VW Lupo 3L --> 2L

[Vekke]

there is engine brake possible on fifth gear also. Also next tank done once again I chickened out and made the fill too early. Anyway cars own fuel gauge is accurate. Gauge showed 3.0 l/100 km and calculated result was 3.066 l/100km. 80% of that tank I drove 100 km/h speed so there is only one liter which needs to disappear . Too sad that in pecentages that is 33%.

Starting point calculation:
Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com

My current estimations/calculation of my mods savings:
Aero 15% cd from 0.29 to 0.24
Tyres and Taller gears 10% RR 0.008 to 0.005 (calculator is not able to estimate taller gear effect so I put smaller value than it will propably be...
Engine effiecieny (tuning and ecodriving) 12% engine eff 0.36 to 0.41
weight loss of the car + driver=total mass (150kg) 3% 1000kg to 850 kg
100W less electrical load (led lights +xenons) 2%

http://ecomodder.com/forum/tool-aero...ToStep=40-65-1

What this means I need to use P&G when doing 100 km/h to get the engine effiency figure where I put it. Also the CD value is only 0.24 so its a great possibility that I dont even have to build a huge boattail etc. However if those calculations arent valid I can easily drop the CD to 0.2 which drops the calculation from 2.0 l/100km to 1.72 l/100km which should be still in my reach. Frontal area is only a estimation and that will get little bit smaller with mirrors and lowering and if need roof chopping. The roof is at least 80 mm too high for my 193cm body...

All comments welcome.

[Piwoslaw]

Originally Posted by Vekke

weight loss of the car + driver=total mass (150kg) 3% 1000kg to 850 kg

How will the weight saving be distributed between car and driver?

It looks like you've got quite a challenge, but looking through your estimates I think you can do it
If you decide to go all out and chop the roof, then will it just be a normal lowering, or will you Kamm it? Maybe a small change of the windshield angle at the same time?

[Vekke]

Driver try to lose at least 15 kg but the target is 20 kg . Starting weight of the driver is 108kg and my height is 193 cm...

All out roof chopping happens only if nothing else will work. There will be also some new parts coming what I havent seen nowhere before and the effects of those mods is pretty difficult to estimate...

[euromodder]

Originally Posted by Vekke

All out roof chopping happens only if nothing else will work.

There won't be many takers for a roof-chop on their Lupo I'm afraid, and the investment is never going to be paid back. But it'd be .


Check out the new Kia Rio 1.1 diesel, Kia's in-house testing shows it at 3.2 L/100km (73.5 mpg) on the NEDC - slightly better than the VW Polo Bluemotion and only 0.2 L/100km above the Lupo 3L.
I just might get one of this misery with my Volvo continues.

[Vekke]

Originally Posted by euromodder

There won't be many takers for a roof-chop on their Lupo I'm afraid, and the investment is never going to be paid back. But it'd be .

Yes roof cutting is so difficult and illegal task that I will only do it for my own Lupo...

I got the lowest fuel consumtion figures on the fueleconomy race. Result was 2.814 l/100km. My target was 2.5 liters but the route was so challenging that it was not possible.

Today I also installed DRL led lights. Those should save that 0.1 to 0.2 liters of fuel...

http://www.youtube.com/watch?v=voRfojLP6ok

[Vekke]

Today I calculated Lupos frontal area and got a result that can be rounded to 2.0 m2. Also I did some sckecthing of full boattail on the lupo.

https://www.facebook.com/media/set/?...type=1&theater

If you estimate that with full boattail you will get cd close to 0.17 the fuel consumption estimation would drop to 1.46 l/100km @ 100 km/h.

[Vekke]

With DRL led lights and full frontal grill block I was today able to reach 2.78 l/100km (84,54 MPG US) @ 95 km/h avg speed with my lupo 3L. For very short time it is possible to drive the car close to that 100 MPG us mark but I dont have the patience for it. It would require avg speed which is about 70...75 km/h. Behind a truck @ 88 km/h you can reach 2.4 l/100km with cars gauge. Today my gauge was off by 0.2 liters or 7%.

Rest of the weeks mods will be 135/80R15 tires to front and smaller wide view mirrors. I will try new idea with my mirrors.

[euromodder]

I've seen the round mirrors in your album. Are they flat on the front ?
Putting them inside the car would help a fair bit.

On a very short car like the Lupo, a boattail would really be useful to reduce the drag.

[Vekke]

They were flat but not anymore . Those arent yet ready either or at least I will try to make full mirror boattail to them. + some tweaking with the bodykit seams.

https://www.facebook.com/media/set/?...type=1&theater

[Vekke]

Some changes has been made after last post including both small mirrors. No mirror boattails yet :/.

I got my VAG-com cable and now I can see what happens with the engine. With full airdam @ 100 km/h water temperature was at 93 celsius and intake temperatures @ 63 celsius. On 120 km/h speeds same figures were 97 and 73. I decided that I can take the intercooler off and I need to make that small adjustable grill block.

Also the 135/80R15 front tires are now in place and those smooth convex wheel covers were very difficult to manufacture. They needed to be over 50 mm (2") convex. I was only able to make them that 50mm convex. That is the reason I had to use self drilling screws and not the planned ziptie plugs. When I tried to make them more convex the surface of the ABS started to burn from too much heat.

https://www.facebook.com/home.php#!/...type=1&theater

Tomorrow is a testing day and I will try to break the 2 liter mark @ 85 km/h. So this will mean driving behind trucks. Route will be the same as I had my old work route for 2 years. With Seat I was able to get that 2.6 liter figure on the same route.