Improving mpg in Vw TDI

[UFO]

Originally Posted by dremd

Torque limiting maps are pretty common on tuned turbo diesels.
Basically you limit fueling (and boost) to the max torque you think your driveline can handle.

Chrysler crippled the Liberty CRD with this technique rather than addressing the root cause, a poorly designed torque converter....

[Arragonis]

Quite a few generic remaps just move the torque limit around.

Conn.
I kind of think the 5.5/100km vs 5.6/100km is inside any margin of error IMHO.

[keepl00kingup]

i bought a tdi mk4 golf that an idiot had modified to be straight pipe all the way out, so i'm looking at needing to install a catalytic converter and muffler.

any recommendations for what type of cat works best with our engines?

Most other tdi forums are full of folks talking about cat deletes and mufflrectomies.... i know the ecomodder crowd is into efficiency, so i hope someone is still monitoring this old thread and has some bright ideas about the best cat for an mk4 tai.

thanks!

[MaxHedrm]

That actually will make it make more power andbe more efficient. So, unless you want it quieter, I wouldn't worry about the muffler. As for the cat, I'm not sure what that age would have had, mines the DPF Mk6.

[keepl00kingup]

Originally Posted by MaxHedrm

That actually will make it make more power andbe more efficient. So, unless you want it quieter, I wouldn't worry about the muffler.

i personally don't care about the increased sound, but i couldn't pass state inspection without muffler so looking into what to do about that..

and i'd been ignorant and thought only gas engines had cats!

[ConnClark]

Originally Posted by keepl00kingup

i personally don't care about the increased sound, but i couldn't pass state inspection without muffler so looking into what to do about that..

and i'd been ignorant and thought only gas engines had cats!

throw a cherry bomb muffler on it. It will work until it packs up with soot. It may get you past inspection. Diesels don't use cats per say, They have a DPF (which the newer ones have catalytic properties ) and you will have to buy a new one because it is against the law for junkyards to sell them used.

[dremd]

I don't know, but I think you may find that just a catalytic converter may get the noise level to your liking. Probably easiest way to get one is a post on the private for sale area of TDI club.

I'm running a generic catalytic converter for a 1 ton diesel pickup on my car, along with the cat back for a 1.8T. I used to think it was really quiet, but now that I EV it seems kind of loud, but no worse than a Prius (with ICE running).

[dremd]

Originally Posted by ConnClark

throw a cherry bomb muffler on it. It will work until it packs up with soot. It may get you past inspection. Diesels don't use cats per say, They have a DPF.

US spec Diesels typically do have a catalytic converter (his TDI did in the states), newer (07+) typically have a catalytic converter and a DPF, VW has taught us that a NOX trap with DEF is basically necessary as well.

[keepl00kingup]

Originally Posted by dremd

US spec Diesels typically do have a catalytic converter (his TDI did in the states), newer (07+) typically have a catalytic converter and a DPF, VW has taught us that a NOX trap with DEF is basically necessary as well.

would it matter if my 2004 Golf is actually a Canadian?

[dremd]

Originally Posted by keepl00kingup

would it matter if my 2004 Golf is actually a Canadian?

I don't know, if I had to guess I'd say the emissions system was the same.