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So something I that I just thought about now that it's getting closer to me boosting me the car was planning on doing it this weekend. How is boost controlled on the jdm tt ecu if I'm not running any type of boost control solenoid? Don't I need some type of unit to control boost on the cold side of the turbo?
 

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Discussion Starter #62
if you have a single turbo like a T3 or a T4 then they normally have an external wastegate and the boost is controlled by the wastegate spring and you connect a vacuum line from the front of the turbo to the wastegate. The ecu does not control the boost when you go single turbo so basically on any na-t its mechanically controlled by the wastegate. the tt ecu does not care it just sees what psi you are at via the map senor and its happy as long as you dont hit boost cut.

For example, I have a 9 psi wastegate spring in my car. with just the vacuum line from front of turbo to wastegate, my car will boost to 9 psi and then hold right there.

to get more boost, you can run a boost controller, for example I have a manual boost controller inline on that vacuum line, and if I turn the knob on it it will raise the boost level, usually I have it set to 18 psi. so the car will boost to 18 and then hold.

The TT ecu has a factory boost cut at around 14 psi (at sea level) or like 16 psi if you are at an elevation like me (Denver is a mile above sea level).
so if you plan on booting more than tht, you need a boost cut controller (like greddy) but be careful cause this removes it completely, so if something goes wrong and you overboost (like the wastegate vacuum line melts of comes off) ten you are on your own to let off the gas to save the engine when you overboost to 20 psi in a second or so...

or you can also bypass boost cut with a piggyback and larger injectors like I run the map ecu with 550cc injectors and it gets rid of boost cut and actually lets me set where the I want it, so I have my boost cut set to 20 psi cause I run 18 psi, so if something goes wrong and I build more than 20 psi boost cut kicks in and saves the engine. I prefer using the map ecu because of this. the emanage can do similar I want to say, even the aem fic. you can even raise boost cut with an safc, but its not as clear cut.
 

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thanks alot ali for always having quick replys this is what i thought until someone i worked with asked me how i would control the boost. got me second guessing myself... haha but this confirms what i thought i already have my wastegate set to 8 psi going to run this for a while and see how it fairs. have a tt headgasket and 440's. hoping to see atleast 300 wheel on this and depending on how the w58 holds up to that i will go from there. thanks again and will post my setup once im done in the nat pics section!!!
 

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well i finally got everything on and situated!im fairly happy with the outcome running on 8 psi. the only thing is i am still running rich on which is weird. so at start up it will ready okay 14.7 give or take a few then once i start driving i almost never get into the 14,s when i come to a stock it pegs out at 10 if im daily driving around 2k or so ill read 12,s it seems to be doing just fine at wot dipping into mid low 11,s im really not sure why my afrs are weird like this. im still on 1 wire o2 will be switching to 4 wire very soon hoping it might be a bad o2. Any ideas on what else it could be was going to test the map sensor and iat to rule those out. my setup is stock bottom end tt headgasket arp headstuds, distributor delete with coil on plugs, tre performace 440's, offcourse running map sensor and iat on jdm tt ecu, comp 6265 turbo tial wastegate on 8psi spring as of now. ANY HELP IS MUCH APPRECIATED THANKYOU!!
 

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Discussion Starter #65
could be the o2 sensor is old and slow, or the 440's you have flow a bit more than the stock ones, it seems like its 1-2 afr points richer than stock. try the new 4 wire o2 sensor, if that doesn't do it then get a safc or something and trim a little fuel back, this is normal when using aftermarket injectors for it to be off a couple % or so. if its running and driving fine then its not the map sensor, iat normally doesn't make a huge difference on these ecu's once warmed up. boost afr sounds good though, so also maybe jsut give it some time to drive around and learn.

also if you are in Japan like your signature says, you could be at elevation (not sure what it is), sometimes that can affect the exact fueling but it should be pretty close.
 

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thanks for the input man. i wired in the 4 wire and it still does the same thing. im at sea level. what is weird is right at start up its 14.7 then within 1 minute it drops to 10 flat and just daily driving while its starting to warm up it will be 11-12's. then once fully warmed up if im riding at about 35-40 mph in 4th gear and if i stay on the throttle itll be low 14's the second i let off it goes to 10's. and during engine breaking wont get higher then 13.5 depending on rpm. if not map sensor im thinking of just changing injectors upgrading fuel system and getting safc seeing that the injectors are a cheaper ebay brand (TREPERFORMANCE)
 

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Just a fyi for anyone doing it. I used a regular old relay on my jdm NA supra with an aristo ecu for the a/c amplifier problem. The ground signal from the hvac triggers the relay and sends 12v to the ecu to turn the aircon on
 

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Discussion Starter #68
thanks for the input man. i wired in the 4 wire and it still does the same thing. im at sea level. what is weird is right at start up its 14.7 then within 1 minute it drops to 10 flat and just daily driving while its starting to warm up it will be 11-12's. then once fully warmed up if im riding at about 35-40 mph in 4th gear and if i stay on the throttle itll be low 14's the second i let off it goes to 10's. and during engine breaking wont get higher then 13.5 depending on rpm. if not map sensor im thinking of just changing injectors upgrading fuel system and getting safc seeing that the injectors are a cheaper ebay brand (TREPERFORMANCE)
is it an aem wideband? aem widebands always say 14.7 when you start it, then after a few seconds it goes to the right number, thats the heater heating up and getting the readings. so that means it was never at 14.7, its probably at 10 when you start it which is way too rich. starting afr's should be 11-12 and when warmed up it should be like 13-14 without an o2 sensor, so you are a whole 2 AFR points off according to how mine works. its likely the fuel injectors, one time with the cheaper ebay brand members could not et their cars to run proerly, its a waste of money even though it seems like a good deal. installing good injectors fixed the issue in that case, it was literally nothing else. the only ebay injectors that are good and reasonable seem to be Oside tiger, as they are rebuilt ones here in the US. the ones from china or resold out of cali stay far away from, then are not real oem quality and your 2jz will never run right.

Just a fyi for anyone doing it. I used a regular old relay on my jdm NA supra with an aristo ecu for the a/c amplifier problem. The ground signal from the hvac triggers the relay and sends 12v to the ecu to turn the aircon on
you can use the regular relays but they are sort of large to stick down by the ecu, and they say they don't trigger as reliably with these lower level signals vs like 12v from a line from a battery, (they have like a threshold switching voltage) but if it works it works and def easier to get at a parts store.
 

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Ali_SC3 do you have a write up for the tt auto trans? I happen to have one sitting around from the IS build lol. I believe I could rob the wiring from an IS300/SC300 auto harness, and I could rob wiring for the coils and igniter. I would love to build in stages as I think going from N/A to 600whp would leave me in the ditch.
 

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Discussion Starter #70

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Ali_sc3, have you figured out how to, or find someone who has, swapped a JDM 2jzgte ecu into a USDM 98+ vvti 2jzge? Such as a 01 is300. It's already got the coil on plugs.
 

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Im running a JDM GTE ecu with the wasted spark COP set up from the vvti set up and it works fine.

What are you having problems with? The wiring?
 

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Discussion Starter #74
Its been done and you use the JDM 2jz vvti ecu, it has the same connectors as the 2jzge vvti ecu but there are a few wires that are different.
if you run that ecu you will need the tt maf also as those ecu's run on a maf sensor for fueling (or some type of maf delete piggyback like the map ecu etc...), and they also have a map sensor for turbo control etc..
I'll see if I can find the post on it, it was posted somewhere in the tt ecu mod thread on club lexus.
 

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Discussion Starter #75 (Edited)
check out this page
https://www.clublexus.com/forums/sc-1st-gen-1992-2000/492459-2jzge-na-t-tt-ecu-mod-86.html

and this was also posted by a member (click on it a few times to zoom in).
RmtSUTO.jpg

the advantage of using this ecu is that vvti will still work, but obd2 port will not work like stock.
connect the tt maf to your existing maf plug, and wire in the extra map sensor separate.
for the map sensor you can tap into the 5v power and sensor ground at the tps, and run a signal wire to the ecu.
you could also run all 3 wires and tap at the ecu, but note the map sensor uses the sensor ground (for 5v sensors like map, tps etc..) and is different from chassis ground.

injectors are 330 stock, so you will need to upgrade them to 440 as I think the jdm vvti uses 440cc, do some research to confirm.

As a general reminder, the vvti 2jzge has a weak bottom end and you have a real chance of breaking it with a turbo.
most people wont push more than 8-10 psi with a solid tune, as the harder you push it the more likely it is to break, do some research on how much is safe to run.
alot of people change the block out for a non vvti block, and put the vvti head on it with a tt headgasket, then you can run alot more boost.
 

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I'm just trying to figure out how to do the swap. Wiring the ecu doesn't sound too difficult and with all the info on here i should be able to figure it out. Just trying to figure out the process ill have to go through and the parts required. I have a 01 USDM vvti 2jz so I already have the COP, or is the wasted spark COP somthing different that i will also have to do?

Sorry for all the dumb questions, lol
 

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I'm curious about doing this with Hyundai Coils: DENSO 6738312 (Hyundai PN: 273013C000) They are 2 wire and use the same connector as the GTE coils, I've heard they have been used with good success at high HP and are readily available for cheap at junkyards or even brand new. Would they be wired in just like GTE coils? I'm not sure if they return their own IGF signal like the ZZ coils or need an IGF simulator like the LQ9 coils? Looks like they would fit nicely under the stock intake manifold though.
hyundai coil.jpeg
 

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Discussion Starter #79
you could use those coils but they are just regular 2 pin coils like factory gte coils so they wont have the built in ignitors like 1zz coils.
They are also individual cylinder coils, so you will need 6 of them, and you will also need to wire up a tt ignitor instead of the ds 62 ignitor as the ds62 only has 3 channels, and for individual coils you will need the 6 channel gte ignitor and also the extra wiring.

I would honestly run the 1zz/2zz coils for individual, they have internal ignitors so you wont have to run the separate gte ignitor
 

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Hmm, good point. The reason I looked past the ZZ coils is that they wont fit under the intake manifold... how about the Audi/VW coils (Bosch 0986221023) or the Toyota Yaris (Toyota P/N: 90919-02240 // Denso P/N: 673-1306) 1NZFE / 2NZFE Coils?
http://www.turbofast.com.au/lexusignition.html
Would they wire in like the ZZ coils?
Ohhh.... and what about Nissan R35 coils (HITACHI IGC0079)? They're 3 pin I believe...
 
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