I'm planning to enter the Silver State Classic "race" this year. It's more of a rally than a race really. The track is a 90+ mile stretch of almost completely straight two lane blacktop across the Nevada desert that is closed for the event. There are maybe 10 gentle curves. Each entry picks a class, and the class defines both a max speed and a target speed. The winner of each class is the car that completes their run closest to the exact time required at the target speed for the class. IE, the car that comes closest to averaging the target speed over the entire run. Target speeds range from 90 upward in 5 MPH increments to 180.

I race Miatas, so I have some skills, and I'm thinking I would be comfortable targeting 140 MPH. No need to go crazy, especially with the required navigator in the car.

My questions are these.

Can anyone speak from experience about how aero stable an S with the spoiler up is at those speeds? I have not tracked mine yet so have not come close to those speeds so far.

Can anyone speak from experience about how well an S tolerates sustained runs of 30 or 40 minutes at these speeds? I'd expect only slowing to around 120 for corners and only briefly.

The Nevada desert heat will stress the cooling system. Can the stock cooling take it? I'll remove the engine cover. What else should I be thinking about doing? I understand there are some plastic coolant fittings that are failure prone that I should replace. Should I replace the coolant mix with distilled water and Water Wetter? Mine is a 2017 sold in 2016 and will have approx 9,000 miles by race date.

I'll be running on nearly new PS2s on 19" rims.

Any other concerns or thoughts? Thanks.

 

Running these speeds should not be an issue for an F-Type. I have no experience with an S but I have had my R well above that many times. (I spray Water/Methanol though).

From a stability standpoint, the cars are solid, and aerodynamically sound. The wing raised will add drag at speeds, but without modding, cannot be avoided.

The answer to most of your questions will relate to heat/heat soak. So as long as you monitor and/or control that, the car will perform well. High sustained speeds like you are suggesting won't be creating as much boost/compressed air/heat...So actually better on the car...You will have lots of airflow helping to keep it cool (of course if the ambient air temps are really high, it won't cool much). If you do run it hard, and then stop it, that is when you will see the temps spike. The ECU's on these cars are very good, so you will just get some timing pulled and lose power when you heat it up too much.

I would add, if you are comfortable doing any of this in a Miata, then definitely no worries in any F-Type. (I cannot fit in a Miata, so no experience there either)

DC

 

I have a '16 S coupe and my car was very stable doing 142 on rt 84 from ,PA. Driving at 120 many times, of course not for extended periods of time compared to your event. Please post photos and experience during your "race,"
Good luck!!!
Frank

 

Having done a few “runs” over the last 5 years at extended 120+ many times I can confidently say it is not a problem for this car. In fact my experience is that the Ftype “settles down” nicely once over 100 and does not feel remotely unstable at 140 (albeit safety first, good road conditions and aligned and balanced tires a must). It’s high speed sweet spot seems to be between 120-135 or so, you almost don’t realise you are travelling at those speeds. 140 was only a little disconcerting for me as that was the first time I got any vehicle that high. Got used to it rather quickly once I realised the car liked it.

 

140 MPH. 30 or 40 minutes.

Been there. Done that. (In the "F" and even the "e")

 

Having run the Silver State Challenge before, I can say the F-Type should not have any worries. To average 140mph you will need to travel at around 165mph. It's amazing how a little slowing for the canyon turns plus the initial climb to speed affects the average. I drove a 1981 911 wide open which hovered around 160mph and only averaged 137. This was before classes and rules so the goal was just to go fast. I didn't lift once for the first 70 miles. The good ole days!

 

I didn’t really notice a difference between 80 and 130 - car is stable. I was gripping the wheel too hard at 140 to notice, though my brother was the passenger. Elsewhere, spent an hour between 100 and 110, on lousy pavement, and the car didn’t care.

V6S, by the way. Also, top down at 120 is ok.

 

I often drive at 120+ and live 20 minutes from an unrestricted Autobahn so needless to say have driven the car much faster than that... as others said stability is definitely not an issue.

 

I would not be in the least concerned. I have many track days on my BMW Dinan Stage 2 M135, but haven't tracked my V8S yet. However, I have run 0- 1/2 mile drag races in the Florida mid summer heat in Ocala. To me this V8S has been bullet proof. I have run 14 races throughout the day, pretty consistent 1/2 mile trap speeds of 144 mph, 117mph at 1/4 mile. No cool downs or shutting the engine off during the day. I like the A/C running at 90F plus ambient :-). Other vehicles , shutting off their engines, pushing to the start line, cooling devices. etc etc. So I have been very surprised and pleased. My BMW power starts to go away as the turbos get hot but the Jah supercharger shrugs it off.
So I haven't run an event like you are planning, would love to, but I wouldn't hesitate doing this for a second. My feedback fwiw. Have fun.

 

That rally sounds like a lot of fun. If you plan on exceeding 155 MPH for any period of time the manual recommends adding a few pounds of air to the tires. That seems counter-intuitive to me, I figured that the heat generated at those speeds would expand the air in the tires and raise the pressures but someone explained on another thread that there was something else going on and you should in fact raise the cold tire pressures before prolonged high speed runs. Have a good time and be safe !

 

I have long thought that would be a fun thing to try. A former neighbor has been running those events for many years now, with wins in multiple classes. One of his wins had a variance of 0.0001mph from target. It seems timekeeping is one of his strong suits :-)

I haven't had mine up that fast but with the encouraging comments above I hope you follow through, regardless of the target speed you end up selecting. Good luck!

 

As it was explained to me, many years ago, in motorcycle context: Tire temperatures increase as the tire carcass flexes. Higher starting pressures mean less flex, so less increase from cold to hot.

We used to check hot temperatures immediately exiting the track and look for a specific rise over cold. Not enough temperature rise? Lower the starting pressure. The trick there was not getting burns from the brake rotors.

 

My first question is have you read through the rule book? https://sscc.us/global/pdf/2021_rulebook.pdf
Since this is your first time for this event you would need to get a waiver to enter the Grand Touring Division to go up to a max target of 125 MPH with a max speed of 140 MPH. Plus in order to enter the Grand Touring Division you would have to install a five or six-point safety harness system for both the driver and navigator, are you willing to do that? Otherwise you would be in the Touring Division with a Max target speed of 110 MPH and a Max speed of 124 MPH, so not nearly as fast as you're thinking.
Here are a couple of the relevant sections of the rules;

8. Open Road Challenge Divisions and Classes
Division Classes (Target Speed) Tech Speed (max allowable speed)

Touring 95, 100, 105, 110 mph 124 mph
Grand Touring 115, 120, 125 mph 140 mph
Grand Sport 130, 135, 140, 145,150,155 165 mph
Super Sport 160, 170 180 mph
Super Sport 180 180+
Unlimited Unlimited 180+

H. First time drivers may not enter any Division/Class above a target speed of 110 mph unless otherwise
waived by the SSCC.
I. Drivers in Grand Touring must have prior successful SSCC driving experience in the Touring Division
or a waiver from the SSCC.


7. Grand Touring Division
Classes: 115, 120, 125 Technical Speed: 140 mph
The following are the Minimum Requirements for the Grand Touring Division:
A. In order to enter the Grand Touring Division, the Driver must have successfully completed
at least one previous SSCC open road event in the Touring Division, or received a waiver
from SSCC.
B. A 2 ½ pound fire bottle containing at least BC is the minimum, with a secure quick-release
mounting bracket made of metal and must be within easy reach of the driver.
C. A five or six-point safety harness system that includes three-inch (3”) shoulder and lap
belts as a minimum (see “Restraint Systems” section, including note on Harness Bars). All
belts must be in “as new” condition, no more than five (5) years old from manufacture date
or not aged past the manufacturer’s printed expiration period. Exception would be FIA
rated belts which may have 5 year expiration by default. If a harness has both FIA and SFI
tagging, the longest date will be honored. Sternum belts are recommended for seats that
do not support the shoulder straps, however large metal buckles on the sternum strap are
not recommended. The use of a “cam-lock” seat belt locking system is recommended.
D. Arm Restraints or window nets are mandatory.
E. A competition approved Roll Bar for an open vehicle is required (see “Rollover Protection”
section)
F. DOT approved “V” rated tire (or better) will be considered the Minimum Requirement. DOT
approved “Z” rate tires are recommended (see “Tires” section).
G. 2021 events will require a SNELL Foundation SA2015 (or

 

I'm unclear about why the max speed would be so much higher than the target. I watched a video of a Vette doing the course and he only slowed down about 5 MPH for the curves. Looked like more of a "confidence" lift than a real need to slow. He ran the whole course around 145 to 155. I get the need to exceed target to compensate for the start, but I'd think that compensation period would be short.

Of course if you have to slow a lot below target in the curves then you'll need more compensation speed above target. It seems like the lower the target speed the less time under target in the curves and the lower the compensation speed needs to be. At a target of 120 I was thinking I would not want or need to go much faster than that to comp for the start and maybe a slight lift at turn ins.

What am I missing? Thanks!

 

Read the rules last year. Almost entered then but had a date conflict with a race event. The mods to install the belts are the issue, as you said. I'd probably have to swap in racing seats as well for the submarine belt. I'd want this to be done in a cosmetically reversible way, so carpeting would have to be removed as well. Not sure if I'm going to go to that much trouble to bump into GT. But, based on this thread though I'm confident the car could handle the pace. Thanks.

 

Thanks to everyone for the great info!

 

Maybe the best thing to do is just enter Touring this year and get that first year under your belt in your stock car and you won't have to worry about getting a waiver or not to run GT. Then you can decide for your self if it's worth it to spend the money modifying your car to meet GT rules; 5-6 point harnesses, arm restraints and harness bar just for the extra 15 MPH Target and Max speeds and you will be qualified to run GT without a waiver. Plus you'll know for your self how your car is handling, it shouldn't be any problem, haven't you made some trips to Vegas or up HYW 5 where the minimum speed is 90-95 MPH? :-)

 

I think the fastest I've ever been* was about 105mph, but the car was as rock solid as when parked.


* with my mother in the car

 

65 MPH* and it felt as if we were standing still.

* with my wife in the car!

I have to drive with the speedo switched to km so I don't get accused of speeding.
She doesn't believe in the 10MPH over rule either.
If she learns to convert, I'll have to put tape over the speedo.

 

That's because it doesn't exist. The EU regulation states that the speedo is tested at 3 speeds, 40, 80 and 120 km/hr. The difference
between the indicated speed and the true speed at each of these points must not be negative (ie it can't show a speed lower than the
actual speed) and not more than 10% + 4km/hr above the actual speed. (In English this means at a true 25mph it can read up to 30mph, 50 mph it can read up to 57.5mph and at 75mph up to 85mph.)