Long trip ahead, little prep time - best aero mod?

[jtbo]

Originally Posted by NachtRitter

Did a "test run" today with the Jetta 'as-is' (none of the mods discussed in this thread implemented yet) and got 68.x mpg over 280+ miles (per the Scangauge)... promising for the long drive coming up with a few more mods!

Cleanspeed1 - I am heading to St Louis (to be with our FIRST Robotics team for the FIRST Championships), coming from the Central CA area (Sacramento). Car is not lowered, and since I already scrape the skid plate, I don't think I want to lower it!

Indeed, those VW cars were sold here and quite soon they started offering bad road package, which rises car 20mm or bit more, as our roads those were constantly scraping the ground, good for level smooth roads, but as our roads are rather the opposite (with exception of main roads) going very low is not quite a possibility.

It was perhaps one of the lowest from all those typical cars that were sold at the time, one could think that it was factory lowered

[NachtRitter]

Had my "one day of work" yesterday... did the best I could. Added a belly pan from the rear axle back, did a minor amount of wheel cover work, and added a "Home Depot" air dam. Belly pan came out pretty good (IMHO) while the air dam is kinda crappy looking. I also worry that I put the air dam too low, increasing frontal area rather than just keeping the air off the areas that stick down anyway. We'll see how it goes.

I'll try to get pics up as soon as I can, but it may not be 'til I get back from the trip.

Also decided to take the southerly route when we go eastward, and the central route when we go westward.

[NachtRitter]

Done with the first leg of three... averaged 57mpg over 786miles; I drove ~65mph and had the AC on at least 9 of the 13 hours. Today's stop is about 6000ft higher than my start. Somewhere around hour 9, the leading edge of my belly pan came off, turning it into a huge air catcher... I wasn't able to mess with it until ~150 miles later, when I took it off completely. Sometimes it's hard to judge if i'm going uphill slightly or not, but it did seem like the air catching belly pan had a significant impact on my FE.

Hopefully tomorrow will be better.

[COcyclist]

Originally Posted by NachtRitter

Done with the first leg of three... averaged 57mpg over 845miles; I drove ~65mph and had the AC on at least 9 of the 13 hours. Today's stop is about 6000ft higher than my start. Somewhere around hour 9, the leading edge of my belly pan came off, turning it into a huge air catcher... I wasn't able to mess with it until ~150 miles later, when I took it off completely. Sometimes it's hard to judge if i'm going uphill slightly or not, but it did seem like the air catching belly pan had a significant impact on my FE.

Good numbers! Just out of curiosity, do you still have a functioning EGR valve? Any manifold clogging issues?

[WD40]

Quote - "Sometimes it's hard to judge if I'm going uphill slightly or not"
This is the easiest and cheapest way to see that info, mount them on the A-pillars.
Gallery
This is a big aid in knowing when you can either start a or end a coast.

[BamZipPow]

Originally Posted by WD40

Quote - "Sometimes it's hard to judge if I'm going uphill slightly or not"
This is the easiest and cheapest way to see that info, mount them on the A-pillars.
Gallery
This is a big aid in knowing when you can either start a or end a coast.

You should be able to find something like that at Walmart...in their RV section.

[big shafe]

Nice turnout, very impressive.

[NachtRitter]

Second leg done. This time I averaged a little over 66mpg over 884 miles, averaging 65mph according to the scangauge. I drove between 65 and 70 mph most of the way. Altitude is 5000ft lower than where I started this morning. AC was on most of the way again. An amazing car! Filled up before starting out and had gone 650 miles at the half tank.

Front air dam is holding up well. Ran it up over a curb at a stop today and thought for sure I'd rip it off backing up. It just flexed up & over and then was fine.

If it weren't for necessary bio breaks and stiff joints, there wouldn't be a reason to stop all day. Meanwhile (amusingly) I see the sme 2 or 3 cars fly by 5 or 6 times... every ~200 miles or so they have to stop & fill up and then they fly by again... craziness.

Bed time now... I'll respond to your q's tomorrow

[BrianAbington]

a couple times on my way to chicago I see a new Nissan skyline fly by doing about 120, that dude passes me about ones an hour. lol

[NachtRitter]

Last eastward leg done. This time it was 62.5 mph over 490 miles at an avg speed of 63mph, according to the scangauge. Altitude is 700ft lower. AC was on the whole way. A lot of rolling hills and a lot of construction along the way.

Overall, I'm fairly pleased with the trip FE. I drove faster than normal yet got better than avg FE. Not sure how much the air dam helped... as flexible as it is, I'm guessing that basically folded under in the middle at freeway speeds. Tough to tell without having someone with a passenger drive along and take a look... or rigging up a camera...

COcyclist - still have EGR and no clogging at the moment. Cleaned out the intake last year so I hope it'll be good for a while.

Sunday I head back; hope to be able to get similar numbers that direction!