secondaries or not secondaries

[drivebymashing]

3l engine with 3l heads what about the intake manifold part?

[Big Jim]

Most likely you will get better fuel economy as well as better low end throttle response using the secondaries (two stage intake manifold).

The very slight downside is that you may lose one or two ponies at the top end. If you intend to drive high on the pipe ALL the time, then you may not want to worry about the secondaries.

[svttour]

3L W/ 3L heads SVT UIM and LIM W/O secondaries!

[Ray]

I'd take the secondaries. I have NO reason to say that they are "required" for me, yet I would still like them. The rush is insane, comparatively.

[svttour]

Im just tired of having to change the IMRC every 15-25k miles.

[DemonSVT]

3L engine, 3L oval port heads, Custom EH'd UIM and custom proted LIM with NO secondaries is my vote for my car.

I probably would only have one vote so I'll abstain from the choices I saw. I can tell you using the 2.5L heads is not the way to go though.

[DemonSVT]

I'd take the secondaries. I have NO reason to say that they are "required" for me, yet I would still like them. The rush is insane, comparatively.

The rush??? A brief torque spike under 2500rpm on a 3L engine. The 3L has a much lower usable rpm range on just the primary ports being it naturally takes in 20% more air. In the usable powerband, 3000rpm and up, using both ports is far superior so there are zero performance benefits from using the secondaries. The secondaries are designed and used for low rpm cruising and especially considering the original car was designed to mate with a slushbox. I would imagine over 80% of the V6 CDW-27's on the road are slushboxes and you know even Ford figured that out as well.

My hatred for the quirky IMRC is well known and even more strongly supported. I still recommend the majority of folks keep it though because it requires proper datalogged tuning to compensate for its removal. Turning off the CEL is one thing but getting the proper timing and fuel curves, the idle circuit, ect is quite another.

[warmonger]

Personally my vote is for "Worked" 2.5L heads with 3L valves.

- A custom port job on the heads, followed by another single pass extrude hone on the UIM/LIM and Heads to help smooth out any imperfections in the porting process.
- gentle reworking of the combustion chamber to keep compression in the 10.2-10.5 range maximum

- operational secondaries.

- braided steel drain line or tubing attached to the back of the 2.5L heads and piped into the 3L drainbacks, then sealed of course.

-customized tune with Xcal2
- true dual exhaust
-cold air intake with open filter in the fender

THAT would be my optimum config for this car

I have some more things that would really help this configuration on top of the above but they would be experimental.

[drivebymashing]

im just trying to see whats my best bet
so the most popular so far is the 3l engine with 3l heads and svt intake manifold w secondaires
what about the cams
svt cam or 3l cam?
i dont use 6k that often im between idle and 3500 80 percent of the time

[Bugzuki]

I would have voted for 3L w/ 3L Heads, SVT UIM and LIM w/o secondaries. That is what I am doing on mine. I will take the advice, DemonSVT, and keep the IMRC until I someday have a tune to get rid of it.