does anyone on here now at what RPM is the maxima's peak power on a 90 SE auto

ive seen people with stock vehicles running much quicker than expected ET's just by knowing when to shift...any ideas or could you point me in the right direction

 

It's going to be COMPLETELY different with a boosted or modified engine. look at your dyno charts and do some calculations.

 

well considering your an auto you cant really tell your car when to shift so just dont worry about it

 

peak power is before redline however it seems as though those who have the jwt ecu (with the 7,000 rpm redline) are quicker than the cars with the 6,000 rpm redline. both cars that did the test were near equally modded (minus the ecu of course). so, it seems that if you get the jwt its a good bet that taking it up to 7,000 rpm will make you a bit quicker. more than likely this is due to keeping you higher in the power band.

the absolute best way to know when to shift is to get your car dynoed and find out at what rpm would land you the best power in the next shift but that definitely takes some time and money to do.

 

7000 rpm with ecu upgrade??? i have an auto, but i can get it to shift from the 1st or 2nd gear at about 6000. i only do that on the weekends. i have pretty good control on when to shift by feeling the pedal, so i go for about 5000 rpm. the thing is, when i go up till 6 or so, i noticed that i get some kind of strange sound coming from the engine right at the peak. like, a puttering sound, about 5 or 6 little putters, as soon as i hear those i release the pedal a bit and it shifts and runs just fine.

is there a reason for those putters? would the ecu upgrade get it to shift 7000 and ruin the engine?

 

On a VG, extending the redline to 7k is really a waste of time. The VG doesn't make any decent power over about 5,500 rpm if you are na.

But on my VE, JWT's extended redline to about 7,200 is perfect. I'm still pulling right to about 6,800-7,000 so shifting a bit higher puts me into the power band after the shift.

 

just a bit of warning... After rebuilding my transmission a few weeks ago, I ran the numbers on the bearings through some searches.. the input and output shaft bearings are only rated for duty to 6000-6400rpm (depending on which bearing).
that obviously means that if you spend much time near the stock redline, you're going to significantly reduce bearing life, and if you extend the redline, you're just going to make that worse.

i.e. here's what happens when you spend your driving time above 5krpm:
http://mattblehm.com/pics/car/tranny/

 

I wouldn't necessarily say its a waste of time performance wise. Someone has already proven that the 7000 rpm limit on the VG helps quite a bit however with what Matt just said it may be a waste of time due to the bearing issue.

I've seen too many bearings like that, 3 trannies in all but 1 tranny twice. I'm definitely sick of it.

 

How can it help "quite a bit" when the VG won't make any decent power over 5,500 rpm? The VG will breath up in the higher rpm range BUT not without every bolt on and some head work. My bro had a VG 5-sp with a Y and intake. It still ran out a breath well below 6,000.

 

Jeff, I've run Kaleb's VG a couple years ago, and he was nearly even with me- he could keep up if he shifted at 7k.. then again, that was before a lot of my other mods. I think I had a CAI and UDP at the time... he's "full bolt-on"
y, ECU, intake, UDP, advanced timing, etc etc etc.

the better ignition and fuel maps extend the torque curve out a lot farther than you would expect.

 

Yeah, there were a couple guys who tested that out with their cars. From what I remember, they both had pretty equal mods except that one had a jwt ecu and the other had something that the former didn't have.

When they raced the car with the JWT ecu running it to 7,000 always pulled a head however when they kept their shift points the same (right around 6,000 rpm) they were near equal.

I'm attempting to remember all this from a very old post on here but I'm pretty sure that's nearly exact.