secondarries

[Dynomite]

Originally Posted by janozr1

Hi to all ,
Im going to eliminate secondarries with Haibeck prom - got vacum
hadecke with this nassesary sistem....everything will go out
Will cruise control - tempomat , afer that still working?
Thanks fo repy.
Jano

As Paul says....Cruize Control is still functional as long as you do not eliminate the Cruize Control Vacuum on Passenger Side of Plenum. I think the passenger side Vacuum is Cruize Control and HVAC Vacuum ONLY which I think is what Paul is saying

Originally Posted by Paul Workman

As you can see, the vacuum port on the right side of the plenum supplies vacuum for the cruise and everything HVAC else.
P.

see # 3 of LT5 Eliminated Systems
See Vacuum Systems (Secondary and Cruize)

[Dynomite]

Am I missing something

[Pete]

Yeah,secondaries. LOL

Originally Posted by Dynomite

Am I missing something

[Fully Vetted]

Holy crap! This turned fugly fast.

Scott, and this is an honest question, what is the difference between removing the secondaries and removing unwanted metal aka porting. In each instance we are removing something that was put there by the manufacturer to, in our opinion, either improve performance OR improve reliability. My secondaries were removed by the PO so I'm trying to put myself in the shoes of someone that is considering this procedure.

[Pete]

As everybody knows my secondaries have been out for about 10 years.

My understanding as to why chevy put secondaries was emissions and gas guzler tax.
I can also see the point where our Z's are known/famous for the power key.

I really never had anybody in my Z that asked me to run her with the power key off.
Another point i would like to make is the C6 ZO6 with the exhaust flappers most replace them,does that make it a lesser ZO6? i call it a mod.
It would not stop me from buying it,unless i was looking for a NCRS car.

If someone was looking for a collector low mileage stock Z there are plenty of those and for those that are looking for a clean fast Z plenty of those and they don't have to worry about vacuum leaks.

Either or way people decide to go it's there choice.
I will add it will not effect drivability,w/chip reprogram.
Just my thoughts.

Pete

[Dynomite]

Originally Posted by Pete

As everybody knows my secondaries have been out for about 10 years.

My understanding as to why chevy put secondaries was emissions and gas guzler tax.
I can also see the point where our Z's are known/famous for the power key.

I really never had anybody in my Z that asked me to run her with the power key off.
Another point i would like to make is the C6 ZO6 with the exhaust flappers most replace them,does that make it a lesser ZO6? i call it a mod.
It would not stop me from buying it,unless i was looking for a NCRS car.

If someone was looking for a collector low mileage stock Z there are plenty of those and for those that are looking for a clean fast Z plenty of those and they don't have to worry about vacuum leaks.

Either or way people decide to go it's there choice.
I will add it will not effect drivability,w/chip reprogram.
Just my thoughts.

Pete

Excellent Description of the issues regarding Secondaries and Elimination of Secondaries

Here is yet another description of Secondary Elimination issues including some facts regarding effects on Horsepower

Another Professional Opinion on Removing The Secondaries

[Hib Halverson]

Originally Posted by Pete

As everybody knows my secondaries have been out for about 10 years.

My understanding as to why chevy put secondaries was emissions and gas guzler tax.(snip)

Exhaust emissions and beating guzzler had nothing to do with the existence of the port throttles. In fact, guzzler was never and issue with the LT5.

The secondary port throttles exist soley to improve low speed torque and throttle response.

Another point i would like to make is the C6 ZO6 with the exhaust flappers most replace them. (snip)

Actually, most C6ers with cars having NPP do not "...replace them". Admittely, some folks do swap an aftermarket exhaust for the stock dual-mode system, but more C6 people retain the NPP system but add an device ("Mile2Wild", "Exhaust Commander" and similar products) which allows them to manually control the exhaust bypasses.

[Blue Flame Restorations]

Originally Posted by Hib Halverson

Exhaust emissions and beating guzzler had nothing to do with the existence of the port throttles. In fact, guzzler was never and issue with the LT5.

The secondary port throttles exist soley to improve low speed torque and throttle response.


Actually, most C6ers with cars having NPP do not "...replace them". Admittely, some folks do swap an aftermarket exhaust for the stock dual-mode system, but more C6 people retain the NPP system but add an device ("Mile2Wild", "Exhaust Commander" and similar products) which allows them to manually control the exhaust bypasses.

Any data to support "most"?

[Pete]

Originally Posted by Hib Halverson

Exhaust emissions and beating guzzler had nothing to do with the existence of the port throttles. In fact, guzzler was never and issue with the LT5.

The secondary port throttles exist soley to improve low speed torque and throttle response.


Actually, most C6ers with cars having NPP do not "...replace them". Admittely, some folks do swap an aftermarket exhaust for the stock dual-mode system, but more C6 people retain the NPP system but add an device ("Mile2Wild", "Exhaust Commander" and similar products) which allows them to manually control the exhaust bypasses.

If it was for low speed torque then they didn't do a very good job.
My Z stock was peaking 330RWTQ @ 5200 now i make that at 2500 and peak is right at 400 @ 5200.
If you look at Z's with ported top end and no secondaries they make anywhere from 300-330tq @ 2500-3000rpm and close to 400 peak.
If you tune the car right you will loose nothing at low speed,my Z with huge cams for a 350 can cruise at 1300 rpm and get 24 MPG highway.
A lot more has been done with todays technology in the tuning department for our Z's.

If you ask most will post there before and after dyno sheets.

If it wasn't for guzler tax then it must have been for emissions,back in the old days when we had that thing they call emissions (rollers) i forgot my secondaries on it failed next day with no changes just kept secondaries off it passed.(same location)

On the C6 ZO6 mufflers there are half dozen for sale as we speak on top of the half dozen i have bought the most recent (2 weeks ago) the gentleman replaced them with B&B's,there's a few ZO6 guys that replace them,you might not be one of them.
Most car shows and dragstrips i go to i see most have replaced them.

Pete

[FU]

And I thought that Pete took out the secondaries for weight saving's.....