Vacuum line routing - M62 + Ecotec: low boost - Boost Forum

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Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 8:21 PM
Okay so Ive had my supercharger installed since about March. it runs okay now with the tune finally keeping fuel levels reasonable, but I still max out at 8-9lbs (usually 8). Once I go WOT, it literally hits 8 like its a wall on the boost gauge.
one guy i ran and pulled had *17lbs but no h/e working, eco + s/c
one guy i ran and pulled was a stock 06 SS/SC
should I be getting more boost if Im running so many ppl? Maybe Im getting more and its the boost gauge sensor thats off? why would it start to read then stop instantly though? it works from -10 vacuum to +8lbs no problem..then doesnt even budge past as i stay WOT.

Few relative parts to help:
1. 3.065" pulley
2. stage 1 belt (stage 2 wont work with the spacers, its too tight to allow the tensioner to come back into position)
3. both phenolic spacers (relevant due to increasing belt distance about 16mm total)
4. upgraded the tensioner pulley to an idler pulley to take up more slack on the belt
5. ZZP S3 h/e
6. M62 obviously
7. 42.5lb Stage2 injectors
8. Racetronix Wbody/Fbody high performance pump/harness

I dont know what else would effect boost..but those are my main fuel/air parts.

here is how its setup right now...
Red is from boost gauge to "T"
Blue is from "T" to top of intake manifold
Green is from "T" to fuel pressure solenoid or whatever it is on the fuel rail
The Orange bypass valve LOWER nozzle is open to atmosphere...never had it hooked up to anything
Yellow is from the solenoid behind the power steering box to the larger nozzle on the throttle body adapter
you cant see it but there is a narrow/smaller nozzle on the tb adapter that Ive closed off with a vacuum line cap.




04 Cav. 2dr. 5spd. My DD. 'Nuff said.

Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 9:13 PM
What does the gauge read at idle?

PSI is just a measure of resistance, it is possible your setup is flowing really well giving less psi, but more flow.



FU Tuning



Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 9:59 PM
its like -10...then any gas it goes between -10 and 0, and if i go into any half acceleration or more it'll go +1 to +8. Or if Im in 4th or 5th at lower speeds obviously..


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 9:59 PM
Ill try to get a video of it.


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 10:25 PM
Your vac line routing looks fine. My money is on a bad bypass valve. I had the same problem last year, car would hit a wall around 5psi. Got a new bypass valve from ZZP and good as new. I took apart the original one, and found a 1/2" tear in the rubber diaphragm.






Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 10:46 PM
are the bypass valves supposed to whistle? i noticed when i drove my friends 06 SS/SC his is a lot quieter of a blower (not nearly the loudness of a whine) and his doesnt whistle as it goes from vacuum to boost (passing 0 on the gauge). Mine whistles like austins, but not as much as his (ScrapZ).

is the ZZP bypass valve the same as Factory or an upgraded one? ill look into it, thanks Evil!


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 11:14 PM
well its $100 for the new bp valve from ZZP..and no one else seems to be selling them. So I hit up the CobaltSS site...
so...can i safely take off my bp valve and inspect it without ruining it? This way Ill know if i really need one or not. Its a great suggestion though..now its got me curious!

between this and rerouting my h/e piping setup..id love to have the potential this setup is capable of running!


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 16, 2012 11:41 PM
a bypass from an m90 will work too, you just have to do the vacuum lines on it backwards.



Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 12:12 AM
id imagine thats even harder to find...but good to know!
perhaps I should just upgrade to a staged m90 or tvs and not worry about my bypass valve


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 1:14 AM
$100?!
Look again, I paid like $50-55 shipped. And no, you cannot inspect it..it's a sealed unit. I cut my old one open with a cut off wheel. I'd imagine if there is a tear in the diaphragm it could whistle due to the air pushing itself out. I replaced mine on a hunch since it was a cheap component to replace, and I figured with a 60-70k mile blower, a new one couldn't hurt.






Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 5:10 AM
My vacuum reads about -21 according to my interceptor and boost gauge

Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 7:03 AM
yeah a reading of -10 at idle means something is up. a stock motor should idle very close to -20 at idle. Even with nice cmas it shuld idle around -15.

Something is up, and it could be the bypass.



FU Tuning



Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 7:37 AM
EVILution (KGM Godfather) wrote:$100?!
Look again, I paid like $50-55 shipped. And no, you cannot inspect it...


http://shop.zzperformance.com/store/p/1060-EATON-Bypass-Valve-for-LSJ.aspx - $99.99 (before shipping)



Hmmm...so this further prooves Evil is most likely on to something... because mine sits at -10 im pretty sure. I think it goes to -20 on the gauge, maybe -25. Ill need to go look.

so if thats the case and Im hitting 8lbs, and replace it with a new bp valve that allows me to hit 12lbs or more now, I should notice a pretty big increase with 50%+ more boost pressure right?


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 8:26 AM
Is the -10 idle in inches of mercury or psi? -10 psi for idle is -20 inches of mercury, which is a perfectly fine idle. If it isn't psi then you have a bad vacuum leak or an inaccurate gauge. I had a problem with my bypass which caused me not to hit boost in 1st and 2nd. Replaced it and now its all good.
Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 17, 2012 8:55 AM
my friend with the 06 SS/SC is here now in my office (he's military, Im admin support), and we're gonna take it to his house after work and swap by pass valves. See if we can reverse the issue.
thanks for the help and suggestions..we'll see if this makes any difference!


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 23, 2012 2:24 PM
so I never chimed back in...but heres the latest on this low boost thing...

Still at 8lbs....
We swapped his 06 SS/SC bypass valve with mine. Both cars operated as they were, so no difference.
We moved around all the vacuum lines anywhich way we could think of, and could not get the boost to budge.
We went to O'reily's and installed a cheap analog boost gauge, ran it to the driver side window where we could monitor it....the gauge was consistant with my digital gauge. It would go to 8lbs and stop. The vacuum seemed to go just a bit further though to maybe -15. So with two different gauges, the boost level is the same.

Not the bypass valve.
Not the gauge.
Not the vacuum line routing (according to multiple ppl that have seen the layout)
Stil not sure what to do with the lower port on the bypass valve (if anything).
I have not seen another cavalier or cobalt with my similar setup running anything less than 12-13lbs, some goingas high as 17-18.

I find it hard to believe im making the same power at 8lbs and as wonderful as that sounds...it cant be so...i have 2 spacers and the ZZP S3 h/e, nothing special beyond that.


04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 23, 2012 2:39 PM
You seemed to miss the part where they said psi is a measurement of resistance, not power.

It's perfectly logical that a car at 8 psi can make the same power as a car at 17 psi, it's about the CFM.


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 23, 2012 3:02 PM
blu04DD wrote:Okay so Ive had my supercharger installed since about March. it runs okay now with the tune finally keeping fuel levels reasonable, but I still max out at 8-9lbs (usually 8). Once I go WOT, it literally hits 8 like its a wall on the boost gauge.
one guy i ran and pulled had *17lbs but no h/e working, eco + s/c
one guy i ran and pulled was a stock 06 SS/SC
should I be getting more boost if Im running so many ppl? Maybe Im getting more and its the boost gauge sensor thats off? why would it start to read then stop instantly though? it works from -10 vacuum to +8lbs no problem..then doesnt even budge past as i stay WOT.

Few relative parts to help:
1. 3.065" pulley
2. stage 1 belt (stage 2 wont work with the spacers, its too tight to allow the tensioner to come back into position)
3. both phenolic spacers (relevant due to increasing belt distance about 16mm total)
4. upgraded the tensioner pulley to an idler pulley to take up more slack on the belt
5. ZZP S3 h/e
6. M62 obviously
7. 42.5lb Stage2 injectors
8. Racetronix Wbody/Fbody high performance pump/harness

I dont know what else would effect boost..but those are my main fuel/air parts.

here is how its setup right now...
Red is from boost gauge to "T"
Blue is from "T" to top of intake manifold
Green is from "T" to fuel pressure solenoid or whatever it is on the fuel rail
The Orange bypass valve LOWER nozzle is open to atmosphere...never had it hooked up to anything
Yellow is from the solenoid behind the power steering box to the larger nozzle on the throttle body adapter
you cant see it but there is a narrow/smaller nozzle on the tb adapter that Ive closed off with a vacuum line cap.





you have both phenollic spacers? and the s3? that right there will drop your boost. I lost 2-3 LBS of boost but gained power when i added a cobra heat exchanger. perfectly normal.

also what exhaust do you have? i am running the same setup you are blower wise, with a LSJ pacesetter header, 2.5 inch downpise, and full 2.25 exhaust after the DP and make 12-14 depending on weather.



Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 23, 2012 3:27 PM
Roots blowers do not compress the air inside the blower. The air in compressed inside the intake manifold. With those spacers you basically made the intake manifold bigger and that would drop psi.

I only saw 10psi with a 3.1" pulley and only see 12-13psi now with the 2.9"(both intercooled). I think you are fine and there is no problem. Running less psi and beating someone is actually some pretty good bragging rights.


Error: Sig not found.

Re: Vacuum line routing - M62 + Ecotec: low boost
Wednesday, May 23, 2012 3:59 PM
And me with a completely stock setup im seeing 12 ish psi but that's a stock blower setup on a stock motor with no cooling.

And im sure at lower psi you'd still rape me lol
Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 24, 2012 12:10 AM
My setup only made 10psi on a 3.0, full.2.5" exhaust, both spacers and ls1 tb. From everything I've read I'd say your fine everyone said what I would've.








Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 24, 2012 1:19 AM
Yea I think Tink is right...i forgot your running both spacers, which will essentially add more area to the manifold. I expect to see a drop in over psi on my own setup this year, with adding a spacer and ported head, but still make more power.






Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 24, 2012 8:27 AM
Blu04dd- your good bro, don't sweat it. If tinkles, evofire, and evililution says your good, your good. Eco cavy s/c elite makin wisdom in ur thread.



Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 24, 2012 9:39 AM
Your fine, hell I only get about 12-14 psi and I'm on a 2.8 pulley.



13.520 @ 98mph! 220whp 234tq
Re: Vacuum line routing - M62 + Ecotec: low boost
Thursday, May 24, 2012 1:26 PM
well it makes me feel a lot bettter getting a unanymous decision on that
i know the lbs doesnt matter as much but when some cars are almost identical in mods, thats when i get worried that im running HALF the boost..

and yes, Evofire Im running the armor coated LSJ pace setter with 1.75" primaries, 2.5" dp into a highflow spun cat (basically no cat lol) and 2.5" back exhaust into a 2.25" i think Borla Pro XS muffler. Im going to be getting a second muffler if i eventually get ahold of my RK Sport lipkit I want.

so i get great exhaust flow even if i upgrade my blower it should be more than sufficient.

so that to me is actually great news...im getting equal power at much less boost which essentially isnt as hard on the motor right? so now my goal is to go down to a 2.8 pulley from smooth flow, to get a little more power. I think i can even keep the same pulley hub and simply swap pulleys. drop on the stage2 belt, and Ill be good. that'll have to do for now though until im ready to upgrade top end parts..cause she's got a lot of miles on her..



04 Cav. 2dr. 5spd. My DD. 'Nuff said.
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