TOP END REFINISHING

[mike100]

Originally Posted by Schrade

I'm lost. Again.

If a vacuum solenoid - EGR, ZR1 secondaries, etc., is in the vent position, ...

then it vents the actuator diaphragms to the atmosphere speeding up their closing. You should be able to vacuum charge the little black can reservoir at that point. You may have to apply 12v to get the vacuum to pass to the secondaries- I'm away from my FSM's at the moment, but that is the testing path i would take.

[Paul Workman]

Of course, there is another solution -



Parts that don't exist never break...and they don't cost much! (read: chuck the secondary port throttles - same approach Lotus took on the LT5-II prototype).

Just sayin...

[Schrade]

Originally Posted by Paul Workman

Of course, there is another solution -



Parts that don't exist never break...and they don't cost much! (read: chuck the secondary port throttles - same approach Lotus took on the LT5-II prototype).

Just sayin...

Would I have to pull the IH's to remove the sec vac system? Is it reversible? Hasn't someone mentioned 'fixing' the secondary Valves OPEN? THAT I have thought of here...

Where the link here Cliff?

[XfireZ51]

Originally Posted by Schrade

Would I have to pull the IH's to remove the sec vac system? Is it reversible? Hasn't someone mentioned 'fixing' the secondary Valves OPEN? THAT I have thought of here...

Where the link here Cliff?

I just tie-wrapped mine open. Later on I took the throttle plates out and left the shafts in. Need to modify the cal so the ECM thinks the secondaries are OK and won't throw a code. I ran like that until I put on ported heads and cam. With just top end done, it pulled 400 at the wheels w headers.

[Paul Workman]

Completely reversible if you tie them open. Just the cost of gaskets and the chip and the tune. I doubt you would ever switch back!

[Schrade]

Is there a vac schematic that shows where to cap off vac lines? To retain Cruise and EVAP functions?

How do you know that the tied sec linkage is holding the sec ports' butterflies perfectly vertical? Or are they vertical when 'pegged'?

[Dynomite]

Originally Posted by Schrade

Would I have to pull the IH's to remove the sec vac system? Is it reversible? Hasn't someone mentioned 'fixing' the secondary Valves OPEN? THAT I have thought of here...

Where the link here Cliff?

LT5 Eliminated Systems

I retained the secondary system on my 90' and eliminated secondary on 91'

I just wanted to experience the power key on my 90' and not have anyone accuse me of not being able to get a secondary system functioning

What you should do is eliminate TB coolant....naw.....I promised GC I would not mention that...so forget I said that

Originally Posted by Schrade

Is there a vac schematic that shows where to cap off vac lines? To retain Cruise and EVAP functions?

There is not a schematic in this link but everything is described in detail LT5 Eliminated Systems

You can tie wrap or remove secondary plates or remove shafts completely. With your mechanical talents, anything and everything is reversible

[Dynomite]

Originally Posted by Schrade

That's this one - correct?



Why can't it be removed as well, with a cap on the plenum port?

Looks like Paul W has it out???

Allen Head Aluminum Plug like this where it says Plenum Vacuum

[XfireZ51]

Originally Posted by Schrade

That's this one - correct?



Why can't it be removed as well, with a cap on the plenum port?

Looks like Paul W has it out???

Because you'll want to use it when u install the DynoMax Ultraflos
w the Z06 NPP tips/actuators.

[Paul Workman]

All the HVAC, cruise, etc gets it's vacuum from the starboard-side plenum nipple between #4 and # 6.

On mine I left the port side vacuum connector (the one that serves the SPTs) and a short piece of the hose tucked under the plenum. But, the hose is plugged, giving it an "un-altered" appearance. Same goes for the TB bypass. The IH is plugged, but I left the hoses "as tho" everything were stock. (That way Scottfab wouldn't have a cow if ever he saw a photo of my motor () (Oh, I like Scott a lot. But, he definitely sees thing trough a different prism than I do...make that MOST do! LOL!)

Hats off to you. You may not have all the answers (most of us don't), but you haven't let that deter you from forging ahead anyway. Serendipity is one hell of a teacher!! In the end, you'll know more about the top end (at least) than more than half of the ZR-1 drivers do, I'd bet! Good on you!!