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Craig,
Just wanted to say GOOD LUCK on your project. I know this is not auto related but living here on the Gulf Coast we are bombarded with mosquitos as you are in Florida and I have come up with a simple solution. Several years ago I started planting certain plants to repel those pesky things. Each year I plant more and we just don't have them anymore, well maybe one or two in a blue moon. My favorite two are Rosemary and Lemon grass and there are plenty more listed on Google.
Please feel free to delete if you wish.
Craig,
Just wanted to say GOOD LUCK on your project. I know this is not auto related but living here on the Gulf Coast we are bombarded with mosquitos as you are in Florida and I have come up with a simple solution. Several years ago I started planting certain plants to repel those pesky things. Each year I plant more and we just don't have them anymore, well maybe one or two in a blue moon. My favorite two are Rosemary and Lemon grass and there are plenty more listed on Google.
Please feel free to delete if you wish.
Thanks Bill! Yeah, there weren't any mosquito issues for many months and I really wish I could have worked on the turbo job during that time even when it was cold out. Whenever it gets warm and especially muggy out or after a rain it just pays to wait until the air is cooler again even if that means waiting until nightfall. The bugspray still has to come out in force but it makes things easier. The daytime is easier too apart from the sun. I have a massive temporary vehicle tent port that I can put up but it has already proven easy to blow over once, frame and all and so I'll need to secure it extremely well if I try to use it again.
The house yard has far too many areas of grass that the mower hits so put lemon grass and rosemary plantings everywhere but just around the house there is plenty of room for small plants to be seeded. I may try that, thank you for the tip! Hey, the way I see it it's good advice for anyone in a similar situation. Working hard with tools while getting bitten up by mosquitoes is never fun!
Originally Posted by RudysSC
If and when I pull them off I'll be sure to check to satisfy my curiosity!
I think you're off to a good start. You're very methodical and I love your attention to detail. Now I'm just ready to see those new turbos spin!!
Haha, thanks Rudy! At this point I've parked the SC and am not using it again until I get the turbochargers replaced. I don't have anything major scheduled right now and my plan was to get it started around this time anyway.
Voluntarily withholding myself from the convenience factor of "Well it does drive normally so I don't HAVE to fix it right now..." and refusing to drive it and/or get caught up into yet another big side project seems to be the only way it's going to get done. I'm also less than 100 miles from being due for the next oil change anyway and I figure why waste $80 or so of good synthetic oil just to drain it soon and replace it all over again?
I'll be curious to see what you find whenever the time comes Rudy but honestly so long as those stock twins are working well, get cooled down properly after hard drives and always have fresh enough oil going through them every 2500-3000 miles I'd leave them be. I don't know offhand what the safe BPU boost level for late model CT20 sequential twins is supposed to be but as long as you don't go over that you should be fine for a while.
Then again technically any boost over the stock setting will reduce the long term life of any stock twins. By how much depends on many factors but the CT12B's and CT20's with steel exhaust wheels are still pretty robust overall. I've been told that if left at stock boost always the factory CT12B's can last up to and beyond 300k miles depending on the driver's style, oil changes and other care and maintenance. I'm not sure if hte CT20's with steel exhaust wheels are similar in that regard but it wouldn't surprise me.
I'm eager to get my new turbos spinning, myself! Now that I've voluntarily forced myself not to drive the SC until I replace them the pressure will force me to do it once and for all ;D
I've been meaning to ask - on those stock frame upgraded twins are you able to run your stock ECU up to 500 or so HP like you can on the JDM ecu's?
Yes you can but the stock ECU’s inherent tuning limitations still apply as does the stock fuel system’s limitations.
But that is an easy starting point to begin tuning from. Without changing any settings from stock or and with the complete factory exhaust system (USDM/Export) the GT28 Hybrid CT12B’s add about +50hp. I’m not sure what the added figure is on a totally stock car with the JDM versions. Their spooling time is only slightly different from stock in both versions.
I’m not well versed on how people tune with the hybrid twins but keeping them in sequential mode is one of the desired features. That’s not possible with just any aftermarket ECU option (easy with the factory ECU of course). I believe Stu Hagen has used a Vipec ECU system for his hybrid stock twin cars.
...
I won’t be having any Stu Hybrid fun but my stock twin turbo replacement project has begun
I’m trying to stay uninterrupted to make it as short a job as possible. I’m taking pictures along the way and will post them later. For this the TSRM and other existing guides will remain the most exhaustively detailed available but I will focus on the notable and difficult parts of it.
I got a late start and only got partway into removing the metal lines on top of the turbo air piping. That's well enough for one evening.
The only thing to note is that the SC's Heater Control Valve gets in the way a bit when trying to remove the rear 2JZGTE Idle Air Control cross-back coolant pipe hose and the hose going into it from the engine needs to be unhooked and pushed aside to gain access. That and I can't believe I went this many years without the ever versatile electric impact gun (for those difficult exhaust pipe bolts).
haha here we go baby! I can't wait to see the process. Interesting on the tuning front... I feel as though you could remove the factory boost cut and let those baby's sing on a stock TT fuel pump (especially on USDM injectors). What do you think Gerry?
Just the Craig (KahnBB6) I know .... a perfectionist . He wouldn't settle for less. He wants that damn car always it tip top condition.
LOL. There may be some truth to that, Gerry I wish I could afford perfection with this car but I just do my best. Getting both "new" turbos installed and working normally will make me happy. Short shifting at 3500 RPM finally made me cave in and do this.
I remember your words to me, warning that the stock twin removal was a major PITA. Well... it is. But it's also okay. Once I resigned myself to not rushing and taking my time with it one day at a time I think anyone can do this.
To anyone reading who has never done it before, know that you just need a good work area, research and preparation in advance with the manual and the right tools, somewhere to organize all the little parts and above all.... patience. Both with the engine and with yourself. And Beezupra's recent new method for removing that one horrible bolt on the EGCV housing. His technique made it astonishingly easy (to be covered in my next post when I can catch up).
This also means I'll be able to travel normally with this car at long last!
Side note... while I only put 3000 miles on my oil (with regular dipstick checks and top-offs due to a minor lower pan leak) it came out fairly black. I take a long time to put that many miles on my car so maybe that has something to do with it but now I'm thinking of scaling back to 2500 or 2000 miles between changes if I happen to boost a lot. I think you said all your SC's see oil changes around 2000 miles each but you have built engines in several of yours and the bearing and piston tolerances are different from a stock 2JZ.
Originally Posted by RudysSC
haha here we go baby! I can't wait to see the process. Interesting on the tuning front... I feel as though you could remove the factory boost cut and let those baby's sing on a stock TT fuel pump (especially on USDM injectors). What do you think Gerry?
Ha, yep!
I'm covering all of the really troublesome parts of the stock twin removal to fill in critical details but not every single step. The reason is that the TSRM already covers 90% of it thoroughly and in practice it's mostly straightforward and easy to follow just from the manual. I did a few things in a different order than the order Toyota specified but only after first attempting to do it with the their way first.
It's a complicated, very drawn out and very tedious process but that doesn't make it a "bad" process overall. It just has SO many steps that it's not something you can do in a single day. You have to pace it. There's a reason this would be expensive to have any dealer or independent shop technician do for you... assuming they even agree to work on it at all and understand all the steps involved. A good shop that specializes in MKIV Supras would probably be more familiar.
I work slowly and like to sleep enough to recharge myself so for me it takes me a few days doing only a few steps per day
There are pictures to catch up on from last night. So far I was able to get to the point of removing the Exhaust Gas Control Valve housing (USDM type, different from your JDM type) and with Beezupra's special method it wasn't too bad.
As for tuning, I could easily take my SC up to 450whp "BPU" spec with several key changes. The stock 550cc injectors and Denso TT fuel pump would handle it easily. That won't be in the cards for this car though. It's engine is going to stay stock. I'm happy with the power as is (especially once BOTH turbochargers work and I can get to 6800 RPM!). I never set out to beat any records with my SC. For me it's about the all around package and how it drives as I have it set up. I loved the car from the start. I wanted to give it all the hardware it deserved to perform as well as it looked and make sure I could drive it anywhere for the long haul
haha here we go baby! I can't wait to see the process. Interesting on the tuning front... I feel as though you could remove the factory boost cut and let those baby's sing on a stock TT fuel pump (especially on USDM injectors). What do you think Gerry?
what do I think ??? don't ask me cause Craig won't like my answers ..lmaol.
take out those hard to remove and install twins and put a small single turbo 58 to 62mm sized Precision .. and he will be happier with how the car performs.
what do I think ??? don't ask me cause Craig won't like my answers ..lmaol.
take out those hard to remove and install twins and put a small single turbo 58 to 62mm sized Precision .. and he will be happier with how the car performs.
then register it in FL ... screw CA smog tests.
Hahaha! Gerry from both technical and practical perspectives I completely agree with you on installing a modern 58mm or 62mm Precision or other current technology turbo! They're easier to service and superior to old turbo technology from 1993.
Not being able to go with even the most modest modern options available and stay registered in CA is annoying. The CA smog and BAR requirements are what they are though so since I will be moving back there and taking the SC with me I have to abide by them. If the plan all along had been to keep my SC in Florida my entire build would have been very different starting way back in 2013.
At the end of the day I love having a turbo manual SC and for all the trouble the stock twins are to remove and replace they're rock solid and very smooth while still giving plenty of violent acceleration when you floor it. It's just not the night and day 700whp++ (or ++++) violent acceleration that your monster SC's and MKIV's have, Gerry!
Quick update for tonight. It took the better part of a month working around the weather, through a few setbacks and whenever I could set aside the time to work on the SC but the "new" rebuilt CT12B turbos are now in and the car is running again smooth as can be!
After all of that work I am taking it easy for the first 100-200 miles and generally avoiding most boost (other than the 1st turbo since it nearly always spools quickly) but I'll open it up soon enough and will finally see what BOTH functioning stock twins feel like
Two write-ups will be forthcoming soon with pictures:
1) One focusing on how to get through the difficult parts of the stock twin removal and reinstallation with the engine in the car while otherwise following Toyota's TSRM instructions. It won't cover every single step since that's already been documented. What I'm going to focus on are the gaps in how to do the hardest parts.
2) Another focusing on how I re-wired the auxiliary cooling fan control circuit the way Toyota designed it for the MKIV TT after my Mishimoto fan controller had an issue using three extra fans at once in addition to my main clutch driven fan (and a couple of theories as to why that happened since I was pushing close to how many amps it could handle).
...
Let me just say that while I do feel that anyone with mechanical know-how can remove the stock twins in the car with all the right tools (which I will list in my writeup) it's a mostly straightforward but VERY time-consuming and at times exhausting process whether removing or reinstalling them. It's a repair job to finish when its finished after triple-checking all your work along the way.
And yes I did make sure to unplug the fuses for the injectors, spark system and fuel pump and remove the coils and plugs to cycle fresh oil into the turbochargers without compression and build up oil pressure before putting those parts back in and starting the engine (very important final step!).
I am very happy with the result. I may just be imagining things but these "new" factory turbos feel stronger than the old ones with 167k on them that were used hard before I bought them
....
My next two small projects will be to get the instrument cluster's sticking tachometer and speedometer gauges repaired by Tanin Auto and to get a better/newer 6-phase alternator in the car. That'll be either the DC Power 180 Amp unit, a 2003-2010 SC430 130 Amp alternator (with modifications) or a Tundra 130 Amp alternator (with modifications). I've got to address both of those issues before the SC is truly ready of a road-trip.
Awesome news, Craig! I can't help but be a little bit jealous about the twin upgrade. I'm really looking forward to hearing about the results when you start letting them sing.
You've got some great projects planned and I always enjoy the updates on this mean machine.
Awesome news, Craig! I can't help but be a little bit jealous about the twin upgrade. I'm really looking forward to hearing about the results when you start letting them sing.
You've got some great projects planned and I always enjoy the updates on this mean machine.
Thanks Rudy! I hope the small DIYs will help some folks! I've been so busy this last month I haven't had time to write them just yet. I know you've wanted to get some more info on the stock twin removal process yourself.
I don't want to mislead you though-- these are the same stock specification CT12B's that were in the car to begin with. They're the other set I picked up thanks to Gerry(!) some months back and which I had rebuilt a year ago. They aren't upgraded in any way, just standard USDM stock twins Although I think the shaft balancing for both is many times beyond Toyota's standard tolerances. The main difference is that they're basically "new" and now both of them work, lol.
At higher than stock boost your car's factory twins are currently are more powerful than mine
04-27-21, 07:10 AM
I wish I could afford perfection with this car but I just do my best. Getting both "new" turbos installed and working normally will make me happy. Short shifting at 3500 RPM finally made me cave in and do this.
