WTF? im building mad boost in neutral!?! [Merged 12-7]

[98TsiAWD]

I want to test my pcv valve under boost. Is there anyway I can get the turbo to boost by reving the engine under the hood?

I recently blew out my dipstick, I did a leakage test and my intake valves are sticking open a little so that would mean boost is getting in there when it shouldnt be right? Causing excess crankcase pressure.

My valve cover breather works fine, I pulled the pcv valve, I can blow through it easily, I also pulled the hose that goes from the pcv to the intake. I make sure it and both fittings where not clogged.

So, basically i want to have the engine under boost just for a second to see if the pcv blows off excess crankcase pressure. But being as there is boost in the intake that will keep the pcv from opening wont it? So my intake valves sticking open is what is causing excess crankcase pressure?

 

[95EclipseGSX]

With my old t25 my car boosted to 15lbs while in neutral. Then got a good blow off, even with a light (Fidanza) flywheel. You have to create a load MASH THE GAS DOWN TO THE FLOOR FAST WHEN YOU SEE THE RPMS COMING TO RED LINE QUICKLY RELEASE.

 

[dope96clipse]

ya i disagree it happens to be my brother who started this thread but i have a 2g gst an i build up to 10psi of boost under nuetral, an so does my freind in hise 3000gt vr4

 

[Defiant]

Cant make boost in neutral

Why, in the name of all that rotates, would you try to?

Don't.

 

[805eclipse]

before my car broke down i could rev in neutral and hear the blow off valve go off meaning there was some pressure build up now when i rev the blow off valve does nothign meaning there is no pressure being built up thats what im tryin to figure out

 

[tsunari]

Yeah, I know exactly what you're talking about . . . seriously though- head over to VFAQ and build one of their intake leak testers and pressurize your intake. Fix any/all of your leaks and give it a try. I'm almost positive you'll find a significant leak somewhere

before my car broke down i could rev in neutral and hear the blow off valve go off meaning there was some pressure build up now when i rev the blow off valve does nothign meaning there is no pressure being built up thats what im tryin to figure out

 

[dope96clipse]

we have one built, we plan on using it when we get the car back from the mechanic, hs lookin into the timing issue cuz theres a slight missfire that we cant get to go away

 

[Bens95TalonTSi]

Every 2g I have seen can build boost in neutral. I have a T28 and I can build 5PSi@5K rpm's in neutral.

 

[Defiant]

Every 2g I have seen can build boost in neutral. I have a T28 and I can build 5PSi@5K rpm's in neutral.

Good, that's useful.

for something, I guess.

 

[Thomas91169]

i think hes asking if you can rev it at a certain rp for a period of time and it build up and keep boost. if thats what youre asking, then its no, you cant hold it at, say, 5k rpm and have 5lbs of boost. thats not how it works, theres no load and youre not giving it full throttle.

if you were to rev it to 5k then stop, it should build a good 5-8lbs of boost(does for me stock t25), but to rev and keep it at 5k, the boost goes back down to -15 or so. the engine does not create that much exhaust pressure at idle or something of that technical nature.

 

[dope96clipse]

no we r just say it used to blow off if u rev'd in N but now it doesnt after a head rebuild, but as an update we had our mechanic look it over n set the timing n it turns out we had it set right but the car still has a slight mis fire..and the turbo spools at an odd time, n isnt as powerful as it used to be, his car is only got -10hg on the vac, neideas? (we think vac leak) an we r gunna test it today but if neone knos nething else plz dont hesitate to let us kno, its been 8 months worth of a project due to lack of funds an laziness on my brothers behalf .. an im sick of it i just wanna get it done

 

[Defiant]

English.

Learn it.

Use it.

See you then.

 

[Generation1JeY]

Alright my friend just bought a 2g talon, today i was checkin it out in the parking lot at our school, and i just couldnt help but notice that when he revs he gets boost. I guess its just that the t-25 it spools up a lot quicker than the 14b, but i can NEVER EVER create boost when i'm just revving, the higher i rev the vacuum just stays the same almost.

His talon is completely except he has a hks ssq blow off valve, so it was really easy to tell that he was getting boost cause the bov is loud. I mean i look at the bov and when he dropped the throttle it moved and everything and it was like he had almost full boost cause the bov was so loud.

He doesnt have a boost gauge right now so i cant tell how much boost hes gettin and all that, but i'm just wondering are all 2gs like that? If all 2gs are like that then i kinda envy u guys cause i'm into the SRT-4 turbos that spool up quick as hell, i'm into show turboing i guess, i love my bov too much.

Also is there anyone with a 1g that can build boost by just revving? cause i know i cant.


Sorry its a stupid question, but i'm just curious

 

[midnght]

Is he automatic?

 

[doodie]

Um... No. Not even the T25 can build full boost at idle. My bov rings off pretty loud at idle when I rev beyond 6k at idle. When I still had my T25 in, it used to reach 1psi for a split second and fall back down right away. Don't even bother looking at the stock gauge, its useless and inaccurate.

 

[psychlow]

I build 10 PSI in neutral on my Big16G.

 

[doodie]

My friend's 2g with a Keydiver chip can build 5lbs of boost in neutral. But on the other note, I doubt that a stock 2g will build boost like that.

 

[Generation1JeY]

alright i'm not worrying about pressures right now because he doesnt have a boost gauge so theres no way i can tell, all i did was when i was looking under the hood with it idling, i pushed down the throttle body level to rev it, and even if i revved it a little the bov would still blow so loud. Maybe hes not building boost it might just be the bov? I just dont understand how hes doing it cause its not like he has to be at 6 grand to build a little. I'm talking about just pushing down the lever and letting off it and the bov sounding loud as hell. Lots of bovs open at vacuum, but when they open at vacuum that means they leak at idle right? and he has the bov vented, but his idle isnt messed up at all. I dont know i'm so confused right now as to why his bov is so loud when just revving, and how hes not having a ####ed up idle sinc the bov has to be leaking to open at that low of a pressure.

And no its a manual tranny

 

[CowPimp]

I can build boost in neutral with an FP Big28. I try to avoid it though. It's not good for the engine. The drivetrain isn't fully "hooked up" and ready to distribute the vibrational load.

 

[Generation1JeY]

ok this is all i'm trying to figure out. Is it because he has a 2g? or a t-25? or that hk ssq blow off valve?

Any of these three will be a fine answer for me. Again he has a bone stock 2g with just the hks ssq VENTED bov. Now his idle is perfectly fine so his bov isnt leaking at idle.

Someone just answer this question for me, do stock 2g cars build boost by just revving? or not build boost but can u hear their bov by just revving? Only thing i've seen that on is the srt-4, they build boost sooooo fast, either that or theyre bovs make noise just by opening with vacuum.

 

[My96AWD]

mine will build boost while in neutral. 14b 1 g motor hks bov vented. of corse you have to rev the shit out of it though.

 

[SnowWhite]

I have a 2G t-25 with an autometer boost gauge. When I rev my car in neutral my boost gauge will go to 0, no boost and no vaccum. My Greddy Type S BOV does sound, but it is definately not because I am building boost. I think the aftermarket BOV's are made to make sounds so they do with every little chance. I have a feelings it is the same way with your buddies HKS BOV.

 

[yoshimitsuspeed]

I was just testing my stock BOV the other day. My new boost guage spiked a couple times on shifts so I wanted to make sure it was blowing off properly and not sticking or something. I took the BOV out of the intake and reved the motor. It definatly lets out a good woosh of air. I never checked to see how many psi I can build in neutral but I don't think its much. 2g t25 intake, 3" turbo back, boost guage, pretty much stock otherwise.

 

[TheTSiGuy]

ok this is all i'm trying to figure out. Is it because he has a 2g? or a t-25? or that hk ssq blow off valve?

Any of these three will be a fine answer for me. Again he has a bone stock 2g with just the hks ssq VENTED bov. Now his idle is perfectly fine so his bov isnt leaking at idle.

Someone just answer this question for me, do stock 2g cars build boost by just revving? or not build boost but can u hear their bov by just revving? Only thing i've seen that on is the srt-4, they build boost sooooo fast, either that or theyre bovs make noise just by opening with vacuum.

I find that vented compressor bypass valves tend to be louder, more often, at lower rpms than the recirculated type.

I knew a guy who vented, and when he barely hit throttle and released, it would woosh.

 

[Nerfherder]

I'm not yet greatly familiar with the mechanics of turbo operation, so I was wondering why no boost is built with a neutral rev? Does there need to be a load on the engine to create boost?

 

[Talon96tsiAWD]

most aftermarket bov's that vent to the atmosphere sound pretty loud while letting off only 1-5 psi, where as a stock compressor bypass valve takes alot of air to release before you can really hear it. I am running a t25, in neutral it will build about 1 psi. But i never rev it past 4k unless launching.