hey whats happen, finally done with my swap... (bb det) i got 1 question does **** run a stock us spec ecu from a regular sr20de? thats what im doin now and its running very well. and lil rich and a back fire every now and then... i was just wondering if **** else tried it? im planning on going jwt as soon as i get a lil bigger turbo... also when should i change my fuel pump and ignition? thanks 4 the input laters

um you did a BB swap and running a stock DE ECU and it is running rich??? That sounds out of the ordinary. Do you have an AFC??? Do you have any other problems during boost or any signs of running lean??? This could be something new, we might not have to call up JWT to get a BB in our cars!!! Let us know! I am not bashing at all I am just very curious how a 259cc injector program runs on 370cc injectors? Keep us informed!

i think its running rich... it shoots a lil blue flame when it back fires... naw i dont have a afc... but im not really to good with motors im still learning. but i guy that help me said if was running a lil rich... so im not really to sure. but i can honestly tell u i do have my stock ecu... at first when it is cold its really strong but after its warmed up it does seem to have lika detination or sumthing when i hit boost. but its only sumtimes im thinking maybe i need to mess with the timing a lil... i 4 1 thought i needed the jwt ecu but chris( the guy that helped me said jwt is a monopoly but not that big of 1 it'll run and run good i promise..) so i went with what he said and there u got it an sr20det bb with a a stock ecu, running pretty good... needs a lil tuning and i think it'll be ok... i guess ill just c what happens... im sure i would have more horsepower if i went with jwt.. but for now im ok...

I'm running the same way and yes it runs rich. THe ECU thinks it's running 259 injectors, so it's dumping fuel into the engine to compensate for the amount of air entering engine. For example, if the injector pulsates 5 times a second, it is dumping 259cc worth of fuel 5 times per second, but with 370's, it's dumping 370cc of fuel 5 times per second.(not a realistic example, but you get the point.)

Why don't you guy just get a BB ECU from Andreas Miko, Jason Garrett Young or anybody else? You'll have the right timing, right fuel and you will be able to send your DE core to JWT without downtime in the meantime...

So If I got a bb ecu, I wouldnt have to change anything else for the time being right? (Maf to be specific) 92 classic is the vehicle

Yes, this is correct. Loe Lyf had a very good example.

Is that how injectors work? A pulse is a pulse and they just pulse faster the more fuel is needed? Doesn't the amount change too?

If they ARE ciompletely digital, you might be able to make a digital circuit that multiplies the number of pulses times 0.7. 259 divided by 370 is 0.7, so you are running basically 30% more fuel than you should all the time I think. I was in computer engineering for a while, but I dropped out and became an IT guy instead, but I think a digital circuit could be made. importnut or bmoses might be able to make this...

But.... it may not be that simple. The fuel and timing curves themselves are different I believe. What kind of problems they might cause I have no idea. But I would imagine the fuel and timing curves being MUCH different than an NA car.

I'd say pick up a BB ECU for $150 or something and be done with it.

Yeah the cost will me the same:
You buy a BB ECU. -150$
You send your DE to JWT
You sell your BB ECU +150$

Or get an E-manage like me:D

Look at post 'Need help Dyno Results'

all i know is i did a lil test and tune last night and my car is pullingvery strong for haveing a stock de ecu... i got rid of the spuder like effect when going into boost by advancing the timing... i think that if u have a bb det u can get away withhaveing a stock de ecu but if u go to a bigger turbo or a lot of boost i would get a e management or mr. jwt ecu... like i said ** im not a mechanic but i know i have a stock ecu on a bb and it runs just fine...

Originally posted by skrible66
hey whats happen, finally done with my swap... (bb det) i got 1 question does **** run a stock us spec ecu from a regular sr20de? thats what im doin now and its running very well. and lil rich and a back fire every now and then... i was just wondering if **** else tried it? im planning on going jwt as soon as i get a lil bigger turbo... also when should i change my fuel pump and ignition? thanks 4 the input laters

Yes I know at least 3 people who do (and I'll being doing it next on purpose) this and I think more would if they just understood that the computer dosen't care what kind of injectors you have in it. As long as you can make the car idle basically the difference between BB ECU/SE-R ECU is the BB ECU is designed to idle 370cc/min SE-R ECU designed to idle 259cc/min but as we can all see the difference in fuel being dumped into the cyclinders at idle is not significant enough to make the car undriveable. Anytime you put larger injector into a car designed for smaller ones, ......a good rule of thumb is you will run that much richer at idle and maybe a little more in the rest of power band. You will never run lean, you will run lean on a JWT ECU befor you do on a stock ECU.

At idle the car is running super rich and idles like shit, stalls frequently, etc. But under load, it's fine, just baaaaddd fuel economy (230km = 42 litres of fuel:eek: )

Originally posted by Loe Lyf
At idle the car is running super rich and idles like shit, stalls frequently, etc. But under load, it's fine, just baaaaddd fuel economy (230km = 42 litres of fuel:eek: )


JWT $550
SAFC $300
DET ECU $100-150
Stock ECU FREE

1. If you buy JWT you have to pay and wait when you upgrade something (injectors, maf)

2. If you use SAFC you don't pay anything to put a upgraded MAF or fuel injectors up to 388cc/min.

If you want to go bigger than 388cc/min buy a DET ECU and go up to 555cc/min.

3. If you go the JWT route you probably are going to want a SAFC so you can lean out his rich setup thus making in a waste of money to but HWT in the first place.

4. SAFC is indespencable (sp) how ever you cut it.

i idle round 1100-1300 hot and 1400-1500 when cold but it idles just fine, and under load its stright to, i have my timing advanced 18* degrees. and i do also stall out every now and then. but its all good.

Originally posted by skrible66
i have my timing advanced 18* degrees.
I would be carefull with that. FWIW I was under the impression that the turbo ecus have a significantly less aggressive timing curve than NA ecus. On other platforms (drawing from my mustang roots :p) you usually retard the base timing a bit when running on the factory ecu. But hey, no detonation, no problems. Cool.

Originally posted by Ben92SentraSE-R
Is that how injectors work? A pulse is a pulse and they just pulse faster the more fuel is needed? Doesn't the amount change too?The length of the pulse changes too. Thats whats known as "pulse width". When the ecu wants to send more fuel, it holds the injector open longer. It only has a set amount of time (aka "duty cycle", the actual length of which is dependant on RPM) to hold the injector open. Hence when something like the MDM-100 (http://www.sr20deforum.com/showthread.php?s=&threadid=23062&pagenumber=1) is showing you "fuel injector percentage" what its showing you is the percentage of maximum duty cycle allowed the ecu is having to use.

Originally posted by Calum
I would be carefull with that. FWIW I was under the impression that the turbo ecus have a significantly less aggressive timing curve than NA ecus.
It really depends on the computer. Personally, there's no way I'd run that much advance on a DE ECU's maps with a turbo without access to a dyno. The GTi-R guys, on the other hand, crank theirs up to 20* and more, which makes me hella' nervous, but they seem to be making lots of power and not grenading too many engines. Go figure, but get a dyno too.