Marcus_NineLivesRacing
Marcus_NineLivesRacing New Reader
4/15/19 1:55 p.m.

Hello! My name is Marcus and I do customer servicer/web-admin/spell-checker/beer-drinker at Nine Lives Racing (9livesracing.com).  Nine Lives Racing is an aerodynamic company that sells race car wings and aero consultations (aka we scan your car and try to find the nicest way to explain your mess). As a courtesy, we at 9LR are offering to answer basic questions that obtain to aerodynamics. 

 

So just a background of who we are. You're welcome to use this information to validate our answers. 

 

Johnny C - He started in motorsports in 2006  and graduated to professional motorsports in 2012 working with PFC brakes. Since 2012 Johnny has stayed in professional motorsports working for OG racing. Then in 2018 he started Nine Lives Racing where we still continue consultations for all teams, but professional ones included. 

Race Resue

Directly consulted or was apart of a team that has won

- 2 24hour of Daytona overall wins, (01 Chip Ganassi cars) 

- 2012 NASCAR championship (Joe Gibbs racing) 

- Almost won Le Mans (DeltaWing)

- Overall lap record at Daytona road course (Mazda DPI #77)  

- He's 0.2 seconds away from obtaining the Miata lap record at Road Atlanta in my own car. 

 

01-chip-ganassi-racing-riley-dp-ford-lan

gzea1oepsdfjphspp0du.jpg    

 

Partners in crime that work at or with Nine lives racing include. 

Rob Lindsey - Famed car builder that directly or indirectly had a hand in some form of the design with....

Riley Mark XXII

Elan Dpo2 

Elan Np01 

Delta wing

Panoz PWC cars. 

riley.jpg

NP01_rivard.jpg?ssl=1

gzea1oepsdfjphspp0du.jpg

panoz_lede-2.jpeg?w=660



Marcus Luttrell - No not the Navy Seal.  Marcus is in the IT field by trade, but a solid passion for motorsports and miatas. Majority of his youth was spent to the dragon(Deal's Gap). SCCA auto-x when the schedule allows. Campaigned a NB1 in TTE over the past few years with NASA and recently converting ST5/TT5.

TTE trim



TT5 trim



Marcus has been around Miatas over have his life. Involved in multiple ways he can, including helping with Miatas at the Gap for many years - http://gapmiatas.com/ 
And most recently helping with Miatas Before the Gap w/ Jzilla Trackdays - https://www.facebook.com/miatasbeforethegap

 

 

 

 

 

That's us in a nutshell with basic pictures. Hit us with your aero questions. 

 

 

HOODIE LOGO JPG.jpg

barefootskater
barefootskater Dork
4/15/19 2:35 p.m.

Not so much a question, but say one was to have a 79 Thunderbird and say it has a windshield but no other glass (or plastic, just big gaping holes), how pointless would a wing be for autocross? I'd imagine all that turbulence would render the car pretty useless from an aero perspective..

optiguy
optiguy
4/15/19 6:53 p.m.

If you were building a Miata Track Day and Time Trial car with a speed range at your local track of 40 to 100mph. What wing profile would you choose to use? Also we are thinking of a 4" stick out splitter to go with the wing. 

Thanks

AngryCorvair
AngryCorvair MegaDork
4/15/19 8:23 p.m.

i'm just going to lurk here, but i wanted to say a preemptive Thank You for what i suspect will be a highly informative sub-forum.

Marcus_NineLivesRacing
Marcus_NineLivesRacing New Reader
4/15/19 8:33 p.m.
barefootskater said:

Not so much a question, but say one was to have a 79 Thunderbird and say it has a windshield but no other glass (or plastic, just big gaping holes), how pointless would a wing be for autocross? I'd imagine all that turbulence would render the car pretty useless from an aero perspective..


I wouldn't say it would be pointless, just maybe not optimal? Getting it taller and into clean air would be the problem..... and legally. What class are you running?

Marcus_NineLivesRacing
Marcus_NineLivesRacing New Reader
4/15/19 8:50 p.m.
optiguy said:

If you were building a Miata Track Day and Time Trial car with a speed range at your local track of 40 to 100mph. What wing profile would you choose to use? Also we are thinking of a 4" stick out splitter to go with the wing. 

Thanks

That's exactly what my car does! I run the 64" swan-neck, currently at 0* AOA. We're front down-force limited, like most cars I suppose.

My rough estimates on my aero currently. Keeping in mind it's never an exact number since I don't have my exact setup tested. But we do at least have some data to reference.

https://9livesracing.com/cfd-testing
Rear wing @ 0* AOA 
@ 60mph

  • 42lbs of DF
  • 3lbs of drag

@ 100mph

  • 126lbs of DF
  • 9lbs of drag


https://hanchagroup.wordpress.com/2013/01/29/splitter-or-air-dam-which-design-is-best/
OEM aero (NA not NB, NB is better hope to have CFD on it in the near future)
@ 100mph

  • -106lbs of DF, yes negative.
  • 141lbs of drag

Front airdam and ~4" splitter
@ 100mph

  • 193lbs of DF
  • 117lbs of drag


Rear DF ~117lbs
Front DF ~76lbs


I think when I get my air-dam mouth ducting optimized that should help reduce drag quite a bit. Then I might be able to run a few more * of AOA at some tracks, like Barber. The neat thing about the Elan foil, you can set a level on the front of it and on the very end of the wicker. No specialized tool needed to actually measure the AOA.


If you don't go with a splitter, but air-dam only I believe optimizing the under-tray would be your best bet. I've recently learned the trailing edge is very very important.

barefootskater
barefootskater Dork
4/16/19 12:00 a.m.
Marcus_NineLivesRacing said:
barefootskater said:

Not so much a question, but say one was to have a 79 Thunderbird and say it has a windshield but no other glass (or plastic, just big gaping holes), how pointless would a wing be for autocross? I'd imagine all that turbulence would render the car pretty useless from an aero perspective..


I wouldn't say it would be pointless, just maybe not optimal? Getting it taller and into clean air would be the problem..... and legally. What class are you running?

Umm... Challenge class? I thought a wing could be fun. In all honesty though we removed the bumpers for weight and I am very seriously thinking about splitters and diffusers so I’ll be keeping an eye on this forum for everything I can learn about those. 

optiguy
optiguy New Reader
4/16/19 4:41 p.m.

In reply to Marcus_NineLivesRacing :

Thanks for the reply. I have seen the Hanchagroup data before. I am running an air dam on one of our Miatas. The front opening is about 35% of the radiator area. My local track is Thompson Speedway in CT. Which is an interesting track with a variety of corner radii. And one long straight. I know this is a  question you most likely will not want to answer but do you have a favorite wing profile( I am a retired composite fabricator and make everything myself)? And lastly, do you have a preferred fore and aft mounting position of the rear wing in relation to the rear axle?

Thanks, Bill

Ransom
Ransom PowerDork
4/16/19 4:48 p.m.
Marcus_NineLivesRacing said:


If you don't go with a splitter, but air-dam only I believe optimizing the under-tray would be your best bet. I've recently learned the trailing edge is very very important.

Would you mind clarifying this a bit for me? Are you referring to a tray just under the air dam? Trailing edge of the bottom of the dam? Almost a front diffuser, or... As you can see, I'm lost enough by the description to be just guessing...

Keith Tanner
Keith Tanner MegaDork
4/16/19 6:07 p.m.

I think Competition Car Aerodynamics discusses that. There's more going on at the back of the engine undertray than you might think.

Marcus_NineLivesRacing
Marcus_NineLivesRacing New Reader
4/17/19 10:43 a.m.
optiguy said:

In reply to Marcus_NineLivesRacing :

Thanks for the reply. I have seen the Hanchagroup data before. I am running an air dam on one of our Miatas. The front opening is about 35% of the radiator area. My local track is Thompson Speedway in CT. Which is an interesting track with a variety of corner radii. And one long straight. I know this is a  question you most likely will not want to answer but do you have a favorite wing profile( I am a retired composite fabricator and make everything myself)? And lastly, do you have a preferred fore and aft mounting position of the rear wing in relation to the rear axle?

Thanks, Bill

We'd say radiator inlet % of radiator face area is good way to measure that as well. One could adjust that up or down based on the average speed of particular tracks or even for key sections of certain tracks.

We do have a favorite wing profile, the Elan, and that's why we tooled it! 

Rear axle is not as relevant as fresh air and of course..... rules. Many of our mounting positions are dependent on rule structures. For example, NASA ST/TT4-5 the wing cannot protrude 12" past the rear of the air and the wing cannot be higher than the roof-line. For fresher air higher is better and typically further rearward is cleaner as well. Further rearward also means more rear balance, but one could go too far with that depending on the front-end balance.

Marcus_NineLivesRacing
Marcus_NineLivesRacing New Reader
4/17/19 1:19 p.m.
Ransom said:
Marcus_NineLivesRacing said:


If you don't go with a splitter, but air-dam only I believe optimizing the under-tray would be your best bet. I've recently learned the trailing edge is very very important.

Would you mind clarifying this a bit for me? Are you referring to a tray just under the air dam? Trailing edge of the bottom of the dam? Almost a front diffuser, or... As you can see, I'm lost enough by the description to be just guessing...

Referring to tray just under the air-dam. You'd want to make this surface as smooth as possible and as far back as possible. There will certainly still be air coming under the dam and under this surface, so any type of ramp you have behind it should generate a diffuser effect, may be small though depending on how it all works together.

optiguy
optiguy New Reader
4/17/19 7:09 p.m.

In reply to Marcus_NineLivesRacing :

Thanks for all the answers guys. We are lucky as we are building a car with no regard for any rule set. When we get into TimeTrials we will let the chips fall and run whatever class we are thrown into. Like the SCCA says" Fun with Cars".

 

¯\_(ツ)_/¯
¯\_(ツ)_/¯ UberDork
4/18/19 11:04 a.m.

I have a general question- in your opinion, what would be some worthwhile aero modifications for a stage rally (or other offroad racing) car?  Splitters and diffusers need to be close to the ground to work well, so what are the options for something which needs to maintain a bunch of ground clearance and not rip stuff off constantly?  Bonus points if it works at high slip angles!

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