Jump to content

Photo

NA 1.6 Driving Range?

- - - - -

  • Please log in to reply
22 replies to this topic

#1
Carl

Carl

    Member

  • Members
  • PipPipPip
  • 45 posts
  • Location:United States
  • Region:California
  • Car Year:1990
  • Car Number:38

Can anyone tell me approx. how long I should be able to drive a 1990 Spec Miata on a full tank of gas?  Cal Club has a 90 minute enduro coming up in November and I am wondering if I can make it the full time (with a mandatory 5 minute stop in the middle).  I know my 1st gen RX7 would make it, but I don't have any enduro experience with the Miata.  

 

Any suggestion (other than if it goes more than 4 hours call 911) would be appreciated.

 

Carl



#2
Ron Alan

Ron Alan

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 3,450 posts
  • Location:Northern CA
  • Car Year:1995

It will make it! Especially if you drive it like an enduro...short shift and running corners you can in a higher gear. The early cars have a very small tank...like 10 gallons stuffed. Not sure when Mazda went to the next size tank which is more like 12.5 gallons stuffed. But even at 10 you will make it!


Ron

RAmotorsports

2014 NASA SM Western States Champion(Car owner)

2015 NASA 25HR E3 Champion(Car owner)

2016 NASA 25HR E3 Champion(Car owner)

2017 NASA 25HR E3 Champion(Car owner)

2017 NASA NORCAL SM Series Director

2018 NASA NORCAL SM Series Director

Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#3
Carl

Carl

    Member

  • Members
  • PipPipPip
  • 45 posts
  • Location:United States
  • Region:California
  • Car Year:1990
  • Car Number:38

Sounds good!  Just fill it as full as possible and ignore the gauge reading empty near the end?



#4
gerglmuff2

gerglmuff2

    Member

  • Members
  • PipPipPip
  • 67 posts
  • Location:St Paul MN
  • Region:LOL
  • Car Year:1993
  • Car Number:81

i dont think it can do it. esp considering it will starve in corners with under 1 gallon in the tank. you'd really have to baby it. 


Gordon Kuhnley: Rookie


#5
speedengineer

speedengineer

    Member

  • Members
  • PipPipPip
  • 374 posts
  • Location:Michigan
  • Car Year:1999
  • Car Number:84

No crew available to splash a few gallons of fuel in during your mandatory 5 minute stop?  I think you would make it regardless, but it sure takes the guesswork out if you can add a few gallons.


Jason Kohler 

#84 SM

www.youtube.com/user/speedengineering

 

NASA Champs Winner - NASA Champs Winner We have a Winnah! - Won their 1st race... Congratulations! Bona fide - A bonafide Spec Miata driver

#6
William Keeling

William Keeling

    Member

  • Members
  • PipPipPip
  • 243 posts
  • Location:Houston Texas
  • Region:Houston Region
  • Car Year:1999
  • Car Number:8

we did 1:55 in our chumpcar 1.6 all the time


William Keeling
 

Bona fide - A bonafide Spec Miata driver

#7
Carl

Carl

    Member

  • Members
  • PipPipPip
  • 45 posts
  • Location:United States
  • Region:California
  • Car Year:1990
  • Car Number:38

If we could just put in a splash without getting out the car, I would do it.  The driver has to be out of the car though during fueling, so I think I will be taking a chance since it seems likely the car can make it.  Also by not fueling I can avoid the chance of a penalty for spilling fuel.  Last time I did one of these with CalClub I got a 3 minute penalty for spilling literally 3 drops of fuel outside my catch basin.  

 

Thanks for the advice.



#8
Michael Novak

Michael Novak

    Member

  • Members
  • PipPipPip
  • 464 posts
  • Location:Highland
  • Region:Michigan
  • Car Year:2002
  • Car Number:#9

You will be fine. Short shift when possible and save fuel if you get a yellow.


Majors Winner - Instigator - Made a topic or post that inspired other We have a Winnah! - Won their 1st race... Congratulations! Make it Rain - Made Paypal donation of $100+ Bona fide - A bonafide Spec Miata driver

#9
Ron Alan

Ron Alan

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 3,450 posts
  • Location:Northern CA
  • Car Year:1995

Sounds good!  Just fill it as full as possible and ignore the gauge reading empty near the end?

If you plan to run more Enduro races you should be pretty comfortable with your fuel gauge...test it! Best way is to empty tank...add exactly 2 gallons...note if the gauge moved. Go run a session until the car stumbles...watch the gauge during this and count your laps/time. Once it stumbles slow down a little and get back to the pits in 4th/5th gear. Try and pump out and see what you get! I've done this and got less than a pint of fuel! Obviously if you stumble and dont make it back to the pit...make a note :) 


Ron

RAmotorsports

2014 NASA SM Western States Champion(Car owner)

2015 NASA 25HR E3 Champion(Car owner)

2016 NASA 25HR E3 Champion(Car owner)

2017 NASA 25HR E3 Champion(Car owner)

2017 NASA NORCAL SM Series Director

2018 NASA NORCAL SM Series Director

Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#10
Danny Steyn

Danny Steyn

    Zulu rain warrior

  • SMembers
  • PipPipPipPipPip
  • 2,304 posts
  • Location:Fort Lauderdale
  • Region:FL
  • Car Year:1999
  • Car Number:39

Carl, with all due respect, if your intention is to DRIVE for 90 minutes then you are on the right track. You can do it for sure  

 

However if you are planning to RACE, then you need to think again.  :nonono: :nonono: :nonono: :nonono: :nonono:

 

To RACE, you need to be fast, light, and on the throttle, in the power band - short shifting a 1.6 is not the way to make it go fast.

 

Having done lots of enduros with 5 min compulsory pit stops. It is really easy to get in and out, and refuel you car in 5 mins, with only one crew member doing it, without rushing the refueling.

 

You can even change 4 tires in that time and we have done it, but it does require two crew over the wall.

 

This way you can run you car light, with slightly over 1/2 tank for 45 minutes, come in to the pits, get out, drink, stretch and get back in again, and you will have a faster car for each stint, since you are lighter an you won't have to short shift.

 

But thats if you want to RACE!!!  :hugegrin:


  • Adax and Richard Astacio like this

Danny
Danny Steyn Racing | DSR YouTube Channel
Danny Steyn Photography | Adept Studios | Ocean MachineryOPM AutosportsRossini Racing Engines | G-Loc Brakes | 

2018 SCCA Runoffs Champion, NASA Champion, Hoosier Super Tour Champion, June Sprints Winner

2016 June Sprints WInner, ARRC Winner, NASA Eastern States Championships Podium

2015 Eastern Conference Majors Champ, June Sprints Winner, ARRC Winner

2014 NASA Eastern States Championship Runner Up.

2013 SEDiv Driver of the Year, Eastern Conference Majors Champ, SEDiv National Champ, ARRC Winner, Runoffs Podium

2011 SEDiv Driver of the Year, SEDiv National Champ, ARRC Winner, Palm Tree Quad National Champ, SEDiv ECR Champ
2010 June Sprints Winner, ARRC Winner

2009 SARRC Champ, SEDiv ECR Champ, FES Champ
2008 SEDiv ECR Champ

June Sprints winner  - June Sprints winner Series Champ - Won a points based series in a Spec Miata ARRC Champion - Won the ARRC Race in a Spec Miata We have a Winnah! - Won their 1st race... Congratulations! Bona fide - A bonafide Spec Miata driver NASA Champs Winner - NASA Champs Winner June Sprints winner  - June Sprints winner ARRC Champion - Won the ARRC Race in a Spec Miata ARRC Champion - Won the ARRC Race in a Spec Miata Majors Winner - BFG Supertour Winner -

#11
Carl

Carl

    Member

  • Members
  • PipPipPip
  • 45 posts
  • Location:United States
  • Region:California
  • Car Year:1990
  • Car Number:38

In this particular instance I do not have a pit crew, so that means me getting out of the car, refueling (borrow someone to hold the fire extinguisher)  and getting back in the car and belted on my own.  Definitely do-able in 5 minutes, as I do it all the time with time to spare when there is a crew and a new driver is going in.  I have also done it once on my own (two hour enduro where there was not enough fuel to go 2 hours) and it went OK, just hectic.  

 

Since I normally run +7 hour enduros where starting with 1/2 tank of fuel is not an option, the thought of of starting lighter had never crossed my mind.  That makes some sense and I will have to take that into account.  

 

I guess my question has been fine tuned a bit.  Can I drive at race pace (no short shiftiing, etc) for 85 minutes without fueling?  If I can, I will have to decide if starting the race 30 lbs lighter gives me enough benefit to do a mid-race re-fuel.

 

Thanks  



#12
Jeff Wasilko

Jeff Wasilko

    Member

  • Members
  • PipPipPip
  • 236 posts
  • Location:Boston, MA
  • Region:NER
  • Car Year:1995
  • Car Number:08

I have a 1.6 tub with a 1.8 drivetrain (that runs in ITA). We were getting 1:45 on a tank at Watkins Glen with AER.

 

Early cars had 11.9G capacity vs 12.7G on 94+/



#13
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 1,837 posts
  • Location:St. Louis
You said it’s a ‘90, so small tank as Jeff noted. It depends on the track, but what Danny said. That isn’t an enduro, it’s a double sprint, and if you drive it like one I expect you are at risk of coming up short unless tuned really lean. Depending on the track we’ve sometimes burned close to 1 pound per minute in our 1.6s tuned a little rich, but I also seem to recall completing the MW Council Loooong Race on one tank. Dave W, chime in here.
Bona fide - A bonafide Spec Miata driver

#14
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 1,837 posts
  • Location:St. Louis
Ah, the council race is only 50 laps (~97 miles) so that wasn’t a problem in the 1.6 at full pace. Without good data for your car at that track I’d recruit help and refuel.
Bona fide - A bonafide Spec Miata driver

#15
Jaysz28

Jaysz28

    Junior Member

  • Members
  • Pip
  • 2 posts
  • Location:Fort Myers
  • Region:SE
  • Car Year:1990
  • Car Number:varies

Wouldn't the fuel consumption be based more on the track?

 

I burned through 3/4 tank in my 90 miata in 45 mins - 1 hr at Daytona this past May.

 

I grabbed a fellow SM driver who wasn't competing in the enduro and asked them to fill the tank while I held the extinguisher. You have more than enough time to throw in 5 gals and grab a drink in the 5 min mandatory pit stop.

 

-jason



#16
William Keeling

William Keeling

    Member

  • Members
  • PipPipPip
  • 243 posts
  • Location:Houston Texas
  • Region:Houston Region
  • Car Year:1999
  • Car Number:8

if the stop is optional then then straight thru on a full tank will be fastest -- if the stop is not optional then Danny may be right


William Keeling
 

Bona fide - A bonafide Spec Miata driver

#17
luvin_the_rings

luvin_the_rings

    Member

  • Members
  • PipPipPip
  • 175 posts
  • Location:Los Angeles, CA
  • Car Year:1990

Lucky for you, I have done this exact experiment. Unlike the 1.8's, I have consistently measured our tuned 1.6 to use, on average, including going in and out of the pits, about a gallon every 10 minutes.  That is at BRP 13 CW, however its all the same at most of the SoCal Tracks. 

 

The tank holds 10 gallons, so that's 100 minutes of running, minus 5 minutes for the pit stop and you're looking at about 15 min, or about 1.5 gallons to spare using a full tank. Don't forget about safety cars. The tank also uses almost all the fuel before cutting out. 

 

An extra 5 gallons weighs 45 lbs. That could average to 3 or 4 tenths a lap maybe? Loosing a second every two laps to the guy in front who is running a half tank. 

 

hmmm... 

 

Those tenths sure add up. 

 

Spec Miata's run 2:06's in sprint races at Buttonwillow 13 CW, so probably 2:10's in endurance racing in the evening. So that's about 40 laps total, best case including pit stops. 

 

You will be running an extra 5 gallons during the first stint compared to the equivalent fuel stop strategy, so that's 20 laps with the extra weight, loosing 1 second for every two laps, that's about 10 seconds disadvantage you have over the 90 minute race by not re-fueling at half way.  

 

That's assuming you're loosing half a second a lap with the extra 45 lbs. 

 

of course, once off track excursion is worth 25 seconds so... there's that too. haha

 

pick your poison!



#18
davew

davew

    Veteran Member

  • SMembers
  • PipPipPipPipPip
  • 2,297 posts
  • Location:Beloit, Wi
  • Region:Chicago
  • Car Year:1999
  • Car Number:72

We have never had an issue with running out of fuel at That loooong Race. 50 laps / 100 miles at Blackhawk. Takes an SM about 70 minutes.

 

When doing other enduros, I have done an extreme short shift, easy on throttle to save fuel. Gotten 2 hours on about 8 gallons of fuel. About 1.5 seconds slower per lap. This saved us 2 pit stops or 10 minutes. 600 seconds divided by 1.5 seconds per lap is a 400 lap equivalant point. So if I am running a 6 hour race (360 minutes) on a 1:30 lap track, I will do 240 laps. In this case a slower lap time with 2 fewer pit stops gains us overall time.

 

Couple secrets:

 

Blow up the gas tank. Remove the fuel pump access plate, using a rag as a seal, use compressed air in the fuel filler neck to expand the tank. Watch what the tank does through the access panel.

 

Remove fuel pump assembly, reach inside the tank and you will feel the 1" diameter vent tube. It is about 2" off the top of the tank. Bend it up to as close to the top of the tank as you can. You can only fill to the vent tube, moving the vent tube up gets more gas in.

 

I have seen Miatas hold 14+ gallons of fuel in a tank done this way. YMMV


  • Mike Collins likes this

Dave Wheeler
Advanced Autosports, the nations most complete Spec Miata shop
Author, Spec Miata Constructors Guide, version 1 and 2.0

Building Championship winning cars since 1995

4 time Central Division Spec Miata Champion car builder 2012-2013-2014-2017

Back to Back June Sprints Spec Miata 1-2 finishes 2016 and 2017

5 time June Sprints winner in Mazda's

6 Time Northern Conference Champion Car Builder

2014 SCCA Majors National point Champion car builder

2014 SCCA Runoffs winner, T4 (Bender)

2014 Central Division Champion, ITS (Wheeler)

2013 Thunderhill 25 hour winning crew chief

2007 June Sprints winner, (GT1, Mohrhauser)

Over 200 race wins and counting.
www.advanced-autosports.com
dave@advanced-autosports.com
608-313-1230

Survive the 25, NASA Thunderhill - Survive the 25, NASA Thunderhill We have a Winnah! - Won their 1st race... Congratulations! Sponsor / Advertiser - Site sponsor / advertiser... support these guys! Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#19
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 1,837 posts
  • Location:St. Louis
Great tips Dave!

Increasing tank size aside, the rest of the endurance norms don’t seem to apply here. He’s doing 90 minutes less a 5 minute mandatory stop. To short shift or do anything else to save fuel seems like conceding the race if anyone else is really trying. At absolute worst those lost seconds could be added to the pit stop and you still have the advantage of running lighter.

So if it can be done with one tank then fine, maybe it’s worth carrying some extra weight to avoid the risk of a fueling mishap, but it’s not an enduro where the tortoise wins by making fewer stops.
Bona fide - A bonafide Spec Miata driver

#20
davew

davew

    Veteran Member

  • SMembers
  • PipPipPipPipPip
  • 2,297 posts
  • Location:Beloit, Wi
  • Region:Chicago
  • Car Year:1999
  • Car Number:72

I agree Steve. The original question was about a 90 minute/0ne stop race. But the conversation veared away to general enduro stuff. I agree with Danny, if you want to win; start light, add fuel, go fast. If you want to have fun the easy way; modify the tank, short shift a little and walk away grinning!!!!!


Dave Wheeler
Advanced Autosports, the nations most complete Spec Miata shop
Author, Spec Miata Constructors Guide, version 1 and 2.0

Building Championship winning cars since 1995

4 time Central Division Spec Miata Champion car builder 2012-2013-2014-2017

Back to Back June Sprints Spec Miata 1-2 finishes 2016 and 2017

5 time June Sprints winner in Mazda's

6 Time Northern Conference Champion Car Builder

2014 SCCA Majors National point Champion car builder

2014 SCCA Runoffs winner, T4 (Bender)

2014 Central Division Champion, ITS (Wheeler)

2013 Thunderhill 25 hour winning crew chief

2007 June Sprints winner, (GT1, Mohrhauser)

Over 200 race wins and counting.
www.advanced-autosports.com
dave@advanced-autosports.com
608-313-1230

Survive the 25, NASA Thunderhill - Survive the 25, NASA Thunderhill We have a Winnah! - Won their 1st race... Congratulations! Sponsor / Advertiser - Site sponsor / advertiser... support these guys! Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users