Removing Secondary Vacuum System questions.

[ZR1 MK]

Originally Posted by 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.

Im a bit confused, but Im guessing you sell a custom made electric MAP connector?

Originally Posted by 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

That sounds good. Thanks for the clarification.

[DScott600]

I should have wrote this sooner but I deleted the secondaries shortly after I started this thread and I am very happy with the results. I purchased a chip from Mark, removed the entire secondary system except for the sensor under the ECM and wire tied and safety wired the secondaries open. I didn't notice any difference at low speed and Marks tune has improved the idle and gave it more power. In the future I plan on getting the injector housings and plenum ported and powder coated and while I have it all apart I will remove the throttle plates. It's so good to not have to worry about a secondary vacuum leak area under the plenum is much nicer looking without the rats nest of hoses. Thank you for all the advice.

[tccrab]

What about us unfortunates who live where the dreaded SMOG Nazis prowl?
Would removing the secondaries affect emissions to the point of failing our bi-annual inspection?
I would love to be able to ditch them, one less thing to go wrong.

TomC
"Crabs"

[Paul Workman]

Originally Posted by tccrab

What about us unfortunates who live where the dreaded SMOG Nazis prowl?
Would removing the secondaries affect emissions to the point of failing our bi-annual inspection?
I would love to be able to ditch them, one less thing to go wrong.

TomC
"Crabs"

Just an opinion, but it seems to me that as long as modifications are limited to how many injectors are operating (in closed loop), i.e., no other mods are done except for porting, it seems logical that a prom with the appropriate tune should be able to operate two (instead of one) injectors and maintain the proper air/fuel ratio. Two injectors instead of one does not spell emissions failure; only the air/fuel mix would do that (all else being the same such as cam profile and timing, etc.).

But, this would be a question for Dom or one of the pro tuners out there. However, I'll be comfortable placing most of my "chips" on the square marked "won't affect emissions".

So, what do some of the tuner experts say?

P.

[ZR1 MK]

Originally Posted by tccrab

What about us unfortunates who live where the dreaded SMOG Nazis prowl?
Would removing the secondaries affect emissions to the point of failing our bi-annual inspection?
I would love to be able to ditch them, one less thing to go wrong.
TomC "Crabs"

It shouldnt matter.

FWIW, NY emission standards are high and cant be far from CA standards. My 427 with larger than stock cams passed well within the limits.

Reliablity is my main concern and why Id like to eliminate as much as possible. I do bring an extra solonoid to track events just in case, but id be nice to not even need it.

[XfireZ51]

Originally Posted by Paul Workman

Just an opinion, but it seems to me that as long as modifications are limited to how many injectors are operating (in closed loop), i.e., no other mods are done except for porting, it seems logical that a prom with the appropriate tune should be able to operate two (instead of one) injectors and maintain the proper air/fuel ratio. Two injectors instead of one does not spell emissions failure; only the air/fuel mix would do that (all else being the same such as cam profile and timing, etc.).

But, this would be a question for Dom or one of the pro tuners out there. However, I'll be comfortable placing most of my "chips" on the square marked "won't affect emissions".

So, what do some of the tuner experts say?

P.

Paul,

You're on the right track. I have a WB on my car and motor idles and runs at 14.4 to 15.1. BLMs are between 124-131. With secondaries operating the pulsewidth for each set of injectors drops depending on where in the VE table you are. Essentially the aggregate pulsewidth for idle and part throttle cruise will be the same regardless if one or two injectors is (are) feeding the cylinder.
I wonder if it isn't better to have both injectors operating in terms of reliability?

[Locobob]

Originally Posted by 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

Went to NAPA today and asked for the Dorman 555-108 - they came up with nothing??? What gives???

[Pete]

Originally Posted by Locobob

Went to NAPA today and asked for the Dorman 555-108 - they came up with nothing??? What gives???

I don't know why Napa couldn't find them.

I know the Dorman Part # is good.

The only thing i can say is try a different parts store or i can send you a set as a Christmas gift,will have to wait till next week,i'm out of town.

Pete

Originally Posted by Locobob

Went to NAPA today and asked for the Dorman 555-108 - they came up with nothing??? What gives???

http://www.summitracing.com/parts/RNB-555-108/

[Locobob]

Found them at Baxter