Thread: JWT and 25* timing

its not all that bad, it depends on what the cam likes for timing. Back when i had my first se-r with a jdm motor in and full bolt ons and stock cams the motor loved 21-22 deg timing on 93 octane. Any more it would ping, any less it would not have the same power and response.

When i did the jwt s3's i left it at 22 deg timing and it pinged down low and didnt make as much power up top. I lovered it to 18-19 deg and it ran great.

So it all depends on the cam and the rest of your setup. 25 deg is not out of the question in my opinion. It can vary soo much just from exhaust size, header flow, fuel tune, and so on.

The base idle timing starts at 25 degrees on my ECU. Most factory ECU's start at 15*.

I, also, ran my stock ECU around 22 degrees. For the exact same reasoning ashton said.

I have my distributor set around 28 degrees right now. I lost power when I had it at 32 degrees. Brought it back some more and gained nothing so I went back down to a safer 28 degrees.

Either way, whatever you do to your timing, the base idle timing that is programmed on the ECU and the physical location of the dizzy need to be in sync before you fiddle with stuff.

For example, my stock P.O.P JWT ECU program displayed (via nissan datascan and consult) 15 degrees of base idle ignition timing. I had my dizzy set to 15* (via timing light) and the car ran great.

When I got my JWT ECU back from them after being reprogrammed, it would display 25 degrees as the base idle ignition timing. I had no idea that the relationship between the two needed to be matched. This had me running 15* of physical timing on the distirbutor (via timing light) and the ECU was running the program set for 25*. Therefore, my timing was retarded ten degrees throughout the entire RPM range. from zero to redline.

How much you advance it can be done in a huge variety of ways. I recommend using a dyno and seeing where your power drops off. Although that can cost money, you will get the best results.

If not, do it the cheap way. Find a large hill to crawl up in 4th or 5th gear while going WOT and slowly crawl up there. Advance the timing little by little and do runs. If you hear it detonate, go back at least 3 degrees and try it again.

WARNING: I take no responsibility for anyone fucking with there timing because of this thread and my discussion around it. If you want to know what your ECU is programmed for base idle ignition timing, buy a consult cable and email me and I can supply a link for free version of some sort of way to connect your notebook PC to your car via consult. This can DEFINITIVELY identify what your distributor BASE setting should be. All adjustments should be made from that point.

I had plus SEVEN degrees of timing on the factory ecu over the entire ECU timing program. (From 15* to 22*) Makes sense, they tune very conservatively.

For my currently programmed JWT ecu, I have plus THREE degrees of timing over the entire ECU program. (From 25* to 28*). JWT tuning on the safe side, my dyno proves I made more power with more timing and eventually lost power when I added too much.

My dyno also proved how worthless the SAFC II is on a JWT ECU. (ok maybe not worthless, but JWT is pretty good at doing what they do on a large scale for a giant variety of cars in thousands of different conditions) I set my fuel to +8% from 4000 RPM to redline and yes the AFR's richened up a bit as shown via the wideband sensor but it made no power. The only thing I did not do was lean it out some more. I probably, about 95% sure I would have gotten more power by using my SAFC II to lean the mixture a tad.

yep. thats where my old S3 cam'd usdm de made the most power w/ typical bolt-ons. even WITH the jwt ecu

They do not write on every single label what the timing is.

If they wrote nothing on the label and you are not running big cams, it is 15*.

Otherwise, they should have written (25 degrees base idle ignition timing) on the label. At least this is what Ben has told me.

unijabnx2000, they would need the program that is written on the chip inside the ECU that is on the daughter board.

4 screws remove the metal cover lid. 4 more screws allow the daughter board to be flipped over so you can read the program that is hand written on the label. This allows JWT to identify everything that is programmed on your ecu, along with what is written on the label.

Thanks. If my plans dont fall thru, ill be switching to standalone before end of the month. But ill get the code anyway for the heck of it.

A standalone is, by far, the best option. Better than all the factory ECU stuff.

I wish I could get an Apexi Power FC. That is what I have my heart set on as far as engine management goes.

What did you want to purchase?

I already have a AEM EMS, i just need some pigtails and iat and map sensors. then ill be making the appt for the install, i just dont know how much the machining and ceramic coating is going to run me yet.

Awesome. Good for you, I am green with envy.

I'm glad you found out about the 25º BTDC, as you stated that doesn't necesary means that this ECU raise timing over 10º in the whole map, it only means that the raises (increments) around the map are shorter to get the target timing (BTDC plus raises). If the timing is 42º it means 42º - 25º = 17º of raise IIRC

For the cams, You cannot tell a cam by the max lift or degrees, even when they look like the same in paper doesn't mean BC2's are the C1 version of Brian Crower, it's all about area under the curve.

The proper way to find out the differences between these cams would be using Dr Cam or other kind of machines/software to get the 360º diagram of the camshaft.

Take a look to this PDF explains the basic of cams and mechanisms.

As you can see the diagram can show you Displacement, Velocity, Acceleration and Jerk (acceleration derivate), the displacement is the first function you get and the rest are obtained doing simple calculus, if the BC2's lobes have a smooth displacement compared to the JWT C1's all of the consecuent functions will be affected giving you a wide difference between the performance of the mechanism even when they have basically the same extreme position (max lift) and the duration.