# JWT Turbo ECU Question



## zeno (Sep 17, 2002)

What would happen if I put in a JWT ECU w/ the turbo program in my NA car? Would the only effect be that it would run rich? Would I still get the added hp, rev. limit increase, etc. that a normal JWT ECU would provide? I'm just curious because I'm slowly going turbo and found a pretty good deal on a used JWT turbo ECU.


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## James (Apr 29, 2002)

yeah you'd just run rich all the time if you use the 370cc injectors/ECU combo with your NA engine.


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## zeno (Sep 17, 2002)

I read on the sr20deforums that I would have to upgrade the injectors to match the ECU program (in this case, 370cc instead of the stock) or it would run to lean and probably damage the engine. Does this sound accurate?

Also, would I still get all the benefits of the JWT ECU?


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## James (Apr 29, 2002)

if you don't use the 370 cc injectors the time the injectors open will be shorter so yes you will run lean. if you use the 370 cc injectors you will run rich. the only real benefit I can see from using the ecu NA is raising the rev limiter but I don't see how that would really help when everything below is running like crap!


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## javierb14 (Jul 9, 2002)

http://www.nissanforums.com/showthread.php?threadid=25561


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## SE-RtinMI (Nov 3, 2002)

James said:


> * I don't see how that would really help when everything below is running like crap! *


Have you run your car like this? SOunds like you have..... Well I have and my car ran Very strong. I had 390cc [email protected]/Bored MAF program and ran it NA. Ran very well, not rich either. I also ran the C2 program w/o the cams in for 1/2 a year and that was great as well


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## PatScottAKA99XE (Apr 30, 2002)

It should run fine, turbo cars are not always making boost. Remember that.


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## James (Apr 29, 2002)

SE-RtinMI said:


> *Have you run your car like this? SOunds like you have..... Well I have and my car ran Very strong. I had 390cc [email protected]/Bored MAF program and ran it NA. Ran very well, not rich either. I also ran the C2 program w/o the cams in for 1/2 a year and that was great as well  *


Well whenever the couplers pop off the car is basically running NA with 370cc injectors and JWT ecu... it runs like crap and stalls out all the time!


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## PatScottAKA99XE (Apr 30, 2002)

Thats alot different than running NA.


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## UnderDog (Jul 14, 2002)

http://www.nissanforums.com/showthread.php?s=&threadid=25561

javierb14 said he ran the turbo program while n/a and it worked fine.


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## James (Apr 29, 2002)

guess if the ecu ran for a while NA it might run better... dunno... every time I run it like that I get a whole lotta black crap on my tail pipe...


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## PatScottAKA99XE (Apr 30, 2002)

The question is James, When you say you run it NA what do you mean? Having couplers popped off isnt close to being NA. Have you run the ECU with no turbo related hardware on the car other than the ECU?

The car shouldnt run richer with a Turbo ECU/NA engine combo. Why??? The maf flow and 02 sensor readings are what dictates how much fuel to give. Without the turbo on the car the maf will simple not see the huge amount of flow the turbo would normally give it and therefore it wont dump the same amount of fuel as it would if the turbo was on it. Just because you have bigger injectors does not mean the car will run rich. The ECU will learn itself to shorten the injector pulse width(Open time) by reading the O2 sensor. Unless you are running huge injectors it can learn to control itself. Sometimes you will have rich-at-idle problems with huge injectors becasue the ECU cant shorten the pulse width enough, I dont think that would be a problem here. The main point is the ECU can differ the amount of open time for the injectors. The time they are open is not set in stone.


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## SE-RtinMI (Nov 3, 2002)

Exactly, Hit the nail on the head in that post


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## James (Apr 29, 2002)

PatScottAKA99XE said:


> *The question is James, When you say you run it NA what do you mean? Having couplers popped off isnt close to being NA. Have you run the ECU with no turbo related hardware on the car other than the ECU?
> 
> The car shouldnt run richer with a Turbo ECU/NA engine combo. Why??? The maf flow and 02 sensor readings are what dictates how much fuel to give. Without the turbo on the car the maf will simple not see the huge amount of flow the turbo would normally give it and therefore it wont dump the same amount of fuel as it would if the turbo was on it. Just because you have bigger injectors does not mean the car will run rich. The ECU will learn itself to shorten the injector pulse width(Open time) by reading the O2 sensor. Unless you are running huge injectors it can learn to control itself. Sometimes you will have rich-at-idle problems with huge injectors becasue the ECU cant shorten the pulse width enough, I dont think that would be a problem here. The main point is the ECU can differ the amount of open time for the injectors. The time they are open is not set in stone. *


Yeah you're right... was thinking about it tonight on the way home... forgot that it's after the MAF where the couplers keep blowing off! hehehe... sorry!


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## Niceguy (May 30, 2003)

If you use the JWT 100 shot ECU, it has provisions in it for N/A use. You WILL NOT run insanely rich. It WILL NOT have turbo timing and fuel maps. It will be tuned for 370cc injectors, and the timing maps should be setup for an N/A car.

Then, it should have the provisions for nitrous mode. Timing will be decreased, more fuel, and voila. You're making it more complicated than it is.


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## TheVodKA (Sep 19, 2002)

Niceguy,

The idea is well....nice, except for the fact that he wants to go turbo within a short period of time and test out how his fuel system runs w/ the ecu programming (for a more detailed explanation, check out how not to do a turbo install in sr20deforums.) The fact that he would not have the turbo program would be worthless for the sheer fact that he would have to reprogram it for turbo fuel setting & timing when he does, thereby costing more money & a lot more downtime


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