Hauntingly familar secondary failure #3

[tf95ZR1]

See post #56

http://www.zr1.net/forum/showthread....ondarys&page=6

[Schrade]

Originally Posted by tf95ZR1

See post #56

http://www.zr1.net/forum/showthread....ondarys&page=6

Looks like one of the more knowledgeable people made a fool of himself on THAT page!

Also looks like a good example of how to handle it too, like I said before:

Originally Posted by Schrade

This is a good point Scott:

Some engines, when you put too much oil in the crankcase, the crankshaft spins IN THE OIL, and makes a foamy, frothy, jammy mess.

It will make the oil light come on, when the system pickup tube starts suckin' up the froth.

I can't imagine WHAT goes through the PCV plumbing when this happens.

And who knows what would go through the cylinders. And the exhaust...

I don't know how LT5 dynamics would handle too much oil...



(good job Admin on editing - some people don't know a tactful way of telling another that they THINK another MIGHT be wrong. Even if they KNOW they're wrong. 'Cause they might NOT be wrong)

[Blownrunner]

There was a TSB on the wifes Nissan which has a similar setup for the air side of the intake, but only has one injector per cylinder. The plates' screws were backing out also and their fix was installing screws that had nylon on the threads like on a nylon lock nut has, then torquing with a calibrated screwdriver. I did her car as a safety precaution even though it wasn't required for the TSB. I removed the screws and reinstalled using red locktite (high strength). I couldn't find what the calibrated screwdriver was set to, so I torqued to 25 in/lbs, the same that Boeing requires for installing inspection panels on the outside of the aircraft (on #10 steel/titanium screws).

I also rebuilt and adjusted the plates on the throttle body of the ZR-1, and could not remove the screws without destroying them. I drilled them out and replaced with new ones and installed again with the red locktite. I think that having screws on the 'air valves' isn't the problem, having them installed without some type of way to keep them from backing out is the problem. After all, isn't this how every throttle body is built today?

[GOLDCYLON]

Originally Posted by Blownrunner

I think that having screws on the 'air valves' isn't the problem, having them installed without some type of way to keep them from backing out is the problem. After all, isn't this how every throttle body is built today?

Disagree, on my passenger side the shaft failed and fell into the motor along with the screw. The air valves shafts ARE part of the problem. see below the picture where the shaft fatigued. Snipped from my link in post #1






Scope view at point of discovery the awwww Crap moment!!!!!

[Paul Workman]

Originally Posted by tf95ZR1

See post #56

http://www.zr1.net/forum/showthread....ondarys&page=6

I'm not sure if you're asking a question, or making a statement by referring to post #56???

Post #56



Vs. an "FBI 500" motor w/ tuning...



But there's a fly in the ointment (see posts #77 and #78 of that same thread). In short, tuning for both low and high rpm makes a huge difference in overall driveability characteristics with the secondaries deleted.

And, IMO, I think that other thread is slightly out of sync with this one, i.e., an earlier statement (in your referenced thread) was made (in effect) ... pulling the secondaries would make the car only suitable for race applications; ruin(?) it for normal driving. That is just patently wrong, based on experiences of many. Obviously, that statement was devoid of actual experience, as I and dozens of ZR-1 drivers (sans secondaries) can attest!

Note: I invited that poster to come to a BG gathering and test drive mine and some other cars, sans secondaries, and see what he thinks. So far, I haven't heard him accept the offer.

The only "niggling" issue is emissions compliance in your location. Other than that, "no worries mate!"

[bradley]

my callaway 475 supernatural , drives better in every way with the secondaies removed .also since I have had them removed my mileage on the freeway has improved by 2 mpg .example , I go to see bill boudreau 3-4 times a year . before the secondaries were removed I got 21.2-.4 on a round trip now I get 23.5- 24.0 mpg on the trip. my car also has 4.10 gears

[tf95ZR1]

Originally Posted by Paul Workman

I'm not sure if you're asking a question, or making a statement by referring to post #56???

Just providing info on the subject from a reliable source (Graham Behan) who
says you loose low end HP & torque without the secondaries.
Anybody can take it or leave it. Maybe other factors come in to play.
I would probably do what Marc H. suggested ( if I wasn't in the smog state of CA).
He said keep 'em until they don't work, then delete.

[Paul Workman]

Originally Posted by tf95ZR1

Just providing info on the subject from a reliable source (Graham Behan) who
says you loose low end HP & torque without the secondaries.
Anybody can take it or leave it. Maybe other factors come in to play.
I would probably do what Marc H. suggested ( if I wasn't in the smog state of CA).
He said keep 'em until they don't work, then delete.

Wellllll....practical considerations not withstanding, that graph makes a point -- to a point.

In the first place, the graph was clearly a modified motor by LPE, recorded on a Dynojet. Graham might have provided it, but right off the bat, the data (graphs) are specific to a very unique set of circumstances - and so, the data has to be considered in the context of a modded motor.

"Maybe other factors come in to play"? Oh, yeah - fer certain. For instance:

That LPE was NOT a stock LT5; based on characteristics its probably a 368? Point being, the tuning would be significantly changed, and maybe the cams too. Displacement, tuning, pistons (compression) and probably custom cam profiles - combine to cast considerable suspicion on how it proportionately relates to a stock LT5 (NO reflection on Graham!).

Be that as it may, even in the LPE example, with the power switch in NORMAL the torque "advantage" quickly pinches off at 3900. I dunno 'bout chew, but I don't do much driving at WOT where I'm limited to 3900 rpm. So, really, what's the practical relevance then I wonder?

Modified motors allowed, if Dynojet graphs = "reliable source", then I'd like to point out that Dynojet graphs of my "FBI 500+" modded motor WOT torque is ≈ 25#+ over my stock motor* at WOT from 2000 up and beyond 3900 rpm. (NO pinching off at 3900 rpm either!). So, the net loss/gain as result of opening up both runners and chucking the Secondary Port Throttles (SPTs) is actually a net gain through 3900 rpm compared to what it might have been stock with SPTs closed. (I'm sure Graham might agree).

*with secondaries "open" (i.e., removed, to be precise)

Fuel economy? Virtually the same with vs. w/o SPTs for the same conditions on the same 8 hour round trip destination w/ cruise set at 71 mph in both cases.

So.... I'm suggesting the difference in performance between SPTs open (or deleted) at WOT vs. SPTs closed (power switch = NORMAL) is academic, for any practical purpose. And, the real practical advantages of deleting them, far outweigh reasons to keep them intact, with the possible question of emissions compliance, depending on where you live.

Your mileage may vary.

[Dynomite]

Originally Posted by GOLDCYLON

Geez......a little carbon there Daryll
You burning Diesel in AZ?

[GOLDCYLON]

Originally Posted by Dynomite

Geez......a little carbon there Daryll
You burning Diesel in AZ?

pre 380 she was a Dirty Girl