What a difference! Just installed some gutted and bored out secondaries and it made a pretty noticable difference. They were bored out to 36.5 mm and all the rods, butterflies, etc. have been removed.

1turbofocus did the machine work and has a jig set up to do the duratech secondaries. So if you are interested, he can do them.

From the prelimainary test drive it feels like about 10 hp.

All you boosted guys NEED to do this.

Two thumbs up from me

How much does he charge for the service? Thanks.

now just put it on the dyno so we can see some numbers.

yeah, since he is closer than SS, can he put the bigger butter flies in too?

I will ask Tom about the above ?'s when he gets back from the Fun Ford event. I should be able to talk to him early next week.

For now I can only say that the gutted secondaries work for forced induction motors. From discussions on this board it has been said that gutting the secondaries may not be a good mod to do on normally aspirated cars. You will lose alot of low end power for a small amout on the top end.

I will post back here when I find the answers to these questions.

I'm not really looking at getting rid of the secondaries, just opening htem up a bit like SS does.

I see a big problem with going past 34-34.5mm (99 & 00 SVT's only - others smaller yet)

Why you ask?
The head ports are only that large!
Since the head ports would now be smaller than the LIM they would create a very disruptive ridge (atleast 2.5mm) protruding into the incoming airflow.

I'm not worried about that. I need somone to modify the unique 95 lower manifold to at least late SVT specs.

that's why you get the heads / headers port matched! :-P

Originally posted by DemonSVT:

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I see a big problem with going past 34-34.5mm (99 & 00 SVT's only - others smaller yet)

Why you ask?
The head ports are only that large!
Since the head ports would now be smaller than the LIM they would create a very disruptive ridge (atleast 2.5mm) protruding into the incoming airflow.

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Originally posted by RTStabler51:

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that's why you get the heads / headers port matched! :-P

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I whole-heartedly agree. Thus making this NOT a simple bolt-on upgrade.

another problem with using them on a non-boosted vehicle is that the passages are no longer trapered like they are stock. This might decrease velocity a little bit in a normally aspirated motor.

I did not bother to port the heads, maybe later. But it still made a pretty decent gain, granted I would get even more if I had port matched everything.

Originally posted by fst4dr:

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I did not bother to port the heads, maybe later. But it still made a pretty decent gain, granted I would get even more if I had port matched everything.

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Also you are forcing the air past this ridge. Not pulling the air over it. Subtle but noticable difference in flow dynamics.

The cost for boring out the lower intake is $60.

Installing bigger butterflies would be too much of a PITA so all he is doing is boring them out.

I guess if you are interested you can email him at:

hpdyno@aol.com

Do you still have all the stuff you pulled out? I'm interested in the brass plates specificaly. IM me if you want to pass them on to a needed CEG'er

The stock one is still in one peice. I used an old SE manifold to gut incase it did not have positive results.

I'd like top keep it in one peice in case I want to return to stock.

Sorry

Do you think that the 'breathability' you gain from having no rods/butterfly's in the airstream is worth the low-end torque you are losing? The blower can't be generating near enough boost down low to compensate for their loss, and maybe it even makes it worse having the blower on it. Why don't you consider reboring the secondaries with bigger butterfly's so you can have the best of both worlds?

warmonger

When I had my SE SC'ed and pinned secondaries, there was no loss down low at all...