why didn't VW ...

[Smokey Eddy]

Why didn't VW make the 1.6s and 1.9s from the factory with much bigger unrestrictive exhausts and all of their TD's intercooled?
It just, to me, seems like they shot them selves in the foot with that dinky down pipe and no cooling of the boost? the GTD had an intercooler yes but why not all of them?
was alluminium too expensive at the time?

I've found with my big exhaust and ESPECIALLY the IC my car runs 20%-30% more efficiently and scored TWICE as "clean" as it did without the IC on the emissions control test where I live. Not to mention the massive power increase when needed.

ideas?

[truckinwagen]

they didnt want to spend any more money on them.

if they did spend the extra money on the car, they would not have been able to make enough extra selling them that way, so they did not.

-Owen

[Vincent Waldon]

They did actually... Intercoolers and a slightly bigger exhaust became standard on their next versio of diesel engine.

[bajacalal]

Because they were making the "people's car."  I know that sounds silly but I think they took that mentality a little to far sometimes.

[Smokey Eddy]

Ahhhh so i seee.

They did actually... Intercoolers and a slightly bigger exhaust became standard on their next versio of diesel engine.

Hence why the TDI's are a much "nicer" platform to build off of then.
I secretely cry at night wishing my car was direct injection... i'd go all out with the propane, NOS, my huge holset turbo, the whole works...

[Vincent Waldon]

I've got both TDI (ALH 2001)  and an IDI (AAZ 1994) engines side by side in my shop at the moment, down to the elemental pieces... and it's kinda interesting from a CSI:Volkswagen forensic point of view to see the subtle changes over an entire decade of evolution.

On the TDI... intercooler, bigger exhaust, no prechambers to fall out, no IM shaft or bearings, water pump driven by the timing belt finally, one serp belt to rule them all

On the IDI.... no big thick wiring harness(s) everywhere... simple simple simple... tons of space in the engine compartment to work... no computer needed to play with engine settings !

Everything else kinda looks like the engine that I had in my 1979 Rabbit... just decades of slow evolutionary change.  

[burn_your_money]

It's probably worth mentioning that you are talking about the ALH, not the AHU/1Z which are very different

[Vincent Waldon]

Yeah.. AHU is kinda that intermediate step... in between yet again.

And then there's the current gen common-rail... I wonder if there are any bolts that are the same?!   

[Smokey Eddy]

Mmmmmmmmmm common rail.
Why does the TDI HAVE to have a computer?
could you not have a production m-TDI?
i suppose that is what the big hoo-ha is all about right now isn't it.
building a working m-TDI?

[Vincent Waldon]

Always fun to second-guess someone else's decisions... but at a minimum I'd say that for sure cars after 1996ish sold in North America *had* to support OBD-II and a variety of emissions-related readiness codes therein in order to be legal, so the ECU became mandatory by emission law if nothing else.

When you actually start to play with the TDI ECU it is a lot of fun and of course much much easier to tweak things with software then trying new shims, springs, etc etc etc... computers can't be beat from a tuning flexibility perspective.  The system is remarkably well integrated with the chassis as well.. on my latest car I know to expect a dodgy connection at the passenger door for the speaker wire and an issue with the connector to the driver's side power mirror... and I've never actually turned either of them on or had either system apart yet.  The ECU also warned me that I was going to find a lot of carbon in the intake manifold (I did) and that injector #3 was getting worn (and I've posted the pictures of that poor blow-torched piston).

[Smokey Eddy]

Interesting... I dread to see what my pistons look like. Probably a cold lava flow.

[burn_your_money]

Why does the TDI HAVE to have a computer?

It doesn't. The LT in Europe is a mTDI from the factory. I think it's the LT anyways...