Building a 60mpg 1.6TD

[subsonic]

Is it possible?  I am really starting to think I need to change my objective from big power to higher mpg.  $200 a barrel oil scares the *** out of me.  Diesel would be like $6-7 a gallon.  I cringe thinking about buying heating oil, and I have a very efficient boiler.  $2600 to fill up both tanks :shock:  :cry:

 I have a completely rebuilt bottom end, everything done, everything new, so everything will be nice and super tight. Rods have been polished and lightened about 1 ounce each.  Pistons have been ceramic coated and skirts coated with poly moly.  IM shaft has been turned and lightened.  The unknown will be the new head.  When Dave gets it finished, I do not know how the heavily ported 1.9 head will affect mileage.  It will certainly allow for more flow with less restriction. More boost air to burn fuel.   I was thinking of having the combustion chamber area of the head and valve faces ceramic coated as well.  Not the prechambers.  That whole thing will be left uncoated.  I think this will help retain more heat for a more even, complete burn out of the fuel injected.  I will probably use my 1.6TD injectors, and not the Merc units.
The 02A CTN TDI transmission with a .755 5th and 3.157 diff. will certainly help drop the rpm's on the highway.  The flywheel is a eurospec 14lb unit.  It will be a bit lighter than a stock 020 210mm flywheel.  If I go light on the pedal, the super pump should do well.  I may need to send Giles an e-mail and ask about it.  The pump was setup for big fuel with big intercooled boost.
I wonder if I can find a set of those low rolling resistance tires to fit on 13" or 14" rims.

If I keep the speeds down to 55-60mph with this setup, do you think 60mpg is obtainable?

[jtanguay]

if you can find a .655 5th gear i think you're in business.  :lol:

[RabbitJockey]

haha yeah then u can go 80mph at idle

[jtanguay]

haha yeah then u can go 80mph at idle

and make over 60 mpg   but the slightest grade and you'll have to downshift  

[jackbombay]

The ported head should help, I've noticed with my TDI that when its running really lean from dropping nozzel size without changing the tune I get a few more MPGs.

[Vanagoner]

for tires, you could run 4 "space saver" spares, very skinny and low profile like the hypermilage cars run.  It would look silly, but I bet you'd pick up a few mpg (and funny looks as well).
 Short of that, 80 series tires are a step in the right direction (at max psi).  145 80's are made for trailers, would be skinny and drop you down. A good chin spoiler or air dam would make a lot of difference. I have heard that air resistance under the car makes more  difference than that going over it.

[jtanguay]

I've always wondered what would happen if someone successfully put a TDI transmission on the 1.6 TD.  I'm interested to hear about your mpg's.

coupled with a TDI turbo, i think it would work.  the normal 1.6 turbo is a bit too laggy to be useful with the TDI tranny though... any type of grade and you would need to downshift.  mainly because the engine would be humming at 1500 rpm's, but the turbo won't spool until at least 2000rpm.  however if a vnt15 turbo is installed (or even possibly a K03 from a 1.9) i could see the 1.6 pull it off.

[subsonic]

Those are kind of small turbo's.  Do you think they would cause a lot of back pressure?  That would affect engine performance / efficiency right?  I was thinking of going with my Merc .48 hot side turbo.

[mdonau]

hi,

aerodynamic on rabbit/golf ist pretty bad...at least when driving fast the goal is impossible.

for Engine efficiency low-rpm (2000-2500 rpm) at high torque/load should be best, that means a small turbo would be best, more air causing a better combustion and efficiency

narrow tires (like 145 or 155) and lowered weight will also help

at least IDIs are not very efficient..a small optimized 3cyl TDI would do much better.

good luck, Michael