NA-T Questions?? Ask the Guru
 

This is a thread for all my fellow Na-T people who have those random na-t questions they need answered like yesterday.
GTE peeps have too many threads already, this is Na-T related only.

I get tons of PM's for random Na-T questions and I find myself repeating lots of answers.
First, I am flattered yes thanks but after a while its a bunch of the same answers over and over again.
I will likely refer you to post here when you PM me if I think it will help others also.
If you want it to be anonymous I can post it without your screen name, but seriously no question is too easy when it comes to Na-T so just rip the band-aid off already.

Those of you who have asked me something via PM know I try and answer everyone back, so lets just get the common questions in one place on the forum and that will help out everyone (including my free time, thanks)

So ask it here and everyone can see the answers that I magically @%#@ out... seriously its magical.

Topics include Basic or advanced NA-T questions, FFIM, Fuel, ECU's, Tuning, theoretical physics (just checking if you are actually reading), catch can, charcoal canister, ACIS, whatever you can think of that remotely relates to Na-T.

And if you can stump the Na-T Guru... you will earn the title of Na-T Apprentice (or whatever you want really) :cool:

So things don't get crazy out of hand, I ask that you post your question with as much detail as possible, pics or videos are always good too if needed for clarity.

The quality of the answer will be equal to the quality of the question :thumbup:

http://elitetrack.com/wp-content/upl.../love_guru.jpg

I have a 95 5-speed sc300 that has been sitting for a long time because jm stuck on ignition. I plan torun 8-10 psi because i have stock w58. I would like to do the TT ecu conversion with STOCK distributor.
My parts list is: 550cc deatchwerk innectors, 340aeromotive fuel pump, TT HG, safc 2...
Im going to have to read post #4 a couple times to get it clear, but so far i need:Jdm ecu & Ds62 ignitor?
Do i have to run a maf infront of turbo if im keeping distributor? Is wiring the ignitor the only wiring i have to do to use jdm ecu?
What would you recommend i do if my power goals (WAY LATER DOwN THE ROAD) are only 400-450 and wanting to keep stock distributor with wires? Thanks in advance

Some other parts i will be using: 6266 .71 comp billet turbo, greddy rs BOV, tial mvr wastegate, safc2, arp headstuds,

copied your PM that I responded to
Hi, yeah that would work out fine. you can run 8-10 psi on 440cc injectors even and skip the piggyback, but yeah 550's and a safc should get you up to 16 psi on most turbo's even, thats about what I run most of the time I have 550's and a map ecu. safc will work fine and easier to setup just you wont get to set where boost cut is but with 550's I would think it will move it up to 16-17 psi for you at sea level.

you can use the stock distributor for that power yeah, just be sure to get a new cap and rotor from toyota. gap plugs down to .026 (you might be able to get away with .032 at that boost though).
JDM ecu and ds62 ignitor and just pin it up, ignition should work just fine. you can go coilpacks later if you want and add the extra wires. you still have to do the wiring down by the ecu to tie all 6 gte coils to the stock IGT ignitor wire. also note you have to change to map sensor also.

it is way easier than coilpacks and a good place to start. you can always go coils later on.
only tricky part is fitting an intake pipe on the turbo that doesn't rub on the distributor cap/wires, but you can use the 4runner cap to help, although its not the best solution it does work.

Also you run more boost on the w58 just be careful on the shifts like 2-3 and 3-4. I run alot more than that on mine and its been holding up just fine.

So you need the JDM ECU, TT map sensor, universal IAT (intake temp sensor), DS62 ignitor, Injectors, SAFC for 550cc's, and the fuel pump and tt headgasket are both good ideas, throw some arp headstuds to the list if you can afford them. also a 4 wire heated o2 sensor is a good idea and cheap online, its in the tt ecu thread.

The JDM ecu does not use a maf, so you will be needing that tt map sensor and intall a universal IAT and that will replace the maf.
This is ideal for boosted cars and the reason the mod works so well.

If your power goals are going up, then definately go with the 550cc and the piggyback, the safc will do the job and raise your boost cut to 16-17 psi at the same time which is nice, thats a good spot for reliable power on the w58 (assuming you don't have a giant turbo off a cummins diesel). Just make sure to get the new cap and rotor, fresh wires and plugs go with the iridiums BKR7eIX should work out just right. with the dizzy you have to drop the gap down, at low boost you might get away with .028-.032, but when I cranked the boost up on the dizzy I had to drop it down to .024-.026 so you might have to play around with it. you want as much gap as possible without brake up in boost.

If you get the "BKR7EIX" they come pre-gapped at .032 and you should only have to gap down a little bit if at all for 8 psi.
If you get the "BKR7EIX -11" they come pre-gapped at .042, don't get this one for the dizzy, you will have to really gap them down.

When doing the TT ecu mod with the JDM ecu, you completely remove the maf sensor, and install a map and IAT.
There is no maf whatsoever anymore, you will not need the ls400 maf or the stock one anymore.
This is good cause the maf is a restriction, and now you can use a BOV that vents to atmosphere like Tial with no issues.

Yes you still have to do that wiring by the ecu even with the distributor, reason is the GTE ecu has 6 outputs, so to work with the 1 coil, you have to tie the 6 outputs together.

So the run down for using the stock coil w/ TT ecu mod is....
Install JDM GTE ecu (it plugs in)
Install 2jzgte Map sensor and universal Iat (there is a diagram in the tt ecu mod thread for the wiring).
Install DS62 ignitor and tie the 6 gte IGT outputs together at the ecu to 1 stock IGT wire.
Install Injectors.
Install piggyback.
Install 4 wire o2 sensor.
replumb ACIS as in the tt ecu mod thread (simple vac line connection)
Tach mod for tach to work right (again in the thread).
you will need spare pins for tying the ignition outputs at the ecu and for the 4 wire o2 sensor.

Its still a fair amount of work but its worth it. basically when reusing the dizzy you are just skipping installing the coilpacks and running the 2 wires from the ecu to the ignitor.

USDM + MAP ECU on a 96 cali spec

As you are running a map, would there really be any difference between using a JDM and a USDM ecu?

I've read your post #4 dozens of times over the months and my understanding is that by adding a map into the mix, the 'maf' is removed from the system and the wires that used to go to the maf (96) will now go to the map ecu thus 'replacing' the newly needed tt maf with a map from the map ecu. I only have to add in a single tt map sensor.

Does this make the JDM == USDM + Map, so as far as the car is concerned should it not run exactly as good as be just as easy to calibrate? I've often wondered why you don't change to a USDM ecu since you already have a map ecu involved. Would that not solve the 110 MPH JDM speed limit issue as well as give you a base 550cc thus allowing the use of 1000cc injectors with the map (2x limit)?

Maybe there is a downside to the USDM + Map that I am not aware of?

-- Am I right in assuming that I am only going to have 2 o2 sensors on my downpipe with USDM?
Assuming that I run the old maf wire harness wires to the map ecu. As my 96 came with 2 heated o2 sensors on my exhaust (not counting 3rd under car for cali -- no clue what to do with that one) I was going to use 1 for the tt mod and 1 for the aem failsafe. My 3" down pipe currently only has 2 sensors, so wondering if I have to add a 3rd for any reason before I install it.

-- Where is the best place to actually mount the tt map sensor?

So there is a difference between the JDM ecu and the USDM ecu with a maf delete.

The JDM ecu is designed to run off the map sensor, so its internal lookups take that pressure or "load" from the map, and derive the actual "airflow" in another lookup table using rpm and other parameters inside the ecu, and then outputs the correct fuel. the timing is based on similar parameters as well as RPM. This works well with na-t cause changes in load between 2 turbo's will be more "linear" and even though one may spool faster than the other since we are feeding in load to the ecu, the ecu seems to take that load value and figure out small differences in the airflow values without any tuning devices needed (only reason I have a piggyback is for larger injectors not for turbo difference between twins and single).

The USDM ecu takes a maf input, this is basically skipping the "load" step, so the ecu never uses the load in its lookups (even though it has a seperate map sensor for boost cut it does not look at it for fueling), so the maf is giving the ecu the actual "airflow" which the ecu directly can use to inject fuel and timing.
So when you delete the maf and are using lets say a map ecu, the map ecu is taking the load as an input along with rpm etc... and then simulating the "airflow" output to the ecu.
So now the USDM ecu gets the airflow and if there are any differences, it has no idea of the load to apply a simple linear correction, any correction it applies will be to the airflow value, and the differences between airflow on a single turbo or a twin turbo are not very linear, so it wont do a good job of fueling or timing when using a single turbo without some kind of help.
So the answer is if you have a map ecu or vpc, and it is set up to output the correct airflow, then the USDM ecu would be happy and work properly. But if you just had it simulate what the stock maf does for twin turbo's then the USDM ecu would probabl not be happy with a single turbo.

So with the USDM ecu since its already one step ahead dealing with airflow, the ecu doesn't have that same ability to correct really well, so you have to make sure that airflow value coming in is tuned very well.
That is essentially whey there are like 4 different vpc chips and you have to copy their setups when deleting the maf, injector size, turbo type etc...

So that is part of the reason why I never switched, cause it takes more work to get it to run right as far as I understand, but It has been on my to do list to test it out at some point. I do have a map ecu which would be the better choice because you can tune cell by cell so in the end you should have the potential to make it work as good as the JDM ecu, its just alot more work. also I wouldn't go over 800cc on the USDM ecu, that whole double thing is just the upper limit it wont drive well there unless you are talking about 1000cc and E85.

USDM has 2 o2 sensors I believe, so if using a USDM ecu you need both in the downpipe close to each other.
You would need to add a third for the failsafe.

You can mount the TT map sensor anywhere really, just keep the vac hose a reasonable length and not too large diameter and make sure it has its own source, or what works well is Teeing it in with the Fuel pressure regulator on the stock intake. try and mount it on the intake side cause it gets hot on the exhaust side, preferably on metal. I have mounted it to the intake before but not everyone does that, firewall would be fine also.

Yeah, it's Magical! ^^

ALIGURU!
Hey man, Ive got a small one for you.

I decided to go with your FFIM framework from a thread. Mohammed S Bounce fed me everything you just fed him so his bill is payed up and i didn't have to bug you (until noW ;-).

I got everything ordered tonight.

I also got the RMR unit. With the AEM V2, is this still my best choice?

The one I got:

RMR-107-ASSY-CCW+A

82.5mm Throttle Body - CCW Rotation Incl. TPS Adapter

I was told to say "Pull from rear like Supra TT" when they email me.

Is that my best choice?

Thank You ALIGURU!

Yeah sometimes I have to let the magic recharge, but it always comes back...

Rmr is alway a good choice, great throttle bodies and slim. will work with the aem v2 using either the mustang tps or if you have the adapter just use the toyota tps.

CW is the right one for the 2jzge tps....
CCW is for a 2jzgte tps... which turns the opposite of a 2jzge tps.
so you will need a 2jzgte tps, and the 4 wire connector on your harness, you must flip all 4 wires, so if they are 1, 2, 3, 4 then you will remove and insert the wires as 4, 3, 2, 1 if that makes sense.

pull from rear is correct (sounds dirty tho), unless you are routing it from the radiator idle which I have never seen, most 2jz setups are pull from rear.

For the magic, fiber, a brain food like sardines, and a good probiotic will insure "magical" flow..

Ill get the CW instead when they email me. And I'll be pulling from the rear as always......

Are all year SC400 IACV's just as good for this application?

It looks like the only thing i am missing from my orders is the Q45 flange that I think needs to be welded to the shortened plenum. What part is that please?

The throttle body people emailed me. I told them I wanted CW and not CCW. He said do you still need the TPS adapter. I said..... sure. He said well it's CCW. I guess I can't use it if I get the GE, TB. What is the best thing for me to do for TPS if I order the CW model for GE?

hmm my brain food is pizza, those sardines are wayyy to salty.

Not compared to anchovies....

ALIGURU,

The throttle body people emailed me. I told them I wanted CW and not CCW. He said "do you still need the TPS adapter"?. I said..... sure. He said well it's CCW. I guess I can't use it if I get the GE, TB. What is the best thing for me to do for TPS if I order the CW model for GE?

Well the aem works with whatever tps you want basically so you could get the GE one without the tps adapter (and just use the mustang tps), but if the tps adapter only works with the gte one then I would lean towards that just so you have more flexibility in the future.

if you plan to do the tt ecu mod ever again you will need a toyota tps. so just get a GTE tps and re-pin the 4 wires, only takes a few minutes.
Then you can also sell it to gte owners if you ever part with it, basically you have all the bases covered.

you can see in the pic I made below that all 4 pins are just flipped, easy to do... connectors are identical.
GTE is: E2, IDL, VTA, VC
GE is: VC, VTA, IDL, E2
https://lh3.googleusercontent.com/-R...zgte%2Btps.jpg

Curious about your thoughts on a low-powered NA-T setup using the stock auto transmission. I'm talking about something in the 250-270RWHP range. Can the stock auto live behind this? Is it an issue of a 1-2 or 2-3 shift that kills the auto? This is just a fun cruiser car for me so I want to keep it as an auto, for the time being. Would just like a little more oomph when I hit the gas while already rolling. Can't imagine I'd be trying to launch from a dig or anything.

Thanks Ali!
I got the Toyota GTE model with the adapter. I only saw one 2JZGTE TPS for sale on eBay and it was OBD2, Non VVTI. I's imagine i can't use that one right? Unless i can broaden my search, there was "slim pickings" on eBay today for 2JZGTE TPS.