RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   BNR Stage 4, Ebay Type RS BOV. Everything else stock. No boost, no blow off. (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/bnr-stage-4-ebay-type-rs-bov-everything-else-stock-no-boost-no-blow-off-1016030/)

-RotorDemon- 10-26-12 11:27 PM

BNR Stage 4, Ebay Type RS BOV. Everything else stock. No boost, no blow off.
 
http://img195.imageshack.us/img195/4...g0099small.jpg



So I recently bought a used BNR Stage 4 from a member here. Got it and it looks good, no abnormal shaft play, spins freely.

Problem #1
Could be a boost leak (got too dark to check) However on a test run the stock boost gauge will creep up to say where a stock S5 Turbo will go however I don't feel it pulling/boosting nor am I hearing it spool

Problem #2
I got an oil leak possibly from the return line or the CHRA is leaking somewhere as it's wet.

Problem #3
Found oil in the intercooler. Going to pull off the inlet side to see if it pooled up in there. If I was sold a crappy turbo I am going to be pissed.

Now on to the BOV... It's mounted on a steel pipe where the factory charge pipe went, vacuum line is (T)eed from the stock boost sensor and connected to the nipple on the UIM. Doesn't matter how loose or tight I turn it. It will not vent. I'm not hearing any compressor surge when I close the throttle. Does this Ebay knock off still have the dual springs like the original Greddy has?

When I had it out of the box it took some effort to push it open but we rigged up a pipe we can pressurize at work and it vented slowly probably because we couldn't dump a huge amount of air into it at once. So perhaps the spring is too tight?

barkz 10-27-12 01:04 AM

why not run your bov line to where the factory one went?

Furb 10-27-12 01:24 AM

Turbo needs a rebuild
Ditch the ebay crap and buy decent stuff. However, if you don't feel/hear the turbo, maybe there is no boost to vent off.. duhh :p

If you get the turbo up and running, you can get your engine rebuilt as soon as it hits full boost. (Considering you say everything is stock)

tuscanidream 10-27-12 09:35 AM

I had a knockoff greddy type rs. That shitty company called Rotary Works gave it to me with their vmount kit. Nowhere in the description online did it say "knockoff". Damn valve kept sticking when I'd press it in by hand. Garbage. Be sure to test that yours is fully operational before you try to use it on your car.

-RotorDemon- 10-27-12 01:24 PM


Originally Posted by Furb (Post 11268509)
Turbo needs a rebuild
Ditch the ebay crap and buy decent stuff. However, if you don't feel/hear the turbo, maybe there is no boost to vent off.. duhh :p

If you get the turbo up and running, you can get your engine rebuilt as soon as it hits full boost. (Considering you say everything is stock)

Not looking to run full boost without any supporting mods. I just need a driver so I can give the old lady's car back

sclas90 10-27-12 04:22 PM

I had the same happen with the same turbo, oil in the piping and even all the way to the ports on my engine. rebuild time.

RotaryRocket88 10-28-12 12:24 AM

Before deciding the turbo is junk, I'd block off the vent on the bov first to be sure it's not just stuck open all the time. An open bov makes a great boost leak.

Furb 10-28-12 02:52 AM


Originally Posted by -RotorDemon- (Post 11268785)
Not looking to run full boost without any supporting mods. I just need a driver so I can give the old lady's car back

Even so, how are you going to compensate for the extra amount of air that is being crammed in there over the entire powerband..
Even at stock boost levels you will need to tune it

Furb 10-28-12 02:53 AM


Originally Posted by RotaryRocket88 (Post 11269174)
Before deciding the turbo is junk, I'd block off the vent on the bov first to be sure it's not just stuck open all the time. An open bov makes a great boost leak.

And that would mean the car will run like crap, because of the AFM
I don't read that anywhere, so i doubt it

RotaryRocket88 10-29-12 11:33 PM

Don't over-analyze.

It's an ebay knockoff part so who knows if it's opening under low vacuum and staying open under boost. Maybe high vacuum is the only time it decides to work. Besides, it's a 5 minute test of a questionable part. I'd sure as hell rather rule it out before taking the turbo off.

-RotorDemon- 10-30-12 04:15 AM


Originally Posted by RotaryRocket88 (Post 11271008)
Don't over-analyze.

It's an ebay knockoff part so who knows if it's opening under low vacuum and staying open under boost. Maybe high vacuum is the only time it decides to work. Besides, it's a 5 minute test of a questionable part. I'd sure as hell rather rule it out before taking the turbo off.

True that, I got the next few days off so I will dig into this. I'm mostly concerned about the oil that accumulated in the intercooler.

-RotorDemon- 11-08-12 06:12 AM

Here is what I came up with since I can't seem to get much besides criticism about when I'm going to blow my motor up. The BNR needs an oil restriction due to my higher oil pressure. My BOV is opening too soon venting because I pulled one of the dual springs out. The wastegate is fine. Tested that by shortening the rod as far as possible then finally clamping it off.

Blowby is due to the BOV leaking. Oil is possibly because of the higher oil pressure I have plus no restrictor before the turbo.

misterstyx69 11-08-12 08:58 AM

Contact BNR and ask about the oil restrictor.Bryan will gladly answer anything you throw at him about his product.
I didn't run one on my Stage 3.

SirCygnus 11-08-12 09:22 AM

all bnr's uses stock chra's, which have a built in restrictor.

K-Tune 11-08-12 10:47 AM

The only restrictor in place on the stock CHRA is for the thrust bearing assembly. A 2mm restrictor in the oil feed is advised, especially if you run higher than stock oil pressure.

t2ae 11-21-12 03:46 PM

the turbo should not have any problems as i ran this turbo on my car with no problems, dyno vidoes as well. never once saw any oil in any pipes or the intercooler. no restrictor is needed.

-RotorDemon- 12-13-12 03:50 AM


Originally Posted by t2ae (Post 11293482)
the turbo should not have any problems as i ran this turbo on my car with no problems, dyno vidoes as well. never once saw any oil in any pipes or the intercooler. no restrictor is needed.


Then explain while this is literally puking oil from the CHRA into the compressor? I now have a car that I can't drive nor even think about smogging. The car is sitting under a cover until I have enough cash to buy yet another turbocharger.

RoToRhEaD722 12-13-12 10:29 AM

Wanna sell the turbo you have? Why not send it for a rebuild? Just curious.

boosted414 12-13-12 07:37 PM

ill trade you straight out for a stock 87 t2 turbo (i suppose it COULD be an s5 but im fairly certain its an s4). you pay shipping to me on yours and ill pay shipping to you on mine.

barkz 12-14-12 01:09 AM

lol i have a stock one that i KNOW is s4, ill trade ya ;)

t2ae 01-21-13 02:24 PM


Originally Posted by -RotorDemon- (Post 11315586)
Then explain while this is literally puking oil from the CHRA into the compressor? I now have a car that I can't drive nor even think about smogging. The car is sitting under a cover until I have enough cash to buy yet another turbocharger.

i have no clue why its doing that? maybe you have something installed incorrectly. im telling you i pulled this off my car running with not one problem at all! rebuild should run $250-$350 as this was rebuilt already....sorry it is doing that though i wish you the best of luck

-RotorDemon- 02-10-13 01:29 AM


Originally Posted by t2ae (Post 11351639)
i have no clue why its doing that? maybe you have something installed incorrectly. im telling you i pulled this off my car running with not one problem at all! rebuild should run $250-$350 as this was rebuilt already....sorry it is doing that though i wish you the best of luck

You know.. I have to apologize for this since I posted this publicly. The turbo seems to be fine. The crankcase had too much pressure and was seeping into the turbo. As soon as I vented it everything stopped. No smoking at all. I was thinking I had a faulty turbo. Only thing I have left to figure out is why I can't get it to spool. I'll be looking at the wastegate tomorrow.

Again, I apologize.


All times are GMT -5. The time now is 07:54 AM.


© 2024 MH Sub I, LLC dba Internet Brands