LOL Smog/rev limiter's function. . .it's all the same. J/K y'all. So has anyone smogged their car with the TS ECU and have any "worse" emissions? I was more curious if the 100% thorttle valve opening or AF mapping had an effect.

-drew-

 

Smacking the stock 6600rpm rev limiter will not harm your engine nor running it anywhere in it's set operating range (1rpm to 6600rpms). All the rev limiter does is cut fuel and ignition and the sort to cut power. It's just a safe guard. It feels violent, but it's not harmful. The only way to go past the stock rev limiter is to misshift because the mechanical momentum will overcome any rev limit safe guard.

Running an engine hard (higher rpm driving, full out racing) will increase wear, but it really won't harm the engine.

As for the TS ECU and the raised 7100rpm rev limiter, IMO that's too much rev for this motor. The rods in the VQ are not strong and the 3.5 VQ is basically a stroked and slightly bored verison of the 3.0. The 3.5 has a .3" longer stroke than the 3.0 which is actually quite substanial and it makes weak rods even weaker. The 3.0 could happily zing to 7200rpms (stock 6550rpm limiter) reliably because of it's short piston travel, but the longer piston stroke of the 3.5 becomes an issue in the higher rpms. The valve train is somewhat of an issue, but it can handle lower 7000rpm duty without any work. Nissan went to great lengths to make the 6MT 05 G/Z reliable with the increased stock 7000rpm limiter. The block and many components of the reciprocating assembly were beefed up to handle the 7000rpm limiter. IMO, pushing a non-05 6MT 3.5 VQ above 6800rpms is potentially dangerous, especially in the upper gears (3rd+) where the acceleration time per rpm lasts a lot longer therefore placing more stress on the motor over a longer period of time.

When 3.0VQs are misshifted (example: a 4 to 2 downshift at 90mph), the clutch is usually the thing to blow. With the 3.5 VQ, it appears the rods are the first thing to go. Misshifting is not something you want to do in any car, but it seems clear that the 3.5 can't handle high rpm duty. Nissan has even realized this and they run 3.0-3.2 VQs in their race motors and the upcoming Skyline will be a 3.2.

I'm considering the TS ECU, but I'll probably ask for a 6800rpm limiter if they can do it. If I get the 7100rpm limiter, I won't use it.

 

I would think the torque would have the same peak and general shape due breathing limitations. point being you would want to shift later that the stock rev limiter. the question is by how much.