VNT turbo installation
VNT turbo installation
The turbo I used is a GT2256V from a 2003 Dodge Sprinter with the 2.7L CDI engine.
For those that don't know what a VNT turbo is, here is a good explanation: <!-- m --><a class="postlink" href="http://en.wikipedia.org/wiki/Variable_geometry_turbocharger">http://en.wikipedia.org/wiki/Variable_g ... rbocharger</a><!-- m -->
Vane control is with a simple actuator no different than used on a traditional wastegated turbo. It works the same as a traditional turbo too except that boost response is far faster. No electronics are involved.
The flange is 1/2" thick weldable steel. The hole was cut with an oxyacetylene torch and fine shaped with a powered file.
The result is a big change in how the engine responds. Boost builds as soon as you touch the throttle and can hit full boost by 2500rpm.
It has been a little over 1 year with the VNT turbo installed and I'm completely spoiled to it. Driving a 300D with a regular T3 turbo just feels slow now.
Several changes have been made to the engine since then including modified injectors, an intake with runners, better air filters and a method of opening the vanes for better cruising economy.
Update.
The flex pipe I had to stretch to fit leaked badly at the flange and never fit right. I finally got two more flex pipes and merged them to make one long section. I cut the flange off my spare downpipe mount and used it as the coupler ring between the two. I also remade the extension bracket so the pipe lines up more square with the turbo outlet.
[attachment=0]<!-- ia0 -->LMN GT2256V exhaust flex 7-08.jpg<!-- ia0 -->[/attachment]
No more exhaust leak and it looks much better!
This is the first flange I made.
How its bolted to the manifold with my final plate.
I made an extension for the downpipe connection to align the ports more closely. The flex tubes are joined with a steel ring between. The turbo end must be flattened a little to fit. The stock exhaust is used from the downpipe back.
I swapped the GT2256V from my 240 to the 300. It feels quite different in an automatic.
Low-end performance (around town) is a little too close to surge, I'll have to back off the closed vane setting a tad.
some progress in my VTG installation.
GT23V out of 320 CDI
Actuator in stainless steel off some exhaust flaps
Exhaust: 3" stainless steel, 3 pieces, one free flow muffler off a BMW
looking stock
no intercooler yet, the hose between turbo and manifold was too weak, so no test drive. The VTG control will also give me some work.
Tom
How did you get around the long throw rod and having no stop screw on the electronic VNT?
what is a throw rod?
The travel of the actuator was more than the one of the turbo and the angle was wrong. So I cut it and welded a longer one on the shaft.
The ball came from the exhaust flap.
I am still learning about the vane movement. I don't know yet where and why to limit the travel. There was no stop screw on that turbo (ex. electronic actuator).
The first test drive gave me an impression how difficult the control is but I have some ideas.
No smoke, I adjusted the ALDA by one turn, still no smoke. More potential in the full load adjustment and the car is already much faster.
(the tranny shifts like crazy).
First I have to get the control done,
Done, that means it works but could be better. I put an adjustable relief valve directly into the manifold. The out goes to the actuator where also the vac is connected. No I have to play with orifices and/or vac volumes (reservoirs) to avoid jumping of boost. Little overboost and then sudden too low boost. I would like to have a stable max boost.
How does your boost do during acceleration and during lifting the foot and pressing again?
then intercooler and stable hose connection, finally IP and tranny adjustment (start this weekend). After that the new Holly65 IP should be ready.
Tom
A wastegate actuator will only limit boost. A VNT must have a control system that varies boost with engine load otherwise you'll choke the exhaust flow.
(03-30-2010, 03:58 PM)Jtn190D Why does it not work?
Where will you get a electronic controller?
(03-30-2010, 03:58 PM)Jtn190D Why does it not work?
Where will you get a electronic controller?
this looks like the right thread to tack my questions onto.
I'm almost ready to install a GT22V (have most parts)
and have some questions that I don't think have been covered elsewhere:
1. I shouldn't need a flow restrictor in the oil feed - correct? (I assume those are just for ball bearing turbos.)
2. clocking - does the oil feed have to be at top? Or can I rotate the turbo on axis so that the feed and drain are at the sides?
3. If 2 has to be vertical, it looks like I can index the actuator to other bolts on the exhaust casting (though it would have 2 bolts instead of 3).
anyone have problems with 1 less bolt?
4. I'm considering tilting the turbo axis 45 degrees so that the exhaust points at a downward angle (less bend right after the turbo - G-wagens don't have much space after the turbo). has anyone done this? it seems like it should work fine.
5. flex coupler after turbo - is this needed (recommended) for the GT22V?
6. Any good online sources for sprinter downpipe exhaust flange pieces?
Thanks!
(03-12-2011, 12:28 PM)Syncro_G 2. clocking - does the oil feed have to be at top? Or can I rotate the turbo on axis so that the feed and drain are at the sides?Drain has to be on the bottom, otherwise the oil pools up inside.
Quote:4. I'm considering tilting the turbo axis 45 degrees so that the exhaust points at a downward angle (less bend right after the turbo - G-wagens don't have much space after the turbo). has anyone done this? it seems like it should work fine.The oil drain having to be on the bottom will harsh your buzz. It literally has to be very close to straight down.
(03-12-2011, 12:28 PM)Syncro_G 2. clocking - does the oil feed have to be at top? Or can I rotate the turbo on axis so that the feed and drain are at the sides?Drain has to be on the bottom, otherwise the oil pools up inside.
Quote:4. I'm considering tilting the turbo axis 45 degrees so that the exhaust points at a downward angle (less bend right after the turbo - G-wagens don't have much space after the turbo). has anyone done this? it seems like it should work fine.The oil drain having to be on the bottom will harsh your buzz. It literally has to be very close to straight down.
(03-12-2011, 12:28 PM)Syncro_G 1. I shouldn't need a flow restrictor in the oil feed - correct?Its built into the turbo. Look into the oil supply hole, you'll see a 2mm orifice cast in.
Quote:2. clocking - does the oil feed have to be at top? Or can I rotate the turbo on axis so that the feed and drain are at the sides?The oil ports must be within 30* of vertical. If its within that range, its best just to leave the turbine and center section as-is.
Quote:4. I'm considering tilting the turbo axis 45 degrees so that the exhaust points at a downward angle ... it seems like it should work fine.
Quote:5. flex coupler after turbo - is this needed (recommended) for the GT22V?No. MB used a flex because they had the downpipe flange solid mounted to the manifold. If you bolt the exhaust straight to the turbo only a single flex in the downpipe is needed in the exhaust pipe.
Quote:6. Any good online sources for sprinter downpipe exhaust flange pieces?Any exhaust store should have a flange that can be made to work. The clamp can be bought from any MB dealer and maybe still some Dodge dealers.
(03-12-2011, 12:28 PM)Syncro_G 1. I shouldn't need a flow restrictor in the oil feed - correct?Its built into the turbo. Look into the oil supply hole, you'll see a 2mm orifice cast in.
Quote:2. clocking - does the oil feed have to be at top? Or can I rotate the turbo on axis so that the feed and drain are at the sides?The oil ports must be within 30* of vertical. If its within that range, its best just to leave the turbine and center section as-is.
Quote:4. I'm considering tilting the turbo axis 45 degrees so that the exhaust points at a downward angle ... it seems like it should work fine.
Quote:5. flex coupler after turbo - is this needed (recommended) for the GT22V?No. MB used a flex because they had the downpipe flange solid mounted to the manifold. If you bolt the exhaust straight to the turbo only a single flex in the downpipe is needed in the exhaust pipe.
Quote:6. Any good online sources for sprinter downpipe exhaust flange pieces?Any exhaust store should have a flange that can be made to work. The clamp can be bought from any MB dealer and maybe still some Dodge dealers.
very cool, thanks AAA and FI
I'll keep the turbo in the recommended orientation and will probably skip the flex couplers since I'll have a flexible section in the downpipe.
that will buy me a more relaxed angle down like in tomnik's picture.
Also putting some brain time on trying to smooth out the throttle stages in FI's setup. There's got to be some sort of rising-rate spring/ball relief valve that has a lever arm driving spring tension but I don't see anything turning up in searches. they're all vacuum driven off of gas vehicle manifolds.