Contour Enthusiasts Group Archives Forums Modifications Duratec Performance secondaries

wat do u think i should do?? i just got my 3.0L installed and i know i need intake/exhaust to really get the feel of the engine, but as far as the secondaries. wat should i do?? i tried pinning them open and i still get that jerk of power at 3500 rpm, should i remove, crack, pin wat???

Take 'em out and then get a custom chip that has a smooth spark curve all the way form idle, rather than the jump in the stock program.

Wow that sounds like a great idea...

BTW - You should not get a jerk at 3500rpm (standard IMRC point) with the secondaries pinned.

The PCM see's they are open (CEL) and ramps up the timing (but NOT fuel) early.
Even with no chip it does it, just with a chip it is Much more aggressive!

Bull s**t..read 'port & POLISH maybe II..post..

Rods finally removed and I left the secondary linkage at the spring disconnected.. All I can say is MUCH MUCH better, I got that awesome spark advance back!!! Thanks guys.. Demon etc. Car definately comes back to life down low..and MAN O MAN ... nothing like a Brullen 2.5 inch mandrel without secondaries... holy shizzle

By the way Demon, I am assuming the apexi will help with this mod (secondary removal) immensely correct?

Yes. The engine definitely was restricted by the secondaries.
The PCM can not compensate for the extra airflow with them removed & the early timing advance.

The car was faster with them pinned, much less now that they are gone. (Not only butt dyno; but actual track timing)

Not too mention the added benefits at part throttle, acceleration after shifting, and not stagnating the air in the UIM.

Terry - For someone who preaches about not lugging the engine you certaining are concerned with losing some torque below 2500rpm.
I for one am not in the least. The numerous other benefits and gains far out weigh the small low rpm losses.
If I'm driving below 2500rpm, I just plumb forgot to down shift...

...and NO this mod is definitely not for everyone...

I'm talking about cylinder filling and gas velocity at low rpm, not lugging the motor....

Again part of an answer.

I accept the fact that at 2500rpm and below the engine is not running to the efficiency it could be by using just the long runners. I even have real world data to back up your comment about air flow and cylinder filling at low rpms.

That is a trade off I am more than willing to make for the numerous benefits and gains everywhere else in the rpm range.

BTW - I feel that below 2500rpm IS lugging the engine. You may not, that is your call.
However even 2000-2500rpm the engine responds well just not with the torque it had using the long runners only. Below 2000rpm it's a dog.

I never drive below that any way. I normally keep the rpms between 2500-3000 when cruising. The engine seems to be more efficient there anyway since even with my heavy foot I get over 24mpg in mixed driving. (30+ on the highway)

So, what we've got here is TH and his knowledge/experience vs. Demon and his knowledge/experience. I would like to be the judge between you two. Give me the dyno and track numbers to prove the the two points, and I'll decide on who the victor is. Look you guys, you both have valid points. That's a given. But unless we have the meat and potatoes on the table, I ain't having any of it. It's not just me that is saying this. We (all of CEG) need this information in order to better our cars in power and performance. So, show me the money!