to mod or not to mod...

[batossai kenshin]

Hi guys!!! I just got my hands on a real nice 1g bov. It's not crushed and its SUPER clean. I tested it on my old 93 gsx that I sold to my buddy and it works awesome. SO my question is... crush or no crush? I'm running stock boost and I'm not planning on going over 10 psi any time soon. But for the time being stock boost. So can I just install it or do I have to crush it? How about the recirculation? Do I have to custom mod it to recirculate or can it vent off into the atmosphere? I would prefer not to recirculate cause I want the psssshhhhhhhhtt sound but my main priority is not to mess any thing up. So if I dont recirculate will it suck in unfiltered air at all, or will it make my car run richer or what? If I have to crush, can I get a crash course on how to do it cause I've never done it but I researched. From what I've read you have to put it on a vice and crush from top to bottom with a pressure tester on it to know how much pressure its holding? I'm not sure but yea... I dont have a pressure tester so can I just give it a lil squeeeeeeze? Thanks a lot in advance guys I appreciate it!!!

 

John

[D_Venable]

you'll have to crush it or mod it, no question about that, our motor pulls more vacuum being a bigger displacment, and it will remain open at idle (that's a bad thing)

 

what I did with my second 1g on my 88 was install the pipe, install the BOV, start the car, check how far it was open, crush it mm or 2, reinstall, start, check, crush the tiny amount again. I did this over until it was shut at idle, took 10 minutes tops total, and it would let off really quick.

 

as for venting to atmosphere vs re-circ. recirc is better for the car (no rich between shifts), unless you've got a blow thru setup where the MAS is after the BOV (usually only done with the MAFT on our cars)

[Indiana]

http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/351419-1g-dsm-bov-leak-stop-kit-dejon-tool-install.html

 

 

click on that link, it will tell you different ways to mod it

[batossai kenshin]

Thank you both of you. Question for D_Venable... is it real bad to be rich between shifts? what would that damage? and do I have to change the gasket on the bov, did you?

[D_Venable]

the worst that'll happen, you wash your rings in gas, and it gets in the oil, possibly ruining bearings, BUT that's worst case situation

 

...a LOT of people on here (myself included) run the BOV to open atmosphere with the MAS in the stock location, with no real issues other than decreased fuel milage (I saw an average of 3mpg drop in around town driving) so what CAN happen can vary, depending on your motor's condition.

 

I'll be doing a blow thru MAF-T setup on the flatty to eliminate that rich between shifts and to improve city MPGs, and will eventually do the same to my 88.

 

I no longer use a 1G BOV though, I've got a turbo XS RFL on the 88, and I've got a XS power rfl for the flatty, but no I did not ever change the gasket for the 1G BOV, and didn't have any real issues with it.

Edited April 17, 2010 by D_Venable

[batossai kenshin]

I see... thanks for the info bro. As a matter of fact I installed the 1g bov earlier on today with my mechanic, and he didn't let me crush it. LOL. He was like no man you're gonna break it and then its gonna leak and this and that... so... I dont have a vice to crush it with I'm gonna have to go to a shop or something and ask them to lend me theirs. ANYWAYS! I drove the car for a little while with the bov on and the car was running pretty smooth, HOWEVER when I shift the boost gauge instead of going down in pressure it goes all the way up!!! So it's sucking in air instead of blowing it off? And yes the bov is a lil open at idle but when the rpms go up it closes shut... man I need to crush that thing but I just don't wanna break it...

[D_Venable]

it's not sucking in air, it's venting what the turbo is pushing (which is being pulled through the MAS) and the stock boost gauge is mainly a calculation from the MAS

 

you won't break it, I've done 2 in a vise, just take it slow and do a tiny bit at a time. OH, and drape a towel or rag in the vise, to keep from scratching the mounting surface too much

[AndyW]

No need for a vice. I just did one on the car with a C-clamp. Was surprised how easily it crushed too, just lil by lil like D says.

[batossai kenshin]

OK I'm definately crushing the bov today. So is there any way to make only the top of the bov to dent in; instead of any other part of it from bending. Like putting a nut or something on the top part so it dents it in...? Thanks guys!

[batossai kenshin]

soooo yea... I crushed it and it wasn't open at idle any more. BUT, after like 15 mins of driving it stops blowing off. before it would do the same thing but after like 3 minutes instead of 15. So do I have to crush it more or what? Thanks again!

[batossai kenshin]

OK never mind that thing is like PMS ing or something... It blows off when it wants. For example it'l blow off 3 times and then shut up. Or like if I start the car and then take off under hard acceleration it'l go like shhhhhh... tttt and thats it. Like it cuts off or something. Once I shut off the car and start it again, it works again!!! Like what the hell? I crushed it to the point where it's noticeable that it was sunken in and my idle is different, it went down. It was at like at 1,200 before I crushed and after it was at exactly 1,000. So what do you guys think?

[batossai kenshin]

bump...

[Shelby]

did you read any of the threads that were post'd for you to read,,

 

the 1g dsm bypass valve has a built in boost open port,, that opens the valve at aprox 7-8 psi,, that port must be plug'd and an air vent drill'd into the out side of the port passage to the diaphram,, or the upper diaphram will pressure lock and not open

 

fact is the system was design'd to work with a bypass valve system rather then a blow off valve,, federal eminsions would never have pass'd such a thing

[batossai kenshin]

Yea I actually read it and researched on DSM tuners and DSM talk before starting this thread. However all the stuff I read didn't have a lot of precise info except for put it on a vice and crush. There was no specified info. Anyways the only one of those threads posted that said anything about recirculation was the dodge garage mod and I'm not looking forward to doing all that stuff cause #1 I don't have the tools and #2 I'm not too savvy with all that drilling holes and all that. But yea bro I don't know what to do with this thing then; I'm gonna install the stock hose and just buy a damn hard pipe qith a ssq BOV on it...

[batossai kenshin]

Found out what the problem is... It's the vacuum. I tested it out with the motor running and the vacuum works fine but after the motor warms up the vacuum stops sucking air. How can that be fixed or does anyone have a chart for the vacuum lines that I can use for reference to trouble shoot this or rearrange it? thanks.

[Shelby]

http://starquest.i-x.net/album_cat.php?cat_id=2&sort_method=pic_time&sort_order=DESC&start=240

[Shelby]

http://www.26liter.us/gallery/albums/userpics/10009/1g_bov.jpg

[batossai kenshin]

Thanks for your help shelby. Does anyone know if the vacuum lines are supposed to stop sucking in air after a while? or just some of them? I had my bov hooked up to a vacuum next to the tb. Not behind the tb cause there was no space for it. And the vacuum next to the tb stops sucking in air after the car revvs up kinda high...

[mikec]

The "vacuum hoses" on a StarQuest don't all have the same vacuum in them. About half of them NEVER have any real vacuum - they're "return" hoses... they hook into the injection mixer assembly above the throttle plates. They will see boost pressure or just atmospheric pressure.

 

The only "vacuum" hoses are:

* The "row of three" pointing at the fender. The front 2 ports are "ported vacuum" which means they may or may not have vacuum based on throttle position. So these do NOT work for BOVs. The rear-most port is "manifold" vacuum - it sees whatever vacuum is in the intake manifold. (it also sees boost pressure of course)

 

* The port an inch or two below the row-of-three. That's also manifold vacuum. It powers the cruise control and your dash vents; it's a good choice to tap into for BOVs.

 

* The huge hose going to a metal "T" fitting for the ABS and power brake booster... that's also manifold vacuum. No sense tapping that fat sucker though for a BOV.

 

* In the #4 intake manifold runner, auto transmission cars have a port that feeds the transmission. 5-speed cars have this port plugged with a funky screw. You could put a tube in if desired.

 

* early model year cars with the firewall mounted pressure sensor (up through 86s) have an extra vac port above the row-of-three for this sensor. DON'T MESS WITH THIS LINE! Adding additional vacuum hose to this port will further delay the vacuum/boost pressure reading to the sensor and could lead to oddball accel/decel hesitations as a result.

 

* Hose on the turbo compressor or on the over-the-valve-cover-pipe (OVCP): this is BOOST/ATMOSPHERIC only pressure - never vacuum. Same as the port right at the top/front of the injection mixer where the OVCP connects. These are useless for BOV control.

 

Those are where vacuum/boost signals originate or return to the airflow. All other vacuum ports (on the various devices) either use that vacuum to do something or are thermal or electrical vacuum switching devices; such devices enable or block the vacuum flow to the other ports based on engine coolant temps or ECU control.

 

mike c.

[batossai kenshin]

Dude you know your stuff... you just educated me on vacuum lines. Thanks man I appreciate it! Im sure that my problem will be fixed by putting that vacuum line where it belongs. Quick question though... the round space ship looking thing on top of the distributor does not have a vacuum hose going to it. When I bought the car it was already like that. So the other day I put that vacuum I had pulled out for the BOV onto the nipple for that thing on top of the distributor. When I started my car it was as if the timing was advanced... So is that thing necessary? Should I hook up a vacuum onto it? thnx

[jisleyjr]

That is the vac advance, yes it needs a vac line to it to advance and retard your timing. It is NOT the same port as your BOV. I forget which port on the throttle body it needs to be hooked up to. It needs to be on a port that does not see vac when the throttle is closed, as the throttle opens it sees vac (to advance timing). There is vac line diagram around here somewhere. Search.

 

And yes, a lot of people on here know their stuff so you better listen when they take the time to answer your questions.

 

Edit: I read mikec's post, 1st or 2nd port on the tb go to vac advance.

Edited April 29, 2010 by jisleyjr

[batossai kenshin]

WELL... As a matter of fact thanks to mike c's post I found the perfect spot for the BOV and it works PERFECT loud as heck... aside from running a lil rich in between shifts its perfect lol. I used the one under the three behind the TB, the nipple had nothing hooked up to it but I think thats the one for the AC. I put the hose for the vac advance there too to test it but... at idle it sounded great however when I took it for a drive it was hiccuping NASTY. so I blocked it off. my car runs fine W/O it. But is it necessary?

[jisleyjr]

hook the vac advance up to the proper port.

 

Have you set the timing? or even checked it? Is the vac advance in working order? Check the FAQ for how to check these.