MPG Contest, Who wants to play?? Options

[type47]

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.

[TravisNeff]

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

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

[r_towle]

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

[SGB]

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.

[keske968]

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.

[racunniff]

Updated list of contestants

...

SGB 2.0 liter carbed 205/50
SirAndy 3.6/6 225/50
racunniff ELEC


Rich

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?

[SGB]

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.

[r_towle]

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

[effutuo101]

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

[SGB]

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.

[IronHillRestorations]

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.

[HAM Inc]

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.

[toon1]

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.

I'm really interested in building this engine combo.

What are the difficulties?

[r_towle]

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.

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

[toon1]

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.

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

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

[dw914er]

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

[orthobiz]

I'm in.

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

Paul

[SGB]

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.

[HAM Inc]

I'm really interested in building this engine combo.

What are the difficulties?

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. (IMG:style_emoticons/default/driving.gif)

[toon1]

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