, solid pucks and adjustable sways. In that order. If I were to add monoballs that attach to the subframe anywhere it would be the front thrust arm to the subframe to reduce wander even more and next I'd remove the bushings between the rear subframe and the tub. Just one man's opinion but I don't have spare coin to be replacing an entire subframe every five years and the trade off is minimal.
Just back from the shop.
Cup Car LCAs installed. New Cup2s mounted and balanced.
Aligned to:
Front: -2.8 camber, 9.0 caster, -0.03 toe.
Rear: -2.3 camber, 0.15 toe.
Ready for the next event!
(Hard to discern differences on the street - too many changes to the car and not dynamic enough environment. Much quieter due to new tires. Great turn in probably due to increased neg camber in front, and seems to have greater linearity in turn-in - perhaps due to monoball LCA bushings. )
If you don't know what the DSC module is by now you have some beach reading to do this weekend. I've had my eye on one since they released the original last year. The update to a two mode version was a negative for me on the outset because I thought three is better that two. But the seamless integration with the OBC display is a nice feature, the software is easy(ish) to use though it lacks instructions and the reprogramming is simple enough that having two modes (Street and Track) was not a deal breaker after all. So I scored a nicely discounted DSC module last week from a fellow Rennlister and with the help of a few other members and the official DSC thread, I was able to program the control module. Currently, I'll run the standard settings until I get a feel for it and understand what I may want to change.
It really is a 3 minute install. The most difficult part is aligning it back into the bracket behind the carpet, but after some slight contorting it easily slots back into place. A moderately long test drive after installation proved this upgrade is worth every penny even at full price. I could regurgitate the technical reasons why but I'll leave that to Mike Levitas and his team. In subjective terms it noticeably fills holes in terrible Chicago roads and flattens the car. Highway gaps all but disappear. That was an eyebrow lifter for me. I expected to feel the hard *chop-chop* running over a gap in pavement like I did in 'normal' mode with the OEM control module but I didn't. The first time that happened (or didn't happen rather) was when I knew this little box was the real deal Fast bumps... slow bumps... they are all now extremely reduced or absent.
Though the software is 'free', to me that is half the value or more. I'll probably soften the 'normal' mode a bit more like user Quadcammer has done and stiffen the 'sport' mode a bit more to widen the gap between the ranges since I only use 'sport' mode on track.
The only suggestion I have for the DSC team is to put out a user manual or video tutorial. Yes, there's a walkthrough video but to be honest it's not all that valuable in learning how to code the module. Nevertheless, I'm extremely satisfied after the first few days with the unit and will update my continued experience with the product in my ownership journal here.
If you don't know what the DSC module is by now you have some beach reading to do this weekend.
My question is how does it interact/affect SPASM (not to be confused with PASM). I'm not sure of all the differences, but SPASM is an additional option which lowers and I believe tightens the suspension overall. It also means you get an electronic limited slip differential consequently.
Will TPC DSC negatively alter Porsche's SPASM suspension optimization?
nwGTS, obviously you also own a GTS, but does yours have the SPASM option? If so, do you know if ride height lowering was affected by TPC?
SPASM or Sport PASM is for all intents and purposes just lower springs from PASM. The PASM control module is the same for PASM and SPASM cars that I've seen. My car is basically a SPASM car now that I've lowered it on Eibachs.
The DSC module is not going to turn the car's ride into that of a Lexus sedan but it's a very noticeable improvement over OEM.
It's a question for the DSC squad but as far as I know the DSC module will work with PASM and SPASM cars identically.
I've asked DSC about this and with respect to their module operation, there is no difference for PASM or SPASM - they both use the same basic Map (program) as a starting point.
nwGTS - you clearly seem to get softer damping when appropriate. Do you believe the firmer end of the range with stock dampers is enhanced as well (i.e., more firm).
I have been wondering if this system would make any difference for autocross (clearly for DEs, smoothing out transitions and curbing at speed is relevant) and unless the firm end is firmer, I don't see an AX advantage. Thoughts?
I was also wondering if the AX transitions are too fast for the 100ms response, but after studying some (frame by frame) videos of my last AX runs, the transition from neutral to full roll in one direction is on the order of several hundred ms, more than enough time for the dampers to stiffen up; even stock. Video from yesterday attached.
Well if you're focused on the 100ms response rate you need Tractive dampers which push to something like 6ms if memory serves me correctly. I'm at the beach and a few beers in so it may not.
You can change the range to which the dampers respond so you CAN create a stiffer range for the suspension while at the same time allowing the total standard deviation of range to be greater than that of the OEM PASM module. That's the advantage. On flat AX lots it will allow you to get the power down slightly sooner and turn in slightly sooner by modulating the damper setting at each individual wheel. I'm not happy with my explanation there since mobile typing is slower than on the laptop but check out the DSC thread for a better one or give the folks there a call.
Great thread! Awesome job on the steering wheel and associated wiring! Thank you for choosing to use DSC and for your feedback. We will be making more videos on the use the software.
On thing I would like to touch on is your two-mode 997 DSC. Two-mode 997 DSC was launched in the Fall of 2014. To me, the prime feature isn't the mode switching display interface with the factory instrument cluster, yes we are proud of this too but the main course for me is something we call the "Reverse G Table".
The Reverse G Table, what it is is in the main g table we assign a patch(say for example an area that's within 0.2g in any direction), and we then assign a % of rate of movement and a default damping value. So if you are driving leisurely at under 0.2g and rate of movement is less than the assigned %, then to shocks are as soft as the assigned default value(that can be 1% or 10% or any % you choose). But the moment that rate of movement threshold and/or 0.2g threshold is exceeded then the shocks go to the main g table values which is 50% or higher stiffness. The g patch size, rate of movement %, and default value is all selectable by the preference of the users. This is very clever.
On the DSC software G table, at the bottom you'll see "G Comfort Parameter" box. In that box you'll see the following from left to right.
Default Rate is the % stiffness(from Shock Calibration) within each mode(Normal or Sport mode) when there's no load or within rate of movement and g patch threshold. For example, if you want the damping to be stiffer when there's zero load then increase the value in this box say from 1% to 10%. Or if you want Sport mode to immediately feel stiffer then go to Sport mode and increase this value by 10% or so over the % that's in Normal mode.
Offset, DSC engineers ask that we don't play this is.
Sensitivity is the % of rate of movement threshold to get out of the Reverse G Patch and into the main G table. The smaller this value is the more readily the damping commands gets out of the Reverse G Patch and into the main G table. For example, if you want the dampers to stiffen up with less movement then lowers the value in this box.
G Rate Max is the assigned patch size area of the Reverse G Table. For example, if you want Normal mode to ride more cushy say under 0.2g than you want to assign 20.0 in this box. If you want the patch to cover within 0.35g then enter 35.0 in this box.
With the use of the Reverse G Table, we have implemented race car mapping on the all tables and still producing comfortable ride over bumps. Whereas with the old 3-mode there's no Reverse G Table so the system is less dynamic and has street car maps instead of race car maps with Reverse G.
My question is how does it interact/affect SPASM (not to be confused with PASM). I'm not sure of all the differences, but SPASM is an additional option which lowers and I believe tightens the suspension overall. It also means you get an electronic limited slip differential consequently.
The original PASM was the "Sport" offering for 997.1 cars. which was standard equipment on S model. PASM was 10mm lower and around 10-15% than the base suspension. For the 997.2 cars SPASM with the extra "S" was offered. Basically the extra "S" option is another 10mm lower and around 10% stiffer than the original PASM.
Electronic LSD, to me anyway, doesn't mean what it sounds like. There's no electronics in the LSD, the differential itself is 100% mechanical. Where the electronic comes in is the ABS module activating the rear brakes to try to mimic some of the characteristics of a motorsports limited slip differential. How DSC or other suspension mods effects this you asked? If DSC and/or other mods make the car more stable/more grip, the grip threshold is then raised, then the electronics won't be activated until the higher threshold is exceeded.
Originally Posted by love2drive
My question is how does it interact/affect SPASM (not to be confused with PASM).
Well, the PASM or SPASM control module is completely replaced by the DSC module. So the damping control is improved by DSC to a level that is superior to PASM and SPASM, in both comfort and performance.
Originally Posted by love2drive
Will TPC DSC negatively alter Porsche's SPASM suspension optimization?
No. Off top of my head I can think of two DSC users with SPASM on rennlist. Cloudspin and RS4Canyon are at opposites ends of the country and they both have been both enjoying quicker lap times on track and more compliant ride on street.
Originally Posted by love2drive
do you know if ride height lowering was affected by TPC?
SPASM ride height is not lower than aftermarket lowering springs. DSC has proven to work well even with the lowest springs. But actually don't prefer more than 20mm to 25mm drop from base height because it reduces usable shock travel. SPASM height is very ideal.
We have swap springs up to 500/700 lbs on PASM/Damptronic shocks for track focused cars with DSC and they work extremely well. This spring rate over shadows the PASM and SPASM spring rate by quite a bit, so PASM/SPASM are well within the control range.
Last edited by Tom@TPC Racing; 07-06-2016 at 12:07 PM.
Thanks for the kind words. Your info is very helpful. One thing that you can help clear up for me which will also help me with other follow up questions... when you say 'rate of movement' throughout your post are you referring to the rate of movement of the damper or rate of movement of the car (g delta) relevant to the three axes?
I have been wondering if this system would make any difference for autocross (clearly for DEs, smoothing out transitions and curbing at speed is relevant) and unless the firm end is firmer, I don't see an AX advantage. Thoughts?
Yes. Just reducing front dive from heaving is huge. This subsequently reduces rear lift... to get on power better. And reduce body roll is mange tire grip better.
Originally Posted by dbbarron
I was also wondering if the AX transitions are too fast for the 100ms response, but after studying some (frame by frame) videos of my last AX runs, the transition from neutral to full roll in one direction is on the order of several hundred ms, more than enough time for the dampers to stiffen up; even stock.
I've address some of this in another thread you have posted in. Its not just the reaction time alone it whether or not an OEM shock reacts to the command before beginning a stroke(either compression or rebound). Unlike Tractive DDA shocks, current OEM shocks cannot react to command until stroke is completed. I know of a very small percentage of DSC users (less than 1% out of over 1000 units) have experienced a delay feel from the shocks during quick side to side transitions at high g's. The common denominator is they have the old 3-mode DSC which doesn't have the Reverse G Table so I think the issue is the transitioning occurring as the commanding g-reference point happened to be at the "soft" spot of the g table under a very specific set of circumstances. This is completely eliminated with the Reverse G Table's "Sensitivity" function. See post #57. We've been working together to get these guys updated to 2-mode firmware and software.
Another data point, now that I think about it as I'm writing, we ran the old 3-mode DSC box extensively(for years) without any feeling of delay with the TPC sway bars(stiffer than 997.2 GT3/GT2 bars). The added roll stiffness of the bars must have "filled" the soft spot in the old 3-mode and reduced bar stiffness reduced the stroke travel/duration of time of stroke as well. Bar stiffness is still a welcome addition to offer more tuning options but not needed with 2-mode DSC with Reverse G Table.
This is very helpful. One thing that you can help clear up for me which will also help me with other follow up questions... when you say 'rate of movement' throughout your post are you referring to the rate of movement of the damper or rate of movement of the car (g delta) relevant to the three axes?
Rate of movement of the g delta.
Unfortunately the 997-series cars aren't factory equipped with linear shock position sensors on all four corners, so unless the sensors are hard wired in there's no data. The 991-series cars do so DSC for 991/981 use a table called "Velocity" to tune by shock travel velocity.
06-14-2016, 07:29 AM
