economy tip, or just daft?

[320touring]

Originally Posted by yostumpy

Yes I want to interupt the boost hose to the FIP, so that it can be 'partially ' restricted, in a similar way to the VW 'umwelt' eco engine IIRC. but then be opened up to give me max power when needed.

IIRC, the "umwelt version of the AAZ had NO boost pin, as the turbo was essentially just used to make sure there was sufficient air for a total clean burn. The turbo offered no performance (HP/Torque) gains

[yostumpy]

sounds about what I'm thinking of, leave turbo on, restrict boost hose to FIP, so turbo makes more air for more effient lean burn. how much better was the unwelt over std turbo deisel, for milage. Question is will my plan give me any gains, or make it worse.

[UFO]

Originally Posted by wdb

All the turbocharger does is increase the amount of air entering the combustion chamber. Either the computer, by keeping the injector open longer, or some other mechanism, adds fuel to match the extra air. Stopping the additional fuel altogether, with no other compensating changes, could cause you to run dangerously lean.

That is wrong. Diesels ALWAYS run lean - because diesel fuel is designed to be ignited by the heat of compression and burns slowly regardless of fuel/air mixtures, this allows them to burn fuel completely and with greater expansion, resulting in better fuel efficiency.

[yostumpy]

Ok ! bit of an update. As today was nice, it did a bit of tinkering and washed the truck, then i noticed the leak off pipes were not looking too good, so replaced them with something that I had lying around, then I thought that looks the same size pipe as the boost pipe. So I nipped round the other side, and whipped off the boost pipe from the turbo, and plugged it with a screw, then pushed a small length of pipe on the turbo outlet and plugged that one too. Started it up. and it ran. So I took it for a spin. Well I have to say i was VERY surprised indeed. Folks had said it would be pants, wouldn't pull over 50mph etc etc, but I wasn't convinced by the doom and gloom merchants, ( I never am).
So what was it like then? well as I said I was surprised. As I pulled away initially i waited until the road was completely clear just in case it was really slow as predicted. BUT it wasn't, moving off isn't much different really, obviously its less powerful, but it is MUCH more powerful than a 12J n/a, prob on a par with a 19j TD. it seems happy to rev freely, seems more fun to drive, dare I say it, (round country lanes anyway). I took it out on the dual carriage way, and it pulled a desired 60mph up a long ( 1 1/2mile) incline. I decided to accelerate and although much slower, it DID pick up well. Then on the return, on the flat, I planted my foot, and (again obviously not as quick) it accelerated from 56- 75 with ease and prob would have gone over 80 with ease had I not had to turn off. So It is VERY drivable but the funny thing I noticed (as I drove with one eye in the side mirror) there was ABSOLUTELY no smoke whatsoever.

So To recap I've blanked off the turbo boost pipe, so I still have a fully functioning turbo but without the extra fuelling on boost.
The BIG question is MPG. Will it be a gain, a loss, or same as. If it is a reasonable gain (10% would be nice) then I'll plumb in some copper micro bore pipe and a small gas tap fitted in line, in the cab, so when up a long hill, or loaded I'll turn on the 'gas'. It really does go very well indeed.! Can't wait ti fill up after a couple of hundred miles ( always fill up twixt 200-250)

[oil pan 4]

Originally Posted by yostumpy

Now would this work, I mean the turbo boost on without the xtra fuel, would it give ANY xtra power, over 'no turbo' and would it cause it to run lean.

Yes had my diesel set up to run N/A. Then I added a turbocharger. Now I have the turbos boost and quite a bit of extra power with adding any extra fuel.

[yostumpy]

Originally Posted by oil pan 4

Yes had my diesel set up to run N/A. Then I added a turbocharger. Now I have the turbos boost and quite a bit of extra power with adding any extra fuel.

Did you gain any milage adding the turbo without the xtra boost?

[oil pan 4]

Originally Posted by yostumpy

Did you gain any milage adding the turbo without the xtra boost?

I picked up little over 2mpg on my daily drive and looks like I picked up at least 3mpg on pure highway driving.

[dmafanp]

interesting

[yostumpy]

Originally Posted by oil pan 4

I picked up little over 2mpg on my daily drive and looks like I picked up at least 3mpg on pure highway driving.

Thats a good gain. IIRC about a 9% gain on daily. If I could get 10% THAT'D put me in 32-33mpg (uk) daily and prob 37-38 on a run, (best is 35.4 at the mo) My goal ( the HOLY GRAIL) is 40mpg on a run!!