TRIP_rock

I am curious as to what changes the 2.5s performance when it hits 3500 rpms? I am aware of the dual stage intake but I thought that didnt kick in until >5k. When I am driving may car and it hits 3500rpms it almost feels like a 4 barrel kicking in. Is this normal or is it that something is not working correctly at the lower rpms?

Go90go

It's a 3 stage manifold, Idle - 3299, 3300-3899, and 3900-redline. Stage 2 is pretty noticable but stage 3 is by far the biggest change in engine sound.

~Cheers~

triggerc

I think it's the torque, we peak at 3900 rpm, and if you look at our torque graph it climbs really sharply from 3000 to the torque peak, maybe that's what you are feeling. I don't really understand why our torque peak is so low with a 6800 rpm redline. We would accelerate much faster if the torque peak was later.

TRIP_rock

So essentially that is the sweet spot? I just replaced my blown motor with one that has 70k miles on it and I never noticed prior to that. Maybe it was that the other motor was a wore out POS? With the new engine the performance above 3500rpm is awsome, below that it leaves a little to be desired. Also the motor was out of a 98, any different internals on a 98 vs. the 96?

I am aware that the valve opens in te last stage but what happens at the 2nd stage? Also I thought, or read in te service manual that this did not occur until around 5k rpms, is that wrong? Is there any literature on this on the web where I can get a better understanding?