cruising boost

[pointynoggin]

howdy,

i've got  1.6td t3 91 jetta

I have been tuning down my giles pump to find a good balance between egt, acceleration and economy.

my problem is that to have the pump turned down to get better than 6l/100km i dont get enough boost at highway speeds to use cruise control.  that is 100km and 2700rpm or there abouts. 

I have only been adjusting the max fuel and boost pin screws.  feels like the lda doesn't move until greater than 5psi and by that time i am 3000rpm flooring it.  once the boost is on i can climb steep grades at 110km/hr 10psi and 1200-1300F on the egt gauge.

i think what i am looking for is quicker lda response with less fuel at the higher boost.

no matter how i adjust the fueling i cant get smoke with out boost, although i don't turn the max fuel in pass where giles set it.

also if i turn down the max fuel so i dont blow coals i cant build early boost.

I like it best when i boost 4-5psi at 100km/hr and still can build fast without blowing black and hot when the power comes on.

am i asking for too much?

[rodpaslow]

When I had a t3 in my car 1.6td, the boost doesn't start climbing till 2500+ rpms.  I'm surprised you get any boost at 100km, because I didn't even at 120km/h.  If you have enough power to get to speed (accelerating with boost I'm assuming) why worry about boost at cruising?  You may save a bit mpg, but off boost cruising should not be a problem.

At 120 km/hr with my old t3 boost would be immediate.  I would set it for that but that's me.  If you want boost at cruising speed, my VNT 17 will do whatever you set it too.  I've had it as high as 8 psi cruising, but now it's set to about 3, I don't find any more or less mpg at 8 vs 3.  My Giles pump is set to what Giles set it to, with .97mm timing.  Only a wee bit of smoke for a second at full throttle.  I have a new engine so I set my boost max to 14psi for now.  My $.02.

[gldgti]

it is a bit of a pain of a turbo because of the smaller compressor side.... I played around with one for ages trying to get it right and never did... until I swapped it for a merc spec T3. It has the larger compressor side (much larger inducer) and gets the boost going a lot earlier (at the risk of surge!!!)

Mine was on an aaz, so I had a bit more gas flow off boost to help spool, but the net effect would be similar.

I think to get any decent spool you will have to accept some smoke.

[JessaBug]

I think we cruise around 2psi, unless we hit a hill, then it goes to 5psi or more, depending on the grade. No cruise control but it seems to be responsive. We have a 2.5" exhaust and a Giles pump timed to .95.

[pointynoggin]

Thanks, i have the same numbers as you guys.  I disconnected the pressure line from the lda and did a highway run, only got 5psi and 800F max.

[8v-of-fury]

I am going to assume it is a full 1.6 TD pump. And that you have the smoke screw on the very top of the pump?

If you do, this is the adjustment needed for when the "boost" fueling comes on. If you want more fuel prior to making enough boost to send the plunger in the LDA down, then this set screw needs loosened and turned in a bit. Put the settings back to where Giles had them as a starting point. The man knows what he is doing, if you don't want the power why get a SuperPump? lol

If your boost and EGT's are too high at cruise with where he has it set, then you either need to let off the pedal and stop hammer timing it or get an Inter-Cooler. There is nothing wrong with a high cruising boost, in fact the Electronic controlled tdi's would manipulate the waste gate (and later the vanes) so that they would be cruising at a higher boost level.

Also fwiw, having the pump turned up does not decrease your economy.. being heavy with the right foot does however.

[pointynoggin]

I hear ya, and i am working on the smokey foot.

Timing is ok, maybe a bit retarded.

With the max fuel turned out 1/8th i get a nice gray haze and 1250F at 15psi 110km/hr climbing the long grades around my Okanogan home.  That seems a bit more better.

IC is next but I have AC and for some reason i have never been able to find a vwdiesel.net standard solution to this problem. I have a Isuzu IC that almost fits under the hood and would be better if i could move the batt into the trunk.

I've read partial treads about fitting a saab 900 IC in there.  I am almost thinking that a Subaru style hood scoop would be a good way of doing it.

Ditching the AC is not a option, i dont understand why people delete AC, i hate being hot.

If anyone has IC setup advice please feel free to express it.  Or if you have a GTD setup for sale PM me!

[R.O.R-2.0]

I hear ya, and i am working on the smokey foot.

Timing is ok, maybe a bit retarded.

With the max fuel turned out 1/8th i get a nice gray haze and 1250F at 15psi 110km/hr climbing the long grades around my Okanogan home.  That seems a bit more better.

IC is next but I have AC and for some reason i have never been able to find a vwdiesel.net standard solution to this problem. I have a Isuzu IC that almost fits under the hood and would be better if i could move the batt into the trunk.

I've read partial treads about fitting a saab 900 IC in there.  I am almost thinking that a Subaru style hood scoop would be a good way of doing it.

Ditching the AC is not a option, i dont understand why people delete AC, i hate being hot.

If anyone has IC setup advice please feel free to express it.  Or if you have a GTD setup for sale PM me!

saab 900 blackstone ic is what you want..