If you look at the bottom most line in this picture it's what you want to tee into for your map sensor. Its the same one that goes to fuel pressure regulator.

 

That's what I thought the vacuum diagram was showing, good to know I was reading it right, thanks!

 

Hi everyone. I hope everyone is doing well, especially nowadays. I am planning to go back to NA-T on my 99 VVTI sc300, this time with the TT ecu instead of a Greddy emanage ultimate. I have a couple of questions which I am slightly hazy about so some clarification would be great. My power goals are MAX 400-450whp, but probably more along the lines of 300-350whp.

1.Will I need a fuel return setup? Will I need a fuel pressure regulator (with and without return)? What size fuel pump is necessary?
2. How good is the XS Power Kit? The pricing seems very fair for what you get, but Ive heard conflicting things about it. I am leaning towards piecing together a simple kit unless there are any kit recommendations.
3. How much power can the GE VVTI handle? Ive heard conflicting info here aswell.
4. Will I need any additional controllers with my TT ecu?
5. Lastly, any other notable points for NAT that seem overlooked?

Thanks everyone.

 

I finally had a smoke test done to figure out lean issue (goes all the way lean immediately upon cold start and stays there when engine heats up).

Found smoke coming out from boost controller, egr block off plate, and the two nipples on the Q45 throttle body 😬

I removed the manual boost controller and ran vacuum line from turbo to wastegate, tightened bolts on egr block off plate, and capped nipples on TB.

Started her up and still immediately goes all the way lean (AEM wideband showing the three dashes “_ _ _”)

Got frustrated, so I decided to let the engine heat up and take it for a drive. The idle seems a lot more steady (600ish), no more surging idle, and pulls nicely at wot. Wideband still showing lean af and does not go rich even letting off throttle.

I’m thinking my AEM Wideband is malfunctioning. Well, I hope that’s what it is.

 

crevasse, there should be like a brass looking square plug on the back of the intake manifold that can be removed for the map sensor filter thing, it is hard to see its next to the one with the line going to the canister but it's down there. you can instead tee into the fpr, either way works.

Joe, I have used several aem widebands and they all generally worked fine, so maybe you have another issue going on.
did you reset the ecu? you need to reset the ecu if you found and fixed some leaks, so it will be forced to relearn faster.

if it is still going lean, then I think you may still have a leak somewhere or something physically wrong.
I would not keep boosting when it is lean, it is an easy way to blow the motor or loose compression.
maybe put the stock intake back on. the only other thing would be a downpipe leak, sometimes the v bands don't seal perfect and you get air in the exhaust and it leans out the o2.

 

Ok guys, this na-t support has gotten way off track now I just get a bunch of people pm'ing me lately thinking na-t is super easy and don't want to do any research or leg work. I will not be walking anyone through little issues or answering obvious questions anymore in great detail.

I think alot of us talk about na-t in a way that makes it sound simple or easy to do, but in reality there are tons of small things you need to do and understand.

NA-T is not easy, it is super complicated. It takes a lot of research. There is no set guide. You will redo things plenty of times over trying to figure stuff out.
Don't make too many changes at once or troubleshooting will be a nightmare. Don't do wiring with the power connected.
You will probably need a better transmission, and I don't care how low your power goal is you shouldn't be boosting a stock vvti 2jzge block without doing rods and pistons.

If it sounds like you did zero research before you asked your question, you probably didn't do any research and you probably won't get an answer.

If all of that sounds like too much work without someone explaining everything to you, and you would like to do zero research and still have a turbocharged SC, then buy a gte swap, buy a professional swap harness, and have a shop install it for you... it is really that simple.

If you are the type of person who can research and figure things out on their own, are excited about learning what works and what does not, and willing to ask questions when you get stuck (not for everything), then na-t might be for you.

Last but not least, if you mention you want to use the stock automatic GE transmission, you should not go na-t. Buy a gte swap or just leave it stock.

 

Fixed my lean issue. It happened to be the AEM Wideband Sensor. I had the sensor to close to the turbo and think that’s what broke it.

Nevertheless, with all the troubleshooting it allowed me to find small vacuum leaks here and there. Now the AFRs are almost perfect.

Thanks Ali

 

That is good news Joe cause I honestly ran out of ideas of what else it could be.

 

All good points, maybe pin some of that in the original post but not like people skim through this thread at all, everything you need is in this huge thread but people just skip to the end.

Honestly depending the route you go for some of this NAT stuff, it would be cheaper and easier to GTE swap.

I appreciate your help Ali it was super super helpful to me and my car is almost finished!

I have an easy question for you that I've probably asked and forgot. What can i do with the tank line that went to the charcoal canister now that I've deleted it?

 

Probably should add it to the first post, thought it might be too discouraging but I am starting to feel maybe some people need to know clearly what they are getting into before they start like a slight reality check that it takes a lot of work even though you already have a "2j" in your car. Just about everything else needs to be addressed for putting on a turbo and having it actually work right.

Alot of people run that line to the passenger fender where the is already a hose going down there that was previously connected to the bottom of the canister but that basically vents it to air.
Id say at least stick one of those clear fuel filters inline when doing that to keep some of the gas from evaporating etc.. depends how much race car feel you want but it can also get smelly in the garage and on hot days etc... I prefer to leave the evap system in place. I think one can even go to the vvti evap system that is located on the fuel tank on later years, but that is a whole lot of extra work I think I have seen that on one of gerrbs setups in his build thread, might have been the vvti na-t one.

 

I'd make a bullet point list, "you must read these before asking questions" with some of those points you just made. I was a total newb to the NAT 2J until i came across this thread, i've gone through probably just about every page of it, and then Jimmymac's thread fueled my build haha. Ironic that i talk to the owner of that car on occasion.

I pretty much just removed it to fit a catch can up there. I'll throw one of those filters in and run it to that lower hose. If it's annoying with smells i will maybe fit it back in there. It's nice to have a box with all the stock parts for bolts and stuff like this!

Thanks Ali

 

Not sure if anyone has insight here, but i couldn't ever get my tach working with the standalone (ecumaster black) using Pin #8 on the orange plug in the kick panel area passenger side.
My car is a 1997, do i need to do that resistor mod to the gauge cluster (bypass r109?) for this to function? A friend of mine has it setup without any gauge cluster mods but his car is older than mine.

 

I don’t want to make crazy power, I’ll start with that. Maybe 350-400. I have arp head studs coming in soon and a tt head gasket from tomei. My question is what is needed to add a 2jzgte jdm ecu without messing with the distributor and wiring in coils. Wiring isn’t my specialty. If anyone could point me in the right direction with an ecu that will take the least modding and wiring work that would be awesome. I want to keep the distributor and wires unless someone knows a simple harness or plug and play kit that will convert it to coils but I don’t see how without a vvti head.

 

Literally almost everything is not plug and play with NAT. I bought wasted spark coils for $50 and wired it in.

 

Hey Ali,

How do you keep your vacuum lines from popping off? The most important ones, like the WG > MBC and MBC > Turbo are barbed connections and I also have them clamped. Many of the other vacuum ports on the Intake Manifold and the one way valve on the heater valve are not barbed and they keep popping off after boosting. My boost cut is set at 20 PSI and the max I boost is pretty much 17 PSI before blowing a line. Then I have to pull over and find the one that blew off to put it back together.

I've added some zip ties to the ones that are barbed, but is there anything else that you have found that helps with the ones that are not barbed?
Example, the one in the red goes to my MAP sensor (connected to the Haltech Elite 2000):