Alex-7

Did Racing beat ever figure out why the secondairys on their six port Holley kit wont open off vacume?
I've been away from my car for a while so I haven't followed up on this issue.
I'm gonna call them in the next couple of days unless any of you guys know how to go about fixing this problem (without a screw in the linkage )




Thanks in advance,

-- Alex

Jeff20B

iTrader: (13)

A screw in the linkage is the prefered method sometimes.

LongDuck

(EDIT: Before you start reading, I just realized that you're taking about Carb secondaries, not '6'-ports - so disregard the following unless you're running a '6'-port 13b engine - SORRY!)

My first impression on this is that Racing Beat would have figured out that the '6'-ports operate via PRESSURE not vacuum!

In all seriousness, the '6'-port engines are designed to scavenge a bit of the exhaust pulse coming through the exhaust manifold into the Cats, where the pressure would be greatest. This pressure is then piped up to the '6'-port actuators where they are opened between 2.7 and fully open at 3.5 psi, if it's all working smoothly and correctly. When you add a header to these cars, while reducing backpressure at the engine block, and superceding the cats, it also drops pressure below what is normally required to run your '6'-ports. Racing Beat and Mazdatrix use a modified presilencer with a correctly placed 'feed tube' for the pressure pipe to the actuators. This does work correctly, and if you look into the end of the presilencer, you can see the belled input end of this pipe is directed toward the oncoming gases to make use of the pressure wave as much as possible.

To get back to your original question, the Holley setup may not generate adequate backpressure with an inadequate exhaust system so equipped with the feed tube. In order to make use of these additional ports, I recommend getting the correct '6'-port exhaust system from Mazdatrix or Racing Beat. They have put the energy into fixing this kind of stuff for you.

On the overarching question of 'should I wire tie them open' - there are many opinions out there, but Mazda's opinion was that you need to have smaller intake ports at lower RPM to increase airflow VELOCITY, which is necessary to build low end torque. Once the engine gets up to speed, you can open up more airflow volume when needed (and ONLY when needed) and not negatively impact the intake airflow velocity for maximum high RPM power output. Mazda's opinion seems very intelligent to me, but you're welcome to do whatever you want with your car.

When your '6'-ports are working correctly, there is no substitute - you get the best performance of both low-end torque and high speed power. This was the VVT technology about 10 years before piston engines starting utilizing it. Most who complain about these systems either don't understand them, or can't appreciate the performance because the system's not working correctly. HTH,

Alex-7

BUMP!

italian_stud02

bump

Alex-7

Bump one more time.

LongDuck,
A little off topic but thanks anyways. I always apreciate your detailed responses and you have answered many questions for me in the past. Now, if you only knew what was wrong with my Holley....................Thanks Dude............

Jeff20B,
I know the screw is the prefered method some times, but I paid for vacume secondairys and I want one last facet of something idiot proof on my car. Every time I let a freind drive it, they bog the the **** out of it and don't understand what their doing wrong..........Thanks Dude ...........

italian_stud02,
Thanks for the bump yo, I get you back.


I'm drunk,
--Alex

italian_stud02

now if there was a way to make them mechanical seconds then we would really be talking. FI mechanical 5th n 6th ports. you know come to think about it i wanna leave my 5th n 6th open. anyone know of a thread on how to do it with instructions and pics. i got that 85 gsl-se and shes either tired, or thats the prob right there.

sgieldon

I'm not sure if this relates to this subject, but there is a cheap and easy fix to all Vacum Secondary Issues!- All Holleys-

Buy the Holley Quick Change Seconday Diaphram Kit # 20-59 and the Assorted Sec Diaphram Spring Kit # 20-13 i.e 6 Springs (Total Cost from Summit Racing for $29.95US

I did this upgrade 2 months ago and if you Install the Long Yellow Spring witch is second to the lightist your 7 will SCREAM when you Punch Her.
I started with the Plain Spring and worked my way Lighter to the point of
(No Bog But Pure Power).
Anyone have any Q's on this one???
I got it Down any Dyno'ed Her to Prove the Spec's
sgieldon
steve

Directfreak

iTrader: (2)

Good to know,

So, how much power?

Alex-7

Thanks for the info. I'll try that out as soon as I get back to my car. I assume you can buy that kit out of Summit or some place similar eh.


Thanks
--Alex

sgieldon

Good Morning All;
Yes Summit Racing Carries Both Parts.
QuickChange Secondary Spring Housing Kit # HLY-20-59 $10.95US
Secondary Spring Assortment Kit # HLY-20-13 $ 8.88US

The cool part about this setup is you can change the Springs in about 5mins.
and no Holley owner should be without this Mod.
Sure fixed my Vacum Secondary Problems!!!
Have Fun.
sgieldon
steve