NX Highway Cruisin'...

[JaretR1 at aol.com]

It has nothing to do with the 55 mph thing.  My 2006 RSX Type S spins  at 
3700 RPM or so at 75 MPH (and that's with a 6 speed!).  Its about  keeping 
the engine spinning where the power is.  I made many a trip in my  SE-R and 
even at 80 Mph, closing in on 4k RPM, it still got 32 MPG on the  highway.  I 
really do not find engine noise to be the problem with these  cars at 
highway speeds.  Road noise is much more of a problem.  I am  not sure dropping 
engine revs is going to make a whole lot of difference in  noise.
 
 
In a message dated 8/20/2009 2:57:39 P.M. Eastern Daylight Time,  
grega at pobox.com writes:

Back  when I bought my brandy-new 1984 Rabbit GTi, I thought I was in 
heaven. For  those of you who were still suckin' your mammy's teet back then, 
that car was  a breath of fresh air in the stale environment of post-emissions 
and -safety  automotive dregs. Bigger engine, more torque, close-ratio 
gearbox. Car only  had one annoying downside: buzzy at highway speeds. But, back 
then they had an  excuse: the NHMSL of 55 mph. After all, why optimize a car 
for 70 mph cruising  when you can only do 55? Hell, they even had 
speedometers that ended at  85mph...

Cut to 10 years later, and Nissan offers a nice improvement on  the theme, 
with the SR20-powered B13/B14s. But, similar problem: 3500 at 70  mph? Why?? 
Nissan can't even lay back on the old "55 mph excuse" as the NHMSL  was 
repealed. Let's move forward another 15 years, and I'm playing with my  NX2000, 
installing an even more-torquey and -flexible engine, so I *really*  don't 
need to be pulling a noisy 3500 RPM at highway speeds.

So, what  to do about it?

Well, I'm looking to take the same tactic as we did in  the Rabbit GTi. 
Back then, the big trick was to replace the GTi's fifth gear  (0.91) with one 
from either the convertible (0.76) or the diesel Rabbit  (0.71). It was an 
easy in-the-car swap and brought the revs down to reasonable  speeds while 
cruising. It didn't really hurt performance, because if you were  racing or 
doing best accel (or drag racing) you'd never used fifth anyway.  Yeah, the 
4th-to-5th shift was a tad annoying, but that annoyance was quickly  eclipsed 
by the fact you were turning <3000 RPM on the highway. And, you  got used to 
it. Like, the second time you shifted.

So, what are my  options with the RS5F32V? Are there parts in the "family" 
to let me do  this?

The 5th gear in my NX is 0.756:1, giving me about 3500 RPM at 75  mph. 
Optimally, I'd like to find something that will drop the revs to 3000 or  below, 
which would require a ratio around .65; nothing I can find in the  RS5F32V 
family has that. Closest I found was the RS5F31A trans which had a  .733 
fifth, but that only drops the revs 100 or so, hardly worth the effort.  In 
fact, the ONLY gear I found that was in the range was the sixth gear from  the 
SpecV/Altima trans (RS6F51H) and it's 0.63 (~2900 RPM in fifth). I'm  
perfectly OK with that jump from 4th to 5th; again it's all about maintaining  
acceleration from 1-4 then dropping the revs for cruising. But will that gear  
fit? Are the shaft sizes the same, are the gear centers the same? Of course 
I  have no clue.

Then again, if it DID fit, then I could even consider  dropping in the Suny 
Lucino 4.437 final drive, IMPROVING acceleration in 1-4  *and* improving 
cruising RPMs on the highway (~3100)!

So....what's the  chances ANYONE would have a clue on the physical specs 
for that sixth gearset  (or even one they could send to me)? Are they even 
close enough where I could  modify/broach the splines to make it work?

Alternatively, I suppose I  could install the SE-R 6-speed in my NX, but 
that just seems like overkill.  I'm guessing it's neither cheap nor easy...

Thoughts  appreciated.

GA

+----------------------------------------------------------------------+
The  mailing list home page is http://www.se-r-list.org/
To modify your  subscription, go to  
http://www.se-r-list.org/mailman/listinfo/se-r


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.se-r-list.org/pipermail/se-r/attachments/20090820/9a1152ba/attachment-0001.html