1HZ Turbo thread (1 Viewer)

[lshobie]

Hi Guys,

I thought I would start this thread here and possible have it mirrored on the expedition/challenge/rally page later as this is a performance issue.

I am going to be adding a turbo to my truck shortly and have been doing a bit of research. So far I have heard a few different things about turbos and would like to see what everyone here thinks.

A junk yard turbo is not an option for me as I don't like to cobble things together (ok, maybe sometimes if I have to), I'd rather use what has been designed - or best suited for my engine.

So, a Mapped Turbo seems to be the best route for my application - My application is add more power at a little lower rpm than say the stock 1HDT turbo that I think starts producing boost at about 1800 rpm and carries it up throught to 3500 rpm. We all know that we don't use these engines int eh 3500 rpm range - I rarely peak 3000 on mine. So it would be nice to use a turbo that is useful from a lower rpm - say 1400 or 1600 and up to about 2800-3000 rpm.

So this is what has been suggested to me so far:

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT25/GT2554R_471171_3.htm

GT2554R - 471171- 3
* Ball bearing
* Oil & Water-cooled bearing system
* Smallest ball-bearing turbocharger
* Internally wastegated turbine housing
* T25 turbine inlet flange
* Great size for applications w/ packaging constraints
* Ideal for smaller displacement engines making up to 270 hp

GT2554R COMPRESSOR TURBINE
Turbo CHRA
471171-3 446179-24
Wh Dia Trim A/R Ind Exd 42.0mm 54.3mm 60 0.80
Wh Dia Trim A/R Type 53.0mm 62 0.64 Wastegated

AND:

GT2860RS - 739548 - 1
http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2860RS_739548_1.htm

* Ball bearing
* Oil & Water-cooled bearing system
* Upgrade turbocharger for GT2554R (471171-3) and GT2560R (466541-1); turbine housing flanges are outline interchangable
* T25 turbine inlet flange
* Great size for applications w/ packaging constraints
* Ideal for smaller displacement engines making up to 36 0 hp
* Turbine Housing option available

GT2860RS-The Disco Potato COMPRESSOR TURBINE

Turbo CHRA
739548-1 446179-66
Wh Dia Trim A/R Ind Exd 47.2mm 60.0mm 62 0.60
Wh Dia Trim A/R Type 53.8mm 76 0.86 Wastegated

TURBINE HOUSING OPTION
Part Number
430609-230 Wh Dia Trim A/R Type - - 0.64 Wastegated

GT2860RS-The Disco Potato COMPRESSOR TURBINE

Turbo CHRA
739548-5 446179-66
Wh Dia Trim A/R Ind Exd 47.2mm 60.0mm 62 0.60
Wh Dia Trim A/R Type 53.8mm 76 0.64 Wastegated

TURBINE HOUSING OPTION
Part Number
430609-231 Wh Dia Trim A/R Type 53.8mm 76 0.86 Wastegated

I am told that the GT28 is the direct replacement for what is on the 1HDT now, and, the garrett site says the GT28 is a replacement for the GT255 (according to garrett site), so in order to get the same type of turbo that produces boost through a lower rpm range it seems that either the GT28 can be used with a smaller exhaust section or use the GT25 with the larger exhaust section - but boost maxes out quicker in the rpm range.

 

[lshobie]

Here is a company that sells trubos in the USA:

GT25 795 USD
http://www.frsport.com/Garrett_GT25..._Ball_Bearing_Turbo_w_Internal_WG_p_2303.html

GT28 1095 USD
http://www.frsport.com/Garrett_GT28...to__Dual_Ball_Bearing_Turbo_Opts__p_2309.html

 

[crushers]

get your truck dyno'd now so you have an accurate comparrision later.
once turbo'd you might be surprised how ofter you go past 3500 rpm.

that truck is going to rock with a turbo and 4.3 gearing...

 

[canucksafari]

Ishobie, the disco potato with a turbine of a/r of .86 seems to be the most prefered for the ubuild system in the Nissan 4.2. Not sure how similar the 1HZ is to the TD4.2 but it must be somewhat similar considering you are looking at the same turbo I have been looking at. BTW, it is also the turbo which Turbo Glide has in their systems for the Nissan TD4.2. Guys that have gone to the smaller .62 a/r with this turbo -although apparently the best mapping turbine - have had issues with high EGTs. The draw back with the .86 a/r is they don't get much boost on low RPM. They get boost coming on at around 1,600 RPM and have 8-11 lbs starting at 2,000 (usually waste gated to 11 lbs). Apparently the perfect turbine for my application would be an a/r of .82 but Garret does not make a turbine with this a/r.

BTW, I know basically nothing about turbos and am pretty much regurgitating what I have read. When considering a ubuild turbo, I think one of the safest and easiest bets is to study what the aftermarket companies are putting together and to copy them.

 

[lshobie]

I have booked it in for a dyno next tuesday.

This turbo thing is interesting, I always do alot of research before I start a project just to make sure I get exactly what I want and need.

Thanks for your help Wayne.

 

[lshobie]

Canuck, that is basically my feeling as well, although there are lots of choices for turbos, there are actually very few choices for turbos - if that makes any sense from what I am finding out.

 

[lshobie]

From another thread:

Quote:
Originally Posted by lshobie
Any suggestions on what guys are running with their 1HZ's?

One fellow I talked to runs a GT25, a turbo supplier in OZ recommends a GT28 with .86 A/R.

Any opinions?

"I'd go down a size on the GT28 exhaust housing. A 0.64 A/R will give you more low end boost and torque.
For diesels you want max boost at cruise and below. If the turbo has a bigger exhaust housing then you need to use the revs more and economy goes out the window.

My fuel economy leapt by 15% when I upped the gearing from 2500 to 2000rpm at 100km/h cruise. Having the boost to haul top gear at low rpms can save you a lot of fuel. "

And another repsonse:

"That may indeed be posted in their catalogue (and indeed it is), but it's not strictly adhered to.

Have you ever pulled apart a garrett turbo? I have, all the "R" designated turbo's are designed to rotate anticlockwise. This designation is carried over into MHI turbo's as well which are not manufactured by garrett.

By all means, get a GT28 however it defeats the purpose of his goal. He wants boost below stock 1HDT levels. 1HDTs use GT28 sized turbo's on 0.63 rear ends and spool at approx 1800rpm and hold through to 3500rpm. Drive one if you don't believe me. The GT25 with 0.63 rear end spools at more like 1300rpm and holds through to a bit over 3000. Granted it doesn't have as much kick as the GT28 as the 28 obviously flows more CFM but it will provide much better low end response.

Your other option is a supercharger, but there's nowhere to put it."

 

[canucksafari]

Ishobie, yep that makes a lot of sense and the conlcusion I have come to after first looking for a ubrew using a used turbo off another vehicle. I decided given the price, the difficulty to find a good match and the probable need to rebuild it, that I might as well buy a new one. Here is a related post from the Patrol /Safari forum:

For under 15 boost you need to use .86 A/R turbine. If like your mates who has a .64 it will boost big time at 2000rpm but with fuel and timing he will have lower EGT due to boost but mate you will have 186rwkw as he has. You cannot just wastegate the extra boost for a lower boost high spool because you EGT will sky rocket, Hence you need a bigger turbine for lower boosts values the ideal is .82 A/R for the TD42 but garrett don't have one for the GT2860RS. Also OONDY with the .64A/R the turbine will be starting to over rev with these boost values on the TD42 and will not last very long. There are lots of things that effect the end result if you are using a very efficient intercooler and 16psi boost you need a 1.06A/R turbine to keep boost undercontrol with a GT28, one of the pitfalls with turbo's is having a turbo too efficient which will cause very uncontrolable EGT.

 

[crushers]

Your other option is a supercharger, but there's nowhere to put it."

i'll call BS on that one...there is plenty of room in a 1HZ engine bay...check with Rosco on this one...

 

[Tapage]

I'm inder the impresion that the GT28 create much more lag than the GT25 ..

Anycase if you check the numbers for your engine and the turbo map for both options you will see both deliver plenty of aif flow for your engine ..

 

[denis]

Hi Guys,

I thought I would start this thread here and possible have it mirrored on the expedition/challenge/rally page later as this is a performance issue.

this just doesn't make sense. On that account every single thread could basically be duplicated in several sections making just an even bigger mess of these forums
IMO

 

[lshobie]

Ok, thanks for that.

 

[crushers]

copying the thread over might be excessive but a thread designated to a particular application is a good idea...at least to me.

there is LOTS of turbo threads but it would be nice to punch in 1HZ turbo into the search and end up with just a couple threads to read over...

 

[Entaran]

I havent' had an EGT issue with my GT25, top mounted GTiR intercooler and 17psi of boost.

Course I may not have been looking hard enough, I will investigate further when I get my truck back (in 2 weeks) from the snapped axle.

 

[Dougal]

There are two problems you can experience with a turbo that's too small.
The first is overspeed, if the compressor is too small it has to turn too fast and the turbo lifespan is reduced. Sometimes severely.
The second is choking. If the combination of turbine and turbine housing is too small then the backpressure on the engine spikes out of proportion with the boost. This isn't soo bad for the turbo (provided it's not overspeeding), but causes your engine EGT's to climb rapidly.

I wouldn't be comfortable putting a GT25 on a 4.2L diesel unless the rpms have been limited to 3500rpm or less. But of course it depends on the boost required as well.

I'd recommened the GT2860 with a 0.63 exhaust housing.

 

[Tapage]

I would choose if I had the option the GT25 more than GT28 .. only for trail boost at low rpm with less lag ..

 

[VTCruiser]

from what I understand, the GT28*RS is at the upper end of the GT28 line, perhaps a "smaller" GT28 would be better suited. Turboglide uses GT28's in their 1HZ kits with good results (so i hear).

 

[Tapage]

One thing that I always thought it's the turbo kits are designed to improve your engine performance and fuel eficience .. but trying to make the less impact in reliability and long lasting ..

Actually if you place a turbo that make 8 PSI at 2500 rpm means that at 1400 rpm you wil get 2 -4 PSI . ?

And if you see a 1KD-FTV engine it start boosting at 1200 rpm ..

Actually if i drive my 2H 10 km per week usually and I'm not interested in long lasting issue I want 10 PSI @ 1400 rpm

 

[lshobie]

Just had the truck Dyno'd, I'll post the graph tonight or tomorrow. Bottom line is 96HP at the wheels and 170 foot punds of torque at the wheels. The dyno guy figured with all things considered the flywheel values are 130 and 200 based on all the erros between the engine and the wheels.

So, as was expected.

 

[lshobie]

Dyno Data

Here is the data sheet: