diffrence in van 3400 and N-body 3400

[01GPGT]

van also has no u-bend like on w-bodies not sure if the N has the U-bend or not as well

the intake is the exact same i am using the stocker from my GT in mine when i broke it



i will get a pic of the pipe tomarrow the thing also has 2 resinators a muffler and a cat but it's a straight line no bends really

[prophiseer]

Unless I'm mistaken - I think the real big difference between the n-body and the u-body is in the transmission.

The u-body has mated the T65 to the 3400, whereas the n-body has the T40 (in the case of the GA or Alero the T45). That's quite a hefty difference in gear ratios between these transaxle series, and the PCM will require different tuning to accomodate the demands of the tranny as well, and to "bump" the engine's output in it's powerband to improve the amount of force being supplied to the transmission.

If that makes any form of coherent sense . . . It's rather late here and being overly tired isn't good for technical discussions

[01GPGT]

oh yes the 4t65e (or the 4t65-awd for some of the vans) is deffinantly a stronger unit compaired to the 4t45-e in the Gts and 4t40-e in the SEs

but the N body is a good 1,000+ lbs less then a U body

[prophiseer]

I meant due to the transmission . . . not in the transmission

There is the massive weight difference - hence the need for the T65. The T65 (which can handle a higher torque output than the T45) also requires higher torque output than the T45 does to drive the unit . . . but, overall, the T65's demand isn't a range the 3400 can't handle; so, it's all in the PCM's calibration for the installed transaxle.

The gearing makes up for the difference in the vehicles weight . . . with steep enough gearing, you can easily move a 10,000lb truck without getting the motor to break a sweat - you just need a motor to produce enough torque to turn the transmission. As well, the torque converter matched to the application makes a lot of difference, too (I can't remember the specifics, except that the T65 has a larger and higher stall converter than the T45 GAs do).

[01GPGT]

i was agree. the 45 is also weaker so GM could of lowered the power to have it last longer. the 65 they did not have this issue becuase it was designed for the supercharged 3800

[prophiseer]

The T60/65 has also gone through a hellatious amount of revisions and updates over the course of it's 30+ years in service (I'm including the older 440T4) - so has the T40/45

One thing I've never quite understood, though . . . why GM partners certain transaxles with unusual motors. i.e. '96-'98 Grand Ams with the 2.4L Q4 had the T60 transaxle, while the 3100 had the T40 - just seems like it should be the other way around.

[01GPGT]

yup or the LS4 5.3L with the 65-e wile the N* got the 80-e even though it made less tourqeand the cars where of simular wieght

[[ChaosweaveR]]

That's GM for ya.