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Discussion Starter #1 (Edited)
NOTE : The bottom line (TL;DR) is : 0.4 Bar / 6 PSI of Boost , 1:1 RRPFR at 3.5 Bar / 50 PSI on a 62mm Turbo and you should have a reliable boosted IS/GS300 that makes around 290hp/300lb/ft at the flywheel on the stock ECU without any piggyback whatsoever and it should last as long as your motor is healthy. Mine cracked a ring landing at 0.6/0.7 bar, don't be like me, fit a 0.4 / 6 PSI spring and run gate pressure as a boost controller will tempt you to turn it up, and when that happens, RIP Ring Landing / Head Gasket

Good day My.IS Users,

After doing a ton of reading and research, I finally decided to slap a turbo onto my 2JZ-GE VVTI and I'd like to share my experience with you.

I'm not an IS300 owner but rather a GS300 owner, I've had my car for just over a year, it has 123 000km on the ODO (+-76500 Miles). My car is well maintained, no prior issues at all.

The only mods before I did the turbo conversion was removing B1S2 and B2S2. Being from South Africa, our ECU's don't care about those two sensors as emissions isn't even a thing here, so I have no CEL, just two heater codes, no big deal.

My parts list included the following

Rev9 6266 Twin-Scroll AR70 Turbocharger
Generic eBay 2JZGE Turbo Manifold
Excell 38mm 2 Bolt Wastegate (Local brand, pretty much the best and most reliable wastegate around here)
-4AN Braided Line and Fittings for the oil feed (1/8 BSPT to 1/8NPT Adapter to use the oil sensor port for oil feed)
-10AN Braided Line and Fittings for the oil return (2JZ Oil return flange used instead of tapping or welding)
Aeromotive 1:1 Rising Rate FPR with -6AN to 10mm Hose Barb Rubber Fuel Hose for the Fuel Return
550mmx140mmx65mm Intercooler with Custom Piping and no BOV
Plug and Play O2 Splice made by myself
3" Downpipe made by a friend of mine, bolting to the stock exhaust system
Zeitronix ZT2 Wideband Gauge

Things left stock

ECU
Injectors
Fuel Pump (Because I bought a Walbro GSS340 instead of the correct GSS342 so this will have to wait, rather opting for a Quantum 340LPH due to the built in check valve)
Fuel Pressure (43.5 PSI)
MAF Housing (Chopped the MAF housing out of my spare air box so it reads 100% correct)

Things still to do

Make an intake
Run PCV hose to said intake
Run PS pressure release pipe to said intake too
Redo boost pipes so that my front bumper fits
Fix the minuscule leak on the sump because FIPG costs $60 here, ridiculous, but I'll just have to bite the bullet
Fit Transmission cooler

I've had everything fitted and running for 2 weeks now, boost set at 5 PSI. I've been keeping an eye on my AFR's and this is what I've learned.

At Idle and cruise my AFR's sit at a comfortable 14.5-14.9 and in boost around 11.4-11.9, never seeing above 12. The car feels great so far, I haven't had any issues. I don't rag on my car too often, I generally just do a pull into boost and then let off, but I've done a 3rd gear pull already just for the hell of it.

I'll update this thread with any issues or problems I run into over the course of the cars life, this is just so that there's more information regarding boost on the stock ECU.

This is my daily, I use her everyday however I do have another car should I run into issues.

Before





After

 

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Nice lookin home brew turbo GS300! Sounds like good branded parts, also.

" removing B2S1 and B2S2."

I know you stated you don't have emissions, but if the ecu operates similarly to USDM, then you need to splice your primaries: B1S1 and B2S1. These regulate off boost closed loop operation. These set the short term fuel trims that the open loop boost map is derived from. Here in USDM land if the stft are off then the fuel table changes every time you drive it. USDM emissions are based on B1S2 and B2S2, you can get rid of these with a simulator. Watch for detonation too. The stock ecu seems to pull timing pretty good but it really needs a piggy or standalone to alter timing based on boost.
 

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Discussion Starter #3
Hey man, thanks so much for the feedback, I actually made a mistake, it was like 2am and I was tired as heck. It is B1S2 and B2S2 that's removed and B1S1 and B2S1 that's tied together so not to worry about that. I'll do some more logs to see how bad the ECU pulls timing as well. I will eventually move over to Dezod AEM EMS V2 but that costs half of what I paid for my car, so that's a few months of saving.
 

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Hey man, thanks so much for the feedback, I actually made a mistake, it was like 2am and I was tired as heck. It is B1S2 and B2S2 that's removed and B1S1 and B2S1 that's tied together so not to worry about that. I'll do some more logs to see how bad the ECU pulls timing as well. I will eventually move over to Dezod AEM EMS V2 but that costs half of what I paid for my car, so that's a few months of saving.
I forgot to say "Welcome!"

I figured you had it wired correctly, but wanted to make sure. Yeah it'll be interesting to see how the stock ecu copes with boost. Definately keep the thread updated.
 

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Discussion Starter #5
Thanks for the welcome :)

I've been driving it a bit more, changed the Wastegate spring to a 6 PSI spring, it spikes to around 6 PSI and settles at around 4.5 or so. AFR's still around 11.5-12.1. I'm going to get that fuel pump ASAP and perhaps bump my base fuel pressure just a little bit for some overhead. I'll report back once I've done that. Also did a 0-60 run just to check the improvement, but for now I'll be driving it like I'm driving miss daisy.

Before


After


Both on the same stretch of road under similar conditions, ETC in PWR
 

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Discussion Starter #9
That light was me turning the traction control off manually before the run started to see if it would make any difference. I'm currently running a '6 PSI' spring, it spikes to 7'ish and settles at 5.5'ish PSI. 1st and 2nd has some good pull, but 3rd is such a long gear that you don't really feel anything.

Also, whenever I watch other Lexus 0-60mph videos, their transmissions shift from 2nd to 3rd at like 52mph or something like that, where mine is bang on 60mph. Weird.
 

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Discussion Starter #10
Did a dyno run this morning, our dyno's do a conversion to crank power and our measurements are in kilowatts and not horsepower. I'm pretty impressed with the gains actually, I'll note them down below. My boost is set to 6 PSI with a 6 PSI spring but drops to like 3 PSI, I don't know why, maybe my wastegate is defective.



Stock run : 148.5kw/265nm (198hp/195ft/lb)
NA-T : 182.5kw/378nm (246hp/279ft/lb)

Overall I'm quite happy
 

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Interesting to see running especially on a stock ECU, how is it adjusting the fuel map for the boost? I'm no expert but i would have thought it would go lean out under boost, but looks like its quite rich under boost (maybe too rich?).

I wonder if it is the JDM engine or the rest of the world 2J? The JDM version of the 2J has weaker rods in it for some reason, so going NA-T becomes a little more complicated than a simple bolt on for those of us with the Altezza variant. :(
 

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Discussion Starter #12
Well, fuel wise the only thing I've got helping the fuel system out is the 1:1 RRFPR, other than that the ECU is doing what it feels it needs to do. As mentioned before, at peak boost AFR is around 11.5-12.1.

I have the 2JZ-GE with the paper thin rods as well, I'm just working well under the limits from what I've read and researched.
 

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Discussion Starter #14
Just a quick update. She's still going strong. Added an MBC to try and assist with boost as I'm too damn lazy to remove the wastegate right now, it's such a massive effort. Fitted a Turbo Blanket and Re-ran my oil feed and wiring harness that sits right next to the head just to keep it out of harms way.

Anyhow, 6 PSI Spike, 4.2 PSI at 4500RPM, 3.5 PSI at 6000RPM. 6 PSI Spring installed. Ran against a friend of mine in a K20 FN2 Euro Civic Type-R, (217Hp, 2862lb) and it was dead even until around 125mph where I slowly started creeping away. Not bad for a 3736lb car that only makes 250Hp.
 

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Discussion Starter #16
125mph before you started creeping away�� Holy crap I hope you were safe and away from traffic haha
Ah it was like 1am on a Tuesday, zero traffic, not even a car in sight and on the freeway. I don't do this often, haven't for a while but I needed a benchmark of some sort, I'll probably never do it ever again. Next time I race it will be at the track.
 

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Ah it was like 1am on a Tuesday, zero traffic, not even a car in sight and on the freeway. I don't do this often, haven't for a while but I needed a benchmark of some sort, I'll probably never do it ever again. Next time I race it will be at the track.
Hey man, I race on the streets.(not always) What ever, as long as you play it safe and smart. I was shocked cause my races usually end about 110mph if that. Usually people back off or traffic keeps the race from finishing.
 

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Hey man, I race on the streets.(not always) What ever, as long as you play it safe and smart. I was shocked cause my races usually end about 110mph if that. Usually people back off or traffic keeps the race from finishing.
Haha yeah, sometimes we tend to not watch the speedo until we stop racing and then take a quick glance only to realise that we were going way too fast.

Ha, SA where its all legal till you get caught :)
Man, usually the first few things that go through my mind after a spirited drive are : Were there any cops, did anyone see me, were there any mobile speed camera's, am I screwed. That's why I tend to just be calm on the streets these days, I don't want to go to jail.
 
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