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Posted by: r_towle May 7 2008, 08:25 PM

I started this on another site...not alot of joiners.
The idea is to test, tune, and tweek your car, and your driving style, to get the most MPG in a 914.
This is a redo of a contest that the NY region did with 356's back in the day.
These guys got 70mpg with one guy getting 100mpg.
Alot of it is tuning, more if it is driving style.

Here are the ground rules.
We have several classes.
1.7, 1.8, 2.0, 2.0/6, and modified (all the rest of you), and vendors (special class)
This is for 914's

Using the honor system the goal is to win the mpg goal in your class.

I am in 1.7 and aiming for 40mpg this first round out..
The contest will run from Memorial Day till Labor Day...this gives us all time to change things and tune things.

This is meant to be fun with the 914magazine offering t-shirts as the prize...so its not meant to be for cheating.

So, if you want to join, list the following.
year, motor, tire size
Use GPS or highway mileage markers to verify your odometer so we are all being fair.

Rich

Posted by: Wanna9146 May 7 2008, 08:31 PM

2 gallons has lasted me almost 1 yr.




Of course, the car is on jackstands, but that still ain't bad.


There may not have been a lot of "joiners" on your other forum, but there are a lot of smart-azzes here!

Posted by: Vacca Rabite May 7 2008, 08:51 PM

The electric guys are going to smoke us.

Well, okay "smoke us" is not the right term, given.

But you get the idea.

Zach

Posted by: jcd914 May 7 2008, 08:52 PM

Is there a required minimum distance covered?

If I put air in my tires and freed up the brake (a little rusty) and push it down the street (it does not run) I would be getting infinite MPG, right.

Maybe I could calculate (with my daughters help) the evaporative fuel loss over the distance traveled (100 yrds) and come up with a figure.

Jim

Posted by: SirAndy May 7 2008, 09:17 PM

Year: 1970
Motor: 3.6L /6
Tires: 225/50 x 15
MPG: ~24


speedo is from a 944 and is veryfied to be accurate.
Andy

Posted by: r_towle May 7 2008, 09:22 PM

damn, 24mpg for that beast is pretty interesting.

What do you think you can get it up to???
I know you just got it running again, so you sure need time to tune and play.

BTW (OT) I found an article in Up Fixen der Porsche regarding foam in the oil filler. The cure was to add air (open a port) in the head/valve cover.
Apparently the issue is that there is no fresh air getting into the system so the oil foams up due to moisture. The moisture is cured by allowing air into the system....so, you have have these ports, and they may be blocked or closed...take a look.

Rich

Posted by: Root_Werks May 7 2008, 09:23 PM

Keeeerap, my 914 would loose right now (carbs suck and suck even when in good shape). I have a 74' stupid beetle that gets upper 30's average. It has 914 2.0 fuchs, can I enter that?

Posted by: racunniff May 7 2008, 09:24 PM

This got me to thinking. To put it on a level playing field, I propose we would allow electrics, under the following conditions:

* The electrics would have to drive the same kind of course as the gas (still TBD)
* They would start fully charged
* They would be allowed to use the gas or diesel generator of their choice to fully recharge.

The amount of fuel used for the recharge would then be used for the MPG calculation.

I *think* I'd still come out http://volt914.com, but it would be interesting to find out...

Posted by: SirAndy May 7 2008, 09:25 PM

hmmm ...

i do have the vent on the oil filler neck go into a puke bottle that has vent holes in it. so there *is* venting on the neck. but it might not be enough ...
Andy

Posted by: r_towle May 7 2008, 09:26 PM

There will not be a course. This is a worldwide contest.
It wont have a specific course, but the duration is memorial day to labor day.

Rich

Posted by: racunniff May 7 2008, 09:28 PM

Well, that makes it harder. I guess I could recharge from a generator during that duration and record miles driven and gallons used...

Posted by: r_towle May 7 2008, 09:35 PM

Record miles driven, term and type of charge...you should be able to figure out total energy input/output over the summer.

Then you get to figure out how much fossil fuel you used....that will be tough...unless you use solar panels.

Rich

Posted by: SGB May 7 2008, 10:06 PM

I'm in.

2.0 liter group

I think all these will effect results:
Kumho 205/50-15 @ 35 psi (Good for MPG?)
Street Hydro Webcam (bad for MPG)
40 IDE Twin Webers (bad)
Mallory Unilite (good)
SSI (good?)
Triad dual outlet (bad?)

The best and easiest way I've found to get MPG is to add 10 gallons when the light comes on. Set odo to 0.
Go intil the light comes on. Add 10 gallons. Note miles. Divide by 10, OK MPG.
Repeat several times then average all your MPG conclusions. It should be statistically sound ( I think 90 or 95%) after 9 or 10 fillups.

But for my car I will need to GPS actual miles and correct my ODO. I'm thinking I would need an indicated 33 mpg to equal actually 30. I think I can get that (to start). We will see.

Posted by: r_towle May 7 2008, 10:13 PM

fill it to the top, drive it for a while..fill it to the top again.
the light is pretty random..I can make mine go on and off going around corners..so its good for 2-3 gallons difference IMHO.

If you are not racing it, you can get smaller vents and jets for the 40mm carbs to get them perfect...the cam should help.
The exhaust should help.
Rich

Posted by: ChrisNPDrider May 7 2008, 10:17 PM

1972 1.7, tires TBD

This is awesome! I just started a new job which has me out of the Lab and Into the Wild, with a 70 mile round trip on the twisties of West Marin. My Suby gets about 28 mpg and the 914 is on jack stands...should be done and cruzin/racin in 1-2 weeks (Memorial Day or BUST). I plan to move to Marin when my lease in Emeryville expires Sept 1 = Labor Day. Now I can spend all summer driving the 914 to work. I plan to have corner balance, alignment, and possibly new commuting tires in the next month.

Posted by: r_towle May 7 2008, 10:19 PM

lookup "low roll resistant tires"
The tires for the Insight and Prius are these types.
They are good for a few mpg's

Rich

Posted by: r_towle May 7 2008, 10:28 PM

So far here is the list.
Class 1 (1.7)
Towle, 72 1.7 205/50 (speedo calipbrated, using GPS also)
ChrisNPDrider 72 1.7 (TBD)

Class 2 (1.8) none
Class 3 (2.0) none
Class 4 (2.0/6) none
Class 5 (modified)

SGB 2.0 liter carbed 205/50
SirAndy 3.6/6 225/50
racuniff ELEC (TBD)


Rich

Posted by: Root_Werks May 7 2008, 10:56 PM

I'll be in for class 5

1976 914-6 Modified 2.5, carbs. I'll probably loose, but it'll be fun.

Posted by: jd74914 May 7 2008, 10:59 PM

My 1.8 should be registered in 2 or 3 weeks, once it is I'll try to start recording mileage too.

Posted by: racunniff May 7 2008, 11:00 PM

I use wind power Looks like it's time to get that plug-in watt-hour meter I've been wanting...

Posted by: type47 May 8 2008, 11:10 AM

i'd like to participate just for the fun of it as i probably won't do anything special (tuning, and i already drive like a grandmother). i have a 1974, 1.8L, L-jet. i have access to a GPS. i have been keeping track of the MPG and get around 27 mpg in combined driving. unfortunately, i will get a low average as the gas evaporates so much between rather infrequent use. next scheduled trip is vienna to carlisle on may 17.

Posted by: Travis Neff May 8 2008, 11:17 AM

I am in, just fixed the odo over the weekend.

72 D JET 1.7, pertronix and 2.0 exhaust.
205x55x15
Speedo not recalibrated

Posted by: r_towle May 8 2008, 11:37 AM

Updated list of contestants


Class 1 (1.7)
r_towle, 72 1.7 205/50/15
ChrisNPDrider 72 1.7 (TBD)
Travis Neff 72 1.7 205/55/15

Class 2 (1.8)
type47 1.8 (TBD)

Class 3 (2.0) none
Class 4 (2.0/6) none

Class 5(modified)

SGB 2.0 liter carbed 205/50
SirAndy 3.6/6 225/50
racuniff ELEC (TBD)


Rich

Posted by: SGB May 8 2008, 11:50 AM

I think modified with stock displacement should go into the displacement based cat.

Sure it is unlikely I can get the same as an FI car, but it doesn't seem right to compare to a six.

...just a thought...

Oh, and my "add 10 gal when light comes on" is just to make sure there is capacity for that much. I just like the simplicity of diviiding by 10.

Posted by: keske968 May 8 2008, 03:18 PM

Awesome... I'm the first in class 4!!!


Body 1970 914
Engine 1967 911 2.0l/6
Transmission 1974 Side Shift
195 series tires (not sure on sidewall height Ill have to check)
Tripel Webers
MDS ignition
27mpg on the highway before the engine tune and carb adjustment and having no weather stripping....

I'm curious to see what I get now that everything has been adjusted and I have new weatherstripping.

Posted by: racunniff Jun 3 2008, 11:00 PM

Update on my Class 5 - I found a kWh meter I can use to measure the actual charge wattage. Right now I'm running at $0.04 per mile - http://volt914.blogspot.com/2008/06/measuring-power.html

I assume everybody else is keeping track? And we'll update this post on Labor Day?

Posted by: SGB Jun 3 2008, 11:08 PM

I have not been tracking, but have barely used the car. I'll start now. The best chance for me to get several fillups is my trip to the upcoming PCA Parade in Charlotte. Its about 450 miles each way, and there will be some mileage while there which should balance out the highway miles.

Posted by: r_towle Jun 7 2008, 08:57 AM

Are we still doing this??
If so I would like to request this as a sticky thread so we can find it.

Last two tanks for me.
29mpg...I was having a bad week, pissed off alot...aggresive fun driving.
35mpg...I restrained...good boy, hard to do BTW...really hard.

I think that a taller 5th gear would make a huge difference, so I have started to rebuild a gear stack for this...
The highway is a gas sucker in this little car...its always fighting to keep up...

Rich

Posted by: effutuo101 Jun 7 2008, 11:49 AM

Driving from Castle Rock Colorado to MOAB UT to Seattle Washington.
average fuel economy 33.5MPG
70 914 with 73 2.0 FI stock motor

Posted by: SGB Jun 7 2008, 07:04 PM

I got Dr Evil to rebuild my gear stack and we talked about taller 5th. He discouraged it (we all know- for cooling). I really thought about it and wanted it too. But ultimately I think the engine cooling must really be "at the edge" already, and extended highway time torque loading (like a long hill) would provide less cooling than is really needed- cooking the life out of the oil even faster and contributing to higher wear.

Posted by: 9146986 Jun 8 2008, 11:13 AM

Is a new 914 (986) eligible? A year ago I did a hack and accessed the on board trip computer in my Boxster and then drove it like Grampa to get 30 MPG! I had been getting around 17.

Posted by: HAM Inc Jun 8 2008, 11:24 AM

As tall as the stock 5th is I feel that a stroker engine with plenty of torque in the rev range the top 2 gears see makes the most sense.
If the engine isn't struggling to deliver the need torque, then it will run cooler and use less fuel.

A 2016 IMHO is an excellent combo that should work very well in a 914. Small bore (90mm) and long stroke (78.4). Coupled to the heads I developed (based on 1.7 castings) for this combo for Jake, it will deliver fabulous MPG if the induction and spark are properly tuned.

Jake says the 2016 is a pain in the ass to build, but for the experienced DIY'er it might be worth consideration.

Posted by: toon1 Jun 8 2008, 11:58 AM

I'm really interested in building this engine combo.

What are the difficulties?

Posted by: r_towle Jun 8 2008, 02:00 PM

I have never seen any data to support this claim.
I am just rigging up a full gauge setup to monitor heat, and then I will play with gears...

If we stick with stock motors, the tranny is the next thing to futz with that delivers better mileage.
A taller gear will still keep the car above 3k (my goal at 75mph ish)
I will test to see what the differences are with several 5th gear sizes to monitor not only MPG, but heat...I think there is alot of room for different and taller gears here...its a light weight car, and with its relatively low co-efficient of drag, it should be ok with a taller gear...its not a bus guys...

If I talk with someone who actually put a taller gear in a 914 (nothing else) and has experienced heat/cooling issues on the highway, I will consider the myth subtantiated, but till then...I will have to run the test myself to see real world data...its really the only way to know for sure at this point..

My gauge setup will have CHT on all four plugs, and oil temp, and oil pressure..along with fuel pressure and amps...
I am looking for a decent mileage/trip computer to use so I can keep long term track of things...right now its pen and paper...

I am totally open to suggestions on this..I will attempt to try and test as many decent ideas as we come up with and share the results.

Does anyone have the stock torque curve for a 1.7 (72) dJet motor? I would like to see the chart to plan the gear selection with the idea to keep it right at the peak torque with the gears...the most efficient area for shifting.

Rich

Posted by: toon1 Jun 8 2008, 02:43 PM

Although I don't have documented data, I have played around with different rpm's and wached the CHT's.

I have noticed that anything under 26-2700rpm's in a taller gear will create heat.

recently while driving a backroad and climbing a small hill in 5th gear and about 2600rpm's,the temp's started to climb, I downshifted to 4th(about 3k)and wached the CHT's come down by 7-10*.

I repeated this a couple more times to prove to myself it wasn't a fluke.

Cross winds are a killer. Case and point. on a drive yesterday, I had a TRUE crosswind. It was a bit of a tail wind BUT mostly blowing accross the car.

The CHT's rose by ~8-9*'s. the road was PANCAKE FLAT. I feel that the air going across the car disrupts the low pressure area behind the back window and the engine is now fighting to pull air in. turbulant air can be easily disrupted.

I am going to fabracate some scoops soon for the B pillar to force air into the engine bay to see if this stablizes the temps.

JM .02

It will be interesting to see your data

Posted by: dw914er Jun 8 2008, 03:08 PM

How do you sign up?

Ill be in class 1 (73 1.7) (it is bored to a 2.0 though, but has 1.7 heads, etc)

i dont remember my tires, but i can find out in a few days

i average at 28 on the freeway

Posted by: orthobiz Jun 8 2008, 07:58 PM

I'm in.

Stock FI 1.8 1974
205/55 tires
Only have a speedo...

Paul

Posted by: SGB Jun 8 2008, 10:22 PM

I've conceded to the easy. I'll track "nominal" miles for a few tank ups, then apply the expected tire size multiplier (I'll crosss check with a GPS). I probably won't change my practices with the car. I've been doing some carb balancing and valve adjusting (including test runs) which will blow any attempt at on road miles for this tank. And when I go to the parade, I'll do the AX, and who knows what other spirited driving. So I'll end up with a figure inclusive of a lot of highway miles, plus some zero and low mile actions that burn gas too. So I think this will be more specifici to my driving - no, I guess just owning- and my car, than 914s overall.

Posted by: HAM Inc Jun 9 2008, 08:41 AM

I think it has to do with the pin hts and long stroke. Maybe we can get Jake to chime in on this thread when he gets back from the left coast. I doubt that he will tell anyone how to build it. He put a bit of time into this one and with fuel prices on the rise, we may see some demand for turnkey milage motors soon.

From what I understand the build is time consuming and requires a lot of patience and engine building experience. Even so, if I were going to build a daily driver from a T4 this would be the combo I would pursue. Mainly because I am a big fan of long stroke, small bore, short rod, small intake ported engines for my DD.

Posted by: toon1 Jun 9 2008, 08:54 AM

Jake seems to be very tight lipped about this engine , and for good reason.

Posted by: HAM Inc Jun 9 2008, 01:28 PM

I think it's a sweet combo. It's not brutish as far as HP goes, but it will make a 125 no sweat and get good MPG.

Jake is a business man and, ofcourse, he needs to protect his secrets. Maybe if there is enough interest in the combo he'll develop it into a kit offering. But be forewarned, IIRC he said it would cost more to produce in terms of dollars/hp than any other kit he offers due to its labor intensive nature.

When we started this development a couple of years ago I had hoped it would gain some traction with the public. It quickly became obvious, however, that I would go hungry waiting on interest in MPG to exceed interest in raw, brutish HP. And since even the 180+hp 2270's get 25mpg or so (if driven and tuned properly) it seemed likely to me that the 2016 mpg engine idea was destined to die on the vine. Maybe now that will change. We'll see.

Posted by: r_towle Jun 9 2008, 05:22 PM

I will update this thread later tonight to include all the new contestants.

Rich

Posted by: racunniff Jun 17 2008, 09:31 AM

Any updates? I confess to selfish motives - I'm trying to create an accurate comparison of the costs of my electric to a typical gas-powered 914.

My own update: Since I began tracking at the beginning of June, I've driven 111.4 miles and used 54.9 kWh to recharge, at a net average Wh / mi of 493. Given that my cost per kWh is 7.5 cents, and that the average cost of gasoline is $4.00 / gallon, that nets out to the equivalent of 108.3 MPG.

http://volt914.com

Posted by: SGB Jun 17 2008, 05:30 PM

This thread needs two spinoffs-
Rich's re-gearing / cooling tests
and
High MPG Raby/Hoffman motor.

Then this one can stay on topic and we don't lose this good stuff.

Somebodies out there gotta hep this ol' man, though, cause Ah kaint dew it.
Len?
Rich?
Mods?
Jesus?

Maybe we will find out...

Posted by: black73 Jul 8 2008, 04:27 PM

Is this thing on?.....


My stock 73 1.7 Djet is getting 26.841982416556445965922352758111 mpg. Looks like I'm in first place.

I recently replaced the fuel pump and filter and changed spark plugs, so I was expecting a little better than that.

90% of the miles were at about 80 mph. 3500 rpm in 5th gear on 195/60 15 Michelins. Not exactly a mpg run, but I wanted a real world figure. I used Google maps to track my exact route to calculate the miles traveled.

Posted by: Rusty Jul 8 2008, 09:06 PM

Carbed 1.7.

Average 28.1 MPG during 1010 miles... measured by Mapquest route, not by odometer.

Posted by: Elliot Cannon Jul 8 2008, 09:18 PM

THOMAS had a 1.7 with single throat carbs and got over 40 mpg. He's working on a new engine for a daily driver that should be about as good.

My car is 3.2 with 275/17 wheels. I get 23mpg with the windows up and roof on. I get 20 with the roof off and windows down. That's at about 80 mph.

Posted by: toon1 Jul 9 2008, 05:14 PM

I'm not playing(probly should) but I just recently got 30 MPG.

1.7L with MS/ford EDIS to control timing.
195/60/15's

Things where not very well in tune with the last tank of fuel and I still got 30MPG

I am getting ever so close to having the fueling in good tune. My accel enrich #'s are getting smaller ( which means it's injecting less fuel) and the VE table is staying the same.

I can run around town with an AFR about 14.0:1 with no issues. But on the HWY I have to run about 13.5-13.8 or it will get hot.

with the tune getting better, I might be able to get 32MPG. I will also have larger dia. tires soon, that will also help.

35 MPG is the goal


P.S. I still want to build a stroker engine!

Posted by: SGB Jul 9 2008, 05:54 PM

On my trip from Huntsville to Charlotte I was getting something over 30 mpg at a constant 78 mph by GPS, 90 by speedo (roughly 31.5 mpg by my mental calcs after a few 10 gallon buys and knowing approx miles from H'ville to Atlanta, Atlanta to Charlotte, then to Knoxville and to Huntsville again). I'll try to locate my en-route mileage notes, correct for tire size, and publish the result. I expect the average to go down from stop/ go stuff in Charlotte, and the autocross too, but I still think a 30 mpg average will be achieved.

Posted by: Joe Owensby Sep 1 2008, 07:54 AM

When my '73 1.7 was fairly new, it routinely got 40 corrrected mpg. Car was stock FI This type of mpg was for long trips on roads that were all fairly level interstate, driving at about a smooth 75 mph. This was in 1974 during the gas crunch. I used to routinely drive from west of Charlotte, NC to Philadelphia on one tank of gas, and still had 2 gallons in the tank upon arrival. I was working in Philly at the time, and this kind of milage was great during the gas crunch of 73/74when some areas closed the gas stations on Sundays. I could fill up in my hometown on Saturday in NC, cruise back up I 85 and I 95 on Sunday, and not have any of the traffic normally associated with the NE folks coming back home from the beaches, FLa, etc. For quite a while, I would have the stretch of I 95 almost to myself and a few police cars. Quite a difference from when the gas stations were open before the gas crunch, when that stretch of interstate was a nightmare with traffic. That was back when the average car maybe got around 12 mpg. It was also the time when gas prices jumped from about 25 cents/gal to almost a dollar. I recently rebuilt it with carbs, and only get about 28. Need to do some more tuning, but I plan to put in a modern FI system. JoeO

Posted by: Al Meredith Sep 1 2008, 08:50 AM

I drove my 1976 912E to Charlotte for the PCA event and got 28 MPG with a 2056 and 40MM webers. For those of you with 912Es , I did correct for the spedo correction and I have 205/50s. Speco reads 12% high.

Posted by: racunniff Sep 1 2008, 10:14 PM

Well, it's Labor Day, the end of our little contest. I kept track of my electricity usage all summer, as promised. I drove 498 miles. And I used 244.3 kilowatt-hours of electricity. At 7.5 cents per kilowatt-hour, I spent $18.32 on electricity. This means the average cost per mile over the summer was 3.7 cents. At $4.00 per gallon gas, this is the equivalent of 109 miles per gallon.

If you're interested, you can see all the gory details at http://volt914.blogspot.com/2008/09/measuring-power-iii.html

Posted by: SGB Sep 1 2008, 10:22 PM

Well....

How do you hold a gallon of electricity anyway?



So now you need your own photo voltaic recharge station.

Posted by: r_towle Sep 1 2008, 10:28 PM

I consider the consumables as part of your math...
Battery life is what...3 years on an electric conversion???
(That is if you actually drive the car....500 miles in 90 days...hmmm)

Anyways...I think that the battery value should be factored in...you will need to replace them.

Rich

Posted by: racunniff Sep 1 2008, 10:51 PM

Yes, in other calculations I've included battery replacement cost. I expect these batteries to last 5 years (I rarely discharge them more than 20%). They cost $1600. The amortized cost over 3 months is therefore $80 (much more than the cost of the electricity). Including electricity, the total cost of the three months was $98.32. This gets it to 19.7 cents per mile. Which is just over 20 mpg equivalent at $4.00 per gallon.

One thing I need to look into is whether I can actually get *money* for the batteries when they are at the end of their life. They still have probably 600-800 pounds of lead in them...

Posted by: Dr. Roger Sep 1 2008, 10:53 PM

my buddy clifford swears he got a combined highway/city ~15% better MPG taking his tire pressures to max. no tuning.

just thinking out loud.


i'm in category VI, "Worst gas mileage".

Posted by: racunniff Sep 1 2008, 10:53 PM

One thing to note - if we are going to include consumables and maintenance, the current federal allowable cost per mile is 58.5 cents. This is high because it includes expected depreciation of the vehicle. FWIW.

Posted by: Root_Werks Sep 2 2008, 08:48 AM

A cool thing about 912E's is the size of the tank. I think still 16 gallons! The factory touted a 600 mile range I believe.