On 21 Sep 1998 Shaun.Hendricks@bergenbrunswig.com wrote:
> I'm not seeing a full exhaust treatment in this list. I may be mistaken,
> but without a clean y-pipe and a good cat-back system, it seems like you won't
> improve much with the JBA's. The factory headers aren't all that awful, but a
> straight, large diameter, mandrel bent exhaust would probably do wonders for
> this truck. If you've still got the factory y-pipe on it, you're choking the
> engine's ability to exhale. That thing is terrible.
>
> my guess as to why the times didn't improve.
>
> Shaun H.
That seems to be a good assessment. You could sort've compare it to
putting a 1000cfm air filter on a throttle body that will only flow 500cfm.
You can try a 750cfm filter or a 500cfm filter, but you're performance
will remain the same because the filter is no longer the limiting factor.
You've got to remove the major bottleneck, then find the next one and
remove that, etc...
The stock Y pipe really is pretty bad. I took some pictures of it
when I put in my ATR Y pipe, which I'll get around to posting one of
these days.
Before installing my ATR Y pipe, I had run a best of 14.85 on drag
radials (about 14.98 or so on street tires). My times corrected to
standard weather conditions were usually in the 14.8 range. I installed
the Y pipe, removed the cat and ran an actual time of 14.80, which
corrected to a 14.66. I wish I could have tested it with just the
Y pipe, but I was under some time pressure and I didn't feel like
screwing around with it; it was just easier to replace it all with
a 3" pipe. I still have some restrictions and leaks in the system
since I just patched it together temporary-like until I can get
some pipe bent up, so I feel its got more to give. Also, the 14.80 run
was the first run after resetting the computer, so it would've gone
faster on the next run. I didn't get a chance to test it out any
further because my rearend went on the next run. Last week, the weather
was very humid but I did manage a 14.86, along with a string of 14.9s.
For the record, the JBA's alone didn't appear to make any difference
(prior to the Y pipe change). They seemed to help Bill more than
they did me. I suspect the reason for that is his '93 has a larger Y pipe
than my '96 did.
-Jon-
.--- stei0302@cs.fredonia.edu ----------------------------------------.
| Jon Steiger * AOPA, DoD, EAA, MP Race Team, NMA, SPA, USUA * RP-SEL |
| '96 Dodge Dakota v8 SLT CC (14.80@92.97), '96 Kolb FireFly 447 |
`--------------------------- http://www.cs.fredonia.edu/~stei0302/ ---'
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:09:53 EDT