NASA Time Trials classification for 2019: TT5 or TT6?

[Jamestl]

Originally Posted by Pat

Yes, that's right.

Ugh that's annoying... Should've gone with 9 inch to begin with!

[lutfy]

Originally Posted by Jamestl

Off topic here but my understanding is that the 225 Hoosiers run closer to 245 in width in a street tire. Is that right? If so I may need to get wider wheels as well b/c 245 street tires on an 8 inch rim seems too pinched.

Hey James, you'd be fine. Edgar Morales (Endless Pain on this forum) was the top running TTC BRZ in NorthEast/Mid Atlantic last year. He ran 17*8 with 225/40/17 R7 with no issues and the tires did not look pinched.

Lutfy

[lutfy]

Originally Posted by Pat

Thanks again, lufty. I appreciate you sharing your knowledge and experience.
It is becoming clear to me I just won't be competitive in TT after this year. I'm not willing to spend $1,500 to $3,000 per year on race tires. And I'd rather not run E85 if I don't have to. There is no E85 close to the track I go to the most. I suppose I could fill up jugs and bring it with me, but riding around with 30 gallons inside my car doesn't sound very appealing, either.
It sounds to me like there are ways I can be competitive in TT5. Unfortunately my priorities don't align well with what it takes to get the job done. I may just have to resign myself to driving in an class where I'm not at all competitive, or maybe even just start driving in HPDE again.

I hear you and want to run petrol/gas for the same reason. I am thinking of stripping the s**t out of the car. Which would mean extra 200lbs. I make 2850 with no pass seat and half tank of gas now.

This was the reason to NOT run TT5 this year but I was delaying the inevitable. While my FRS was built to be on the front of TTD it will be just another TT5 for next year as the competition is very stiff. Which in some ways I dont mind, as it would be a driver's race.

Lutfy

[Jamestl]

Originally Posted by lutfy

Hey James, you'd be fine. Edgar Morales (Endless Pain on this forum) was the top running TTC BRZ in NorthEast/Mid Atlantic last year. He ran 17*8 with 225/40/17 R7 with no issues and the tires did not look pinched.

Lutfy

Sweet! I will keep my SSRs then. They're light as hell so that'll help. Hoping to be at the very back of the TT5 pack in 2020.

[Jamestl]

Since we’re off topic now... do you guys know how nonBTM wings are assessed if you have multiple ones? Like if you have a car with a rear wing from the factory and then got a real wing, it’s the same point or is it assessed double since there’s two? Trying to find a trunk with no wing is hard these days...

[lutfy]

Originally Posted by Jamestl

Since we’re off topic now... do you guys know how nonBTM wings are assessed if you have multiple ones? Like if you have a car with a rear wing from the factory and then got a real wing, it’s the same point or is it assessed double since there’s two? Trying to find a trunk with no wing is hard these days...

Rear wing of any kind is free (from my interpretation of the rules). You take points for front splitter only.

Canards/diffuser is illegal.

Lutfy

[Jamestl]

Originally Posted by lutfy

Rear wing of any kind is free (from my interpretation of the rules). You take points for front splitter only.

Canards/diffuser is illegal.

Lutfy

I'm reading the provisional rules and this excerpt specifically:

"Vehicles that maintain the unmodified Base Trim Model (BTM) body lines, do not have non-BTM aerodynamic aides or modifications, and do not have a rear wing or rear spoiler may assess the Modification Factor for “BTM Aero” in calculating the “Adjusted Wt/HP Ratio”. Under this specific rule, an aerodynamic aide is considered non-BTM if it did not come configured on the base trim model (BTM) of the vehicle from the manufacturing factory. Except for those vehicle-specific higher level trim models (nonBTM) listed in Appendix B, there is no updating or backdating across trim models or the addition of dealer installed options permitted." Underline from the source doc, not mine.

Here's the source: https://nasa-assets.s3.amazonaws.com...1--7-31-18.pdf

Seems like the factory wing counts, no?

Edit: I think I know where we are disconnecting. I think you mean free as in no penalty, and I think of free as in getting the benefit of not having a wing (+ factor). So I think the question of how many wings are acceptable the answer is you can have as many as you want as there are no points against it. I guess to clarify my question - is the 0.4pts of not having any wing and sticking with BTM aero worth it or are those points better spent on a giant wing (because the stock wing is of no use and suboptimal for the 0.4pts)?

[lutfy]

Originally Posted by Jamestl

I'm reading the provisional rules and this excerpt specifically:

"Vehicles that maintain the unmodified Base Trim Model (BTM) body lines, do not have non-BTM aerodynamic aides or modifications, and do not have a rear wing or rear spoiler may assess the Modification Factor for “BTM Aero” in calculating the “Adjusted Wt/HP Ratio”. Under this specific rule, an aerodynamic aide is considered non-BTM if it did not come configured on the base trim model (BTM) of the vehicle from the manufacturing factory. Except for those vehicle-specific higher level trim models (nonBTM) listed in Appendix B, there is no updating or backdating across trim models or the addition of dealer installed options permitted." Underline from the source doc, not mine.

Here's the source: https://nasa-assets.s3.amazonaws.com...1--7-31-18.pdf

Seems like the factory wing counts, no?

Edit: I think I know where we are disconnecting. I think you mean free as in no penalty, and I think of free as in getting the benefit of not having a wing (+ factor). So I think the question of how many wings are acceptable the answer is you can have as many as you want as there are no points against it. I guess to clarify my question - is the 0.4pts of not having any wing and sticking with BTM aero worth it or are those points better spent on a giant wing (because the stock wing is of no use and suboptimal for the 0.4pts)?

You are right! OEM wing should count for Base model trim and credit of .4

Challenge is lets say even if you put down 186 average (196whp peak) on E85 and no aero and say running RE71R (fastest tire treaded tire out there) and get .3 credit there. 14 + .8 A Arm - .3 tire -.4 no rear wing = 14.1 + .1 for under 2850lbs.

186*14.2 = 2641 fully loaded (w/driver). Remove 200lbs for an average driver. No way we can get our car to 2441!

Based on that rationale, I added the Hoosier R7, front and rear aero to get up to the weight

Currently barely clicking by 2850 with half tank of gas and no pass seat. Or 1/8th empty with pass seat.

A completely stripped at the back with exception of rollbar. Race seat (driver's side), pass seat removed. No muffler (track pipe), header, light weight wheels....

I need to average 186 or 196whp max in order to make it with current weight. Essentially, switch from gas to E85 to make it worth without removing AC, door cards, front carpet, stereo, lighter battery.

That .8 factor is really hurting us. An E36 with a rear wing will be at 220 average hp and times 14 flat for them = 3080lbs with driver. Greg always favor the E36 hence its such a pain to beat their lap records at most tracks (but doable and done).

That is the car to beat in TT5.

Lutfy

[conehead]

Wow that factory hp limit has me confused. I am/was planning to build an SSC autox car that was also decent for TT6. It would fall in at about 17.2 so I was thinking it could be competitive. It seems a little strange to use lbs/hp, but then also add a stock hp limit.

[200hp/tonne]

Originally Posted by lutfy

Currently barely clicking by 2850 with half tank of gas and no pass seat. Or 1/8th empty with pass seat.

A completely stripped at the back with exception of rollbar. Race seat (driver's side), pass seat removed. No muffler (track pipe), header, light weight wheels....

How heavy is your roll bar? I have a full interior and barely any mods and i was 2730 with me, a helmet, and 3/4 tank of gas

[lutfy]

Originally Posted by 200hp/tonne

How heavy is your roll bar? I have a full interior and barely any mods and i was 2730 with me, a helmet, and 3/4 tank of gas

I am going to guess 75lbs. It was pretty heavy but I will be speculating if I said 'a concrete number'. Its an OTS Autopower half welded rollbar.

Weight savings came from lighter wheels and tires (Hoosier R7), no muffler but a pipe, header, removal of front pass seat, everything behind the front seats being gone (save for the speakers). Race seat with slider and mount. I am 200lbs on the spot. With half tank of gas and the above setup I am exactly 2850lbs so know I need to run a touch above half tank or come in earlier before being weighed. I tend to go out with full tank of gas or half tank (and try to come in closer to 1/4 if I have a pass seat in there).

2730 with driver and 3/4 gas is very light!

Lutfy

PS: I see your sig. I have stock battery, driveshaft and exhaust save for the header and race pipe for muffler.

[200hp/tonne]

Originally Posted by lutfy

2730 with driver and 3/4 gas is very light!

Lutfy

PS: I see your sig. I have stock battery, driveshaft and exhaust save for the header and race pipe for muffler.

Battery, trunk junk, header, front pipe cut big chunks out of the weight, more than i expected. Now i will HAVE to go TT5 when i make it out of HPDE

[lutfy]

Originally Posted by 200hp/tonne

Battery, trunk junk, header, front pipe cut big chunks out of the weight, more than i expected. Now i will HAVE to go TT5 when i make it out of HPDE

Depending on how long you have been in DE Solo or DE3/4 you can request a check out ride for TT. Once you get your provisional lic, you can start competing. Its fairly safe (in our region) with good/fun competition. Your DE insurance will cover you in TT as well.

I instruct with NASA Mid Atlantic (mostly) and sometimes with SE and NE. Heading to Dominion Sept 15 for a TTD showdown (we have a bunch of participants).

Hope to see you and your car out at the track.

Cheers,

Lutfy

[lutfy]

I guess TTD is done! Won the regional championship and broke the previous lap record at Summit Point (set by an E36 M3 in 2014) by over a second.

With 1/4 tank of gas, I came in at 2845 with me in the car. My goal is to remove all the airbags and module for likely 20lbs saving. I dont have passenger seat (when in TT trim) and want to keep some creature comfort (stereo/ac) as I drive to and from the track.

When the battery goes, I'll go ligher. Same when the clutch goes, will opt for lighter flywheel....

In a nutshell I'll be around 2825. Dynoed in a 195 raw on E85. 185 corrected which gives me 174 average (when using the DynoJet file).

Have the front splitter, rear wing. 14 plus .7 for A Arm, .5 for splitter and .1 for under 2850 = 15.3

With current power, still 16.2....

Looked at MCA Traction Mod is not legal. Guess thats going to be it, easy shift to TT5 I guess.

What is everyone else doing?