Did you eliminate your Secondary Throttle Vacuum System? - ZR-1 Net Registry Forums

MuRCieLaGo · 11-17-2017

Just thinking of eliminating my Secondary Throttle Vacuum System. Having some idle issues and I would like to eliminate that leak possibility.

I'm wondering how many of you guys eliminated that system.

secondchance · 11-17-2017

Sure did. Allowed injector housing porting to make the most out of 4" pistons and 3.75" stroke crank. LT5 runs flawlessly and never looked back.
Another benefit - 2ndary runners look clean like the primaries always.

Dynomite · 11-17-2017

Quote:

Originally Posted by MuRCieLaGo

Just thinking of eliminating my Secondary Throttle Vacuum System. Having some idle issues and I would like to eliminate that leak possibility.

I'm wondering how many of you guys eliminated that system.

I eliminated secondaries completely on a 91' but kept the secondaries on several 90s' and a 95'. The Secondaries perform great on the 90s' and the 95' once the vacuum system is restored with no vacuum leaks. And....And....once you have eliminated vacuum leaks, the vacuum leaks do not reappear for a very long time

I like that Power Key Option albeit I keep it on Full Power. That Full Power Option is very unique to the ZR-1s

Kevin did a great "How To" write up on rebuilding the Power Key
See Item #2 CMHSL LED, Full Power Key and Alternator Pulley

Jerry some time ago had available complete secondary vacuum lines and rubber connectors for the 95' (for around $100 as I recall) but he ran out I guess which is not surprising for such a bargain

PhillipsLT5 · 11-17-2017

All gone, GREAT!

efnfast · 11-18-2017

I did, but miss them when it is time to tell the story about the key. "That key is for this, but not anymore."

XfireZ51 · 11-18-2017

Eliminated the secondary actuation pretty soon after buying the car. Never noticed anything detrimental because if it.

Paul Workman · 11-18-2017

Pulled mine out 8 yrs ago when I ported the top end. Runs great. No regrets!

WARP TEN · 11-18-2017

I did on my '95. Marc did the work as part of a 510 package. One caveat: When they are eliminated, the injectors are set to run at a 50% flow rate so if you turn off the power key (i.e., return to "normal") the car will run too lean as it would shut off the secondary injectors. (I think I explained that correctly but please chime in if I did not.) I removed the key from the car and put a keychain tag on it to remind a future owner of the situation. --Bob

Paul Workman · 11-18-2017

Quote:

Originally Posted by WARP TEN

I did on my '95. Marc did the work as part of a 510 package. On caveat: When they are eliminated, the injectors are set to run at a 50% flow rate so if you turn off the power key (i.e., return to "normal") the car will run too lean as it would shut off the secondary injectors. (I think I explained that correctly but please chime in if I did not.) I removed the key from the car and put a keychain tag on it to remind a future owner of the situation. --Bob

Mine and Ami's switches are hard-wired ON. Made that correction after my switch contacts started getting funky. (Already experienced a burned valve - due (I think) to a injector gone bad.)

tiegsd · 11-18-2017

Secondaries work great on my 90. Love the DR Jekyl Mr Hyde character of the car!

Sent from my SM-N920V using ZR-1 Net Registry mobile app

View Poll Results: Did you eliminate your Secondary Throttle Vacuum System?
Yes.	21	55.26%
No.	17	44.74%
Voters: 38. You may not vote on this poll

11-17-2017	#1
MuRCieLaGo Join Date: Aug 2014 Location: Trois-Rivieres (QC) Posts: 473	Did you eliminate your Secondary Throttle Vacuum System? Just thinking of eliminating my Secondary Throttle Vacuum System. Having some idle issues and I would like to eliminate that leak possibility. I'm wondering how many of you guys eliminated that system.

11-17-2017	#4
PhillipsLT5 Join Date: Aug 2005 Location: Scottsdale, AZ Posts: 2,452	Re: Did you eliminate your Secondary Throttle Vacuum System? All gone, GREAT!

11-18-2017	#5
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,478	Re: Did you eliminate your Secondary Throttle Vacuum System? I did, but miss them when it is time to tell the story about the key. "That key is for this, but not anymore."

11-18-2017	#6
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: Did you eliminate your Secondary Throttle Vacuum System? Eliminated the secondary actuation pretty soon after buying the car. Never noticed anything detrimental because if it. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

11-17-2017	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: Did you eliminate your Secondary Throttle Vacuum System? Sure did. Allowed injector housing porting to make the most out of 4" pistons and 3.75" stroke crank. LT5 runs flawlessly and never looked back. Another benefit - 2ndary runners look clean like the primaries always. Last edited by secondchance; 11-17-2017 at 08:48 PM.

11-18-2017	#7
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Did you eliminate your Secondary Throttle Vacuum System? Pulled mine out 8 yrs ago when I ported the top end. Runs great. No regrets! __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

11-18-2017	#8
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,094	Re: Did you eliminate your Secondary Throttle Vacuum System? I did on my '95. Marc did the work as part of a 510 package. One caveat: When they are eliminated, the injectors are set to run at a 50% flow rate so if you turn off the power key (i.e., return to "normal") the car will run too lean as it would shut off the secondary injectors. (I think I explained that correctly but please chime in if I did not.) I removed the key from the car and put a keychain tag on it to remind a future owner of the situation. --Bob __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough" Last edited by WARP TEN; 11-21-2017 at 01:31 PM.

11-18-2017	#10
tiegsd Join Date: Jul 2017 Location: West Chester, PA Posts: 378	Re: Did you eliminate your Secondary Throttle Vacuum System? Secondaries work great on my 90. Love the DR Jekyl Mr Hyde character of the car! Sent from my SM-N920V using ZR-1 Net Registry mobile app __________________ 1990 Black/Black ZR-1 #1155 1993 White/Red coupe (Regrettably sold)