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I'm heading to the Ridge tomorrow. Dropped the driveshaft to test out RWD. Didn't have enough time to also get a corner balance so I'm going to leave the axles/diff in as 70-100lbs is enough to offset the current suspension settings (GT3ish).
The car is noticeably faster. After a long drive the LWFW/LSD are really doing their jobs.
Will report back with results from the track.
Last edited by vandersmith; 07-22-2016 at 04:31 AM.
Brought my fastest lap time here down slightly on a cold lap first session out. That was on my second lap of the day on cold tires. Shocked.
My average with AWD was 1:57-58. I'm pulling 1:56-57 today while making a lot of adjustments and line changes.
The car is over steering some, need to be a little more alert on throttle on corner exit. LSD is working. Car is easy with PSM which will kick in often and ludicrous when Off.
Same suspension.
Same alignment (GT3 specs).
Same sway bar settings (middle on F/R of H&Rs)
Same brakes.
Same driver.
Same track conditions as many other days I've been there. 8 events this year.
Personal Times: AWD Best at the Ridge: 1:56:35 (June)
I can say its taken a whole season but I can now drive the crap out of the car with the AWD system. This is about the best I can do with that configuration.
RWD: Morning, Cold Track, Cold Tires: 1:56:50 (Today)
This was insane. It was 2nd lap of today. 9am. Cold. Windy. Bad tire pressures. You name it.
RWD: Afternoon, Hot Track: 1:54:30 (Today)
40+ laps today. Most under 1:57 on a poorly setup RWD car and I pull out my best yet.
It took multiple events over the past few seasons to break 2:00. Even longer and some add'l parts to get down to 1:58s.
30 minutes.
Drive shaft out.
40 laps on a bad setup.
2 seconds faster.
Still have 70 lbs of crap to remove.
Unreal.
Last edited by vandersmith; 07-23-2016 at 05:11 AM.
The differences in lap time on Awd and Rwd usually play into Rwds favor until around 500whp then it gets close after 600whp there is no comparison the extra traction provided by awd makes for a faster lap time.
I should note this is on a near stock aero level or less then 700lbs of overall downforce. I have not run comparisons at high levels of aero (talking 1,500lbs+ of downforce type levels)
Doesn't make much sense to me, the C4S only sends 5% power to the front wheels, it doesn't have enough power to over drive the rears to heat up the viscous coupling to send more power to them.
I would suspect it more setup and driver favoring a different type of driving style and LSD vs PSM.
Doesn't make much sense to me, the C4S only sends 5% power to the front wheels, it doesn't have enough power to over drive the rears to heat up the viscous coupling to send more power to them.
I would suspect it more setup and driver favoring a different type of driving style and LSD vs PSM.
After hitting the dyno last week, I can tell you after 80 mph the system is absolutely diverting more than 5%. Mistakenly we didn't lock the rollers on the first pull - my rears were topping out 4th at around 110 while my fronts were doing about 20mph. Ya, I know how stupid that was.
On the track it feels similar to the above: Less intrusive in low speed and more diversion at high speed. PSM also makes it much more predictable - strangely I couldn't turn the PSM off with the AWD system as the PSM would kick in at the worst possible times under power in corners. The LSD would be keeping the rears gripping and the PSM would brake the inside wheel, nearly spun a few times in the worst spots to do so.
With the RWD, PSM can be run on or off. Off allows the car to get completely sideways. On provides direct feedback to when turn in was too early/late or when too much throttle is applied for the current steering angle.
My theory is that I learning the line this season with the aid of the AWD system really helped me improve at a steady pace. My fastest AWD laps are clean, uneventful and easier in repetition. The RWD setup allowed me to take advantage of that experience, apply a little more power which led to carrying more speed in and out in a few critical momentum corners. The straights look to be about a wash on the AIM.
I've got well over 400 laps this season at the Ridge I can export from AIM if you want to give it a look over.
Originally Posted by Fishey
The differences in lap time on Awd and Rwd usually play into Rwds favor until around 500whp then it gets close after 600whp there is no comparison the extra traction provided by awd makes for a faster lap time.
I should note this is on a near stock aero level or less then 700lbs of overall downforce. I have not run comparisons at high levels of aero (talking 1,500lbs+ of downforce type levels)
Last week with AWD chasing a 997.2 GT3RS (wet/damp which really made the AWD system shine)
Monday: 3rd Set of NT01s arrive
Tuesday: Dyno Tuning
Wednesday: Corner Balance + Alignment
Friday: PCA day at The Ridge
Can't wait!
For a RWD set up, go with 1º more negative camber in the front than rear. Set up the car with a 20mm rake based off the chassis measuring points. I run 102/123 and it works very well. Make sure PSM is fully disconnected (by pulling the plug under the master cylinder), not just turned off with the dash button.
As far as NT01s, go with a 245/40 and 305/35 combo. Do not go with a 315/30/18. I've run 25+ sets of NT01s over the last 4 years and the 315/30/18 is not good choice. It works but for RWD the taller 305/35 is a much better option, less rollover, higher load rating, larger contact patch, more grip. If you have fully adjustable LCAs and full mono *****, you can fit 275/335 NT01s with a little bit of modding. Those are the best choice.
Bring that thing down to Miller in September to run the 4.5 mile course. We have a group of us going...
07-22-2016, 12:02 AM
