[Gmecm] re: L31 Info Part (2)

[SubZero350@att.net]

GM PART # 12498032
CATEGORY: Fuel Injection Air Meter Body
PACK QTY: 1CORE CHARGE: $0.00
GM LIST: $1,800.30
OUR PRICE: $1,260.21

DESCRIPTION: RAM JET 350 KIT (LESS ELECTRONICS)
This retro-fit fuel injection kit is released for use on small-block v8 
engines using vortec design cylinder heads. The vortec heads are part number 
12558060 cast iron or 12464298 aluminum. This fuel injection unit must use 
an aftermarket ECM and wiring harness with the proper calibration which is 
not included. (350 ram jet Ecm 12489488)( 350 ram jet wiring harness 
12489492).
This unit includes the following parts:

(1115498 coil)
(12097982 marine spark plug wire kit)
(12489371 intake manifold)
(1104060 distributor)
(10456126 knock sensor)
(17096144 throttle body)
(12553918 fuel injection rails)
(17124248 eight injectors)
(16249939 map sensor)
(17123897 fuel pressure regulator)
*********************************************************************

Now lets talk performance.  In my opinion, the stock L31 truck vortec (and 
marine) intake manifolds are horrible for performance.  The reason?  When 
the air comes into the intake from the throttle body, it has to make an 
immediate 90 degree turn to head towards the runner inlets.  Once it gets 
there, it has to make nearly a 180 degree U-turn to get into the runners.

A friend of mine did a GM LT4 HOTCAM kit on his 96 GMC 1500 Vortec 5.7L.  I 
got his tuning done but the engine makes very little power below about 
2800rpm.  Whats worse is the power band falls off sharply after 5400rpm! 
Fuel looks ok and I gave it as much timing as it can handle.  I am convinced 
the stock vortec intakes are horrible from a performance standpoint.  Now I 
know some may not be familiar with, or not like the profile of the LT4 
HOTCAM, but let me give you a couple of examples of what I have used it in 
and the results...

Stock F-body LT1 engine + HOTCAM kit = Strong power from 2700-6300rpm.
Modified 350 w/ TFS heads TPI intake + HOTCAM = Strong power from 
2300-5800rpm.
Modified 350 w/ TFS heads Superram intake + HOTCAM = Strong power from 
2600-6200rpm.

As you can see the HOTCAM has a fairly broad power band, but the stock 
Vortec intake does not take full advantage of its aggressive profile.  Even 
using the stock cam you notice the L31 suffers in the low-end torque arena. 
I think the RamJet PFI intake would produce a similar power band to the LT1 
intake.  Obviously if you have to deal with emissions you are going to be 
limited in your intake choices but if not I think the money would be well 
spent on a different intake.

-ryan
www.gmtuners.com