Toyota CT26 Upgrade - 13BT/12HT/1HDT/1HDFT

[gbentink]

People want to know what parts its made from and prices,photos may help you too.
Im interested in the bored block etc,just bored out to 95mm without stroking what size does it end up?

[Quote from gbentink] Why ask me such a basic calc? You must know the std bore and stoke of your engine. It is ~4.34L with 95mm bores. Nice option but requires custom rods if the other pistons are used - thats not a bad thing in itself......

Well, I owe an apology here to Goldchaser. My response was overly subjective, harsh and uncalled for.

I just looked at Goldchasers HJ61 and it is the best example I have seen of a full HJ61 build up and covet the vehicle!. Praise where praise is due.

 

[Adam B]

Wow. It's amazing to see grown men get all pissy about something like this.

I've been watching Graeme's posts for a long time now and have always been impressed by the amount of time he spends responding to the same old questions over and over again by people who were just to lazy to read an entire thread (myself included on occasion). The guy has spent countless hours researching this stuff and has shared almost everything with the world - for free. Lots of it is theory, which he has always been willing to explain and debate. He's also one of the few people who actually gets out there and tries things, shares the results, and is willing to admit when things don't work out the way the theory suggested they would.

In this one instance he isn't willing to simply give away all his time and effort for nothing and he gets s*** upon for it? What nonsense.

This turbo swap is exactly what I've been looking for. My 7M hybrid turbo is amazing and will outflow the stocker by a huge margin right to max rpm but it's no different off the bottom. Tuning to 20psi+ with slow bottom end boost makes tuning a pain in the ass unless you grind the aneroid rod and even then it's not perfect. There simply isn't enough length of slope on the stock rod to tune over a broad boost range unless you tighten up the spring so much that it doesn't respond until you're already making several psi. The only way to get those first few pounds of boost is to add more fuel to create exhaust energy and you end up with more smoke than you want off boost and at low boost. If you leave the spring looser and tune the max fuel for max boost you end up with too much fuel and high EGTs in the mid boost range - like when you're in top gear at 1500-1800rpm going up big hills on the highway. I've been wishing for a way to make 18-20psi @ 1500 instead of the 10-12psi I make now without simply throwing more fuel at the problem and having to drive to my pyrometer all the time.

I suspect that this turbo will solve that problem to a large extent. I want to find out and I'm expect to pay to be handed an easy way to do it.

 

[dousty]

^ supercharger.

I think Graeme is pushing the CT26 too far, even with a 360 degree thrust, unless of course he is using a bearing housing from another turbo which I doubt. Get on a Supra forum and ask them about the limits of the CT26, even those expensively modified for race performance. I used a CT26 on a 1.6 petrol engine (4AGZE) many years ago and fried the thing whilst pushing 25psi.

I am also concerned about the cylinder pressures Tim is running.

Time, or more information (am I being pissy?), will tell.

 

[Dougal]

^ supercharger.

I think Graeme is pushing the CT26 too far, even with a 360 degree thrust, unless of course he is using a bearing housing from another turbo which I doubt. Get on a Supra forum and ask them about the limits of the CT26, even those expensively modified for race performance. I used a CT26 on a 1.6 petrol engine (4AGZE) many years ago and fried the thing whilst pushing 25psi.

I am also concerned about the cylinder pressures Tim is running.

Time, or more information (am I being pissy?), will tell.

Regarding cylinder pressures, 20psi on a good direct injection engine isn't a problem because the head doesn't have a weakening hole for the precombustion chamber.
20 psi with 18.6:1 compression gives 14.3 MPa without combustion.

A 21:1 idi engine with 14.5psi has the same internal pressure but the heads are weaker.

 

[Adam B]

^ supercharger.

Get on a Supra forum and ask them about the limits of the CT26, even those expensively modified for race performance. I used a CT26 on a 1.6 petrol engine (4AGZE) many years ago and fried the thing whilst pushing 25psi.

Time, or more information (am I being pissy?), will tell.

No, you're not being pissy at all! You're providing real debate, which is good - essential, in fact.

I've spent, honestly, countless hours reading various supra forums (did a 7M swap in my old '85 Toy pickup) and tech about the CT26 and I agree that the common opinion is that they're not able to handle the high boost. I think the vast majority of those people are full of it and are just repeating what they've heard from someone else.

25 psi is high under certain conditions and I'd love to know specifically what went wrong with yours. Are you sure it was the fact that it was a CT26 at 25psi or did it have something to do with existing shaft play and/or the amount of air you were trying to move at a certain boost level? Surge? Choke? Overspeed? I'm searching (and I assume Graeme is too) for the ideal match for this engine and if it can be bolt on, all the better!

I don't know much about Superchargers on diesels. Is there a reason they don't seem too common?

Cheers

 

[Dougal]

25 psi is high under certain conditions and I'd love to know specifically what went wrong with yours. Are you sure it was the fact that it was a CT26 at 25psi or did it have something to do with existing shaft play and/or the amount of air you were trying to move at a certain boost level? Surge? Choke? Overspeed? I'm searching (and I assume Graeme is too) for the ideal match for this engine and if it can be bolt on, all the better!

Or even EGT's that were beyond what the turbo can handle. Petrols run hotter than diesels and petrols with high boost even more so.

I don't know much about Superchargers on diesels. Is there a reason they don't seem too common?

Cheers

Partly the parasitic loss which kills fuel ecnomy and power, partly the boost that is completely unrelated to what the engine actually needs. At cruise you've got way too much boost, at full power probably not enough.

 

[dousty]

Those are some good responses, thankyou. Another question of mine is inlet temps with a CT26 making boost over 16psi. Have these been addressed with Graeme's mods?

There comes a point where increased boost doesn't mean increased volume of air due to the heat produced and their turbo is well into that domain.

 

[Dougal]

Those are some good responses, thankyou. Another question of mine is inlet temps with a CT26 making boost over 16psi. Have these been addressed with Graeme's mods?

As I understand it Graeme's mods are new internals, at which point the CT26 is basically the body donor.
It is the increased efficiency of the new internals that give the performance increase, increased efficiency means lower boost temperatures.

I'm sure Graeme will chime in with a temperature measurement or two.

There comes a point where increased boost doesn't mean increased volume of air due to the heat produced and their turbo is well into that domain.

Actually there's not. Right up past 100psi density will continue to increase regardless of the temperature increase. See the attached graph.

 

[dousty]

As I understand it Graeme's mods are new internals, at which point the CT26 is basically the body donor.
It is the increased efficiency of the new internals that give the performance increase, increased efficiency means lower boost temperatures.

I'm sure Graeme will chime in with a temperature measurement or two.



Actually there's not. Right up past 100psi density will continue to increase regardless of the temperature increase. See the attached graph.

graph no worky mate

 

[goldchaser]

Wow. It's amazing to see grown men get all pissy about something like this.

I've been watching Graeme's posts for a long time now and have always been impressed by the amount of time he spends responding to the same old questions over and over again by people who were just to lazy to read an entire thread (myself included on occasion). The guy has spent countless hours researching this stuff and has shared almost everything with the world - for free. Lots of it is theory, which he has always been willing to explain and debate. He's also one of the few people who actually gets out there and tries things, shares the results, and is willing to admit when things don't work out the way the theory suggested they would.


In this one instance he isn't willing to simply give away all his time and effort for nothing and he gets s*** upon for it? What nonsense.

This turbo swap is exactly what I've been looking for. My 7M hybrid turbo is amazing and will outflow the stocker by a huge margin right to max rpm but it's no different off the bottom. Tuning to 20psi+ with slow bottom end boost makes tuning a pain in the ass unless you grind the aneroid rod and even then it's not perfect. There simply isn't enough length of slope on the stock rod to tune over a broad boost range unless you tighten up the spring so much that it doesn't respond until you're already making several psi. The only way to get those first few pounds of boost is to add more fuel to create exhaust energy and you end up with more smoke than you want off boost and at low boost. If you leave the spring looser and tune the max fuel for max boost you end up with too much fuel and high EGTs in the mid boost range - like when you're in top gear at 1500-1800rpm going up big hills on the highway. I've been wishing for a way to make 18-20psi @ 1500 instead of the 10-12psi I make now without simply throwing more fuel at the problem and having to drive to my pyrometer all the time.

I suspect that this turbo will solve that problem to a large extent. I want to find out and I'm expect to pay to be handed an easy way to do it.

Umm who's pissy?
Cause it ain't me drama queen.
graeme didnt even need to apologise,the point i was trying to make is if you have something toe sell well i'd like to know a little about it or photos of the finished product.
Im not interested in fxxxin around with turbo's but something like that if i wanted to buy it i'd like to know what im getting,ct26?,garret?,new or reco? Old exh housing new housing? etc etc.
Get it.

 

[Tim-HJ61]

I thought I'd mentioned some of this before

It's CT26 body and new. Direct bolt up to the manifold and exhaust flange. Bottom bracket needs mods to fit on 12h-t. I've not done mine yet, too hot outside during the day in Perth at the moment to be cutting and welding. I'm not expecting this to be difficult once motivation arrives.

I'm pretty sure GB wants your old turbo as a swap, but PM him for all the details.

 

[dousty]

Not really Tim. We know the turbo is different but that's about it.

 

[Dougal]

graph no worky mate

Shows up fine for me. Can anyone else see it?

 

[Ducks]

Shows up fine for me. Can anyone else see it?

I can see it just fine.

 

[dousty]

Still can't, just get the red x instead. I will be reading up on it though, thanks Dougal.

 

[Dougal]

Still can't, just get the red x instead. I will be reading up on it though, thanks Dougal.

I'm using firefox if that helps. It's an IH8MUD attachment, but here's the same file linked elsewhere:
http://users.actrix.co.nz/dougal.ellen/forums/Boost vs Density.png

 

[dousty]

Thats better, thanks.

 

[gbentink]

Wow!

First, I apologised to Goldchaser because, honestly, I am not really that narky and some people are good at different things - for example I have never seens a HJ61 like Goldchasers and that is impressive, so to chastise a bit about being lazy (even though that wasnt totally directed at him), according to the way I like to conduct myself; was out of character and uncalled for - simple as that.

now back to turbos in a new post

 

[gbentink]

*EDIT: Now I am happy with up to 24psi, but really depends on fuel flow and if intercooled or not and should be tested. I am happy to talk with each individual and assist with self tuning.*



Boost and air temps.

If a gas in compressed, the temperature will increase if there is not enough capacity to remove it somehow. The old formula (P1V1)/T1 = (P2V2)/T2 (T is always in Kelvin by the way +273.16°C)

However the compressor is not 100% efficient either, and the energy lost due to inefficiency serves to increase the compressed gas temps higher than theoretical. An intercooelr serves to mitigate both issues and makes a substantial difference in most applictaions.

The modified turbo, which uses several different components and is completely new internally is absolutely fine at 21psi.

The 4AGZE being petrol has nasty high EGT's. I just bought an MR2 turbo off eBay to supply me some parts and the turbine shaft was dead due to excessive heat. This is the second MR2 turbo like this that I have seen. These smaller capacity engines work alot harder and the EGT's are typically even higher than for example the 7MGTE (3 litre). I bought 2 very low km JDM 7MGTE turbos ages ago in near perfect condition. However, the shafts are no where near as good in condition after ~ 100,000km on the 7MGTE compared to 12HT turbos I have rebuilt at 530,000km! The 12HT shafts are almost always perfect. After a clean up they totally look new. The original 3SGTE MR2 Gen 2 turbo I dissasembled on friday measured 9.67mm on the turbine side bearing where it should be 10mm! That is unrepairable since you cant buy undersize bearings for the CT26 (they have to be custom made).

In any case, long story short, I had absolutely no problems running my high flowed CT26 on a 1HDT up to 27psi. It had a 270 degree thrust bearing. Nowdays I change that to 360 dgree mostly, especially for manuals but after 50,000km and 4 years, it runs totally fine still. I no longer own the car but a relative bought it so I keep contact.

Everyone is free of course to excercise their own levels of caution and I reccomend to do what you feel is comfortable. If I didnt push the boundaries of things and be ready to suck it up if it fails, I wouldnt have something to offer you. I have only seen one example (not personally, just photos) of a blown apart CT26. If it was caused by overspeed and not by intial contact of compressor wheel coming into contact with the compressor housing, I can only suggest that it was run at choke flow and had dramatic overspeed. A high flow turbo is far less likely to get to that. The way to blow up a CT26 is to disconnect the wastegate on a CT26 with a 12HT/1HDT/1HDFT stock compressor wheel and turn up the fuel delivery. It will smoke up top, egts will be high and after 2500-2800rpm it is on the choke line. Then rev to 3500 and it will probably blowup.

I ran my wastegate disconnected for 30,000km's BUT it had a high flow compressor wheel so didnt hit choke flow.

These are a well designed turbo and very strong but very conservative trim on compressor wheel and turbine - an older philosphy for tuning. I would suggest they are overbuilt given a stock CT26 has a 10mm shaft whearas the coveted TD06 mitubishi that can do >550hp on a petrol has a 9mm shaft. also the CT26 shaft is longer between bearings which gives geater rotating mass support.

21psi is the most I would reccomend on this new turbo (depends on engine you have and rpm range and intercooling etc). This limit is not because I consider damage will happen (it might, but I dont know), it is because it might hit choke flow at higher rpms. It has been run to 1.8Bar in testing ~ 2000rpm but I cant possibly reccomend it.

It is not the answer to everyones requirements, but if you want low rpm performance and more boost up top than stock, it is one answer and the only bolt on solution I have come across in 4 years looking for one!

 

[gbentink]

Just fitted one to a 1HD-FT. It has 3" exhaust and an interheater (thats an intercooler that sits on top of engine without forced flow....)

22psi (1.5 Bar) @ 1400rpm (60km/h at auto lockup in 4th)

Holds 1.5Bar to 4000rpm

Dyno to come on Monday