I just acquired a JWT ECU for my '91 in preparation for going VE or turbo. So I decide to go ahead and plug it up and see if I could feel any difference on the BD(butt dyno). Drove it around a little to let it get warmed up, and I did a long pull through 3rd from about 2500. I wanted to feel what it was like hitting about 4000-4500, when you can feel the cams start working. Well as soon as I hit 5000 it started to spark knock, I've owned 2 SE-Rs and NEVER heard spark knock, even on 87octane. I guessing the JWT has more aggressive timing, plus it leans it out some. I'm gonna mess with the timing a little and see if I can get it out, if not I may pull it back out. I know I'll have to run 92octane when I do my swap but I'm not willing to make the switch yet. I also noticed it idles better warm(stable) but worse cold(rough) as compared to the stock ECU. OBTW I heard a rumor there's a guy around here with a 240sx swapped in Skyline motor and TWIN T-88s turbos, I'm thinking NO. A single maybe, but can you get a T-88 with a small enough turbine housing to spool twin t-88 on a 2.5L?

You shouldn't be knocking at all! Its very dangerous to your engine, fill up to the top with 92 octane, and only 92 octane. If you have a tank of 87 octane gas, or even 89 and it is over half full. Put back your old ECU, I wouldn't risk detonation, personally. Also, your base timing should be 15 degrees. Any more than that, you will loose power.
As for the 240sx. Well, if the guy has enough money to swap a Skyline engine into a 240SX, he probably has enough dough to buy twin T88s. I woudl say he doesn't though, because that is over 1500 HP of airflow, at least. It wouldn't spool until the upper reaches of the RPM band, if at all.

From what I understand (and have read), if you have a JWT ECU, then you have to run at least 92 octane.

Michael.

You MUST use at least 91 octane with the JWT ecu. Otherwise, it'll knock and pull out timing. As far as the 240, I've seen pics of a really sweet 240 with the RB25, not the rb26. I think it's tougher to get the RB26 to fit. Anywayz, yeah, I doubt the twin T88s as there is a Supra here in Austin with a single T72 and 70 shot of NOS running 9.8@153.5, dyno'd at over 800 whp. I doubt there's even enough space in the engine bay to mount two T88's unless you want those things popping out of the hood. This car would only be a drag queen if it were so set up.

You also have to set your base timing to 15 Deg. BTDC with the JWT ECU.

Josh

Screw 92 octane, better run 93 or even 94 if you can find it.

it might be the fact that it's programed for bigger injectors rather than the Stock SR20's. If it's for VE program like u said.

so how about all of us cali people who can only get 91 octane?

will the ECU cope with it?

Sam

Originally posted by Yellow4g63
it might be the fact that it's programed for bigger injectors rather than the Stock SR20's. If it's for VE program like u said.

No I got it in preparation for swapping a VE or DE-T. It's a S3/S4 cam program,I have JG cams but the specs are similar. I pulled the timing back some and now it seems OK. I gonna have to get a new timing light , wire got down on the header and 'smoked' it.

The JWT ECU REQUIRES!!!! premium gas. No less cause they really change the fuel curves for it. Also if you have cams and the ecu you should set your timing to dead nuts on 15. It is really picky about that. Many dynos have shown it for a fact that anymore and you loose bottom end for little to no gain up top.