Orthojoe's GT4 track thread and ramblings
08-27-2016, 04:19 PM
#781
Instructor
08-27-2016, 04:21 PM
#782
Nordschleife Master
Thread Starter
Originally Posted by Leong72
Hi Joe,
Re the blind testing of DSC, is that comparing different maps on the DSC or swapping the DSC in and out?
Re the blind testing of DSC, is that comparing different maps on the DSC or swapping the DSC in and out?
08-27-2016, 05:23 PM
#783
Instructor
We had a track day yesterday. Last time out I'd installed the TPC offset toe links and was happy with that. (Write up on the TPC toe link thread) but didn't get to try the TPC DSC settings with it.
Yesterday, once comfortable with track conditions, good but windy, Jeff put the TPC settings in the "Normal" suspension slot, so that I could compare it with the setting that we have come up with for my car - it's in the "sport" slot. Did the first half of the session with "our" settings and the second half with TPC's. Found that with their setting the car understeered coming out of turns, where our setting it didn't. Lap times showed a 0.5 sec difference. Interestingly that was on a near empty fuel tank. After filling up to full, much less noticeable.
So IMO and FWIW the DSC allows you to have more control over your car's shocks. Whether the DSC (compared to standard PASM) improves your car or not will depend on the settings on the DSC at the time and whether those settings match your current sway bar setup especially. I think TPC have their suggested setup, including the rear toe they're running published somewhere, and if your car matches this then you should get an improvement. If not then with all due respect, IMO AND FWIW etc
, I'm not quite sure what you're trying to accomplish?
I mention rear toe because the amount you're running, you'd sorted out the problem most of us had on hard braking and corner entry but you may be out of spec for the TPC settings.
Yesterday, once comfortable with track conditions, good but windy, Jeff put the TPC settings in the "Normal" suspension slot, so that I could compare it with the setting that we have come up with for my car - it's in the "sport" slot. Did the first half of the session with "our" settings and the second half with TPC's. Found that with their setting the car understeered coming out of turns, where our setting it didn't. Lap times showed a 0.5 sec difference. Interestingly that was on a near empty fuel tank. After filling up to full, much less noticeable.
So IMO and FWIW the DSC allows you to have more control over your car's shocks. Whether the DSC (compared to standard PASM) improves your car or not will depend on the settings on the DSC at the time and whether those settings match your current sway bar setup especially. I think TPC have their suggested setup, including the rear toe they're running published somewhere, and if your car matches this then you should get an improvement. If not then with all due respect, IMO AND FWIW etc
, I'm not quite sure what you're trying to accomplish? I mention rear toe because the amount you're running, you'd sorted out the problem most of us had on hard braking and corner entry but you may be out of spec for the TPC settings.
08-27-2016, 07:11 PM
#784
Nordschleife Master
Thread Starter
Leong, you make excellent points. This is why I wanted to try a blind test to see if the unit has any perceivable improvement with my setup.
08-28-2016, 12:01 PM
#785
If I wanted to swap front springs only (number of reasons) and keep rears stock; can someone give an opinion on the Swift 336 lb vs 392 lb for front replacement? Rear is 457 I believe.
08-28-2016, 01:22 PM
#787
08-28-2016, 03:28 PM
#788
08-28-2016, 03:57 PM
#789
Reasons:
Much lower cost: $180 spring set vs $700 for Tarett
Easier/cheaper install - Swift makes a 7" spring same as stock. Rear is not same.
Simple alignment vs another full corner balance required.
Not sure the rear needs to be firmer for me personally. As you say, 100 is not much and Tarett only changes rear by that.
Eliminates potential concerns over warranty for rear, given leaky struts, etc
Anyways, that was my thought process. About to install my TPC rear links and wanted some sort of spring change as well. My goal is to keep the car close to stock, but feel comfortable on the limit at the track. Thanks for the responses as always.
08-28-2016, 06:37 PM
#790
Rennlist Member
Well, 392 is 135 lbs or 52% more than stock. Changes the balance from 56% (257/457) stock Front/Rear, to 86% (392/457) F/R ratio. That would likely have a significant change in balance? I guess I am asking if 86% ratio is too much. I know Spec Boxster runs a 90% (450/500) but wanted feedback. Tarett kit is 80%
Reasons:
Much lower cost: $180 spring set vs $700 for Tarett
Easier/cheaper install - Swift makes a 7" spring same as stock. Rear is not same.
Simple alignment vs another full corner balance required.
Not sure the rear needs to be firmer for me personally. As you say, 100 is not much and Tarett only changes rear by that.
Eliminates potential concerns over warranty for rear, given leaky struts, etc
Anyways, that was my thought process. About to install my TPC rear links and wanted some sort of spring change as well. My goal is to keep the car close to stock, but feel comfortable on the limit at the track. Thanks for the responses as always.
Reasons:
Much lower cost: $180 spring set vs $700 for Tarett
Easier/cheaper install - Swift makes a 7" spring same as stock. Rear is not same.
Simple alignment vs another full corner balance required.
Not sure the rear needs to be firmer for me personally. As you say, 100 is not much and Tarett only changes rear by that.
Eliminates potential concerns over warranty for rear, given leaky struts, etc
Anyways, that was my thought process. About to install my TPC rear links and wanted some sort of spring change as well. My goal is to keep the car close to stock, but feel comfortable on the limit at the track. Thanks for the responses as always.
08-28-2016, 07:18 PM
#791
Great info here. Thanks. Going back to your original posts you describe the cage/harness bar install as well as the harness install. Question re the passenger seat. My 2016 does not have a sub belt slot in the upholstery or apparently in the carbon bucket on the passenger side. Hate to cut it up. Anyone have a solution?
08-28-2016, 08:46 PM
#792
GT3 player par excellence
Lifetime Rennlist
Member
Lifetime Rennlist
Member
If you want something better, then MCS, JRZ, OHLINk, PENSKE are better.
There are a bunch of us have little or no understeer, I am not sure what's taking every so long to dial it out.
Run BIGGER front tires, it's ok for rub ;-)
-----------
Joe,
I tested the roll bar. I tried to hit the road bots and drive over dips at 40-50 mph (yes my lip died for your cause!!!) dead silence. So once your bolt down your bar, test again to see what the noise if from.
08-28-2016, 09:13 PM
#793
Rennlist Member
If u must then go ahead. Trojan and I and many others tried TONS of springs, what we have works..
If you want something better, then MCS, JRZ, OHLINk, PENSKE are better.
There are a bunch of us have little or no understeer, I am not sure what's taking every so long to dial it out.
Run BIGGER front tires, it's ok for rub ;-)
If you want something better, then MCS, JRZ, OHLINk, PENSKE are better.
There are a bunch of us have little or no understeer, I am not sure what's taking every so long to dial it out.
Run BIGGER front tires, it's ok for rub ;-)
However, the stock setup isn't bad, in the sense that people still enjoy driving the car and get good lap times. So isn't something like 336/457, or 392/457 just somewhere between good and optimal? Maybe there's still some dive and bad wear, but better than stock. 336 in the front is 30% stiffer than stock and should be quite a noticeable improvement.
Closer to stock is also appealing because one would be closer to the design parameters of the dampers. (I'll get my spring setup next year, probably the tried and tested 448/560, however 336/457 does intrigue me.)
(I agree about the front grip, just add more tire, however, it seems the dive and wear are different issues that require springs)
08-28-2016, 10:42 PM
#794
I believe in all the homework that was done to settle on the 448/560 swift option. It's most likely the optimal solution for the factory dampers. The issue with the stock 257/457 springs seems to be too much dive and bad front tire wear. 448/560 fixes this.
However, the stock setup isn't bad, in the sense that people still enjoy driving the car and get good lap times. So isn't something like 336/457, or 392/457 just somewhere between good and optimal? Maybe there's still some dive and bad wear, but better than stock. 336 in the front is 30% stiffer than stock and should be quite a noticeable improvement.
Closer to stock is also appealing because one would be closer to the design parameters of the dampers. (I'll get my spring setup next year, probably the tried and tested 448/560, however 336/457 does intrigue me.)
(I agree about the front grip, just add more tire, however, it seems the dive and wear are different issues that require springs)
However, the stock setup isn't bad, in the sense that people still enjoy driving the car and get good lap times. So isn't something like 336/457, or 392/457 just somewhere between good and optimal? Maybe there's still some dive and bad wear, but better than stock. 336 in the front is 30% stiffer than stock and should be quite a noticeable improvement.
Closer to stock is also appealing because one would be closer to the design parameters of the dampers. (I'll get my spring setup next year, probably the tried and tested 448/560, however 336/457 does intrigue me.)
(I agree about the front grip, just add more tire, however, it seems the dive and wear are different issues that require springs)
08-29-2016, 12:36 AM
#795
Nordschleife Master
Thread Starter
Great info here. Thanks. Going back to your original posts you describe the cage/harness bar install as well as the harness install. Question re the passenger seat. My 2016 does not have a sub belt slot in the upholstery or apparently in the carbon bucket on the passenger side. Hate to cut it up. Anyone have a solution?