Page 1 of 2

Turbo + Vacuum

Posted: May 6th, 2006, 3:38 pm
by ModMX3 - (Carmaster2005)
Anyone know of anything you have to change when running turbo around 8 psi ? DOHC b6. I remember reading somthing about the PCV valve, what would you do with that ? and would other vacuum componets be affected like the EGR or anything? any help would be appreasheated.

Posted: May 7th, 2006, 6:11 am
by Franko
Baah.. Pcv valve is a one way valve.. it closes under boost.. otherwise the boost would get into your crank and you dont want that. I dont think nuttin needs a changin. Just wack the boost to her and dont worry.. ;)

Posted: May 7th, 2006, 8:26 am
by ModMX3 - (Carmaster2005)
Thanks! , Oh im going to put some boost on it very soon. just wanna make sure i have everything together and everything i need first.

Posted: May 7th, 2006, 8:37 am
by XxantwawnxX
NOt sure about the 4banger but the v6 has a PCV (you dont need to change if its working) and it also has crank case vent hoses going to the INTAKE side after the turbo that have no oneway vlave in them, u dont want to put those back in the intake.

Posted: May 7th, 2006, 9:52 am
by JWMotorsports
You need to put a 2nd Gen RX-7 Brake Booster Check Valve in your MX-3's Brake Booster vac. line or you will blow the diaphram out of it and your brakes won't work very well. It will also leak boost and blow air on your legs under the dash once it blows the diaphram. Don't use the universal check valves as they aren't strong enough. I've been through all this years ago the hard way.

Posted: May 20th, 2006, 11:44 pm
by nolig2278
where does the brake booster check valve go and what does it look like? what should it cost? what does it do?

Thanks

BPT

Posted: May 20th, 2006, 11:53 pm
by XxantwawnxX
JWMotorsports wrote:You need to put a 2nd Gen RX-7 Brake Booster Check Valve in your MX-3's Brake Booster vac. line or you will blow the diaphram out of it and your brakes won't work very well. It will also leak boost and blow air on your legs under the dash once it blows the diaphram. Don't use the universal check valves as they aren't strong enough. I've been through all this years ago the hard way.
never gave that much though sincei neverheard about people having probs with it. At what psi does the OEM check valve fail?

Posted: May 21st, 2006, 3:40 am
by cjthor
Our cars have an in line check valve from the factory. At least my 94 dohc does.

Posted: May 21st, 2006, 9:07 am
by XxantwawnxX
Both mine did too.

Posted: May 21st, 2006, 11:46 am
by nolig2278
anyone have pics?

Posted: May 21st, 2006, 12:14 pm
by Josh
JWMotorsports wrote:You need to put a 2nd Gen RX-7 Brake Booster Check Valve in your MX-3's Brake Booster vac. line or you will blow the diaphram out of it and your brakes won't work very well. It will also leak boost and blow air on your legs under the dash once it blows the diaphram. Don't use the universal check valves as they aren't strong enough. I've been through all this years ago the hard way.
thasts a damb good idea, i was going to swap it out for the V6MX3 check valve. but that would work better. i have changed mine 3 times, everytime its full of oil and really doesent want to work any more, you can only get so far on cleaning it out with carb cleaner.

all the MX3's are equiped with one, what hes saying is they will eventually go out from boost. when they start to go out your brakes feel like a spunge. its really a pain in the A$$.

as far as the PCV valve goes, its a MUST change. the stock PCV will leak soo much oil in your manifold, definatly change it out. you can go look up a Turbo 323 GTX thats what i put on mine and have no problems. it has a stiffer valve system for the turbo. the other think you can do is put a small clear inline fuel filter inbetween your PCV and Manifold, that way you know if your puting oil threw there. its espically leakes if you running the stok Manifold, it will leak on the seccondaries and when the vicks kicks in you will have a nice puddle built up, and you will get a nice burst of blue smoke, its really not all that cool.

Posted: May 23rd, 2006, 6:15 pm
by nolig2278
Would it be wise to pull the 2nd Gen RX-7 Brake Booster Check Valve from a Junkyard one or where can I order this part. Dealership wants $38

Posted: May 23rd, 2006, 10:34 pm
by slimmyslim1420
If you are planning to turbo a v6 should you still get the rx-7 check valve? Also where are the crank case lines at that you were talking about XxantwawnxX?

Posted: May 23rd, 2006, 10:36 pm
by XxantwawnxX
ONe comes from the rearbank behind the motor and one comes from near the PCV valve , they connect and go into the stock acordian lookin intake thing.

As the vac pulls the air out of the PCV valve more air comes in through those passages so it stays circualting. theres no check valve in them.

Posted: May 23rd, 2006, 11:07 pm
by Bochek
well what about this hose (the one thats connected to the CAI with a little bit of blue pipe, no check valve in this line. it goes from the intake tube to the top of the valve cover, right above where it says "16"

Image

Bochek