Hey,
Try going back to the stock injectors! Or at least check your long term
trim. If its negative by more than 20%, definitely go back to the stock
injectors!
Bruce
----- Original Message -----
From: "news.verizon.net" <wE@.com>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Thursday, November 14, 2002 5:22 PM
Subject: DML: Disappointing day at the dyno... Advice needed!
>
> Well I had a disappointing day at the dyno today. Only gained 1.4RWHP and
> 5RWTQ, this is after the HO cams. This brings me to 225.4RWHP and
283.5RWTQ.
>
>
>
> My guess is that 3.5 degrees of timing out of the PCM is making a big
> difference! Also, you can see a steady decline after 4400 RPM of the of
the
> TQ/HP curve.
>
>
>
> Changes between this run and last run:
>
>
>
> - HO cams
>
> - 21# FMS injectors
>
> - (-3.5) degrees timing on the PCM
>
>
>
> Other things that may make a difference between this run and last run:
>
>
>
> - I have a bolt in cat for the third cat now. There is a minor leak around
> where the cat bolts to the exhaust. I can tell this because water leaks
out
> from where you bolt the cat in (I got ripped on the install job I had this
> crappy shop do)
>
>
>
> - I'm running a Robertshaw 330-180 thermostat. The problem is it's such a
> HIGH FLOW tstat, the truck doesn't warm up a lot of the times, and trips a
> check engine light. I'm thinking I should change it to a GT755-180
> thermostat? Could this be affecting HP/TQ?
>
>
>
> Here are my questions:
>
> 1) I think I need to get that timing put back in! 3.5 degrees must make a
> big difference
>
>
>
> 2) HO intake?
>
>
>
> 3) I'm going to remove third cat, and weld in some pipe between the Y pipe
> and muffler. My question is, should I go 3" between Y pipe and muffler, or
> go 2.5" to like halfway to the muffler. I DO NOT want to loose any more
> power, and I know our engines aren't that large, so we need to be
> conservative on pipe size. Is this even worth doing?
>
>
>
> 4) Anything else you can suggest based on my mods. Do I need to change my
> exhaust?
>
>
>
> Again, my mods are as follows:
>
>
>
> - Mike Leach PCM (With 25 degrees of timing instead of 28)
>
> - FMS 21# injectors
>
> - HO Cams
>
> - 4" Z-tube
>
> - Magnaflow 3" IN 2x2.25" OUT exhaust
>
> - F&B Throttle body
>
> - Robertshaw 330-180 Tstat (180 degrees)
>
>
>
> Sorry for the long post, this whole thing was kind of frustrating.
>
>
>
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