SR20 Forum banner

Another turbo B15 thread.

911 Views 9 Replies 5 Participants Last post by  Shaolin_racer
I'm still a noob when it comes to things like this, but I did search first. I've also searched on B15sentra.net, but most of their stuff is on the qr25. And I still could not find anything on running two ECU's. Is it possible?

The reason I am asking this is because I live in Cali, and I would like to be able to pass smog and keep my original engine. How hard would it be to use a JWT ECU for fuel, spark, boost ect. And run the stock ECU to handle the odometer and smog equipment?

I have also heard that Travis sells Greddy Emanage with everything already set up for a B15 sr20det. But I could not find that thread.

Thanks in advance.
1 - 10 of 10 Posts
your question does not make sense to me. I may not be familiar with B15's but i am assuming your car is like mine and there is only one plug for a computer. running 2 is nonsense. what you are suggesting is a piggy back system or using a SAFC. these are tuned with your original computer to run your injectors and monitor the maf. to my knowledge you could run a jwt ecu and it will work fine with your smog equipment.(if JWT makes a ecu for the b15) the problem is that turbo manifolds dont have places for the smog equipment to bolt. unless you buy a smog legal kit your not gonna pass smog legally in cali. there is a visual test and i dought you will even pass the sniffer at idle with 370cc injectors. i imagine you would need to do some fine tuning with a safc to get it to pass the sniffer. it is even gonna be hard to pass it with a smog legal kit.
Shaolin_racer said:
I have also heard that Travis sells Greddy Emanage with everything already set up for a B15 sr20det. But I could not find that thread.

Thanks in advance.
And Travis doesn't use the Greddy Emanage at all. He had problems with one on a B15 and hasn't tried another one since. I think he just had an early one, and didn't upgrade the firmware.
JWT does't make an ECU upgrade for the b15 sr20. They believe that there isn't enough of a market to make one. The b15 sr20 was only made for 2000 and 2001. I think that their solution and a 97 ECU and a re-pinning of the harness. Which will make most of the smog equipment useless(correct me if I'm mistaken).

If I do use the S-AFC with 370cc injectors, I can only tune it to lean out 50%. 370cc is 70% larger than stock(259cc, I think). This means even if I lean it out as much as possible, I'm still running 20% rich. If my understanding is correct.

I also think I could bolt smog equipment to the down pipe. I believe another member of this forum did it on his silvia/240sx.

Thanks wedge02specv. You just saved me from looking at the entire b15sentra.net performance forum, again.
Shaolin_racer said:
If I do use the S-AFC with 370cc injectors, I can only tune it to lean out 50%. 370cc is 70% larger than stock(259cc, I think). This means even if I lean it out as much as possible, I'm still running 20% rich. If my understanding is correct.

You could most likely control the 370cc injectors with an AFC, but they are very close to the limit. (259 * 1.5 = 390) So you would be very close, but I bet you could do it. The only other option you may have is the Greddy Emanage, but no one has done one on a B15 yet (atleast to my knowledge). I'm trying one out on my Spec, which has the same ECU archetectire (sp?), I'll update you when I get it done and tuned. Should be within a couple of weeks.
Shaolin_racer said:
JWT does't make an ECU upgrade for the b15 sr20. They believe that there isn't enough of a market to make one. The b15 sr20 was only made for 2000 and 2001. I think that their solution and a 97 ECU and a re-pinning of the harness. Which will make most of the smog equipment useless(correct me if I'm mistaken).

If I do use the S-AFC with 370cc injectors, I can only tune it to lean out 50%. 370cc is 70% larger than stock(259cc, I think). This means even if I lean it out as much as possible, I'm still running 20% rich. If my understanding is correct.

I also think I could bolt smog equipment to the down pipe. I believe another member of this forum did it on his silvia/240sx.

Thanks wedge02specv. You just saved me from looking at the entire b15sentra.net performance forum, again.

I believe all of the SMOG equipment would work, as long as you have it on the car. You have to re do your harness somehow and run a 95-97 ECU. Travis will have to help you more on that.
You are confused about a few things. First of all the ecu does not store the odometer reading.

If you are woried about passing california smog then you are going to have a ton of issues trying to turbo your car at all. There are really no manifolds that allow you to run the egr because there is no bung to allow it. Not to mention all the parts on your car won't be carb legal.

As far as actually turbo'ing your b15 you do have a few options. Some people have run a afc, it does work but takes quite a bit of work to get it tuned right. The other option is choosing to run some other ecu, this will involve modifying the wiring harness to allow for it though. The easiest and most elegent solution which I choose was to use the b15 engine harness and cut off the ecu connector and splice in the b14 ecu connector. You have a lot of other options though, its just a matter of what you feel will be best for your car.
"The easiest and most elegent solution which I choose was to use the b15 engine harness and cut off the ecu connector and splice in the b14 ecu connector."

Do I have to cut the ecu connector, or could I re-pin it with some kind of pin extraction tool? Where could I find a wire/pin-out diagram of the harnesses?

"There are really no manifolds that allow you to run the egr because there is no bung to allow it. "

I'm pretty sure I read in a thread that another member made a bung for an EGR valve on the down pipe. I believe it was for a 240sx. Not sure how it worked however.
You could repin but the pins are differeent sizes between the model years so that isn't the best solution. They could easilly pull out. Best sure connection is to cut and re solder.

Yes that could solve your EGR if you have a shop that is only looking at that. But most shops don't really care in less they see a carb sticker.
Should I just get good at swapping sr20's if I can't find a "turbo" friendly shop?
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top