VW Lupo 3L --> 2L

[ausias]

On my 1.9TDI engine (with pd) on a polo 9n, the ecu reduces the power, if intake air temp. will go over 60 degrees.

My 1.9 TDI BXE 105 cv intake warmed to 40ºC with full power with upper grill block of my Seat León II. This car runs cold, I checked my thermostat warming water and with a thermometer, it opens at 87ºC as it is rated, but vag-com obdii reading give me 80ºC, and only goes to 90ºC when city driving after road driving. Other funny thing is that fuel temp. gets stabilizadez aroun 70ºC and when using full power, or returning city it gets even hotter than coolant. It has FMIC as stnadard.
But 1.9 TDI AHF 110 cv air intake warmed over 60ºC and maintained maximum power constant so, cold air intake is necessary if driving Autobahn at full throttle on that Skoda Octavia. Highest Fuel temps I measured are about 40ºC or less, and Coolant in 10 min gets 90ºC, less than 100ºC even full load, full power or city driving. It has SMIC, with custom selfmade ventilation to wheel.


Some interesting Boat Tail alternative or improvement could be that System Drag Reduction (invented 10 km from my home, world patented) - System Drag Reduction | www.sdr-sys.com/ing -

[ausias]

Originally Posted by Vekke

I tested my 600mm long boattail with aba test @130 km/h speed
Here are my todays boattail test results:
on N 4.7l S 4.0l
on N 4.6l no data
off N 4.9l S4.3l
off no data S4.3l
off N 4.8l S4.2l
on N 4.7l S4.1l
on N 4.7 l S4.1l

avg on N = 4,675l avg S 4,066l
avg off N= 4,85l avg S 4,266l
diff N = 3,6% diff S= 4,7%
Total difference 4,15% less fuel in this test. My test route was not perfect due to hilly motorway, but the difference is clear. Also my cars fuel gauge shows only 0.1 liter accuracy which was also little problem. That is the reason for so high speed in the test. Also during driving the differences came in the uphill sections. Without the spoiler fuel consumtion rise much more...

Logs of Throttle Load (different of 0 in vag com only if not using cruis control), or Torque (maybe your engine has injection mg/R instead of Torque)
Channel 6 and 15 records will help to understand if some non linear eficiency interference is hiding better aerodynamic improvements than measured.
MY car burns 6.6 L/100km at 120km/h and wheel force must equal 660N of drag. But at 184km/h burns 12L/100km but drag force is 1400N, +16% efficincy at full power full throttle 4000rpm than . But at 130 kph my car with -10% drag coefficient need -8.4% Force but -6% L/100km.

[Vekke]

Here is the tuft testing final setup at the moment. Tufts at the side of the kammback are little bit turbulent with this last roof angle.

http://www.youtube.com/watch?v=Md_Zl9tEk08

Also tried again if I could reach better figures but no luck. Smooth hubcaps were not in place in the last test so that might effect the result. Also I had talk to my phone so that effected a lot to the rest of the tank. First half I was able to rech 2.3 l/100km with boardcomputer. On the way back the same figure was 2.5...

[ausias]

Maybe 3mm (or less) polycarbonate kammback would help with driver visibility and tail lights. I'm wondering if a kammback spoiler (or semi boat tail) will help vans (REanult Kangoo, VW LT,Iveco DAily...) but they need easy open close the doors even 180º or 270º.
Do you have any problem opening the trunk door?

[vtec-e]

must....join......wheel skirts......to.....kammbackkkk!!!!!

[Vekke]

I am wondering will I built similar cargo box people have done here or not. Final kammback will be the same tinted polycarbonate as the rear fender skirts. I did not want to waste that material in the demo versions because its more expensive...

No problem with rear hatch opening with me, because I have long hands. With shorter people the kammback is little bit on the way, but you can avoid with that by little ducking down

Kammback did make the car little bit more unstable at 160 km/h or 100 MPH speeds but nothing dramatic. So i might have to use both hands on the steering wheel at the moment if it is windy...

[cycleracer88]

Could you build a diffuser at the rear untertray to handle the problem with instability?

Have you ideas to increase the pressure on base form dead water? .... I think you could do something with air hose. You can utilize the high press in the wheel housing and bring it back to the low pressure on the base.

[Vekke]

Instability is not really a problem I have driven stock cars which handle much worse already at lower speeds. Lupo still goes like on track but heavy side winds shake it little bit.

Rear diffusor will be build but it will not cure the problem, which is caused by long boattail and short wheelbase. Sidewinds just make torque forces to the car, which effect the driving. When the car is also light it does not help.

You can lower those torque forces :
- lowering the car
- making also long front bumber to compensate long boattail
- making smaller aero tweaks here and there and try to calculate them with CFD or wind tunnel.

[Vekke]

My new 175/70R14 hakkapeliitta R winter tires arent working at all in my favor. Fuel consumtion is at 4 liter levels. Wife took of the rear spoiler and need to put it back to see what is that effect to Fuel consumtion. Starting to think buying 155/65R14 hakkapeliitta R and try to sell current tires.

[G2TDI]

Originally Posted by Vekke

My new 175/70R14 hakkapeliitta R winter tires arent working at all in my favor. Fuel consumtion is at 4 liter levels. Wife took of the rear spoiler and need to put it back to see what is that effect to Fuel consumtion. Starting to think buying 155/65R14 hakkapeliitta R and try to sell current tires.

Winter tires usually have softer rubber mixture = more traction = more friction