12ht turbo q's (1 Viewer)

[_Mitcho_]

hey guys,

im just wondering what is the biggest turbo someone has run on a 12ht?? im looking at a t66 turbo and before i buy it i just wanna know if it will work on not?? if some of you dont know the 12ht will be going in my 40 and i will be running a front mount intercooler so cooling wont be an issue, heres a pic of the turbo:



also the oil overflow?? at the top of the motor, can i just put a little filter on there as im running intercooler piping and i wont be able to plumb it back in

 

[bigluxs]

thats a BIG turbo.....what boost you going to run 23psi??

 

[Tapage]

Can you share with us the T66 numbers .. A/R turbo map .. the hotside woul be my concern, coz you can adjust the max boost with the wastegate ( internal o external ) but not the turbine side as that easy.

 

[Dougal]

That's a monster, I don't think the 12HT will shift enough air to get anything from it.

But if you do get it to spool the top end will be exciting.

 

[_Mitcho_]

Turbo Specs:
APPLICATION for mazda rotary ,6 cyl,v8 or twin turbo set up with the smaller exhaust housing
TURBINE
EXDUCER DIAMETER 66.5mm,INDUCER 86.00mm T04z specs
exhaust housing sizes , A/R .68, a/r.100ar ,1.15 a/r.132 , T4 foot
# INDUCER 66.1mm ,
# A/R 0.7, 4-INCH INLET MOUTH
# IT IS OIL COOLED AND HAS A 360' THRUST RACE BEARING (NEED AS HAS THE LARGER 66MM FRONT WHEEL .)

 

[troopie]

Why do you want to run a bigger turbo then the CT26? Crank the boost up to around 18 PSI and with an intercooler and the right exhaust it will be scary enough to drive.

If the 12HT you have has a broken turbo, i'd say that you'll need to either get that one rebuilt or find a comparable ball bearing turbo to replace it. But don't go bigger, the engine likes to run low revs and anything above 3000 rpm is useless, where a bigger turbo will finally spool up.

I run a stock turbo on 18PSI with a front mounted intercooler, a 3.5 inch dump pipe and a 3 inch straight trough exhaust. The injection pump has been fiddled with by a diesel specialist. This is as far as i want to go because it's really scary to drive in the rain. Even with a heavier troopie. Altough i only run 255/85-16 tires.

Just my two cents.

Mark

 

[Tapage]

I run a stock turbo on 18PSI with a front mounted intercooler, a 3.5 inch dump pipe and a 3 inch straight trough exhaust. The injection pump has been fiddled with by a diesel specialist. This is as far as i want to go because it's really scary to drive in the rain. Even with a heavier troopie. Altough i only run 255/85-16 tires.

Damn Mark .. those number are impresive ... did you run a CT-26 .. ? at 18 PSI thought it a little out of it's VE island .. and close to the surge line ? how are your EGT .?

Anycase your cruiser must fly with this kind of powa .. 3.5" exhaust .. I have some hard time to route the 3" in my 80 series.

 

[troopie]

David,

Yes, i´m running a stock CT26. I´m not a turbo expert, i just experiment with boost and intercooling and find out what the results are. For now i guessed right with all the stuff i did to the engine, because it runs better and better everytime i fiddled with it. There´s no enginering here

The EGT´s are pretty low when cruising. Around 300 degrees Celsius. When going down the freeway at 75/80 mph it gets to 450 degrees Celsius. When i stomp the skinny pedal to the floor it reaches 650 degrees Celsius, but it does not go higher. It did go higher before i made the 3 inch exhaust.

I made the dumppipe/elbow myself with a Suprasport flange and made it so it points outside the frame rails into the wheel well. From there i could run the exhaust and it exits right in front of the rear wheel. With the original elbow i could not fit a 3 inch system.

And yes, it flies pretty well for an old LandCruiser.

Mark

 

[Dougal]

Are these temps after the turbo? 650C is quite hot measured there.

 

[troopie]

Are these temps after the turbo? 650C is quite hot measured there.

Nope, before the turbo in the exhaust manifold. I really have to stomp it before it reaches 650. It normally never sees above 500.

 

[Dougal]

Nope, before the turbo in the exhaust manifold. I really have to stomp it before it reaches 650. It normally never sees above 500.

Wow, that is low. How much boost do you run at that 300C cruise?

My Isuzu runs around 430C and 9psi boost at 100km/h.

 

[troopie]

I'm not sure, but i'll be doing a little trip coming saturday and will pay extra attention to it.

 

[The Dude]

We just finished a 12000km tour with our HJ61 running 12psi with a FMIC and I have noticed that I am getting some oil bypass from the turbo. My intercooling piping is weeping oil.

I am assuming it is time for a rebuild, so this thread is perfect. I was contemplating a bigger turbo but if you are getting 18 psi out of the stock unit and your EGTs are in check, is this the way to go?

I would like to be running in that 15-18 psi range. Is the stock turbo up to that task? What are the downsides of doing this? What alternatives should we be looking at?

thanks

 

[troopie]

We just finished a 12000km tour with our HJ61 running 12psi with a FMIC and I have noticed that I am getting some oil bypass from the turbo. My intercooling piping is weeping oil.

I am assuming it is time for a rebuild, so this thread is perfect. I was contemplating a bigger turbo but if you are getting 18 psi out of the stock unit and your EGTs are in check, is this the way to go?

I would like to be running in that 15-18 psi range. Is the stock turbo up to that task? What are the downsides of doing this? What alternatives should we be looking at?

thanks

Brad,

I am by no means an expert, let me be clear on that. I'm relying on my own experiences.

Personally i think that 18 psi is to high for a Cruiser like yours, with more weight and a lot bigger, heavier tires. You will probably spend more time in the higher boost "zone" than i am, so it will put more strain on the turbo bearings and cut the life of the turbo short.
Especially since you do big trips with the Cruiser you will want reliability above performance. I would stay around 14 to 15 psi and call it good. I do shorter trips and i'm almost never more than one and a half our away from a diesel shop i trust.

I'm also running a brand new CHRA in my CT26, so it is really fresh, thats why i dare to run such pressures. I just took my old CHRA apart and will get an Ebay rebuild kit and keep it as a spare. The shaft is still in perfect condition so it should still be balanced.

About the the oil in the intercooler, are you sure it's the turbo and not a little blow by from the engine itself. There's alway a little blow by. Don't go spending a lot of money when the turbo is still in good shape.

These are my two cents.

HTH
Mark

BTW. Dougal, i left my notes with the EGT's in the truck.
I'll get back on it monday.

 

[The Dude]

Thanks for the good advise on the boost pressures. Question though, are you concerned about the turbo at the higher pressures (premature wear, ect) or the engine (bottom end, head gasket, ect)

if it is the turbo, is there a better alternative to the CT26? What is a complete rebuild with new CHRA worth? And what kind of life expectancy are we talking? 25000km or 150000km? I could live with replacing my turbo at the latter... I would just think of it as a wear item, much like my tires that I am sure cost more and will not last as long

 

[troopie]

Brad,

I'm mainly concerned about the turbo itself. The bottom end of the engine will last, as long as you do regular oil changes. I don't really know how the headgasket will hold, but i haven't got any issues yet and this is around 45.000 km after the rebuild.

I would say that the turbo would last at a minimum 200000 Km, but again it's related to the way you drive, the cooldown period after a long run and oil changes.

About the cost of a rebuild. I don't really know what the prices are like in Canada. I spend around 450 Euros on the CHRA and i fitted it myself. It really isn't hard to do since all the balancing has been done. It all comes down to availability of a CHRA over there and the price of it. I got mine from All American Imports here in the Netherlands. You could contact them and find out what the price of one is right now and shipping cost. Their website is: www.all-american.nl . But find out first if the turbo needs a rebuild. It's a waste of money if you're rebuilding a prefect turbo. That money is better spend on tires and fuel.


And now to the results of the EGT testing:
At 100KM/h i got 340 degrees celcius and 5 psi
At 120KM/h i got 400 degrees celcius and 10 psi
At 135KM/h i got 460 degrees celsius and 13 psi
At 165KM/h i got to scared to pay alot of attention to the gauges. But it was around 640 and 18 psi and a crap load of noise.

I hope this all helps you some.

Later,
Mark

 

[Dougal]

And now to the results of the EGT testing:
At 100KM/h i got 340 degrees celcius and 5 psi
At 120KM/h i got 400 degrees celcius and 10 psi
At 135KM/h i got 460 degrees celsius and 13 psi
At 165KM/h i got to scared to pay alot of attention to the gauges. But it was around 640 and 18 psi and a **** load of noise.

I hope this all helps you some.

Later,
Mark

Thanks, that's great information. How many rpm do you have at 100km/h?

 

[Tapage]

Those EGT numbers are pretty pretty low .. are impresive coming from a CT26 if you where as me, but all depends on the amount of fuel that are you adding in your IP ..

The only thing that concern me, it's the VE for the Ct26 since we have no idea of the range of work of this turbo .. and any other info from Toyota.

 

[troopie]

David,

It indeed depends on the amount of fuel delivered. In my case, it could give a lot more. But one litre diesel fuel is 1.40 Euros. I would add more if i could afford it. It uses more than enough as it is right now.
I watched your Marilu video's and mine sure doesn't smoke like she does. Crank up the boost some. You know you want to! Also, the 3,5 inch dump pipe made a big difference in EGT's

@ Dougal. The rpm's are around 2500 in fifth gear doing 100KM/h

 

[Dougal]

@ Dougal. The rpm's are around 2500 in fifth gear doing 100KM/h

Thanks, I figured you'd be lower geared than me to have EGT's that much lower. Mine spins 2000rpm at 100km/h.

What sort of drop did you get with the bigger pipe? I've heard others report up to 50 deg C.