CT26 VNT upgrade/ modification (1 Viewer)

[gbentink]

For a 3 litre diesel engine they are all bad.

For a~ 4 litre engine running max 16psi under road conditions (not race), they are all good compressor wise and should have a 0.64 exhaust A/R. In that case I would go the R not the RS. But the RS is still OK.

Honestly, if going Garrett, go Gt25 turbine side or even GT22 (probably better actually). Personally, I would look at a used Toyota CT12B from a 1KZ as a guarranteed winner (I have a friend with one who would sell it, but you should see them on eBay), they would be a really great turbo and designed for a 3 litre diesel no less - a real performer even on an IDI engine!

Otherwise I would go with a TD04H with a 16T compressor.

People must be desperate to have a BB garrett on their truck to run a GT2876. I could be tempted to go GT2871 (48 trim) IF I had one laying around. But if your spending the $ and buuying all new, get something closer to perfectly matching your engine. The compressor rpm is so much lower that with such a small turbine the BB would barely show any benefit. The turbine is no where near its peak efficiency area as its operating torque is out of its range and there are so many better options - like TD05 with 16G small - awesome turbo for road, ultra efficient and awesome turbine design and despite big trim comp wheel, no surge issues!. They can be bought with garrett flange if thats what you have. United Fuel Injection in perth sells them. They do a few turbine mods and will supply with a compressor trim to suit your requirements - speak to Matt. They have dynoed heaps.

Hi guys. Thanks for all the replies. very useful information. So on the Garrett website, they list five GT2860's. Which one of these are you guys referring to, or are they all bad?

GT2860R - 707160-5
GT2860R - 707160-7
GT2860R - 739548-9
GT2860RS - 739548-1
GT2860RS - 739548-5

TurboByGarrett.com - Turbochargers

 

[Tapage]

who make the TD04H .. ? it's a Mistu turbo .?

 

[gbentink]

MHI (Mitsubishi Heavy Industries)

who make the TD04H .. ? it's a Mistu turbo .?

 

[Tapage]

thought I saw few SAABs and 2.3 volvos with that turbo .. ( 950 IIRC )

 

[Winch]

For a 3 litre diesel engine they are all bad.

OK, thanks Graeme. I appreciate the advice, but others have said that the GT2860R - 707160-5 would work for what I need it for, so now I don't know. Maybe I just haven't provided enough info here to look at this turbo from my perspective, so I will do that and I hope that you and others can confirm that this turbo won't work. I really need to get this sorted out in the next couple weeks before I start fabricating adapter plates etc. I already have this turbo and got a smoking deal on it.

So here's the background and the math that I did and it seems as if this turbo fits really well on the compressor map.

I'm working on a fairly ambitious project. I have a Toyota Tacoma, but are swapping the V6 engine out with a 3.0 litre Toyota Turbo diesel. It is the 1KD-FTV (D-4D).

This intercooled motor makes 170 Hp at 3600 rpm (red line is 4400 rpm) and 260 ft/ lbs at 1600 - 3600 rpm (all the way through). To make this work for me, I am swapping out the electronic fuel injectors with mechanical injectors from a 4.2 litre Toyota turbo diesel 1HD-T (which would provide plenty of fuel) and the electronic fuel pump with a mechanical fuel pump from this motor's pre-decessor (1KZ-T). I will end up removing most of the other electronics as well and the motor will not be electronically controlled at all by an ECU. All the tuning will be done mechanically (old school). It has a 5 speed tranny.

As such, I also need to get rid of the electronic turbo and swap in a mechanical turbo, and while I'm at it, was thinking that I would also like to upgrade that turbo for more power. I am aiming for about a 25% increase in power (roughly 170 hp to 212 and 260 ft/lbs to 325) which is nothing extreme because guys are easily getting these figures with chips and other upgrades.

I've done the math on the Garrett website and came up with the following:
TurboByGarrett.com - Turbo Tech103

Airflow:
Wa=HP*A/F*BSFC/60
= 212*20*0.4/60
= 28.3 lbs/ min

Target Hp is 170*25% = 212
A/F Air/fuel ratio for this diesel is about 20:1
BSFC Brake specific fuel consumption is about 0.4

Manifold pressure:
Map= Wa*R*(460+T)/VE*N/2*Vd
= 28.3*639.6*560/0.97*4400/2*183
= 26.0 psi

R is the gas constant
T is the average intercooled air intake
VE Volumetric efficiency for the 4 valve engine
N is red line
Vd engine displacement in cu inches

Compressor discharge pressure:
P2c= Map+Ploss
= 26+2
= 28

Assume 2psi pressure loss between compressor and manifold (due to intercooler, etc)

P1C= Pamb- Ploss
= 14.7- 1.2
= 13.5

Pamb Average Air pressure in Calgary
Ploss Pressure loss due to eir filter, piping

Pressure ratio:
IIc = 28/13.5
= 2:1

I then looked at the compressor maps and found that the Pressure (28) and ratio (2) fit very well for the GT2860R - 707160-5. Map:
TurboByGarrett.com - Catalog

Looking at the maps for the GT25, it doesn't fit as well as the GT28.

I will likely just keep the stock air-to-air intercooler, or maybe go larger because I have lots of room in front of the radiator. My main goals are to have some good highway power for cruising around 120 km/h (75 mph) and my RPM would be around 2750 at this speed and also have some good low end torque plus good fuel economy. My truck runs on 37" tires, have a 10" lift on it and alot of extra weight, which is why the V6 was no good anymore, so I need lots of torgue at highway speeds. Not so much at lower speeds or for off roading and definately not for racing or speed.

Thank you very much for your help

 

[Dougal]

You're going to lose all torque below about 2,500rpm with this turbo.

The variable vane turbo you have, is it one with an integrated electric/hydraulic drive or is it one that can have the electric actuator removed and replaced with a pressure/vacuum unit?

Honestly, I'd just put the effort into waterproofing the 1KD electronics or sell it, buy a 1KZ and convert that to direct injection (1KD head and pistons). The 1KZ to 1KD piston/head conversion has been done, the difference in combustion efficiency from idi to di meant the owner ended up with 1KD power using all the 1KZ parts (injection pump, turbo etc).

You need 15 psi below 2000rpm or drivability is going to be poor and I don't see any GT28 delivering boost that soon on a 3 litre engine and the map you've shown is very close to surge at 15lb/min and PR 2.

In comparison the 1KZ engine with the CT12B turbo (which Graeme has already mentioned) is delivering useful boost by 1400rpm. I think there'll be a slight reduction in boost delivery with the 1KD as the idi toyotas run very rich before boost arrives. But it'll still be your best starting point.

 

[gbentink]

As Dougal said.

Alot of people get lost on the compressor side assuming that there is ample turbine drive. If turbine drive was less important than the compressor, we would have had variable vane compressor houisings before the turbines.

Dougal mentioned that the IDI run very rich before the turbo boosts. This is very true and serves to also spool up the turbo faster hence you will lose boost. I had no idea 1HDT injectors could fit this engine.... very interesting.

I am bit behind on the 4cyl's since my ficus has always been the 6cyl (thats what I drive...). But I recently saw a post on a 195kw 1KD engine with 650nm..... now thats interesting if your a prado or hilux driver - for sure!

 

[Mopov]

Hi,

just one question for clearance.

From 2003 onwards the landcruiser 100 has a vtn Turbocharger, doesnt it?
And this is not the ct26 any more?
the oem number would be: 17201-17070 with egr cooler and 17040 without. It is a garrett GT2359V?

Regards Ole

 

[nibo]

turbo

I am also interested in the answer, did you ever get a reply?

 

[Dougal]

Sounds like Winch's 1KD is running: http://www.toyotadiesel.com/forums/...inch-s-2002-Tacoma-1KD-FTV-(D-4D)-swap/page16

 

[Winch]

I am also interested in the answer, did you ever get a reply?

Yes, I've since discovered that the 1KD actually comes with the CT16V turbo, not the CT26. I haven't found an answer to my initial question and ended up going with a Garrett 2860R turbo.

 

[ozwallaby]

Yes, I've since discovered that the 1KD actually comes with the CT16V turbo, not the CT26. I haven't found an answer to my initial question and ended up going with a Garrett 2860R turbo.

I looked on the other forum and from reading there it seems you not quite happy with what you have or you think it can be improved upon.....

Any idea what direction other improvements will take for your existing settup...

 

[Winch]

I looked on the other forum and from reading there it seems you not quite happy with what you have or you think it can be improved upon.....

Any idea what direction other improvements will take for your existing settup...

Yes, I am overall happy with the setup and the progress, but there is still something wrong because the engine/ turbo isn't making good boost. I have cranked up the fuel volume to the hilt. Even with it being this rich with lots of black smoke and even soot coming out the exhaust, the max boost I'm getting is 19 psi. 19 psi would be fine, but the EGT's go up very quickly, so need to figure out why I am not making more boost so that I can turn down the fuel supply.
Here are the symptoms I'm seeing. I'm hoping that someone might recognize a symptom or be able to provide advise on what might be my issue(s):
1. Max boost under max throttle with fuel cranked wide open = 19 psi
2. Excellent low end torgue.
3. Absolutely no lag at low end
4. Takes off very nicely in any gear from very low RPM, but only lasts for a few seconds and then torgue tapers off and need to back off due to EGT's
5. Going up a hill, EGT's climb very high (1200) and need to back off with almost no boost
6. Boost under load (going up steep hills) at say half throttle do not go higher than 7 psi, even though it can go to 19 under full throttle
7. Boost comes on very nicely and fast and almost seems to drop slightly once it maxes out at 19.

So if the turbo (Garrett 2860) is too big, would that cause these symptoms? If not, are there other possibilities? I have done a boost leak test, clamped off the wastegate tube, clamped the wastegate shut.

Any ideas why it's not boosting? Thanks.

 

[gerg]

After much research into the ct12b (after it was recomended to me) I can say that it is indeed an awseome turbo just on specs. Turbine exactly like a td04h with a steep trim and a compressor thats about a 39/58mm which would map great for a 3.4 and be very surge resistant. It looks like a great all round turbo that can handle very high PR. Winch, you would have done well to buy one.

Great turbo to recomend Graeme. Thanks. Can you get smaller exhaust housings for it other than the 7.4cm one?

g

 

[Dougal]

After much research into the ct12b (after it was recomended to me) I can say that it is indeed an awseome turbo just on specs. Turbine exactly like a td04h with a steep trim and a compressor thats about a 41/58mm which would map great for a 3.4 and be very surge resistant. It looks like a great all round turbo that can handle very high PR. Winch, you would have done well to buy one.

Great turbo to recomend Graeme. Thanks. Can you get smaller exhaust housings for it other than the 7.4cm one?

g

Is this another TD04 based OEM turbo?

If so, TD04 housings aren't hard to find. I have CM to A/R conversion and therefore choke flow (rough turbine map) prediction for the TD04HL, should be the same radius (and hence conversion) for the TD04 and TD04H housings.

The other online conversions from CM to A/R are complete and utter BS.

 

[gerg]

Sorry, had to edit the compressor a bit. Its a 39/58 wheel. The ct12b has many variants like the ct26. Makes it tuffer to nail down specs. The 39/58 wheel is a little short on flow for high boost high rpms on a 3.4, but around 15psi it should be great up to 3500 id say. Cource there are no maps, but a pretty good guess.

The only other Cm to A/R conversion ive seen are all cut and pasted off the same dudes work and were based on a td05... so it doesnt exactly cross over to other sized turbines. I never could actually figure out if it was acurate in the first place, but it is all over the web.

Im quite interested in your cm to AR converter Doug.

The ct12b exhaust housing mates to the center via v-band like the MHI, but dont know the diameters on it and if a MHI housing can be swapped. I would tend to think it could if they used a MHI turbine wheel. All that I could find on the ct12b turbine diameter is 4.48mm where as all the td04s show 7.49

The td04h turbine has slightly less height on the tips (44mm vs 45.6mm) compared to the td04hl and the tips are not as wide either ( 7.7mm vs 8.9mm) so Im not sure how that affects torque production and overall maximum flow and choke.

This seems interesting.
g

 

[Dougal]

Sorry, had to edit the compressor a bit. Its a 39/58 wheel. The ct12b has many variants like the ct26. Makes it tuffer to nail down specs. The 39/58 wheel is a little short on flow for high boost high rpms on a 3.4, but around 15psi it should be great up to 3500 id say. Cource there are no maps, but a pretty good guess.

The only other Cm to A/R conversion ive seen are all cut and pasted off the same dudes work and were based on a td05... so it doesnt exactly cross over to other sized turbines. I never could actually figure out if it was acurate in the first place, but it is all over the web.

Im quite interested in your cm to AR converter Doug.

The ct12b exhaust housing mates to the center via v-band like the MHI, but dont know the diameters on it and if a MHI housing can be swapped. I would tend to think it could if they used a MHI turbine wheel. All that I could find on the ct12b turbine diameter is 4.48mm where as all the td04s show 7.49

The td04h turbine has slightly less height on the tips (44mm vs 45.6mm) compared to the td04hl and the tips are not as wide either ( 7.7mm vs 8.9mm) so Im not sure how that affects torque production and overall maximum flow and choke.

This seems interesting.
g

The CM to A/R conversion involves finding the radius to the centre of the transition from nozzle to scroll. They already give you the area in cm^2, so divide A by R and convert to inches and you have it.
6cm TD04HL is equal to 0.5 inch A/R.

From there the choke flow depends on the exducer area and a trend develops due to the turbine size too.

This is why I'll be trying to siamese a T25 turbine and 19T compressor wheel. My best efforts put the T25 0.49 A/R turbine at ~10% smaller than the TD04HL, it loses another few percent in efficiency but is a good enough fit for now. I can't use the high rpm power of the TD04HL turbine until I get a large intercooler and even larger air-cleaner installed.
In the mean time this combo will hopefully pull 26psi non intercooled from about 2,200rpm to 4000rpm. That's 30kw of turbine shaft power.
The TD04HL turbine should do about 45kw shaft power on an intercooled 4BD1T. A combination of ~10% more corrected mass flow through the turbine, higher efficiency and higher real mass flow from the intercooling.

 

[gerg]

Ahh that is cool. So how do you determine what Kw is required to turn a compressor?

 

[Dougal]

Ahh that is cool. So how do you determine what Kw is required to turn a compressor?

There are several ways which, if all done correctly, return the same answer.

But in metric
Power = Mass flow (kg/s)*Cp (1.005J/kgK)*Temp Rise.

Temp rise is from the adiabatic compression plus the inefficiency

My engine at 2000rpm cruise.
P = 0.093kg/s*1.005*55
P = 5.1kw.

 

[gerg]

or...

you can say "Hey Doug... will this one work?"

Thats what I do