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The day before yesterday I crossed an odometer indicated 565 miles. I let it go for 65 more miles than required because I could not be certain the Yellowbox was working consistently enough to correct the 13% speedo/VSS signal over-read.
The ABS sensor input that also influences the odometer was probably where the odo was getting its information (since the odo never stopped racking up miles) some of the time so I wanted to be sure I was going a little over rather than a little under a true 500 miles of break-in. Not sure if that ABS sensor input to the odometer circuit comes from the front or rear of the car but since my tire diameters have changed from stock front and back I think it might also have a slight inaccuracy.
Anyway, yesterday I ran the engine for three minutes to get it warm and then drained out the Comp Cams 10W-30 oil and refilled with Mobil1 Synthetic for the first time. After verifying the oil level and pressure on the gauge, off I went!
I will probably give it another oil change again soon to make sure more of the remaining Comp Cams oil gets out of the system.
I'm still easing into revving higher than 3500 but what a difference the synthetic makes! Wow! Maybe it's just me letting myself be a *little* more aggressive with the engine now I think I'm supposed to be moderate with the power for almost another 200 miles to break in the new clutch according to the SouthBend instructions but that won't take long to do.
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Now I am wondering... the builder of my bottom end had no further break-in instructions after the 500 mile period on mineral oil but is it not a good idea to be a bit restrained with the new engine until, say, 1100-1200 miles or so? For the sake of longevity by letting it really get settled with itself? Or is it totally fine to go at this point?
...
The JDM R154 VSS sensor and new 3.73 speedo gear with seals and retaining clip arrived in the mail. I'll pursue installing those later. Pictures to follow.
The replacement YellowBox V5 unit and harness are still MIA. Next time when I order international and there is an option for tracking... I'm going with package tracking.
And the 200mm SC/MKIV diff rebuild kit from Driftmotion is on its way.
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I have found a consistent way to instantly fix the sometimes-not-responsing-right-away tach needle issue: whenever I start the car and the tach doesn't immediately work if I gently slap the top of the dashboard above the instrument cluster it will always come to life.
I remembered seeing something about this very issue with someone's SC dash needing a light slap before the gauges came on. I think it could be related to a sticking tach needle motor? I may need to call up Tanin Auto if this is an early sign that my tachometer needle motor is going to need service or replacement.
Go for it , you have more than 500 miles already on the engine. In fact the first minutes of engine running going through the initial heat cycle is what matters most for engine break-in as evidenced by people who bring it to the dyno right after the build. It was always the OGs that recommended the long break in but all performance shops strap these performance engines right away on the dyno without ill effect.
It is the clutch that really needs to be broken in so as not to damage the clutch material. But engine wise , you are good .
Go for it , you have more than 500 miles already on the engine. In fact the first minutes of engine running going through the initial heat cycle is what matters most for engine break-in as evidenced by people who bring it to the dyno right after the build. It was always the OGs that recommended the long break in but all performance shops strap these performance engines right away on the dyno without ill effect.
It is the clutch that really needs to be broken in so as not to damage the clutch material. But engine wise , you are good .
^^ Thanks Gerry! I've started getting used to the power more and more now. I will give another 150 miles (which would be 750 on the new clutch as per SB's recommended break-in) before getting well into the #2 turbo transition and after that.... I'm going to see what this engine will really do! I'm already really impressed getting on it at just 1/3rd and 1/2 throttle. I know that today 340hp at the crank isn't a lot but just coming from the NA engine I love the responsiveness.
The world needs more sequential twin turbo cars! Though now with variable valve timing, quick spool valves and other modern tricks that this one doesn't have
Originally Posted by Ali SC3
Bounce it off the rev limiter and report back!!
Haha! Better than that Ali, I'm currently looking at buying a suction cup smartphone mount to shoot some video with the SC. My sound equipment is all too big to use in the engine bay or at the rear near the tailpipes unless the car is stationary but I may run some interior sound with the mic on the passenger seat.
I'm looking into some extra gear to take advantage of the 1080P video modes on one of my phones (still weird to me that a cellphone does this so well now) and doing a couple of lightweight car camera rigging tests is next on my list. Starting with the interior first. Those exterior suction mounts are great but pricey
After all the problem solving posts to date this thread is desperately in need of some pictures and video of the SC!
Time to get that LSD done now for better gearing .
Definitely! The car needs it so badly I just took delivery of the 200mm diff rebuild kit from Driftmotion. Have been in touch with Jared @ SFS but haven't set a firm date yet. Speaking to him, he'd prefer that I remove the diff pumpkin and either drive it or ship it up to him rather than drive the SC up there for the work. I'd prefer to drive the car up there since I don't have access to the garage I was using before.
Something Jared mentioned though is that Toyota has discontinued the peel-away metal shim kits for the 200mm SC/Soarer/MKIV/GS diffs and for the 220mm MKIV 6-speed diffs. PHR has been making their own shim kits for the 220mm diffs but so far no aftermarket off the shelf alternative exists for shimming the 200mm diffs. I think Toyota discontinued both shim kits back in 2014 or 2015.
Jared suggested I could buy the PHR 220mm shim kit which could then be cut down to size for a 200mm diff. I know that generic peel-away layered sheets of metal for shimming also exist such as from this company:
I've adjusted my driving style to the 4.27 ratio for now.
But before I get the diff worked on I need to coordinate with you to deliver that 2JZ-GE block, Gerry. I'm being pressed upon to move it from its current location to make space. I'm going to rent a little Enterprise panel van and take it up to you.
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In the nearer term I'm going to get a neat little part delivered by the end of the week. Jonathan at AutoExtrude has come up with a part request that I asked him about sometime last year: a version of his SC ashtray bezel that allows for two 52mm gauges plus a DC power port... but in this iteration it is offset with the gauges to the left and the power port to the right. He sells a symmetrical version which I have in the car now. Can't wait to get this installed!
Get the part you need for the diff Craig so it will be a one time affair going to GA ...bringing the short block and diff being done by Jared. I appreciate you wanting to bring my short block quick but please don't waste time and money just to bring my short block. I can wait . Though I already have everything I need to mate to that short block and get it running, I am not too in a hurry and make you waste precious time and money .
All you need to do now is oil all exposed cylinders and the deck then wrapped it with plastic wrap. Put it into a corner where it is not rained on or will get wet. It doesn't have to be garaged. You can let it stand by its end for less space though just be careful of the flywheel end of the oil pan since it is aluminum. It can easily crack or be chipped.
I ordered 10x new 200mm diff ring gear bolts (P/N: 90105-12219). I forgot to add those along with Driftmotion's 200mm SC/MKIV diff rebuild kit.
I also confirmed first through Driftmotion and then at my local Toyota dealer that the shim kits for the 200mm SC/MKIV/SoarerZ30/GS diffs are in fact still available from Toyota at this time. You just have to measure what you need first and then order the size you need. So a little downtime during a diff rebuild.
I was confused in my previous research. It is only the Supra MKIV TT 6-speed 220mm diff pinion and side shims that are no longer available from Toyota and which are now specially made available only through PHR.
Driftmotion made it clear that they still regularly rebuild the 200mm diffs and still always order the shims they need each time from Toyota.
So with that mystery now solved I just need the ring gear bolts and I'll have all I need.
This has me thinking... I now wish I had not sold my original 4.08 open diff a few years ago. I could use it to swap in temporarily while my MKIV TT Auto diff that is in the car now gets rebuilt and not have to drop off my car.
Maybe I should try to find a cheap SC300 Auto 4.27 diff or an SC400 3.92 diff. I probably won't but it's just a thought.
In other news, tomorrow I'll have enough miles on the clutch and open up both turbos for the first time
Another snag that's going to delay the diff rebuild further... it appears that I will need a stronger clutch.
I waited until SouthBend's recommended 750 miles before fully opening up the throttle and once I crossed that threshold I decided to give the GTE some full throttle from 2nd and 3rd (I was already rolling)... but I noticed something that felt ever so slightly like slippage. Huh...?
Sure enough, I tried again and the clutch wasn't holding the power under stock boost once turbo #2 kicked in. It slips pretty consistently by 4000 RPM.
But if I keep acceleration reasonable (and even spirited) below the turbo #2 transition point where I'm not putting down full power, the clutch is fine I think.
This was a "rebuild" clutch kit through SouthBend but I was assured that I was getting their "Stage 2 Endurance" kit which should use an upgraded pressure plate, upgraded disc and hold 395 ft-lbs. There is no way a stock USDM 2JZGTE is going to be putting down as much as 395 ft-lbs with the boost left totally stock.
When I received the kit a while back it curiously had what looked like an OEM/factory Aisin R154 disc. I inquired about this but was assured it was the right kit. OK, I thought... but if it isn't an upgraded disc then that should technically make it more in line with their "Stage 2 Daily" kit which is rated on their website at 365 ft-lbs... and that would not match the order I'd made. Even still... I don't think a stock USDM 2JZ-GTE is going to put down 365 ft-lbs at stock boost.
I have not floored the engine from a stop, revved and dropped the clutch or done anything to glaze over the clutch. For the entire engine break-in period I did my best to accelerate slowly and moderately mostly up to 3000rpm and only late into break-in at 3500rpm max (as was deemed OK by my short block builder).
Given all of that, with only 750 miles on the near brand new SB Stage 2 clutch kit I am already experiencing slippage once I hit turbo #2's boost.
I hadn't planned on spending for a new clutch and install so soon, darn it. But As long as I'm moderate with the throttle and stay at 3500rpm max I'm sure the current clutch will be OK for the time being.
So now I'm doing research on a new alternative R154 clutch that can actually hold the power even at factory stock boost with a full face disc suitable for a DD and also not introduce a requirement for gargantuan pedal effort. I've already learned that an advertised torque holding of "365 ft-lbs" is still not nearly enough for this engine.
A twin disc OS Giken or Exexy is too expensive for me, overkill and not suitable for the high mileage I plan to put on the car. As for puck clutches... I don't want one of those.
I have to wonder... since I'm convinced that what I actually have is just have an upgraded SB pressure plate that clamps a bit harder than stock paired with a 100% stock Aisin R154 disc... would the solution simply be one of SB's *actual* Stage 2 Endurance clutch discs (which are definitely not stock Aisin but still full face) or one of their Stage 3 Endurance clutch discs (also not Aisin stock and a different full face design from the Stg2 Endurance discs).
I see that Driftmotion sells an ACT-XTSS R154 clutch kit that has an upgraded full face disc. I'm researching other kits as I go. If anyone has some suggestions I'm all ears. I want something as close to an OEM feel as I can get that will hold the power and that will last in daily driving. The GTE's 320hp/315 ft-lbs (rumored to be more like 340hp/325 ft-lbs??) can't be that hard for a good streetable daily drive-able clutch to manage.
In any case I'll be running the 4.27 rear end for a while longer and holding off on getting my headlights restored. C'est la vie.
Here's my latest thought on the clutch situation. Going to sleep on this but it might be the most affordable solution:
--Call up SouthBend and order JUST the upgraded disc from either their K16063-HD-OCE Stage 2 "Endurance" kit... or JUST the upgraded disc from their K16063-SS-TZ Stage 3 "Endurance" kit. Either one of those full face discs will have pad material that should exceed the rating of the factory Aisin/Toyota disc for the R154.
--Get some new ARP flywheel and pressure plate bolts
--Resurface my other OEM 1JZ R154 flywheel if necessary to have a fresh surface with a new clutch disc with different pad material to bed in
--Reuse the same almost-new SouthBend upgraded pressure plate that's in the transmission already
--Take all of these parts in and have the Aisin/Toyota/OEM disc removed and the upgraded disc thrown on, swap in a newly resurfaced flywheel if necessary, bolt it all up.
--Break in the new clutch disc and see if that holds better than the current one
OR...
Go with the ACT Extreme TS2-XTSS kit for R154's. Said to be rated for 495 ft-lbs. I've never had trouble with the ACT clutches I've used.
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The way I'm seeing the numbers right now just changing out to a higher rated SB disc would be the most affordable solution given that I already have one of their upgraded pressure plates installed.
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I haven't read good things about SPEC clutches. It's been a very long time since I've been familiar with Centerforce's products but I've never used them before personally. People speak highly of the OS Giken twin disc clutch kits with the movement change but those are far out of what I can afford to get into at this time. And... to hold only 315+ ft lbs... too much overkill I think.
Well... an interesting thing I just learned after talking with DJ at SouthBend Clutch: it is not only possible to damage the clutch material during the break-in / bed-in period by over-driving it too hard but it is ALSO possible to prolong the break-in process even longer by driving the car too gently. He says this is actually a common call with customers who are new to the process.
DJ's suggestion is to drive the car for another 200-300 miles (300 if there is more highway-like driving with little shifting which is partly the case in my area 50/50) as extended break-in but with normal application of power... just minus any super aggressive hard standing starts, etc.
Maybe I never encountered or learned this with new clutches before because I've always owned and driven many naturally aspirated cars and at least a couple with low torque only available in the high revs. Or maybe it was the gradual very easy engine break in that I got progressively more aggressive with the more miles I accumulated which added to the clutch disc not breaking in fully within the 750 miles.
So... more driving to break in that disc and see if it in fact is up to the job or not. It still should be... and DJ noted that while it looks like a stock Aisin / OEM Toyota R154 disc it is actually a higher rated disc from Exedy. The 365 ft-lbs capacity with the upgraded pressure plate is still what he considers a conservative rating and still there is no way this engine is putting out close to that torque figure stock. If it indeed is not up to the job after all and keeps slipping at FULL power after another 300 miles of solid break-in THEN I'll step up to their true Stage 2 "Endurance" R154 disc with the same pressure plate.
Hope this does end up being the cure-- that I just needed to be a bit more aggressive overall breaking in the new clutch disc. Below that turbo #2 threshold there are zero issues and it pulls hard like a freight train!
Overall there are so many new things I have been learning with my first big engine turbo manual car compared to previous manual cars (or previous engine configurations) that I have owned and driven
hahahaha! Well I think the clutch must be *partly* broken in by now since it pulls well until the second turbo kicks in. Plenty of shifting so far. But I do have a mix of small roads with stoplights and loner roads without stops here. So it needs even more shifting... and more of the driving style I've only been putting on it in the last couple hundred miles. According to DJ THEN it should be fully broken in to handle full torque. Fingers crossed. It *should* be a kit that is over-rated for what the engine puts out.
Yeah... I need to get that block to you. I know you want me to kill two birds with one stone if I do have SFS do the diff rebuild by getting it all done on the same trip but I'm still saving to do that job. I should be finally getting that thing wrapped in plastic this week. I'm installing the 97-98 Supra engine brackets onto it for stability on an old tire.
Thought I'd post this discussion from a physics forum since it has to do with the question of whether or not torque multiplication through gearing (ie: tall or low final drive gearing or just different transmission gear ratios) change in any way the output of torque onto a clutch disc.
The answer seems to be "no" since the torque applied from the engine's flywheel goes directly to the clutch and pressure plate, then to the driveshaft and THEN to the final drive ratio (minus the driveshaft and separate diff for FWD transmissions of course) but it's an interesting dissection nonetheless.
This never affected me when I was on the old stock SC300 engine since all my clutches then were well over-rated for the naturally aspirated 210 ft-lbs of the GE.
With the way a boosted engine delivers its power I've wondered if there is a difference in the way a 2JZ single turbo engine and a 2JZ sequential twin turbo hit the clutch with torque at the same general power level. One is very linear while the other is a staged double hit and I wonder if the way the sequential turbos "hit" and load on the clutch disc not once but twice might be the reason I likely need a a slightly stronger disc in there at minimum.
I'm still getting some slippage from my new clutch after about 1,000 miles of break-in so I'm of the mind that I'll need to upgrade it slightly. Not under normal driving conditions or any time I'm only using turbo #1. Just when both turbos kick in together.
I think the 2JZGTE's twin turbos, right at that 3500-4000rpm transition point, just make a lot of torque that is possibly overwhelming the Aisin disc even with the upgraded SouthBend pressure plate. I could be wrong but I think that is what is happening. I have smelled some mild clutch getting out of the car sometimes after allowing for the cool down phase (as a calm drive home or some idle time) before shutting off the engine.
I tried to test whether or not the clutch would slip in 5th on the highway and I did get it to do so some of the time once I crossed well past 3500 but this seemed to be a function of how quickly I was applying the power. Slow and gradual doesn't seem to put as much boost into the cylinders at even 4000rpm. However from a stop accelerating quickly up to the 2nd turbo transition does of course apply a lot of boost and torque.
Interestingly it has gotten a little bit better in some cases. Tonight for the first time I briefly got up to 5100 rpm from 3rd before shifting into 4th. I was beginning to wonder if my 2nd turbo might actually be the issue but I think that pull put the possibility to rest. The car isn't smoking from the exhaust after all.
So maybe the disc, while slipping under any full power throttle application where the 2nd turbo kicks in, has become more broken in at this point but my impression so far is that there needs to be a bit more torque hold rating than what I've got in there right now (a SouthBend Stage 2 "Daily" kit for R154's rated at 365 ft-lbs). Their Stage 2 "Endurance" has a tougher disc with the same upgraded pressure plate rated for 395 ft-lbs... which incidentally is the torque rating for their most basic "daily" clutch kit for the 93-98 Supra TT's V160.
To me so far it seems that for totally stock boost I need a bit more clutch strength than I currently have but perhaps, for the sake of longevity, instead of going just one level up from a 365 ft-lb rating to 395 ft-lbs I should consider their R154 Stage 3 "Endurance" kit rated for 465 ft-lbs.
I'm not really planning to turn up the boost but I think if I did it only makes sense to have that much more torque holding in reserve since I already need to consider stepping up just a bit more for stock boost.
I can drive the car normally and even accelerate spiritedly just fine up to 3500 with no worries. Normal daily driving and mild spirited driving is not affected. It's just any full power full throttle application with both turbos that seems to be hampered by slippage right now.
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Just some thoughts I wanted to share for anyone curious who might have also considered using one of the milder full face R154 clutch kits with their swap.
Of course I'm sure most people will be on a single or will have their stock 2JZ twins pushed to 17-18 psi anyway, lol
Shortly will be the diff removal and rebuild to 3.76 gearing. After the diff is installed again I'll turn my attention back to the clutch.
^^ Following up on my last post I spoke with the always helpful DJ at SouthBend Clutch and he determined that it's not the disc that's the issue but rather the pressure plate needing to be one spec higher than it is currently.
He also clarified that when they list their "daily" clutch discs that are full face organic, these are like the OEM Aisin discs but they are NOT the same. SouthBend takes a stock R154 Aisin disc, removes the pad material from them and re-lines them with their own copper-woven material. This achieves a higher torque rating for those discs compared to an off the shelf Toyota/Aisin OEM disc for an R154.
And since I have a spare new one of those from South Bend I will just need their 86-92 Supra MKIII Turbo Stage 3 pressure plate which as a bonus DJ also explained does not have any increased pedal pressure over their Stage 2 pressure plate. Nice!
I asked why he didn't suggest the Stage 2 Endurance kit with the more exotic disc material and rated at 395 ft-lbs over the Stage 3 Daily kit (rated 400 ft-lbs) which uses the more OEM-like disc but just with increased pressure plate clamping force.
He explained that, since I was emphasizing daily driver use and longevity of the clutch with this engine setup, given that the Stage 3 Daily kit will more than handle the stock sequential 2JZGTE's power it made more sense to stick with their enhanced OEM-like disc for the normal/long lifespan that I am wishing to achieve. The Stage 2 Endurance disc, he said, though very up to the task for performance applications, will not last as long given how I intend to drive and use the car.
The two ways to achieve more torque holding with a clutch are to increase the clamping force (pressure plate) and to use a tougher disc/puck. Usually it's both in some combination.
So what I will now be using is a SouthBend #K16063-SS-O kit: 1986-92 Supra Turbo R154 Stage 3 Daily.
It's on order so I'll have that waiting to install later. I'll also get some new ARP pressure plate and flywheel bolts. The pilot bearing and release bearing are also new but I'll get a new kit for all those too.
And that should solve my issue for this setup.
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I've got to say... I know many of my posts in this thread are probably covering ground that many SC, MKIV, GS, IS and other JZ car folks are very familiar with but with every snag I learn something new.
And I know that 350hp is well under the level of power most people are going for with their builds... hence their use of much more aggressive clutches including twin plate OS Giken or Exedy or in some rare cases the king Tilton multiplates(!)
But at this very mild power level I want to have my 5-speed car set up to drive a LOT and over long, long distances and have at least something like an OEM maintenance schedule. It's definitely fast now but it's still no contender against the more impressive JZ turbo builds and I know it
As an everyday turbo manual SC that's bulletproof, getting the clutch just right brings it that much closer to the overall goal for the car
11-07-18, 01:44 AM
I think I'm supposed to be moderate with the power for almost another 200 miles to break in the new clutch according to the SouthBend instructions but that won't take long to do.
I've started getting used to the power more and more now. I will give another 150 miles (which would be 750 on the new clutch as per SB's recommended break-in) before getting well into the #2 turbo transition and after that.... I'm going to see what this engine will really do! I'm already really impressed getting on it at just 1/3rd and 1/2 throttle. I know that today 340hp at the crank isn't a lot but just coming from the NA engine I love the responsiveness.
