Mike2JZ

I get this every now and again with the new G4X whilst doing first start ups. If you aren't sucessfully able to start car then cylinder is probably full of fuel, making this ignition release problem worse. Get the car started and you probably won't notice it again.

Nice to see a unique difuser, not many of those about! looks good

sketch of extender r154.pdf Here's the dimensions you need if you can find a fabricator to do it

Agreed put it in TTC, thats also a good test. If you still make no boost on TTC then could be a leak or something more menacing. The BOV on a Jspec car does not need to be recirculated for the ECU & engine to function properly. So in that respect, won't make a difference to your problem.

IACV VSV is typical failure for intermittent second turbo. Also. Remove your air filter and stick a mirror down air intake and check the air intake hoses as seen above (black rubber bits). They tend to collapse and can strangle turbo's from doing their job. Also a common failure.

Almost seems like satire. Some good moments in there

VVTi engine is wasted spark one of the following pairs of cylinders should show misifre if an ignition coil failed. 1 & 5 2 & 6 3 & 4 Typically with an ignition coil failure like so you should have an engine warning light as the IGF circuit will not be complete and cause the EML to come on. So check your engine codes. Normally when I hear someone describe loud bang followed by loss of power I'd put my money on a blown boost pipe somewhere on intercooler system. VVTI is a MAF based car so any type of air leak can cause the car not to run or overfuel etc.

Buy a new shortblock from toyota. they will take your old shit in exchange.

New boot build looks great, much nicer than before.

Well if you were tighter before and have now gone looser across the board then that should explain your noise.

Check them again after you have run it a few times. Something could looser than you expect. Typically will make more noise with a loose clearance than a tighter one. How long were you running the engine for? If you have specced to a looser clearance then its expected to make more noise whilst cold, once heated up clearances should tighten up.

What camshafts are you running? If you have high lift 10mm+ then its possible for valves to touch. In which case you need to dismiss the factory repair guide as thats intended for stock cams, different ball game with high lift aftermarket valves as the motor will no longer be non interference as it is from factory. For high lift cams the install procedure should follow like: a) Without cams installed, set crank to TDC, then retard by 30 degrees. this will allow all pistons to be below the top of the the deck so no chance of valves hitting on install. b) install exhaust cam as normal. c) when installing intake cam make sure the lobes pushing down on valves, arent the same as the lobes that are being pushed down as the exhaust cam. that way no valve to valve contact possible. once isntalled. rotate both exhaust and intake to tdc. d) move crank back to TDC, install belt and away you go

The part numbers for those two pipes are: 87248-14240 87248-14230 You can only change them with the heater unit removed from the dash.

Valve seats might need to be recut.

It's certainly not best practive to reuse a headgasket and if possible I'd avoid. That said, I've reused before without issue. Your mileage may vary.

I'd have to disagree with that. Ive had my valve covers, inlet manifold and some other bits in the bay powdercoated for a few years now. Much better than any paint I've used, holds up well against the heat and is much more durable against scratches and such. These days, 2k paint or powdercoat/anodize is the way to go, everything else is a bit of a waste of time. From what I've seen nothing out there will give you a super fresh painted look after a few years unless the car is barely driven. It all turns to shit eventually. For OP, I've tried a few clear coats and such on fresh blasted parts before and its ok for intake side parts, but anything close to the exhaust turns a nice yellow/brown, so bit of a waste of time there. The best results I've had is to leave the parts bare after being vapor blasted, then use ACF-50 to keep it from corroding. Only problem is that if you drive the car enough you will have to apply new layers of ACF-50 on a somewhat regular basis to keep it protected, so bit of a ballache.

Yes connect it to the tach input on orange 36 pin interior plug. Don't forget you will need to bypass a resistor on your NA tach in order for it to work with the signal outputted by ECU.

I think after 2 bar boost its starts dropping boost near redline if I remember correctly. This is the T51 KAI which is smaller than T51R, T51R is a 1000hp+ turbo, so will make more power but less response compared to KAI Ignore that, forgot the bigger ones called SPL not R. Sounds about right for 1.4 bar. Just checked lee's graph at 1.4 he was doing 620whp

@Supraleeturbohas the same turbo, although slightly newer version I think, but still KAI non DBB. At 1.8bar on a non vvti engine with 272 cams he did the following power at the wheels. Basically on full chat at 5k, but getting good momentum from 4.5k. With VVTi I'd expect you would move peak boost about 500-700rpm earlier. Supraleeturbo is going balls deep on a 3.4 stroker and vvti, so will have some data on the future on the worlds most responsive t51

At full whack you will see somewhere between 700-800bhp. Advisable to stick some cams in engine and stock cams dont breath well over 6k and the turbo will want to make peak power after 6k. With VVTi, on full boost around 4500-4800rpm

The reshimming procedure will not require you to remove valve springs or change valve stem seals as you are only changing the shim that sits on the bucket. I don't know how long you have been running with that kind of power, but typically valve stem's dont need replacing unless you have issues with burning oil and you suspect one is damaged or worn from age and has gone brittle from many heat cycles. There are many different valve stem tools out there, I haven't used the one you linked, but have used similar products and they work fine. Given that you have a fully built engine, its possible that this valve clearance issue was a mistake from when it was first assembled, or perhaps the valve seat is damaged/moved in some way from running under high stress.

HKS cams typically use similar valve clearance specs to stock. A quick bit of googling shows that they should be 0.2mm intake & 0.3mm exhaust +/- 0.03. So going to stock specs will be fine. In the case of the valve that is to tight you won't run the risk of the valve touching the piston with these cams, however once they engine gets warm and everything expands you might find that you lose performance on cylinder one as the valve runs the risk of not being able to seat itself properly back into the valve seat. Over time this could lead to issues with burning out a valve for instance. You could confirm if this is the case by getting the engine warm then doing a combo of compression & leak down test, if valve isnt closing fully then you will have a leak from intake valve. I assume this is a stock engine, or has it been built before previously? It would be useful to know, but very hard to see with the head still on, if the valve clearance issue has been caused due to a movement in the valve seat or if something else has worn out over time. I'd start with changing the shim on that valve to bring it back into spec and see how it goes.

Correct, not flowing enough to cause a restriction at "lower" boost (though still flows enough to make rediculous power). Argueably better for longevity of all components as well. Thanks, everyday is a school day for me but always working towards trying to understand more and help guide other people, not enough good info out there sometimes. Turbine housing A/R is interesting. Seems counter intuitive, but sometimes bigger is better.

Copper is typically used for EMAP set ups as its cheap, easy to manipulate the shape, disapates heat decently and easy to flare the ends for various fittings. Although I have seen some people run braided hoses for this kind of thing as well. On my setup I typically have a MAP/EMAP ratio of less than 1. So exhaust pressure is lower than inlet manifold pressure, even at high boost whilst under 7000rpm. After 7000rpm my exhaust pressure starts creeping higher than inlet pressure. I don't rev my engine beyond 7500ish as the heads flow is done (1.5jz life), so exhaust pressure isnt really an issue for me which is nice as it let me identify other restrictions with my setup. However if you look at the above graph on a 2J stroker 6870 with all the bells and whistles comparing 1.8bar versus ~2.8 bar (100% wastegate duty). Then you can notice two highlighted areas. From everything I've seen with the 6870, the green area is it's most efficient point. In this area your MAP/EMAP ratio is less than 1, and the compressor seems to be working very efficiently. So the potential gains in this area are huge. If you command more boost here it will make it very easily, I've seen it on multiple occasions making north of 900ft.lbs of torque here with 2.4bar+. Obviously in the real world sometimes there are restrictions with traction, mechanical reliability, engine breathing/restrictions etc etc, so normally the boost is regulated in a way that you don't get hit with such a huge wack of torque. But the above image shows the potential gains in that area and how happy the turbo is to make power. Now looking at the yellow area. You can see on the red run, that power is nice and linear and torque hardly falls by redline. 1.8 bar on this turbo is efficient for the compressor and exhaust pressure is not a massive issue. Once you start turning the boost higher notice how the torque drops off significantly faster, and the power also drops earlier in the powerband. This is a good example where the turbo is being asked to work as hard as possible and physically it reaches a level where it runs beyond its compressor efficiency and the backpressure from the extra exhaust flow causes it drop boost as the turbine wheel and turbine housing can only flow so much before bottle necking. By redline, even though the wastegate duty is still 100%, the inlet manifold pressure is back down to ~2 bar from the amount of restriction it is working against. So although it makes more power and torque, from a reliability standpoint the turbo will have a much harder life being run like this hard compared to being run at 1.8 bar. All SRD builds are running 1.0 A/R's on 6870. Seems to be the best fit for the way the 2J wants to breathe whilst having a broad powerband. Running a smaller A/R will just become a restriction on the high end quicker than what you can see in the example above.