i bought Garrett GT22 VTN turbo. for my honda jazz. for street use. do you think that turbo are good for gasoline? how can i controll the boost?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by evans_art &raquo;</TD></TR><TR><TD CLASS="quote">i bought Garrett GT22 VTN turbo. for my honda jazz. for street use. do you think that turbo are good for gasoline? how can i controll the boost?</TD></TR></TABLE>

Good question! We've been looking at playing with the VNT turbos. The Variable Nozzle Technology is very intriguing. We talked to our Garrett Performance Rep, and he kind of scared us away from the project, due to the difficulty of controlling the boost. He claims it is pretty complicated to contro it, and suggested we stay away from it.

We'd love to see what you come up with, and also what other's have done with this type of turbo.

Craig

 

isnt the vane controlled by the pressure in the exaust mani...therefore when the pressure increases it opens to allow more flow, i didnt think they were that hard to control????

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nateg &raquo;</TD></TR><TR><TD CLASS="quote">isnt the vane controlled by the pressure in the exaust mani...therefore when the pressure increases it opens to allow more flow, i didnt think they were that hard to control????</TD></TR></TABLE>

X2

 

interesting....pictures??

 

we have them over here, they do take some fiddling to get up but are awesome, we use then on a 1.4 renaults.....a normal t3 hits full boost at 4k but the vnt of the same size hits full boost(25psi) at 2.5k....on a honda b16 u would be looking 2.2k for full boost, make it bigger, to say gt30 size and id think full boost(15psi) by about 3-3.5k

 

VNT's are nice i like the ideal of instant boost and no WG because the nozzels control boost as RPMs go up or down an there compact.

 

so when theres no wastegate. how to set the maximum boost??maybe the turbo can works until 15psi, but the maximum boost that we want is 7psi. should we use external wastegate??

 

Sounds pretty good. In for more information

 

NO you dont not need a WG boost is limited by the size of the varible nozzles and by how much cfm the turbo can flow max boost will only hit when the nozzle are fully extended this can happen between 2.5k or 5k RPMs

 

Found some cool pics:

 

sweet...still not entirely sure how they work, but good deal...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schister66 &raquo;</TD></TR><TR><TD CLASS="quote">sweet...still not entirely sure how they work, but good deal...</TD></TR></TABLE>

X2, but in for some info on them

 

Those pictures are missing the key ingrediant in the workings of a VNT,which is the vains themselves. These surround the turbine wheel and act as little gas defelctors. I work for Garrett. Our plant makes the turbine and compressor wheels and until recently enough used to manufacture the vains for the VNT's.
The idea is that at low revs,the vanes have a narrow opening,which causes fast flowing gasses to spin the turbine wheel quickly,giving low down torque. Then as revs increase,the vanes get wider and wider,producing large torque figures at high revs.
What it essentially does is take a large volume turbo that will normally spool slowly,and give it the characteristics of a smaller,quicker spooling turbo,without compremising the power that turbo can make at high revs.

 

In the second and third picture above, you can see the diaphram that controls the movement of the vanes,but not the vanes themselves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egsir2 &raquo;</TD></TR><TR><TD CLASS="quote">In the second and third picture above, you can see the diaphram that controls the movement of the vanes,but not the vanes themselves.</TD></TR></TABLE>

you can see the vanes in the second last pic in the center hole.

A friend of mine is getting ready to tune his ZC crx with a VG turbo from a Dodge sprinter; should be interesting

 

in example like these, at 4K nozzle are fully extended and reach 15psi boost. but i have stock internal engine that can carry only 8psi boost. how can i limiting the boost to 8psi maximum?
when i desprate i think to change the turbin housing, in order to get standart turbo like gt22. is that possible?

 

correct me if i'm wrong but.......about the variable "nozzle" isn't it more of a movable restrictor plate in the turbine housing that acts kindof like a sideways divided t4/t3 turbine housing but the "vane sorta controls how much exaust goes through the housing....hence when a low pressue is seen in the ex mani the "vane forces the ex gasses to go through a smaller port and thus directs a higher velocity of ex gasses directley(or so goes the theory) at the center of the turbine wheel.....then when a "full sool" is acheived the said vane backs off and lets all the ex gasses flow through the turbine housing"however large it may be: its like the porshe that makes what
???550tq at like 2200? or so and keeps it til redline.....wait isn't that the new 911????????

 

yes you are on the right track and just so you kno porsche wasnt the main company to make use of this technology they only made it a little popular

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by model x &raquo;</TD></TR><TR><TD CLASS="quote">you can see the vanes in the second last pic in the center hole.

A friend of mine is getting ready to tune his ZC crx with a VG turbo from a Dodge sprinter; should be interesting</TD></TR></TABLE>


Well spotted, i didnt notice them myself. This technology has been on the commercial diesel scene for a long time. Its been a few years since they stopped making the vanes at our plant,and they had been making them for a while befroe they got moved somewhere else. Although we've never been told the price,i hear they are very,very expensive.

 

The vast majority (which is 100% of the ones I've seen) use the fins (they look like diverters) to chance the characteristics like the A/R was changing.

The mechanical ones use a more typical wastegate actuator bulb/rod, which pushes the fins open (pointing away from shaft center) as boost builds. Few Dodge Shelby Chargers had them in the 80's, but they were known for sticking, meaning severe overboost. I've always thought a pop-off valve would be a good idea in this case. I know a guy into Chargers, and he said the VNT's are really amazing. Nateg is on the right track as to why this controls boost.

I know there's a Gt35 or Gt30 variant I've seen on ebay a few times that has this, as they used it on some diesil truck in the USA. THe only way to get VNT's for a decent price is used, inventory liquidation, or just by chance.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nateg &raquo;</TD></TR><TR><TD CLASS="quote">correct me if i'm wrong but.......about the variable "nozzle" isn't it more of a movable restrictor plate in the turbine housing that acts kindof like a sideways divided t4/t3 turbine housing but the "vane sorta controls how much exaust goes through the housing....hence when a low pressue is seen in the ex mani the "vane forces the ex gasses to go through a smaller port and thus directs a higher velocity of ex gasses directley(or so goes the theory) at the center of the turbine wheel.....then when a "full sool" is acheived the said vane backs off and lets all the ex gasses flow through the turbine housing"however large it may be: its like the porshe that makes what
???550tq at like 2200? or so and keeps it til redline.....wait isn't that the new 911????????</TD></TR></TABLE>

 

i knew very little about these until a freind of mine told me about the porsche with it and thats when i started researching them....i think the are fing sweet turbo's....for the street!!???

 

We need more info

Edit: http://en.wikipedia.org/wiki/V...arger

2nd Edit:
The 2006 Porsche 911 Turbo has a twin turbocharged 3.6-litre flat six, and the turbos used are BorgWarner's Variable Turbine Geometry (VTGs). This is significant because although VGTs have been used on advanced turbo diesel engines for a few years and on the Shelby CSX-VNT, this is the first time the technology has been implemented on a high production petrol car (only 500 Shelby CSX-VNTs were ever produced). Exhaust temperatures in petrol cars are much higher than in diesel cars and this normally has adverse effects on the delicate, moveable vanes of the turbo. BorgWarner engineers however have managed to combat this problem with the new 911 Turbo.
TWIN TURBO 3.6 means each supports 1.8L LOL....anybody thinking what I am?


Modified by z6 at 8:09 AM 4/17/2007


Modified by z6 at 8:11 AM 4/17/2007

 

so when there is a low amount of exhaust flow, it will channel the vanes down to create a higher gas speed, and as the engine creates more exhaust, the vanes back out and use the volume of gasses to make boost, like a nomal turbo.

am i on track so far?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93supercoupe &raquo;</TD></TR><TR><TD CLASS="quote">so when there is a low amount of exhaust flow, it will channel the vanes down to create a higher gas speed, and as the engine creates more exhaust, the vanes back out and use the volume of gasses to make boost, like a nomal turbo.

am i on track so far?</TD></TR></TABLE>right