SC3Monster

My car is a 97, just put the turbo kit on saturday, stock fuel, MAF in blow through, with an SAFC-II on 9 PSI. My question is tuning related. I had the car on the dyno today and it made 254whp at 9psi through the stock auto (which seemed a little low but its tuned on the safe side) and it pulls like crazy at full throttle BUT (always a but lol) if i'm not full throttle ( IE crusing, or normal accel) it spits and pops and wont idle well AT ALL, but as soon as i floor it she wakes up and is just fine . . It seems like it gets progressively worse the more i drive, When i first start the car and drive it, shes fine until the first hint of boost and its like i lose all low end power until its floored. I didn't tune the car myself, I had someone do it for me,its going back on the dyno tomorrow to see if he can fix it, but i was just wondering if there was anyone that had ran into this problem before?!? I know he didnt do anything at all with the lo throttle setting?? and throttle point is like 24 lo- 75 hi i think?? I'm lost lol anyone???

lexforlife

iTrader: (7)

welcome to the world of obdII tuning .. been there ,done that with piggybacks esp on a obdII car .. the stock ecu is fighting the safc setting at closed loop .. open loop you can control but i assure you during the transition , timing is jumping all over the place =not good

the only way a na-t will run safe ,strong and stable is on a standalone .. i have tried all of the piggybacks from safc to greddy e damage ..

some will say otherwise but they dont always preach the truth about its true running condition

Ali SC3

iTrader: (10)

everyone who has run a piggyback on the GE ecu has experienced that before, you need an ecu that will be friendly with boost, like a standalone, or the tt ecu mod.

SC3Monster

Yep, thats what i was afraid of. This car is a DD so the turbo will be coming back out tonight :'( . . Now my next question. Anyone ever used the V1 AEM on an AUTO NA-T?? I know the V2 has better control for the auto but my power goals are only 400-450hp anyway??

Ali SC3

iTrader: (10)

yes many people have you can run it on the aem v1.
If your goals are 500, you can also just wire up a 2jzgte ecu with some 550cc injectors and be done no tuning required if you use a usdm ecu which you can also possibly even keep odb2 working as well.
I am running an aristo ecu with 440's on mine and it feels like stock again except with boost.
https://www.clublexus.com/forums/sc-...t-ecu-mod.html
Drives very similar to a stock tt supra which I have had the pleasure to drive several times recently and compare it to. There is more lag but thats expected between the twins and an aftermarket single.

with the ems you will have to get it tuned at least once and in my experience it can take several tuning sessions to get it running good enough for a daily driver with a standalone. boost always works fine its the idle and part throttle and all the little stuff that will have to be tuned by an expert, dont expect to just load up the basemap and it drive and boost good, because the basemap is basically just good enough to get the car started and rev it a little the fuel on the basemap is generally all over the place.

also for now if you stick the maf in front of the turbo like its supposed to be it will run much better.
Its not really supposed to be in blowthrough although some can get away with it, its supposed to be in drawthrough.
for low boost levels it should be tolerable with the maf in front until you get a better ecu.
I wouldn't go and pull the turbo off, thats alot of extra work if you plan to put it back on.

SC3Monster

Well my tuner found a way to make it "driveable", it runs perfect under full throttle,idles close to stock, and under normal accel it can be a bit "jerky" (for lack of a better word), but other than that its fine. . I'm setting aside funds as we speak for a standalone, but this should get me by for now . .

HiPSI

iTrader: (2)

Do you have any pictures of your setup?

Ali SC3

iTrader: (10)

I bet it is idling too lean most of the time (been there done that), you will never get partial throttle right in blowthrough as its hard enough to get working in drawthrough already.
you must realize full throttle is the easiest thing to tune as the ecu makes no changes whatsoever, but everything in between idle and full throttle the ecu tries to correct everything to 14.8 including when you hit several pounds of boost on partial throttle, so it adds a bunch of fuel, but as soon as you are off, it will need to pull fuel, and if you use the pedal like most people do, it is constantly adding and pulling fuel. The only way you can counter this at all is to put the maf in front of the turbo so it has somewhat of a real idea how much air is being compressed, and if you have a wideband and can monitor the afr's try disconnecting the o2 sensor to prevent the swinging and hope it works better, but a turbo ecu or standalone is what you really need.

SC3Monster

There is 2 02 sensors, so try unhooking both or?? I just dont know how i'd move it in front of the turbo, there is 0 room and the coil wire runs right in the way of the inlet, it doesnt even have an intake on it, just a screen lol. It runs pretty decent now.

Ali SC3

iTrader: (10)

both o2's, and normally people go 4" to 3" reducer coupler, 3" pipe to go past distributor, coupler to the maf, and filter on other side. this also allows you to recirculate your bov back into the 3" pipe.
Its up to you though, if you are alright with how it runs then leave it be, it wont be perfect in front of the turbo but should be as good or a little better.