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Greg G.

NASA 2018 ST5 Rules Released 11-29-17

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Greg G.
Hi Greg,

how do you see a 350z early production 03-04 fitting in ST5, the new st4 rules put my car sort of way down on power, hoping to run fairly stock on the engine side.

 

Thanks

Rafael

 

 

Remember, we have been Dyno Re-classing these cars for over 10 years, using our NASA magic, and if you look at the PT Base Class table, you will see that this is also built in.

We are going to start conservative, as we can always decrease the assessment in the future if we find it appropriate.

 

But, think of it this way, if you have a lightweight vehicle, is it not worth 110 lbs of ballast (or 7 hp) to have an A-arm suspension design over a strut or trailing arm design? Similarly, for a heavy car at about 3400 lbs, wouldn't you rather have the much better engineered and designed suspension than to remove 160 lbs (or 11 hp) from the vehicle? If the answer is no, you haven't driven a car that has power that is absolutely unusable because of inherently flawed suspension design, as you watch Miatas and S2000's at full throttle sticking around corners.

...over 265 OEM HP--not eligible for ST5

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Greg G.
Greg - section 6.1.5 part 4 has info:

6.1.5 ST5 Aerodynamic Modification Restrictions and Limitations

If not using the BTM Aero Modification Factor, aerodynamic parts/devices/aides

shall be limited in ST5 to the following:

4) Single rear wing or spoiler that does not exceed a height above the roof

line, or width greater than the vehicle’s body width, or end plates greater than

12” in length or height, or 12” protrusion from the rear of the vehicle. Body

width does not include flared fenders, mirrors, splitter, door handles.

 

I know for ST4, that the rear wing was limited to 8" above the roof, but I read the above for ST5 that the wing has to be level or lower than the roof height. Was that the intention, or was a value left out of the above section? I was just thinking about a rear wing on a hatch in ST5 vs a coupe or sedan. Also, is the 12" protrusion from the rear from the rear most part of the body (fender cover), so the rear part of the wing has to be within that area? Thanks!! - Jim

No mistake--increasing Aero restrictions as move down in classing.

Yes, 12" from the rearmost part of the vehicle body. Safest would be from the rear edge of the decklid in terms of a possible protest that a vehicle has some funky bumper cover that isn't part of the "body", but it would seem that from the rear bumper cover would be reasonable for most vehicles.

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Greg G.
My wife's WRX is rated AT 265hp. Would her car qualify or does it have to be rated UNDER 265 peak crank horsepower?

The '08-'14 was/is listed as a PTC**/TTC** vehicle currently, so it is not a vehicle that NASA intended for this class. If I recall correctly, this might have been the vehicle that caused the wording to state "Under 265 hp"

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Greg G.
Greg, thank you for getting the rules posted as promised!

 

I have a question about rule 6.1.4 (8) this has to do with flared or rolled fenders. It does not state if there can be a material change for a flared fender. Often a flare will be made from fiberglass.

Is a fiberglass flare and/or complete fender allowed?

 

Thanks

Your welcome!

 

Flares would generally be added on, and could be from a different material. I would be very careful with a complete fender, as any change in body line other than the flare itself would be subject to likely successful protest. Also, competitors should note that front flares cannot extend to the front fascia, because the fascia rule says that nothing can be attached to it except....

So, the flare should just attach to the OEM fender itself.

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944buzz

So if I am reading this correctly a full fiberglass fender as long as it maintains the original shape is legal?

 

Does this pertain to doors as well? Does the door have to open and close or can it be a skin?

 

Thanks!

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TurboShortBus
Based on what I am reading the maximum tire size is 245? I am curious why there wasn't another weight break for more tire above the 2750lb mark, maybe like 3200+lbs. My competition weight was previously 3340lbs (TTC) and I have never ran a tire as small as a 245. I hope the durability will be there in the smaller sizes, given they will not be autocross tires anymore. Maybe I read the rules wrong

It seems to me that this nominal 245 mm / actual 266 mm limit is going to penalize heavier cars, while continuing to give an advantage to lighter cars.

 

Let's just say that you have 2 cars in TT5, with one weighing 2850 lbs and the other weighing 3300 lbs (a 450 lb difference). Both hit the weight:power ratio limit of 14.0, and there are no weight adjustment factors for either car.

 

2850 lbs @ 266 mm = 10.71 lbs/mm

3300 lbs @ 266 mm = 12.41 lbs/mm

 

Using the lighter car's 10.71 lbs/mm, a 3300 lb car would need to use a measured 308 mm section width tire. But, with nothing greater than 266 mm measured allowed, that isn't legal.

 

Using the heavier car's 12.41 lbs/mm, a 2850 lb car would need to use a measured 230 mm section width tire.

 

Does anybody else have concerns about heavier cars being at a disadvantage to lighter cars, given the maximum 266 mm width?

 

It's my own theory that assigning weight:width ratio limits or correction factors could help out here, if the goal is truly to make an even playing field for all cars. Not necessarily for 2018, but definitely for the next rule set.

 

Mark

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AZELISE

Mark, in my opinion it is a trade off. The lighter car might exit the corner faster, but the heavier car will be faster at the end of the straight for two reasons:

1. Better unmodified weight to power ratio (due to weight modification rules)

2. Similar drag but more power

So, like before, on twisty tracks the light cars will have an advantage. On tracks with long straights the heavier cars will have an advantage. This seems like what we saw in the TTA-TTG history of NASA. Cars in the same base class had the same base tire size irrespective of weight. I know that one could take points by increasing tire size in the past (and present TTD-TTG), but having a limit makes for easy comparison when inventing a new rule set.

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davidfarmer

I think the 265hp (oem) rule pretty much sums it up, the class is designed for cars in the 200hp sub-3000lb range, other cars (like mine) are forced to go to ST4 or faster. I had hoped to run ST5 next year, but can't due to the 265hp limit.

 

Just like ST4 has a 275mm limit, ST5 has a 245 limit regardless of weight.

 

My opinion.........I personally feel any car that can meet the power/weight rules should be allowed in any class.

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kjbrew01

I wasn't even really concerned about the performance penalty, just mainly whether the 245 R7s can hold up. on 2nd thought I bet they can, I was running 255 A6/7 without any issues so I bet the 245/40/17 (seems wider than the 245/45/17) would be plenty up to the challenge of the heavier car. My cars base weight was 3552 and 232 oem HP so it does fit into ST5, just going to be a bit of an odd ball being so heavy. More motivation for me to focus on weight reduction over any power increases.

 

Unrelated but I noticed the rules allow for essentially replacing the front bumper cross beam, but nothing is stated about the rear. Based on that we can convert our front bumper cross beams over to tubular ones but have to keep the OEM rear ones?

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MemphisRob
I think the 265hp (oem) rule pretty much sums it up, the class is designed for cars in the 200hp sub-3000lb range, other cars (like mine) are forced to go to ST4 or faster. I had hoped to run ST5 next year, but can't due to the 265hp limit.

 

Just like ST4 has a 275mm limit, ST5 has a 245 limit regardless of weight.

 

My opinion.........I personally feel any car that can meet the power/weight rules should be allowed in any class.

 

I know of a TT car that without "restricting" the engine it would have 25-30% more peak power. As it stands, this car is screaming fast out of the corners.. I haven't seen the dyno but I would imagine it doesn't have much of a "curve" and more just flat power band at just under the HP limit from 3000-7000rpms.

 

So, I think that excluding cars that have stock HP higher than 265 prevents them from being "restricted" to just running a crazy flat power band.

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Arca_ex
So, I think that excluding cars that have stock HP higher than 265 prevents them from being "restricted" to just running a crazy flat power band.

 

 

If you think this is an advantage then you don't understand how the average horsepower calculation works.

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Greg G.

Here is how we know when we have something right...........................everyone on both sides complains that the other guy has an advantage

 

So, we are now hearing from the light car drivers that the heavy cars (mostly without the A-Arm suspensions) are at an advantage because of the A-arm Mod Factor, larger engines with better "torque", and better weight table Mod Factors, and now the heavy car drivers stating that the lighter cars have an advantage because of tire size and the need for them to do control arms and sphericals, etc.

 

One region states how the M3 sets track records, and another region has S2000's destroying everyone, and yet another has Miatas and FR-S's leading every event. NASA has been fairly vigilant over the years to try to ensure that no single model becomes the only possible winning model in ST/PT/TT classes. I don't expect that to just stop.

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Greg G.
So if I am reading this correctly a full fiberglass fender as long as it maintains the original shape is legal?

 

Does this pertain to doors as well? Does the door have to open and close or can it be a skin?

 

Thanks!

Since technically fenders and doors are not part of the "unibody", they can be changed out as long as they have identical body lines to the OEM vehicle.

Although there is no current requirement for the door to remain functional, I personally would keep it functional, because this is exactly the kind of thing that NASA executives see during the season, and then say, "What, they don't have to keep their doors functional? They should....fix that in the rules....." Or, it gets added to the CCR, etc. Then, you are stuck trying to make them functional again.

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Greg G.

Unrelated but I noticed the rules allow for essentially replacing the front bumper cross beam, but nothing is stated about the rear. Based on that we can convert our front bumper cross beams over to tubular ones but have to keep the OEM rear ones?

Yes, provided that you have a vehicle that is not being held together by the front bumper cross beam (changing to a tube for such a possibly imaginary vehicle would then be a partial tube frame conversion).

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racefiero1

I'm a little fuzzy on the aero mod factor. I'm running a Miata with no windshield, which is a -.4 factor. Do I have another mod factor if I add a rear wing and a front air dam?

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cadmad

One region states how the M3 sets track records, and another region has S2000's destroying everyone, and yet another has Miatas and FR-S's leading every event. NASA has been fairly vigilant over the years to try to ensure that no single model becomes the only possible winning model in ST/PT/TT classes. I don't expect that to just stop.

 

ALL of those cars have superior suspensions.

incorporating points for upper "A" arm suspensions opens the door for everyone else.

NASA has found the great divide!

great job!

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srproductions
One region states how the M3 sets track records, and another region has S2000's destroying everyone, and yet another has Miatas and FR-S's leading every event. NASA has been fairly vigilant over the years to try to ensure that no single model becomes the only possible winning model in ST/PT/TT classes. I don't expect that to just stop.

 

ALL of those cars have superior suspensions.

incorporating points for upper "A" arm suspensions opens the door for everyone else.

NASA has found the great divide!

great job!

 

 

M3 doesn't incorporate upper A arms.

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Greg G.
I'm a little fuzzy on the aero mod factor. I'm running a Miata with no windshield, which is a -.4 factor. Do I have another mod factor if I add a rear wing and a front air dam?

No

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cadmad
srproductions
M3 doesn't incorporate upper A arms.

 

Are you sure about that?

 

https://www.google.com/search?biw=1310&bih=614&tbm=isch&sa=1&ei=BOgiWoLbBoKHggfFu6b4Ag&q=bmw+m3+STOCK+suspension&oq=bmw+m3+STOCK+suspension&gs_l=psy-ab.3...25611.27296.0.28923.6.6.0.0.0.0.74.363.6.6.0....0...1c.1.64.psy-ab..0.1.73...0i13k1j0i8i13i30k1.0.iMMmqkPl21A#imgrc=_HLJyjE_BL0BOM:&spf=1512237086438

 

Eibach is or was an OEM supplier.

a quick look says it all!

just saying...

 

 

The rule is for upper a arms only so the M3 doesn't take points.

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914porsche209

Hey Greg,

Thanks for getting these rules out. I hope ST5 has a good turn out!

Can I get a clarification on 6.1.8. (5) Theres no mention about torsion bars here. My adjustable camber plates are mono-ball too.

Also, can I remove my torsion bars and switch to coil-overs?

Thanks,

Shane

Porsche 914

PS. That mid engine -.4 hurts!

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esr

How would a spec e46 fit in?

May be a good car to super size and have 2 drivers or double track time.

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srproductions

Greg, thanks for verifying an earlier post that a 245 R7 will work on a 9" wheel. Do you have any info on if it works on a 10" wheel as well?

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f1honda

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