Outer Limits 4x4 Board

Hi, I have been researching turbos for many years now, mucking around with different designs for friends, relatives diesel race trucks, my own stuff and some private clients.

The 12HT is a great motor but it just doesnt deliver in the sub 2000rpm zone (unless you bore and stroke it to 5 litres, then it does - done that too ;-) ). The 1HDT and 1HFT also suffer below 2000rpm, and this new turbo can get big boost 1600rpm without intercooler on these.

Who would like 15-20psi by 1700rpm (on 12HT, even lower rpm for 1HDT of FT) and being able to hold that to redline?

Who would like to simply bolt it on, no adaptors etc and looks the same on the outside (it IS different on the inside).

Who would like ~ 100°C lower EGT's (pre turbo) at crusie 100km/h.

What about less smoke at all times compared to before?

And FAR FAR FAR quicker boost response - no comparison at all.

360 degree thrust bearing for longer high boost life.

No dyno done yet, but hope to get that too in a week or so.

The test vehicle (1988 HJ61 manual JDM) has a 3" exhaust and no intercooler. Totally untouched 250,000km engine otherwise. We have been running 15psi for ages and adjusted the fuel up to max etc. It went VERY well before. This has transformed it.

PM me for information, my first install was done on the weekend and although the calcs said it would work well, I wasnt going to get too excited until I get the final result. Well, it did exactly as expected.

Would this be applicable to a 13BT too? comes with a CT26 from stock

Accurate before and after comprehensive dyno and strip figures on the same motor would add weight to your argument.. but I suspect you know that already...

RED60 wrote:Accurate before and after comprehensive dyno and strip figures on the same motor would add weight to your argument.. but I suspect you know that already...

While this is true, strip times I would only get from a G-Tech.

I will post up some dyno figures eventually. I have been posting for a while on these forums. Word of mouth will spread very quickly once a few have them on their trucks - to be sure.

Name someone with a 12HT that has easy and every time 17psi @ 1600rpm and holds it no problem to the redline? (I am not sure on limits yet - might hold 21psi to redline) Also when changing gears, almost instantly back on full boost - std CT26 doesnt come close.

Even if you heavily over fuel the bottom end a 12HT will not get close to 17psi at 1600 and will have a ton of smoke and all the badness that goes with it. This will hit the values mentioned with no bottom end fueling mods at all.

I had tried basically every std version of high flowed CT26 from Supra comp wheels to Huge 57trim T04e and tried a few of my own specs. Mine all did better than either of the two extremes listed. But for drivability, this new one is a different world altogether and so it should be as it has newer tech on hot and cold ends.

The owner of the HJ61 might actually be on these forums, I am not sure. I will ask and he can comment independantly.

I do another CT26 that flows more air again but doesnt boost better than std. Basically I do two versions. Within those versions there are also two options. The Early booster flows around 500+cfm and the higher does 600+cfm. They are 20% apart in their boost up rpm points. The higher flow has basically stock boost up, the smaller one is far earlier and faster response.

I'm excited!

you probably need to either make smiles or ruin dreams with costs...

I'd say PM the OP if your in the market and after a smile

@ Dirty:

I am not sure I follow that but if you mean its expensive, I dont think its too expensive. Not much more than a 3" exhaust and yet if you were going to change the exhaust or the turbo, I would do the turbo first - no brainer. PM for costs.

It will make smiles and actually thats most of the fun for me in this.

Hey mate i sent you a pm yesterday and still no reply. you can talk the talk now walk the walk, i got a fistfull a 50's and a fresh 12HT ready to go if you can back up your thread starter

Can you post up all the before data now so we can see if its similar or otherwise to my/our vehicles in original tune (or if in non original tune what has been changed)..... all base boost/engine data would also be helpful for the same reason/s..... sounds interesting for sure...

Its called variable vane turbo
thats how you can get a much more efficient spread of boost with different amounts of gas flow over broader RPMs

Actually VNT would be nice, but it isnt.

Having said that, the difference is profound enough that if you told someone that and they drove it before and after, they wouldnt doubt it anyway.

Just more efficient on both ends. Enough to make quite a difference

Why do you have to be in Perth? Is there any special tuning involved or just tuned normally after new turbo fitted?

Just bolt on not changing a thing.

As for tuning up what I assume is a 12HT, it is fairly straight forward.

* set off boost screw to puff mild smoke when out of gear stabbing the throttle
* Remove max boost screw and insert block off short bolt with copper washer for dirt.
* set boost to 17-21psi depending on what your factory aneroid spring tension is set to.
* Enjoy ~ 160-170hp@ wheels (3" exhaust, no intercooler). Adding intercooler will help top end power, lower EGT's but only mildly affect low end torque.

RED60 wrote:Can you post up all the before data now so we can see if its similar or otherwise to my/our vehicles in original tune (or if in non original tune what has been changed)..... all base boost/engine data would also be helpful for the same reason/s..... sounds interesting for sure...

As an old electrical engineer boss of mine used to say....."in god we trust, all others bring data".... am I getting across what is required here yet....
quoting myself too... how far up my own arse can I be....

Well ive spoken to the man and he seems very knowledgable so i'm going to be his first guinee pig and hopefully it performs the way he describes. Besides for the price even a small gain is worth the trouble.

Great stuff Chris, you wont be dissapointed, it is a substantial change.

Have you had your truck dynoed in its current config?

I am really happy that it is on your truck too, considering the effort you have gone too on the other stuff.

Cheers

chris12ht75 wrote:Well ive spoken to the man and he seems very knowledgable so i'm going to be his first guinee pig and hopefully it performs the way he describes. Besides for the price even a small gain is worth the trouble.

Jealous, i'm sure it will work out well. What boost level are you planning? Are you intercooled? 3'' exhaust and dump?

Looking forward to all the details.

hulsty wrote:

chris12ht75 wrote:Well ive spoken to the man and he seems very knowledgable so i'm going to be his first guinee pig and hopefully it performs the way he describes. Besides for the price even a small gain is worth the trouble.

Jealous, i'm sure it will work out well. What boost level are you planning? Are you intercooled? 3'' exhaust and dump?

Looking forward to all the details.

x2 how quickly will this happen?

within about 3 or 4 weeks, already have 3 inch zaust, standard dump as it made 7 hp less with a custom 3 inch dump at the moment it's running a hi flowed CT26 pushing 14 psi, 3 full turns on the screw, 167hp at the wheels. going to run 21 psi with the new turbo and take the fuel screw out completly and blank it off, custom water to air will happen shortly after. The engine is about 5000 kms old and when it was rebuilt it was bored 60thou (1mm) and had armourlite pistons put in it.

Nice rig

I considered but never did wrap the intake crossover in exhaust wrap to limit heat soak. I guess it would be worth doing temp checks first to calculate the value, but for small $$ it probabluy is economic.

Intersting about the exhaust dump causing power loss.....

Was that on the max power run?? The engine may in fact have been running slightly higher boost (but less airflow) with the factory exhaust by the lowering of the violumetric efficiency due to exhaust backpressure reducing the cylinder scavenging.

May I suggest, after you put the new turbo on, set it to 21psi and refit the old dump and do a back to back - you might see a few extra horsepower and less smoke.

In saying all that, I didnt see what the dump looked like. Cheers

also while you have the turbo off, I would consider installing the thermo-couple for your EGT gauge into the manifold just before the turbo flange instead of in the dump pipe. It is generally regarded to be a safer point to measure EGTs.

Dieselex. something like ACL's heat shield could be a good solution to stop heat soak into crossover pipes

http://www.aclperformance.com.au/prod_heatshield.htm

Hi Chris,

Do you have a printout of the dyno session that you could overlay the new results on? That would be just awesome - the shop you had it dynoed on should be able to pull up your old dyno and do that for you.

Cheers,

yeah i have the dyno sheet here, ive taken a couple of photos of it but they keep coming up blurry when i take the pic. I will see if they have i in there computer and get them to copy it onto a disk. we done a variety of tests with the dump pipes as i had already had the custom dump done before i took it to the dyno but from experience with toyota 12HT's 1HDT'S ect ect the guy said as soon as he seen it that i would be better off with the standard one. I thought pfff yeah right but from the tests we did over 4 different boost and fuel settings the hp was 5 to 7 hp lower with the custom dump (it was a well made pipe). He said that the factory dump on a CT26 has great flow and after all the factory dump is 2.75 inches anyway.

Well in interested
But i need to know some more info about you before i can/will send any money

Say a phone number with a checkable address by pm if you like

Also i whould like to buy 1 out right as in no exchange no deposit

Since you are talking dump pipes heres my new dump pipe just back from being ceramic coated




for a 1hdft beudesert system

chris12ht75 thats interesting about losing peak power with the 3'' dump, you got any pics of it? Were there gains anywhere in the rpm range?

I fitted a 3'' dump on my 13BT last weekend, dunno about peak hp (no dyno runs ever done) but the seat of the pants dyno tells me I have picked up mid range torque and I build max boost approx 500rpm earlier now.

A interesting side effect seems to be though some kind of boost spike/surge thing going on. If I hold the car at 100km/h constant throttle, flat road the boost gauge needle will slightly wobble about 5psi and the exhaust whistle also "wobbles" up and down slightly in frequency. If I hold the accelerator flat to the boards it holds the boost fine with no issue, odd.

Hulsty, your right about the turbine spooling up faster, around 500 rpm sooner like you say but the tourque curve dropped off 500 rpm sooner at the end of the rev range. Lost it's legs so to speak. (im not the best at explaining stuff like this so i hope i got the wording right as that's how it was explained to me) Also had the same boost spiking as yours aswell with the 3 inch dump. Now when i back off the gas it gives the big psshhh from the waste gate (seriously loud as in everyone looking going what the f&%k isn't that a diesel) But it would not do that with the big dump on.

Well in interested
But i need to know some more info about you before i can/will send any money

Say a phone number with a checkable address by pm if you like

Also i whould like to buy 1 out right as in no exchange no deposit

Since you are talking dump pipes heres my new dump pipe just back from being ceramic coated




for a 1hdft beudesert systemWell in interested


for a 1hdft beudesert system

I was talking with Graeme for a fair while (maybe 3-4 months) about a year ago. He was helping me with the technical details of my 12HT build. He offered his time, knowledge and experience to me at no cost and was always very helpful. He did'nt initially put himself out there as a "technical guru" or anything. I simply saw through this forum that he seemed to know a fair bit about the 12HT, so I PMed him, asking for some info, and he was more than happy to help.

I ended up buying a supra compressor wheel and housing off him. I sent my turbo (Sydney to Perth) and transferred money through to him. He had it balanced, put a new seal kit through it and sent it straight back, good as gold. He continued to give me advice and help me out on the build well after the return of the turbo.

In my opinion, Graeme is a very knowledgable, honest and trustworthy person. A stand up guy really.

Hope that makes the decision a little easier for you Hamo.

I keep thinking we'll hear- 'just 3 easy payments of $49.99 over 3 months'. I like this thread and am real keen on giving it a go as my turbo needs rebuilding anyway.

Just a zero after the 3 easy payment you might be close!

Jealous of your 12ht's with my 100rwhp 2h!