letitsnow

The temperature continuing to rise is completely normal. Intercoolers are in effect a thermal reservoir, the cooling capacity of the atmospheric air flowing through them isn't on the same level as the heating capability of the turbo. There is more heat going in(turbo) than coming out(atmosphere), so the aluminum heats up, raising the intake temp. Air DOES still cool the IC while on boost, just not anywhere near as much as the turbo heats it. This will hit a steady state at some point, but it is higher than what we want. After you get off the throttle and the turbo is no longer heating the air, then it's relatively easy for the atmospheric air to cool the IC down to ambient. The vertical flow IC's are great for engine airflow, but they sacrifice some cooling capability. My car, on the dyno(not anywhere near the airflow of going down the road), MAT started at 75F and ended at 110F. I see much less of a rise while actually driving.

Post your a screenshot of a 3 or 4 gear run datalog with MAT on it, that'll tell us if you're having trouble with the IC cooling.

You might try a non-projected tip spark plug, stock is something like BPR6ES-11 or something similar, leave out the P. How does the car feel with the timing you've got so far?

Getting on a dyno or to the drag strip is really the only way to determine what's going on. If the combustion chamber with the flat tops is much more efficient, you'll need less timing to make the same power. Who cares if you can only run 14-20 if you're making just as much power as I am at 25-30.

I'm surprised because with 7.4:1 I needed to be around 25-27 deg at peak tq, almost 40 near peak power, to get audible detonation(the dizzy walked on me once). Thinking about it, 14 at peak tq doesn't sound that far off, I bet you can add significant timing after peak tq and pick up some upper end power.

How are you detecting detonation? Det cans?

I finally found a z31 diff that I feel is fairly priced for the miles, so I'm buying it. I was afraid of runout issues with the OBX and in the end couldn't talk myself into rolling the dice. Now I need to find a mustache bar, r200 output shafts, and figure out what to do with the driveshaft. My 280z was unlucky enough to come with an r180 because it was an automatic.

I was planning on keeping the stock axles for now.

Thanks, I wasn't sure if there was another reason besides cost. I don't want the ring and pinion that comes with the z31 diff, I have a spare 3.54 R200 that I would rather put the carrier in, I feel 3.70 is a poor choice for this engine setup.

Am I missing something obvious where the z31 diff is better at something than the aftermarket units? My experience is limited to factory units on other cars I've messed with, never aftermarket diffs, so I very well might be missing something silly.

I'm pretty sure that didn't have a gasket, the one I have doesn't look like it.

My rail from pallnet had the threads cut just a bit deep, the earls fitting nearly bottomed, but I got it to seal so I never brought it up.

My rx7 has a 5.3/t56, the rear gear is a 4.11. I hate it, I'd rather a 3.54 or 3.7 any day over the 4.11.

What is your commanded timing when you're cranking it over to try and time it? I think the MS default is 10deg.

If I might ask, why so much for a likely worn out factory diff when a low mileage used aftermarket diff is the same or just a touch more. If I understand correctly, any aftermarket diff for a 240sx that originally had an open diff will work, right?

Think a 200k mile z31 diff is worth $650? Seems like a lot of miles.

The output shafts for the R200V are different from the open r200 and clsd. One of the outputs on the vlsd is longer so that it can engage the viscous coupling. As far as I know there's no easy way to swap a viscous unit into a Z. The only thing that even comes to mind is the possibility of the splines on the axle bar being the same between the vlsd and the open or clsd. But I don't know if they are and I don't have such parts sitting around to check. Even if they were, you'd need to get adapters and convert to CV axles for it to work.

You shouldn't have to do that, as long as it was in a decent spot before the wheel swap, it should be alright now. Change tooth #1 angle until your commanded timing matches your actual timing. Use the fixed timing option and set it to 15 or 20 degrees, then change the angle in TS until your timing pointer matches your fixed advance.

You guys with the OBX, what are you using your cars for typically?

This: www.youtube.com/watch?v=gm1vv1EkWac

Nice job! I got a 8.3 at 86 last night, 1/4 was 12.9 at 107.

The 1st thing I thought of was starvation in the corners. It might be wise to setup an oil pressure sensor to datalog.

Talking about the factory wheel or the DIY wheel? The DIY wheel should work great for a cam signal. As far as I know, there is no support for the factory wheel hi-res pattern on any nissan wheel. There was at one point some MS2 code available, but due to a disagreement with the author an the MS people, it is no longer available. The 82-83 dizzy with the proper shaft is quite accurate, the dizzy fits rather tightly on the shaft.

I'm using GM synchromesh, according to some datalogs, the time between getting off the gas and getting back on is .100-.150s. The front bearing in the tranny does seem to make a little noise though.

I should have stated that I have a later, 280z tach that was triggered off the negative side of the coil.