Thread: Benefits from a JWT ECU?

With the current prices of used JWT ecu's, it would be a great start. I dynoed my car with and without my jwt ecu on my old S3 cams and lost 5whp/13wtq. IMHO given you don't really want to DIY tune, go with a jwt ecu. Used ones go for $200-350, you might find one with a program that you need too. Otherwise your looking at spending 2hrs on a dyno with a realtime ecu which costs more than the used JWT. For bang for buck jwt ecu is hard too beat.

Another cost factor is the wide band. I don't think it's advisable to go with a Calum ecu -- either the Moates burner or the real time version -- without using a wide band to work with your AFRs on the street. Otherwise, when you show up at the dyo, you may be spending lots of time (maybe equivalent to the cost of a wide band) getting your AFRs set up.

In my opinion, the decision between Calum and JWT should be based on whether you want to learn about doing this stuff, or you just want to plug and drive. It's not really a cost-based decision.

Only place I dont think that last statement you made billc, would realy come into play is if you have a pretty normal car. Straight bolt ons or very little...you can go with anyone's tune out there. The tune in my car, which was one of the many bases that people started with from years ago, has its A/F r's pretty darn spot on. We didnt have to really futz with them at all. For a N/A setup with no cams, its suprising how close to stock the rom can be. Lot of people throw in a rom from the community, and run/dyno just fine with a/f r's that are ok.

Now if you have a turbo, cams, or nitrous....all bets are off. JWT for plug n drive. Or spend sometime with a wideband.


but...it really should be about wanting to do this. to me, people should want to know how to do this like how they want to know how to put a header on the car. its just as easy/difficult to learn

I would tend to agree with your point, Bowlcut, but I wonder how much of the "universal correctness" of the AFR for normal cares is just because people often don't check it with a wide band.

For example, I got a JWT for my standard VE with Fuju, DE MAF, VE injectors, expecting it to be pretty close to what was needed. When I checked it with my LM-1, I found WOT AFRs at 6000 RPM between 14 and 15. I'm not blaming JWT -- they were great and worked with me to reprogram the tune 3 times using my AFR data at no cost to me.

Then, for my bolt-on DE, I started with Calum's DE tune version 4. I found this to be rich at low loads and and lean at high loads/low-mid RPMs for my car.

In both cases, I would not have known had I just driven the car without checking. So, all I'm saying is that there may be more variation than we think, just because most folks who plug and play don't check. Or maybe my cars are just outliers.

Food for thought.

Bill

I love my JWT ECU,best money I ever spent on a performance part on a Nissan.