RE: RE: Hit the dyno today...

From: Bernd D. Ratsch (bernd@texas.net)
Date: Tue Oct 01 2002 - 10:55:25 EDT


I don't disagree with ya on that one Bob. Bigger injectors are required
with these applications (as in yours, mine, and the R/T-2 project). The
reason for the pump is just to keep the volume up as I've seen (many
time) the forced induction trucks go lean in 3rd (or 4th) due to the
volume. The factory pump can keep up in most cases at the track....but
on longer runs, it can't keep up. The auxiliary pumps that are included
in a lot of the S/C kits help out but they're 200LPH pumps...the factory
ones are not (they're less).

Increasing the pressure, in short bursts, won't affect the PCM (LT% or
ST%) as the 1/4 mile runs are followed up by longer trips back home.
Unless the person is (well...like a lot of us) the type who uses the gas
pedal as an ON/OFF switch, then...they definitely need some sort of
custom programming or "Add-On" control devices.

On the rising rate regulator, we've got A/F readings to disprove that
(12.0:1 in most cases). (No poke at ya on that one...just what we found
with the regulator we're using.)

- Bernd

-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of Bob Mankin
Sent: Monday, September 30, 2002 11:39 PM
To: dakota-truck@dakota-truck.net
Subject: Re: DML: RE: Hit the dyno today...

Bernd, the Holley pump(which I use btw) won't fix that and neither will
the pump with the regulator. The pump only gains you reliablity and the
added volume if offers only comes into play in cases of extreme mods.
The stock pump will actually suffice under most conditions.

The rising rate regulator will only counter the 8 psi of boost, but it
won't bring that 15:1+ down to the 12.5:1 range, which is the absolute
leanest you want it with a blower. No shot on that one. At WOT the PCM
is delivering fuel based on a pre-programmed table *BUT* with
compensation based on short term fuel trims plus,.... and here's the
biggie, a compensation for fuel pressure based on a pre-programmed
"standard". Simply jacking the pressure won't do it because the PCM will
counter by shortening the injector duty cycles.

Larger injectors all around or at least for the aux injectors(if your
blower kit has them). At WOT the computer isn't looking at anything but
those pre-set tables with a couple of adaptives thrown in and that works
in your favor with the larger injectors.

Bob
'01 R/T Paxton S/C
13.3@108 first passes and running quite lean with 24s

"Bernd D. Ratsch" wrote:

> It's lean Tim. Needs more.
>
> Holley 12-922 + Rising Rate Regulator will fix all that.
>
> - Bernd
>
> -----Original Message-----
> From: owner-dakota-truck@bent.twistedbits.net
> [mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of Tim
> Berry
> Sent: Sunday, September 29, 2002 6:07 PM
> To: dakota-truck@dakota-truck.net
> Subject: DML: Hit the dyno today...
>
> I had no idea I would be dyno'n today... but lets just say its almost
> where it needs to be w/ ~8PSI...
>
> http://members.cox.net/coolva1/dyno.jpg
>
> she needs lotsa fuel... :)



This archive was generated by hypermail 2b29 : Fri Feb 06 2004 - 11:47:15 EST