Jameslt1TA

Ok, I have went through 3 opti rotors in a very short time. I didn't have the vents hooked up right at all. I have been researching alot and found this https://www.camaroz28.com/forums/sho...opti+vent+line thread with a picture someone drew. If I do it the proposed way, the intake line pre-turbo would be my vacuum source and pull air out of the back of the opti. So, would I just hook the port on the cap of the opti to a line with a small filter? Would I even need to run the orifice? My car runs in speed density so metered air isn't a concern, I don't think. I have read several people running the vents the current way in the picture, but wouldn't that mean it would only pull air out of the opti when the motor isn't under boost(has vacuum)?

If I ran it the proposed way with a small filter, I think that I will run a long line and locate the small filter in front of the intercooler. That way it would pull nice cool air into the opti since the turbo sits right in front of the opti.

I'm thinking that running it this way would work better since there is always vacuum pre-turbo, rather than using the intake manifold for vacuum. Half the time the intake manifold is under boost anyway and thus not venting the opti at all. Maybe this is why there seems to be lots of opti failures on FI cars.

Thanks for reading my late night ramblings, RealQuick I'm sure you will be able to help.

Thread with back story and pics of my failures
https://www.camaroz28.com/forums/sho...d.php?t=769215

MikeGyver

There is no (or negligible) vacuum pre turbo just as there is no vacuum in your intake pipe before the throttle blade.
Vacuum is created by a restriction (i.e. the throttle blade, clogged air filter, or your hand over the intake pipe, etc. WOT = no vac).
Small differences in pressure (like <1in Hg) can be created when under boost by use of a properly constructed venturi.

Since you're speed density, you could run the opti inlet hose pre turbo, and hook the outlet to the intake manifold and use the inline restrictor and a check valve to block boost from entering the opti.
With a turbo V8 you aren't going to be in boost for very long before you run out of road, so it should be just fine if it's not drawing air through for a few seconds at a time.

Fastbird93

I'm actually setting mine up exactly as mikegyver explained. The one line that goes to the manifold, leave as-is because the check valve is there to stop air from being forced into the opti. The line that went to the elbow will now reside in a pre-turbo inlet elbow I'm having fabbed up. This should lend itself to proper operation of the opti vacuum system.

mzgp5x

I have been through six (6) opti's. #6 Opti is an all-ignition.com performance unit (not popular with the boyz). Anyway, I have a 97ss 383 D1 procharged MM6 Camaro. I have had success with Opti #6.

I run the MAF on the intake side of the compressor, and noticed (with a transion from positive manifold pressure to negative) the opti vac line can become positive pressure (bypass valves dump ait to the compressor intake side).

So, I made my own check valve (rolling ball check) to stop this from happening. It looks like it is running OK. I do run a filter on the optical section vent. I never figured that the intake side could become positive pressure. B.

DirtyDaveW

My setup has that big rubber 'Cobra' head on the inlet of the Turbo. I punched a small hole into that and THAT is my source of vacuum. The air filter tube comes off the other side of the Cobra and has the filter on it. It always has vacuum on it when the motor is running and never is pressurized.

leachbuz

I am pretty sure my opti is bad --I have a MSD cap (1997); car is boosted 10psi.

My car is popping at wide open throttle only (when you step on it the car is cutting out and popping).

would switching to a delteq fix these opti failures?

I know that I am going to vent my opti to the interior of my car this next time around, rather than the engine bay.

let me know what you all think!!

97WS6SCharged

I would pull and check the plugs first. Sounds like you have too much gap.

streetbad

What is your a/f ratio?

Jameslt1TA

Thanks for the replies, been real busy but I should be able to get the new opti on this weekend. Hopefully hooking up the vents right will fix this problem.

Leachbuz, How do you have your vents hooked up now?

If your talking to me, my a/f is 13.5 cruising around and 11.5 or so under boost...havent got a chance to read my logs I got right before the opti died.

MikeGyver

I think you may have misdiagnosed the problem.

If the engine is popping and completely cutting out and sputtering only when under boost or WOT, I really doubt it's the opti.

What are your spark plugs gapped to? Do you have an MSD ignition? My spark was blowing out under boost before I got my MSD 6A. With the stock ignition I had to gap down to like .022" on only 7psi with a stock motor.

leachbuz

I don't want to hi-jack this thread.

I have an electronic ignition, gapped at .040, not not my problem (I have had the car dyno tuned ay byan herter from PCM directed on the dyno --made 553hp/561tq)

now after driving it 500 miles, it just started the problem as described above.
I have put new o2's in, cleaned the mass air flow senser (dirt/oil), and just installed new opti (the opti had corrosion on the eloctrods inside and tracking all over --only 500 miles on the msd opti).

vented to the manifold and just re-routed the other line into the interior of car.

I was trying to add to this thread concerning: venting of opti's --I think that the boosted guys need to either go with delteq or install a vacum pump for the vacum source of the opti. As described in the previous threads when positive pressure is in the plenum, oil vapor is going into the opti (at least in mine) which is destroying the opti prematurely. By having a vacum pump this problem would no longer be an issue.

leachbuz

I forgot to mention, the drawback to routing any of your opti lines to the suck side of the blow is that moisture can than get into your opti, especially on a rainy or moist day.

Jameslt1TA

Don't worry about hijacking. My car would pop and backfire before my first optical sensor went out and my second rotor went out. Does the car still run fine besides wot?

leachbuz

the car runs good basically until I step on it.

I just replaced the opti (there was tracking and eltrods were corroded), cleaned the mass air flow sensor, replaced the plug wires and plugs --> the car runs smoother, but still pops at WOT.

I am not sure what to do next?

Jameslt1TA

At what rpm does it start popping or does it just pop as soon as you open it up? Are your plugs still gapped at .40? Maybe it started blowing the spark out for some reason.