turbo specs needed "gurus wanted"

[munch]

i am about to upgrade the turbo in the patrol to a roller bearing unit but after searching for info i am no closer to the unit required. some people have use a gt25 while others use a gt28.

can anyone help with what unit would be better suited and the full specs including wheel sizes, trim and housing a/r. i want to ensure boost is reached at a reasonable rpm, definately not 2000 more like 1400-1500.

i am not after a huge power increase just something that will improve overall performance. pump and other mods will also make a big difference but the funds dont reach that far at the moment.

the patrol is an 04 factory t/i.

cheers

[badger]

after speaking to a few of the "experts" ive been told that buying ball bearing turbos on a deisel is a waste of money and they will make less power than same spec turbo with bush bearings.

dont ask me why but 3 places here in bris all concurred.

also only 1/3 of them recomended a water cooled turbo. others saying it was a waste cos deisels dont get hot enough.

as for a/r and trim noone would gimme hints on this, im guessing because they knew id then but a second hand or reco one elsewhere:P

my current turbo is a t3 with basically vl turbo internals. it spools low but it is getting a lil sad as its 18 years old

[chunderlicious]

ok two of the most powerful (kym boltom and steve waterford) both run GT35/40 Garrett Ball Bearing turbos on their 170 and 250 KW diesels. kyms car runs great with the big turbo and i havent seen steves yet but if someone buys it hope to next year some time. GT 28 would be about right for a patrol if it is getting a bit of high reving action.

[-Scott-]

after speaking to a few of the "experts" ive been told that buying ball bearing turbos on a deisel is a waste of money and they will make less power than same spec turbo with bush bearings.

dont ask me why but 3 places here in bris all concurred.

Did these three places sell ball bearing turbos? Do they do a lot of 4by work, or are they ricer shops?

Technically speaking, all else being identical, the inner bearing races on a ball bearing turbine will add to the moment of inertia and it should take longer to spool up.

Realistically, the roller bearings should have less drag than a bush, so they should spool faster, and reach a higher speed.

OK, basically, FIIK.

If you want one, do it!

[vn15]

i am about to upgrade the turbo in the patrol to a roller bearing unit but after searching for info i am no closer to the unit required. some people have use a gt25 while others use a gt28.

can anyone help with what unit would be better suited and the full specs including wheel sizes, trim and housing a/r. i want to ensure boost is reached at a reasonable rpm, definately not 2000 more like 1400-1500.

i am not after a huge power increase just something that will improve overall performance. pump and other mods will also make a big difference but the funds dont reach that far at the moment.

the patrol is an 04 factory t/i.

cheers

Hi have a modified GQ with RD28T engine, bought a new roller turbo last year. It is a GT2871R, comp A/R .60 and turbine A/R .86. Have all mods you can think of incl 12mm plunger. Start making boost from 1600 rpm, reaches 0.5 bar at 2000 rpm and peaks(1,3 bar) at 3000 rpm. Currently boost compensator is adjusted with minimum smoke in mind, ie doesn`t dump a lot of fuel from just abow idle.

I am sure this turbo would make very good boost from down low and all the way to redline on your TD42.

I have straight trough 3" exhaust with no muffler, exits in front of the back wheel, nice whistle on idle and spool up/down.

Does anyone know how the GT35/40 is down low?

[badger]

one of these shops was a schwitzer and garrett dealer who sells denco kits. and another sells safari. dunno what the other one sold but i think he was a garrett dealer too.
so yes all 3 sold ball bearing turbos

i was suprised to hear it myself too but hey im not gunna argue when 3 shops tell me the cheaper turbo will make more power

come on ppls surely there are more of you with specs out there

[munch]

It is a GT2871R, comp A/R .60 and turbine A/R .86.

it has been suggested to use this size but with slightly different specs.

i dont want to buy one do all the work then find out it wont achieve what i am after. i understand in a way the turbo gurus not giving the technical info out but if they recommended something that would be suitable i would probably purchase it from them.

hopefully someone out there will help.

[munch]

someone out there must be able to help.

[-Scott-]

Since my last post I did a little more reading, and found that roller bearings won't handle really high turbine speeds - but I'm not sure what they classified as "really high", nor the turbine speeds you're expecting on your Patrol.

RD28T is the 2.8? You haven't stated what size motor you're running.
I would expect a 4.2 would need a larger turbo than the 2.8 - unless you want to focus on low rpm boost, and sacrifice high-rpm power.

If you have the 2.8, go with vn15's experience.

[stool]

I have a GT25R Garrett on my Rd2.8t`

{ with smaller housings then what comes out with the standard GT25R}


Compressor ar.48

Exhaust ar.48

Which is the same specs as the OE unit` but with a BB turbo

Turbo comes on strong from 1000rpm which im very happy with.

[balzackracing]

garret GT25R or T04 compressor trim= s3, turbine trim= 0, turbine hsg A/R= 0.69.
air flow should be 33.5 lbs a minute. estimate bout 270 bhp max at the flywheel with large intercooler and correct fuel settings so long as your engine as good volumetric efficency.

[DamTriton]

Wouldn't enlarging the exhaust to ~3" or so drop the revs at which the turbo spins up , due to greater pressure difference acros the exhaust turbine? If you haven't already done so, this may be a better first step. All the ballbearings, A/R ratios, and so on, won't do crap if there is a significant restriction in the exhaust preventing gasses from exiting.

[balzackracing]

that is correct damika, and the best way i have found to do that is with a manometer. you can also us the manometer to test intake restriction too.

[zagan]

i am about to upgrade the turbo in the patrol to a roller bearing unit but after searching for info i am no closer to the unit required. some people have use a gt25 while others use a gt28.

can anyone help with what unit would be better suited and the full specs including wheel sizes, trim and housing a/r. i want to ensure boost is reached at a reasonable rpm, definately not 2000 more like 1400-1500.

i am not after a huge power increase just something that will improve overall performance. pump and other mods will also make a big difference but the funds dont reach that far at the moment.

the patrol is an 04 factory t/i.

cheers

I'm not expert but when I was looking into buying a skyline and buying heaps of import mags they have heaps of turbo info, what to buy etc etc.

Anyway they base the size around the amount of exhuast gas the engine will produce and you can then get an idea of the amount of power/air your likly to pump into the engine.

Which helps to give an overall idea of what sort of power increase you can expect.

This might be of use to you, I looked around for info about diesel engines and what I found was that a Turbo doesn't increase power(HP) on a diesel engine it increases the torque out of it, if you want extra power(HP) then go and buy an intercooler.

An intercooler will cool down that hot air being blasted into the engine which makes sense really for a diesel engine at least, as the colder the intake air is the higher you can compress it, which equals more power when you burn it.


Petrol engines are the other way around, you get a big turbo to up the power (HP) and the intercooler simply allows you to increase the boost presusure, which allows for extra power(HP) out of the engine.

Diesel engine's don't run a high boost presure anyway around 9 to 12 pounds of boost.

Petrol engines stock standard are up around 12 to 15 pounds of boost, and it only goes up from there.

At least Diesel engines are made to handle turbo's on stock factory engines, so no need to upgrade engine parts like you'd need to for petrol engines.

[balzackracing]

not sure where you got your info from zegan but how do you incress torque and not hp. hp is a sum of torque x rpm, so any incress in torque you will gain an incress in power. Second, a intercooler/aftercooler has the same effect on petrol and diesel engines. it cools the air after the turbo to make the air more dence therefore incressing the amount of oxygen carried in the same amount of volume. With a turbo diesel engine their is two main pros for fitting a intercooler one is that the cooler the air going into the engine the more oxygen makes it into the cylinder (which is the whole point of the turbo in the first place to cram more air in the cylinder) which then gives your engine a higher volumetric efficenicy, or better fuel burn, more power and less emmision. secondly, for every 1 deg you drop the intake temp you drop 5 deg on the exhaust gasses. prime diesel exhast temp is 550-600 deg at full fuel and full load, so a lower intake temp means lower exhaust temp which then means you can add more fuel to bring you exhaust temp back up to the 550-600 deg. and adding more fuel means more power. many non factory turbo diesels may run lower boost pressure's but that is because non factory turbo diesels arn't built to handle forced induction, hence the reason they break piston rings, break ring lands off pistons and spin big and main bearings. but factory turbo diesel engines especially late model one's run much higher boost that any pertol engine can handle. for example the 1hftze found in the landcrusier runs 18 pounds from factory, most 3500 series cat engines run 25-35 pound depending on the application, and the euro truck engines which are the leaders in the diesel truck market typically run 45 pound plus, the cat racing truck runs a massive 90 pounds of boost through a inline 6 cylinder diesel.
I mean in no way to put you down, i just wanted to correct your info.

cheers busty

[zagan]

A few different websites wikipedia etc.

All had said the same thing about the turbo and intercooler.

I question the boost pressures though, I tried looking up for some specs on that motor and it doesn't seem to exist, not saying it never existed just saying no one has it listed as being a motor to a land cruiser anywhere in the world.

Also the rest of the diesels are truck motors and cat motors would be earth moving also most people wouldn't have a racing truck out the back.

Also Diesel engines are built to handle the higher amount of compression my turbo diesel is 21:1 ratio (my motorbike is 9:1 and still blows the doors off the diesel for HP and torque LOL) and also goto higher compression for safty reasons.

Because of that you can fit up turbo's to a stock non-turbo diesel without having to upgrade the intranals, look up the denco kits they don't have any parts for the engine bar extrators.

The boost pressures I'm talking about are for your general SUV/4wd turbo diesel, and it'd never be near a petrol engine, you'd have to show up some good proof of that, because stock turbo diesels just don't have the HP outputs to allow for such boost pressures, the higher you go the more HP you should be pumping out, but most factory turbo diesels are lucky to be pushing 90HP out the door.

Anyway, I'm not overally fussed either way just found some of your stuff to be odd and go against what everyone else is saying.

[-Scott-]

A few different websites wikipedia etc.

All had said the same thing about the turbo and intercooler.

Don't believe everything you read on the internet.

I question the boost pressures though, I tried looking up for some specs on that motor and it doesn't seem to exist, not saying it never existed just saying no one has it listed as being a motor to a land cruiser anywhere in the world.

I'm not expert, but I think it could be a typo - try 1hz-fte?

Also Diesel engines are built to handle the higher amount of compression my turbo diesel is 21:1 ratio

That's high for a turbo-diesel. Is it a factory turbo, or aftermarket?

(my motorbike is 9:1 and still blows the doors off the diesel for HP and torque LOL)

Power, yes, power to weight, yes, torque to weight probably. Torque - I doubt it severely. What's your bike?

The boost pressures I'm talking about are for your general SUV/4wd turbo diesel, and it'd never be near a petrol engine, you'd have to show up some good proof of that, because stock turbo diesels just don't have the HP outputs to allow for such boost pressures, the higher you go the more HP you should be pumping out, but most factory turbo diesels are lucky to be pushing 90HP out the door.

This is where you've lost it. You're operating at the limit of your knowledge, and you're wrong.

Diesels regularly run higher compression ratios than petrols, and regularly run higher boost pressures. Most SUV turbo diesels are running more than 10psi, most significantly more.

Power figures? Off the top of my head, Mitsubishi's 2.8 tdi, Toyota's 3.0 tdi, Isuzu's 3.0tdi all produce more than 90 kiloWatts - or more than 120hp, if you like. Mitsubishi's 3.2 DiD produces 120kW from more than 20psi - that's about 160hp. Toyota's 1HDT 4.2 litre turbo diesel produces 150kW, or around 200hp.

You don't understand the relationship between torque, power and boost. Power doesn't "allow" boost - wtf is that?

Diesels do not produce good power - it's not in their nature. Power is a product of torque and engine revs - diesels produce excellent torque (petrol engines of comparable size and configuration CANNOT compete on torque) but they don't rev at all well - so they can't produce the large revs needed to produce good power to compete with a petrol engine.

Anyway, I'm not overally fussed either way just found some of your stuff to be odd and go against what everyone else is saying.

I don't know where you go to find "what everyone else is saying" but I suggest you look further. Because either they're wrong, or you don't understand what they're saying.

[tweak'e]

This might be of use to you, I looked around for info about diesel engines and what I found was that a Turbo doesn't increase power(HP) on a diesel engine it increases the torque out of it, if you want extra power(HP) then go and buy an intercooler.

as allready mentioned HP is torgue x RPM. turbo's tend to favour midrange torque but every application is different. you can set them up for low rpm or high rpm.

An intercooler will cool down that hot air being blasted into the engine which makes sense really for a diesel engine at least, as the colder the intake air is the higher you can compress it, which equals more power when you burn it.

with a petrol motor the cooler it is the more air/fuel you can shove into the motor to make power. diesels are a little different as they don't always add fuel according to how much air goes into the motor. most just use boost pressure.

however with a deisel one big advantage with intercooling is the more air you can shove in the higher the effective compession is which helps the fuel burn more effeciently.

Petrol engines are the other way around, you get a big turbo to up the power (HP) and the intercooler simply allows you to increase the boost presusure, which allows for extra power(HP) out of the engine.

the big turbo is their to pump more air into the motor. the intercooler simply cools it down so you can fit more AND helps control temps so the fuel dosn't detonate/knock and destroy your motor.

Diesel engine's don't run a high boost presure anyway around 9 to 12 pounds of boost.

Petrol engines stock standard are up around 12 to 15 pounds of boost, and it only goes up from there.

later deisels run 20-30 odd PSI easy enough. also most earlier petrols only ran 6lb boost. it often was only a few sports cars than ran over 6 lb boost. 15lb was for seroius streeet cars and often had to run on racing fuel.

At least Diesel engines are made to handle turbo's on stock factory engines, so no need to upgrade engine parts like you'd need to for petrol engines.

yes and no. a lot of petroel engines can handle low amounts of boost ok just like deisels can. deisels can get away with it more as you don't have to add the fuel to match the air input as you have to with a petrol ie the deisel will have less stress dispite the high boost.

[badger]

could we stop argueing and get back to the turbo specs:). Zagan as he obviously has no clue what so ever. zagan please do myself and eveyone else on the forum a favour. if you have no idea about something dont try and prove the guys that do wrong. if it makes no sence to you ask. or stfu and read.

at the moment all you are doing is spoiling good tech with a giant wad of uninformed BS my missus knows more about turbo deisels than you and all she knows is that she has to wait for the glow light to go out before she turns it over. and she has to let it cool when she gets home

[munch]

i will get back to the subject.

i should clarify a few things.

the vehicle is a 04 GU 4.2 factory turbo intercooled, already has 3" exhaust and tuned accordingly.

these are the specs quoted to me. i want to ensure this will produce boost in the rev range required, i cant see the purpose of making full boost at 2000/2200 rpm.

gt2871
comp 0.60a/r, 53.13 wheel, 56 trim

turbine 0.64 a/r, 46.95 wheel, 76 trim

it appears there are a few guys using gt25's so this may be a little to large for the hp that will be produced.

[zzzz]

Munch,

Give Nigel a call at Ice Performance in Melbourne.
He will be able to give you some real world information as he has a GQ petrol making over 200kw at the wheels.

They mainly do skylines, rx7's, evo's, subaru's etc but he loves his 4x4's as well.
He has a massive amount of knowledge regarding turbos and will no doubt be able to help you out with some information.

http://iceperformance.com.au/

[munch]

Give Nigel a call at Ice Performance in Melbourne.


http://iceperformance.com.au/

thanks for that, will give him a call and hopefully he can help answer some of my questions.

[udm]

Power figures? Off the top of my head, Toyota's 1HDT 4.2 litre turbo diesel produces 150kW

Hey Scott, just curious... would these figures be at rear wheels on 31" tyres? Cause my turboed/cooled @12psi hzj80 does only 90kw at rear wheels (on 33's though)...

Ulises

[-Scott-]

Power figures? Off the top of my head, Toyota's 1HDT 4.2 litre turbo diesel produces 150kW

Hey Scott, just curious... would these figures be at rear wheels on 31" tyres? Cause my turboed/cooled @12psi hzj80 does only 90kw at rear wheels (on 33's though)...

Ulises

No, I'm quoting manufacturer's claimed figures, which are normally flywheel figures, not necessarily with all ancillaries (like water pump and fan ) connected. You'll normally lose 25 - 30% through the drivetrain, but power at the rear wheels should be largely independent of gearing effects like tyre size.

Thinking more, I'm not sure I got the 1HDT bit right - I meant the multi-valve version. What's that?

[udm]

1hz-n/a diesel
1hdt-turbodiesel
1hdtf-turbo/multivalve
1hdtfe-all the goodies+efi

[sudso]

not sure where you got your info from zegan but how do you incress torque and not hp. hp is a sum of torque x rpm, so any incress in torque you will gain an incress in power. Second, a intercooler/aftercooler has the same effect on petrol and diesel engines. it cools the air after the turbo to make the air more dence therefore incressing the amount of oxygen carried in the same amount of volume. With a turbo diesel engine their is two main pros for fitting a intercooler one is that the cooler the air going into the engine the more oxygen makes it into the cylinder (which is the whole point of the turbo in the first place to cram more air in the cylinder) which then gives your engine a higher volumetric efficenicy, or better fuel burn, more power and less emmision. secondly, for every 1 deg you drop the intake temp you drop 5 deg on the exhaust gasses. prime diesel exhast temp is 550-600 deg at full fuel and full load, so a lower intake temp means lower exhaust temp which then means you can add more fuel to bring you exhaust temp back up to the 550-600 deg. and adding more fuel means more power. many non factory turbo diesels may run lower boost pressure's but that is because non factory turbo diesels arn't built to handle forced induction, hence the reason they break piston rings, break ring lands off pistons and spin big and main bearings. but factory turbo diesel engines especially late model one's run much higher boost that any pertol engine can handle. for example the 1hftze found in the landcrusier runs 18 pounds from factory, most 3500 series cat engines run 25-35 pound depending on the application, and the euro truck engines which are the leaders in the diesel truck market typically run 45 pound plus, the cat racing truck runs a massive 90 pounds of boost through a inline 6 cylinder diesel.
I mean in no way to put you down, i just wanted to correct your info.

cheers busty

More torque equals more power but how come deisels have more torque but less power than a petrol engine with say a less amount of torque? Rpm difference?
I'd say it's also the higher energy produced by the "high compression bang" and slower burning? of a deisel but at much lower revs.
A petrol engine doesn't produce as much energy with each "bang" because of it's much lower compression (blow up a balloon until it pops and it releases a lot more energy than a balloon with half the air pressure) and needs the revs to keep momentum up (or make power).

my 2c of dribble

[-Scott-]

More torque equals more power but how come deisels have more torque but less power than a petrol engine with say a less amount of torque? Rpm difference?

Precisely. Because the diesels run out of breath at lower rpm the torque x rpm figure isn't as high as a petrol engine. The petrol engine makes less torque, but at much higher rpm, so more power.

I'd say it's also the higher energy produced by the "high compression bang" and slower burning? of a deisel but at much lower revs.
A petrol engine doesn't produce as much energy with each "bang" because of it's much lower compression (blow up a balloon until it pops and it releases a lot more energy than a balloon with half the air pressure) and needs the revs to keep momentum up (or make power).

my 2c of dribble

I'm not sure whey diesels don't rev as well, but I'll guess.

For their higher compression ratio they need to be made stronger, for which they use heavier components - I guess that doesn't help.

Diesels are also (typically) "long stroke" designs, which are great for producing torque, but not good for large revs because they have higher piston speeds (at any given rpm.) But this might be a chicken/egg thing - are they low-revving because they're torquey long stroke engines, or are they long stroke because they're torquey low revving engines?

Another significant difference between petrol and diesel is energy content of the fuel - a litre of diesel contains more energy than a litre of petrol, which contains more energy than a litre of LPG.

[DamTriton]

More torque equals more power but how come deisels have more torque but less power than a petrol engine with say a less amount of torque? Rpm difference?

Precisely. Because the diesels run out of breath at lower rpm the torque x rpm figure isn't as high as a petrol engine. The petrol engine makes less torque, but at much higher rpm, so more power.

I'd say it's also the higher energy produced by the "high compression bang" and slower burning? of a deisel but at much lower revs.
A petrol engine doesn't produce as much energy with each "bang" because of it's much lower compression (blow up a balloon until it pops and it releases a lot more energy than a balloon with half the air pressure) and needs the revs to keep momentum up (or make power).

my 2c of dribble

I'm not sure whey diesels don't rev as well, but I'll guess.

For their higher compression ratio they need to be made stronger, for which they use heavier components - I guess that doesn't help.

Diesels are also (typically) "long stroke" designs, which are great for producing torque, but not good for large revs because they have higher piston speeds (at any given rpm.) But this might be a chicken/egg thing - are they low-revving because they're torquey long stroke engines, or are they long stroke because they're torquey low revving engines?

Another significant difference between petrol and diesel is energy content of the fuel - a litre of diesel contains more energy than a litre of petrol, which contains more energy than a litre of LPG.

The slow reving nature of diesels is related to the lower volitility and slower flame propagation of diesel compared with the higher volatility of petrol and higher flame propagation. It is also related to the diesel operating in "starved fuel" mode, compared with petrol that can only fun at 13-15:1 air/fuel ratio.

Long stroke is used in diesels due to the high forces on the piston. A short stroke diesel would have an unmanageably thick and heavy piston to support the forces that are applied to the outside edge of the piston, and prevent the center wrist pin area from punching through the top of the piston.

[zagan]

More torque equals more power but how come deisels have more torque but less power than a petrol engine with say a less amount of torque? Rpm difference?
I'd say it's also the higher energy produced by the "high compression bang" and slower burning? of a deisel but at much lower revs.
A petrol engine doesn't produce as much energy with each "bang" because of it's much lower compression (blow up a balloon until it pops and it releases a lot more energy than a balloon with half the air pressure) and needs the revs to keep momentum up (or make power).

my 2c of dribble

think that's more to do with the octane (petrol/LPG) and cetine (Diesel)

Diesel engines are a lot more suited to making torque than power, Diesel fuel is only 50 Cetine BP/49 Cetine for Shell, also the air/diesel mix would be far more in favour of air(oxygen) than diesel, diesel requires a high temp before it burns up.

So the extra amount of air(oxygen) would only help to produce more torque, The trade off in diesel engines is the fact they are using the heat from compressed air to allow the diesel to burn.

You need long stroke to first stuck in enough air then you have to allow a certain amount of time to compress it, the burning part would be the quickest part of all.

Petrol has an Octane of 91 to 110 and LPG has an octane of 114+

Onctane is basicly the amount of time it takes before it burns up.

So if you have a highly modded petrol engine you need to use a higher octane fuel to stop pre/post-detation, which can cause damage to engine parts.

The trade off with this, is that petrol burns up easy at a low heat, so you can't be messing around for a long time because your mixing the air/fuel at the same time inside the cyclinder, compressing air produces heat.

[oscar]

If we get into the nitty gritty of why more torque, less kW etc, they are all variables in the design of an engine. The egg always comes before the chicken, it just depends on what you like to call the chicken

I did a fair bit of this at uni in thermodynamics. Obviously that is theory, and here we are talking about the application of theory into the real world.

Along with the standard variables like swept volume, clearance volume (which relate to give compression ratio), stroke length, bore diameter, rpm etc, each type of engine has a different characteristic which is inherent to the combustion process "cycle" it undertakes.

They are all purely governed by the laws of physics relating to how the potential energy is introduced, and the process it undetakes to turn that into kinetic energy.

If you want to really get into this and understand it, there are many texts. An example of which is "Thermodynamics" authored by Black & Hartley