ConradoR

iTrader: (3)

I was wondering what you guys think about removing the cog belt before long trips.

I have searched and there are mixed opinions on that. Some say it removes the stress on the SC and engine, but some say that it can lean out or the oil flow into the v2 Vortech unit w.o the impeller spinning could be a bad idea.
The threads I've found were very old and had mixed opinions, so I was wondering if we could have an updated set of opinions on this.

I have been making round trips every other weekend with my Vortech'ed G (300 miles each way), and it would be quick and simple to remove the COG belt if it helps with the longevity of the system (and I guess save a few bucks on gas due to the parasitic loss)

Quick background, a few of my mods that might affect the decision: Uprev Tuned, Walbro 255, DW 600s & 19 Row Setrab Oil cooler. I also try not to hit boost after a while into the trip to keep the stress down, since the engine is running for so long.

Disclaimer: No, I don't wanna buy a beater and use it to make the trips

Thanks!

ace32x

iTrader: (10)

drive it and stay out of boost, if its not spinning high rpm's in the blower the wear on it will be very minimal.

str8dum1

iTrader: (11)

i removed my cog belt on every long trip i took over the 2 years I has the setup.

some people are stupid as are those reason they suggested.....

Junkster

iTrader: (3)

+1 on staying out of boost. I dont see how it could create a lean situation, however oil flow without the impeller spinning may create excessive blow by due to the oil not having its normal flow through the bearings...Im just throwing out possibilities, dont quote me! lol, this is a good question though...

Subscribed for curiousity

Lee R

iTrader: (10)

What does Vortech say about removing the belt?

djamps

iTrader: (1)

Typically when you remove the belt from what I've seen you're gonna be running rich not lean. Be easy on the gas or it'll bog out rich if you're too aggressive. Stock ECU uses pedal input just as much as MAF to predict fueling.

Sam Mcgoo

iTrader: (1)

I've probably driven about a 1000 miles over the last 2 years with the cog belt off for problem elimination mostly, but never had any running problems and keeping an eye on my AFR it never seems far off.

My only thought is where is the Intake air coming from? Is it pulled though the non-rotating charger making it a difficult route for the air to take or is the BPV open and it draws though there?

I wasn't sure so fitted a filter to the BOV anyway.

I can't see the oil flow being a problem, surely it will still just flow through and back to sump.

str8dum1

iTrader: (11)

That doesnt even make sense. The car will never leave vaccuum without the belt, ie never leave the low MAF fuel cells. If the car was gonna bog out, it would do it with or without the belt. It not like his tune is only setup for 600cc or whatever injectors only while in boost.

binder

iTrader: (8)

wow, that's a great point. A maf tuned vehicle will never get into the "boost" cells since it's based on air flow and air flow will always be in vacuum with the cog belt off.

You will need a filter on the BPV because air will be pulled in through that passageway.

ConradoR

iTrader: (3)

Doens't the tune modify the AF ratios at the higher RPM based on the fact that the high rpms will be seeing boost?
I assumed it would run lean w.o the cog belt due to that fact.

binder

iTrader: (8)

it has nothing to do with rpm. You can drive around at 7000 rpms but only half throttle and still be in vac.

Maf tuning is based on air flow. As boost goes up air flow increases. If you never have boost then the air flow can only get to 0psi which is the same flow no matter what. Therefore the airflow reading (maf reading) won't go into any of the cells that are tuned for boost.

djamps

iTrader: (1)

In Osiris, MAF isn't the only input that decides BFS... throttle input is a huge part, probably even more than MAF.

Plus the MAF tuned ECU has no idea of vacuum vs boost. Vacuum might take up 10-12 columns and boost is 1 or 2.... nothing like you're used to with MAP.

I'm not just making this up I'm going off experience (locals driving around with busted belts) as well as Osiris manual and input from Jared.

Long story short... Floor the gas in an Osiris tuned vortech with a busted belt and you will go rich.

str8dum1

iTrader: (11)

so you are saying that you cant tune a NA Z on 600cc injectors without it going lean when you floor it?

That is the exact same scenario as the vortech with a busted/ no cog belt.

350z006

iTrader: (79)

Or you can block off your bypass valve boost reference so it doesn't open up at vacuum...

djamps

iTrader: (1)

I know what you're saying but I'm going off experience.

The only thing that I can think of to explain it is the fact that throttle input is used in fuel calculations...NOT just MAF.

If you look at the fueling table you will see that the horizontal axis is fuel schedule... NOT MAF/MAP values like you're used to on your haltech/proefi.

According to Jared the primary inputs used to calculate fuel schedule (horizontal cursor position) is both throttle and MAF inputs. Thus, even in absense of full MAF voltage (no boost) with the pedal floored the ECU can still target areas which would have previously been considered 'boost' areas.

str8dum1

iTrader: (11)

interesting...

How do you tune a turbo then when boost and rpm have no relation? I would think that issue would be a real problem, esp with a super fast or super slow lag turbo.

You romp on the gas, the turbo lags, and the car goes super rich (map goes into "boost" cells before the car is actually making boost), or romp on the gas, fast spool, car goes lean..

djamps

iTrader: (1)

There is no concept of boost or manifold pressure in Osiris, at all. You have BFS (horizontal) vs RPM (vertical). BFS (base fuel schedule, in mS) is the final result of a calculation involving throttle position, MAF, corrections, and transient functions. This is way different then a MAP setup where MAP alone is the horizontal axis. There are sometimes issues with fast spooling turbos, whether it's exactly related to this or not I don't know. That said, tuning for boost (turbos, mainly) in Osiris is a black art and is actually quite difficult to get right (example here). Food for thought... in a MAP setup try disconnecting the MAP sensor completely and see if you can get it running -- it probably won't. Try the same with the MAF sensor on a VQ...it still runs (albeit very poorly). In Osiris here is more to the fueling calculations than just MAF input and throttle input is probably the biggest one.

HotRodG35

iTrader: (7)

If not already installed, should use a filter on BPV because air will be drawn through it at idle/vac, or disconnect vac line.

ibelonginprison

iTrader: (1)

I drove around for a week with the cog off my procharger while waiting for a tune, just disconnected and plugged the port for the bpv and had no issues. I accidentally left it plugged in the first day without thinking and it rained, and it sputtered when it sucked in some water through the bpv.... I pulled over under a bridge and yanked it off the plenum then electrical taped it to get me to Advance where I fixed it "the right way."

Thankfully it was just a few drops and it didn't hydrolock, otherwise I'd have been really pissed, and really embarrassed.

Having said that, I can't answer for any other "possible issues" with the Vortech because I don't have one.

binder

iTrader: (8)

hmm, there must be some weird tuning because it did not do this when i tuned my car with osiris. With the belt off I could watch the tracer in osiris and it wouldn't go into the maf cells furthest to the right which were my boost cells. If it's not going into my rich cell area then it didn't go rich. Maybe those guys have their targets screwed up and since they aren't in boost (they would be 0psi flow area of the map with no cog belt) the car is targeting a rich area. Mine targeted directly on what it was for that flow. I think i had it set for around 13 a/f in the cells that would represent 0psi of boost. That vertical cell block was the same target and a/f all the way to redline so when the belt was off it stayed in that cell. If i had osiris tuner and a vortech i would pull some more logs and show you but i don't.

ah, genius idea. simple clamp on the vac line.