Author Topic: Fuel economy  (Read 1340 times)

0 Members and 1 Guest are viewing this topic.

Offline shaunp

  • GT 500
  • *********
  • Posts: 8304
  • Location: Brisbane
Re: Fuel economy
« Reply #50 on: November 08, 2018, 09:28:58 PM »
Quick Fuel Technology Q750

Ah ok  Vac or DP

Offline JadeMach1

  • Thoroughbred
  • **
  • Posts: 189
  • Location: Melbourne
  • Car: H code Mach1
Re: Fuel economy
« Reply #51 on: November 08, 2018, 09:39:36 PM »

Offline shaunp

  • GT 500
  • *********
  • Posts: 8304
  • Location: Brisbane
Re: Fuel economy
« Reply #52 on: November 08, 2018, 09:42:26 PM »
OK QFs can be a bit fat depending on the engine spec, you could try dropping the jets 2 sizes as well

Offline JadeMach1

  • Thoroughbred
  • **
  • Posts: 189
  • Location: Melbourne
  • Car: H code Mach1
Re: Fuel economy
« Reply #53 on: November 08, 2018, 09:46:48 PM »
Will put the car on dyno when the l change the jets.

Hoping to do that next week

Offline shaunp

  • GT 500
  • *********
  • Posts: 8304
  • Location: Brisbane
Re: Fuel economy
« Reply #54 on: November 08, 2018, 09:51:17 PM »
Will put the car on dyno when the l change the jets.

Hoping to do that next week
Yeah you can try it on the road though I do it often Whats the engine spec?

Offline JadeMach1

  • Thoroughbred
  • **
  • Posts: 189
  • Location: Melbourne
  • Car: H code Mach1
Re: Fuel economy
« Reply #55 on: November 08, 2018, 09:58:09 PM »
351 Windsor
Strokes to 393 and 20 thou over
RACING ROLLER ROCKERS
FORD RACING ALLOY HEADS # M-6049-X305
FORD RACING CAMSHAFT # M-6250-Z303
PC7000 PERFORMANCE DISTRIBUTOR
EDELBROCK  MANIFOLD


Offline shaunp

  • GT 500
  • *********
  • Posts: 8304
  • Location: Brisbane
Re: Fuel economy
« Reply #56 on: November 08, 2018, 10:31:39 PM »
Ok that's right carb for that engine, it quite conservative, with small heads and small cam. It should be quite torquey down low to the mid range.

  Those heads are really too small for a 393, they are more a 302 head and they wont move a whole lot of air with the small valves and ports. mild 393 really wants 185-195 cc inlet port minimum,and a 2.02 inlet 1.6 exhaust.  Likewise its not big cam and an older design. I'd say it has plenty of Vacuum as a result of spec, so it maybe pulling some fuel through the jets as a result of this, the less vac you have the more jet you need etc. In real terms for 393 this should be ok on fuel given the spec. Depending on the compression it may take more timing which also help with fuel.

 393/408 I'd normally run 800-850, carb and a cam 235/245 with around 600 thou lift,  minimum 195cc inlet heads, and that will want to fall over around 6500, I'd run a minimum 185cc head on 347/351 for example. The gas speed gets too fast on small port heads, the ports go sonic and choke. 393 would be happy on the street with a 195-205 cc inlet port head.

Offline barnett468

  • Shelby
  • *********
  • Posts: 6531
Re: Fuel economy
« Reply #57 on: November 09, 2018, 02:00:13 AM »
As stated in my first post the key words “city” and “highway” it would be reasonable to expect a difference in consupution due to driving environment.

You are correct, I see that I simply got my numbers backwards as scedd pointed out so I modified my reply to him.

 
Key change to carburettor small capacity accelerator pump 35cc and secondary adjusted engine appears to run smoother. ie engine was running rich on acceleration underload in top gear (symptom blowing smoke on application of accelerator) This symptom appears to have stopped (l consider that a win)

Will assess economy return over the weekend on highway drive to compare with my initial highway figures of 21 litres on the same highway, Still trying to work out if the fuel consumption is normal or excessive noting highway driving will give a fair comparison of the changes that have been made. (Less variables) I am not expecting a massive change just try to ensure that the car work as efficient as possible.

The changes you made can not make any difference in steady throttle driving at any speed.


Offline barnett468

  • Shelby
  • *********
  • Posts: 6531
Re: Fuel economy
« Reply #58 on: November 09, 2018, 02:09:28 AM »
Will put the car on dyno when the l change the jets.

Take some jets with you so they can get the AFR close. They can also set the initial timing and the timing curve and vacuum advance (if you have one) for optimal performance if they know how and/or are willing to. This will take a bit of additional time which will cost more, however, it is an area that is often overlooked by most people and it can have a significant affect on both power and mileage.

Also, when jetted properly, an engine that runs at 200 degrees will get better mileage than one that runs at 180.

Higher air pressure in the tires will reduce rolling resistance and increase mileage, but obviously the pressure needs to remain within a safe limit that won't significantly reduce the tires performance etc.

In general, the thinner the oil, the better the mileage will be.





Offline barnett468

  • Shelby
  • *********
  • Posts: 6531
Re: Fuel economy
« Reply #59 on: November 09, 2018, 02:21:13 AM »
351 Windsor
Strokes to 393 and 20 thou over
RACING ROLLER ROCKERS
FORD RACING ALLOY HEADS # M-6049-X305
FORD RACING CAMSHAFT # M-6250-Z303
PC7000 PERFORMANCE DISTRIBUTOR
EDELBROCK  MANIFOLD

What ratio rockers?

What style of edelbrock intake?

What exhaust system?

Offline scedd1

  • Worked
  • ***
  • Posts: 451
  • Location: Sunshine Coast QLD
  • Name: Steve
Re: Fuel economy
« Reply #60 on: November 09, 2018, 04:00:51 PM »
12 per 100 , shit I would have tow a caravan for the Ranger to use that. It sits just under 10 in the city and gets as low a 6.8 on the Hwy unloaded. My old man reckons his averages 13 towing his off road van mixed on and off road.

Being an unrepentant hoon, im quite happy with 12. I got 8.5-9 for the first 1000kms, then the Fortuner scored a lift kit, mud tyres, steel bullbar, front and back winches, drawers, recovery gear, roof rack and a second battery.
So it now goes 2.9 ton everyday and most of my trips are very long distance at too high a speed out west.
Because of the 265/60-18 Kumho's, it doesnt want to lock up the converter over 110 anymore, so when they flash the new software next service, that might help pull it down.
either way, i still love this truck and the taxpayer is picking up the diesel bill anyway. Thanks guys  :lmao:
____________
./___ _ ____ ___ \.
 ( ]]] _ _ O _ _ [[[ )
\_ o _ _____ _ o _/
 |___|            |___|

Offline GLENN 70

  • GT 500
  • *********
  • Posts: 8203
  • Location: Gold Coast .
Re: Fuel economy
« Reply #61 on: November 09, 2018, 07:55:20 PM »
Without an AFR meter who knows what's going on . A Dyno doesn't always get the best results for street or hwy driving .  You don't want it too lean or too rich ,just right 😂

Offline JadeMach1

  • Thoroughbred
  • **
  • Posts: 189
  • Location: Melbourne
  • Car: H code Mach1
Re: Fuel economy
« Reply #62 on: November 12, 2018, 07:33:05 AM »
Some feedback from the weekend car fuel economy for the weekend:

17.5 lts per 100km highway (travelled 620 km)
24.8 lts per 100 km country roads/urban driving (travelled 86 km)

These returns are better then what I expected and now are looking forward to putting down some km over the summer break Melbourne to Sydney via the coast.

I would like to thank the PM messages sent to me on tuning and carburettor setting as this was a great help.

Offline lukep6470

  • Worked
  • ***
  • Posts: 277
Re: Fuel economy
« Reply #63 on: November 12, 2018, 11:43:11 AM »
You could tune it on the HW like we did in the good old days.  Put some lead in the fuel and see if the exhaust goes grey  :bolt:

 

Visit Custom Mustangs