Removing Secondary Vacuum System questions.

[Pete]

If the 555-011's go in too loose.
Try the 555-108 freeze plug.

I have used the 555-108's on about a dozen heads with no issues.

Nominal Dia.: 5/8"
Metric Dia.: 15.90mm
Type: Steel
Height: 0.220"
Closed End Dia.: 0.633"
Open End Dia.: 0.642"
Brand: Dorman - AutoGrade - Boxed


Pete

[Paul Workman]

Originally Posted by billybaloneey

What did you use to cover/fill the holes left by the bearing once they were removed? VetteVet posted a reply that he used 16mm freeze plugs.

I used the Dorman 555-011s, but I had to splay them with a socket to make them fit snug. Then, just to be on the safe side, I coated the plugs with JB Weld before installing them to make sure they sealed perfectly.

I tried the 555-108s that Pete suggested, but I couldn't get them to work. It probably was due to the fact I was using a socket (to drive the plugs in) that just fit inside the rim of the plug and wasn't allowing the plug to be swagged into the bearing recess. Had I used a smaller socket, or just a socket extension, then they might have fit better (according to Pete).

P.

[VetteVet]

I pulled my receipt and it was definitely the 555-108's that I used. They were a snug fit, but that's a good thing.

I used red Loctite to seal and used a socket that filled most of the cup, but allowed the sides to flex when driving them.

[billybaloneey]

Originally Posted by VetteVet

I pulled my receipt and it was definitely the 555-108's that I used. They were a snug fit, but that's a good thing.

I used red Loctite to seal and used a socket that filled most of the cup, but allowed the sides to flex when driving them.

I picked up 8 of the 555-011's at O'Rielys yesterday...they were only $0.49 each. I'll do a test fit/installation, and if it's to loose I'll try one of the 108's. If I have an odd size secondary bearing hole, I'll try Paul's approach...JB Weld.

NOTE THIS DAY IN ZR-1 HISTORY: a part used on a ZR-1 only costing $0.49

[ZR1 MK]

Originally Posted by Paul Workman

It IS as simple as removing the secondary vacuum pump associated hardware, actuators, and even the friggin throttle plates too! P.

Paul
Are you stating you removed the the whole system and the engine runs fine?

I have the throttle plates and linkage removed plus the holes plugged, but the vacuum pump, vacuum canister, solenoid and most of the vacuum tubing is sill connected. My engine builder told me this part of the system still needs to be in place, but Id like to remove it all.

What do you know that he doensnt? Is there hope?

[XfireZ51]

Mike,

Some of us have a bypass for the ECM/Diff MAP signal.
=Jeff= or myself can make you one. Pretty simple mod.

[ZR1 MK]

Originally Posted by XfireZ51

Mike,

Some of us have a bypass for the ECM/Diff MAP signal.
=Jeff= or myself can make you one. Pretty simple mod.

Simple sounds good.

Whats involved? Cost? Does my current chip program stay the same?

[XfireZ51]

Mike,

I still have my throttle plates in the bores and attached to the actuating mechanism. However, the vacuum canister is zip tied open so plates are perpendicular and open at all times. The prom is modified to have secondaries open from throttle tip in. At TPS = Idle, secondaries are off.
Anywhere over that, secondaries are on in my cal. For me its easier to tune one set of VE/SA tables rather than two. VE LOW (Port Throttle Closed) is the one I use for idle conditions. All other driving conditions use the VE LOW and HIGH (Port Throttle Open) tables. Spark Tables are setup the same way. MPG isn't really affected because in either case, the motor uses x amount of fuel. It'll just be delivered by 2 sets of injectors rather than one.
As for the bypass, its the cost of the correct male connector for the Diff MAP harness. I already had one, so I would need to check on cost.
BTW, we tried my cal with Lgaff's 92 and it ran fine at the track. His secondaries are still operational.

[Pete]

Mike
Doms,plug will elimanate vacuum pump,vacuum canister etc, the only part you need to keep electric solonoid needs to be pluged in (no vacuum).

That's it.


If your prom cal was done for no secondaries then your good to go with Doms part, plug and play.

Pete

[Paul Workman]

I opted to remove everything. Marc Haibeck provided me with a prom designed to satisfy the ECM that everything was "OK", even with everything removed except the vacuum senor located under the ECM (on a 90), which must remain and be left open to the air (as Pete said).

I'm sure the refinements in Marc's chip have more to do with how it runs w/o the secondary stuff than simply running without it. But, the drivability with Marc's chip in it is supurb: quicker throttle response, smooth transition from light to moderate to full throttle (or any combo thereof), and fuel economy remained essentially unchanged, far as I can tell.

In summary, I'd have to say there have been no down-sides to eliminating the secondary system from a driving point of view: if anything it is improved! In some states emissions testing may put a wrinkle in things - IF anyone would know what to look for and be able to see it if they did.

Hope this helps

P.