replacing rubber vac lines with metal

[Kevin]

Rather then continuing to chase vac leaks on our cars I've been kicking around the idea of either eliminating the secondaries via a chip and wiring them open or keeping them in place but finding some kind of hard line that won't leak. Any thoughts?

[Dynomite]

I have eliminated secondaries on a 91' with no issues (I do have a Haibeck Chip in ALL ZR-1s).
LT5 Eliminated Systems (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587644220)

I did NOT remove the Secondaries on several 90's and a 95' but did my TOP END Restoration fixing ALL Vacuum leaks once and for all. On the 95' Jerry sells a New Secondary Port Vacuum System which actually fixes everything.

Once the Vacuum System is Restored there are NO issues for a long time as far as I can tell :p
Secondary Port Vacuum System for 93'-95' (http://www.jerrysgaskets.com/hose-secondary-port-throttle-vacuum-new-93-95-9b3/)

1995 LT5 SPECIFIC TOP END REBUILD TRICKS
A 1995 Top End was rebuilt and best tricks linked here
Post 230 - 1995 LT5 SPECIFIC TOP END REBUILD TRICKS (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759172)
Post 231 - Clean Up of Valley, Installation of Battery Disconnect Switch and Coils (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759173)
Post 232 - Installation of Rebuilt Starter, New Alternator, and Braided SS Oil Cooler Lines (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759174)
Post 233 - Installation of Wilwood Rotors and C4 to C5-Z06 Conversion (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759175)
Post 234 - Installation of New Secondary Port Vacuum System hoses (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759176)
Post 235 - Installation of Reconditioned Injectors with New "O" Rings (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759177)
Post 236 - Installation/Relocation of Plug Wires and New Spark Plugs (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759178)
Post 237 - Blocking TB Coolant, Fluidyne Radiator and Thermostats (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759179)
Post 238 - Reconditioning and Installation of Plenum with SS Allen Head Bolts (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759180)
Post 239 - Addition of Billet Aluminum Power Steering, Water Pump, Belt Tensioner Pulleys (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759181)
Post 240 - Reconditioned 1995 Engine with New Fluids all around including Differential Drain Installed (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759183)
Post 241 - Rebuilt Black Label Transmission Installed (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-13.html#post1592505462)
Post 242 - Installation of Elite Oil Catch Can (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-13.html#post1592505469)

[RussMcB]

There are a lot of people running wired-open secondaries successfully, and loving it. It's a good option.

I'd think hard lines would be a lot of work for no real benefit. You can replace all the rubber lines with new for maybe $20? Even with hard lines you'd probably still need rubber at each end, right?

Using something like Haibeck's or Dynomite's documentation, it's not hard to methodically make sure each hose and part is working properly.

[XfireZ51]

Before porting the heads on my motor, I had ported the top end and removed the throttle plates from the secondaries altogether. I did tie-wrap the actuators OPEN so the throttle plate shafts presented the narrow side to the air flow.
Ran that way for quite a while with no issues. I made some changes to the calibration to accommodate the mod.

[BlackZR1]

Kevin,
In March I purchased Marc's AYBKG chip with the secondary port throttle control delete option, wired the throttles open and couldn't be happier. I didn't start out with a problem - just wanted to simplify the system and simplify troubleshooting. There is a lot less clutter under the plenum and less to go wrong. The only downside I know of is that if the engine throws a code the secondary injectors shut off. Marc cautions:
"The engine will run very lean at wide open throttle if the "Service Engine Soon" ('90 - '93) or "Check Engine" ('94 *'95) lamp is on. Run the engine with light load if the Service Engine Soon or Check Engine lamp is on." For a similar reason, Full Power mode must always be enabled.
No change to driveability, idles great, and the newer calibration drops engine speed quickly to idle when coming to a stop.
Dynomite will be happy to hear that while I was in there I plugged the throttle body coolant circuit at the injector housings too.

[BlackZR1]

Kevin, Check your gmail acct. I just sent you some docs and pics.

Also, in case anyone noticed, after paying my member dues my Tag comes up "Founding Member" instead of just "Member." I notified Mark Horner about that.

[Kevin]

Kevin, Check your gmail acct. I just sent you some docs and pics.

Also, in case anyone noticed, after paying my member dues my Tag comes up "Founding Member" instead of just "Member." I notified Mark Horner about that.

saw it this morning, didn't get a chance to read it over. Thanks for sending it though, I'll look soon

[Paul Workman]

My 2 cents: one of the best mods I did on my LT5. One I have never regretted for a moment!

[Dynomite]

I have full secondary operational on 90's simply because I like that FULL POWER sign lighted up on my panel but maybe with a CHIP that is also on with secondaries removed :D

BlackZR1 I am sooooo excited to here you blocked TB Coolant and remember you do not have to torque Plenum bolts as tight as before since NO Coolant Pressure :thumbsup:

I left Secondsries operational on 95' simply because Jerry has the NEW secondary port vacuum system complete in stock for 93'-95' :thumbsup:

Sent from my iPhone using ZR-1 Net Registry (https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=90383)

[Paul Workman]

I have full secondary operational on 90's simply because I like that FULL POWER sign lighted up on my panel but maybe with a CHIP that is also on with secondaries removed :D

Yes, it is! In fact it serves as an indicator if for any reason the secondaries aren't working; a signal that something is not functioning correctly. Fix it (quick!)

[Billy Mild]

I have thought about replacing all the rubber lines with silicone lines. The issue I have is the small canister under the manifold that has a special 90 degree bend with 2 vacuum fittings on it. I may just use a T fitting with 2 lines. I used silicone tubing on my 944 turbo and never had an issue with boost or vacuum leaks.