NX Highway Cruisin'...
JaretR1 at aol.com
JaretR1 at aol.com
Thu Aug 20 15:07:49 CDT 2009
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repealed.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
More information about the se-r
mailing list