IAP/Greddy-RS Mystery Solved! *Long/Pics*

[darkforcejackal]

Remember all the talk going around about IAP turbo kit owners not able to get their Greddy Type-RS blow-off valves working/recirculating? Well i've been one of those people, for almost a year now, and up till now!

There was a bunch of theories on it, and i've been determined since my turbo install to get the sucker properly opening AND recirculating, FULLY preventing compressor surge. Didn't expect it to take so long to figure out (it's in a nasty spot also).

I hooked up the BOV with the recirc piece as instructed and with the included hose. I think over time i'd tried every possible setting with both springs in, only one in, screw setting all the way loose and all the way tight in both cases. Always surge!

Several months ago, I managed to get the BOV venting to the atmosphere. Pretty much done like any other BOV. The setting for anyones reference was:

-- Both springs installed-- Tightened to several threads from all the way tight

Worked real nice, releasing at 0-1 PSI and sounded awesome!! But this caused driveability/idle issues for me because of the air having already been metered, and besides, I did ultimately want to get it recirculated. On the exact same setting with the recirc piece back on it was surging again!

The IAP kit's Greddy-RS comes with the 19mm recirculating piece, and crankcase vent-sized hose for recirculating tube, with a nipple on the turbo pipe that can't be any bigger than 12-13mm. Herein lies the problem!

On a hunch, I bought a $21 34mm RS-BOV recirculating piece, along with the somewhat standard "Home Depot" (and rather large) flexible plumbing, ready to do some not-so-fun custom work & fabrication.

Attached the new 34mm fitting to the BOV. Plumbed the line upwards (cutting a bit more out of the body...) back into the engine bay. Made a new custom pipe from turbo compressor to air filter with a new extension/adaptor/nipple almost 2x as wide as the IAP one. Attached hose with clamps. Doing this took the better part of a day, but hey that's alright.

After first test drive, got surge, but with a hint of air. Setting was only one spring inside, screw quite loose. So I tightened it a whole bunch to test.

Was all surge. So I unscrewed that screw ALL the way out, and finger-tightened it slightly.

FINALLY!

Just a little PFFF... sound! It sounds great and is actually pretty quiet!

---To recap/summarize how to recirculate the Greddy RS:

-- Get 34mm adaptor for RS-- Get large hose for plumbing-- Use larger inlet for turbo compressor pipe-- Only one spring in BOV, loosened as much as possible-----

So anyhoo, here are some pics of the working set up!

DARE TO COMPARE - 19mm vs. 34mm!

Initial look at the area...

New fitting and hose attached to BOV:

Some shots of the set up:

At last, I can sleep at night again.

[AZhitman]

I LOVE YOU!!!!

[Florida240sx]

LOL...so for us guys running atmospheric I need to tighten it down all the way???

[darkforcejackal]

Adjusting the GReddy Type-RS (IAP kit used):

ATMOSPHERE:-- Use full-size vent piece-- Make sure both springs are in the BOV (comes already like this when bought)-- Tighten the BOV adjusting screw down to about halfway or a bit more-- Loosen more if you're getting surge above 1-2 PSI of throttle release-- Tighten more if it's making a long bird-singing noise after releasing or if your vacuum reading is low

RECIRCULATED:-- Get 34mm adaptor for your Greddy RS!(example - http://www.motiongarage.com/st...id=70)-- Get large hose for plumbing that JUST fits over the fitting-- Get some clamps also to ensure air tight and secure-- On pipe between turbo compressor and MAF, weld on/create a much larger nipple (probably somewhere around the 34mm..)-- Run plumbing from BOV to new nipple (obviously)-- Only one spring in BOV (larger one), loosened as much as possible-- Or make slight adjustments as needed to eliminate the surge

Thanks for the comments! I was very happy as well!! I love you too AZ lol!

[blckkat]

holy cow I gave up on my RS about a month ago. I didn't even know they made a larger recirc fitting! I wound up switching to a 1G DSM BOV and went to a 1" ID hose. I'd say someone should pass the info onto Marc but....I don't think he really cares.

[GEO]

I see mark has made a nice adjustment to the intercooler piping form when I re-designed his intercooler piping design.

EDIT: Broguht ADAPTER! WOOHOO!
Modified by GEO at 9:11 AM 7/19/2006

[bigbadbrad]

lol you guys helped out a lot of people.

[2FourTee]

So they have been selling the kit this way the whole time and everyone has had the same problem??? Wow!

Good work finding a solution for it

[Jookmasta]

i think this deserves to be stickied.................mods what do ya think?

[AZhitman]

I think we'll make it an article....

[darkforcejackal]

Awesome...glad this could help!

I'll see if my bro's willing to do some filming again, then maybe I could upload the sound of it..

[WDRacing]

I'll add it to the sticky at the top of the page...great job DFJ.

[nissanfanatic]

Just an observation, it looks like the tube connecting your MAFS to your compressor inlet is smaller in diameter than your MAFS. That isn't a good idea. Try to make the tube the same size as your MAFS.

[darkforcejackal]

Hey, someone else from KA-T.org!

Anyways, the pipe is actually 3 inches, about the same size (if not exactly the same) as the IAP one. The couplers are sized correctly...and I figure this is a pretty standard size for the pipe, no?

Is that what you meant? Let me know..

And thanks WDRacing!

[Florida240sx]

Somethign else need to be done to this? I'm running atmospheric.Just adjust the screw to halfway down.. if surge then loosen it if whistling then tighten...

[darkforcejackal]

Generally, yes. You might have to play with it a little, or it might just work right away with little or no adjustment.

I was really picky with exactly when mine opened when I was vented, so it took me 5-6 test runs to get it just right.

Your setup looks good, make sure the seal is good on the BOV's gasket. Also, get the vacuum feed for the BOV from your FPR or some other source near the intake manifold...that's about it.

Good luck.

[AZhitman]

Hey Jackal - Are you on AIM? Got a quick question for you i so...

"gregatnico"

[darkforcejackal]

Sorry man, not on AIM...but send me a note at [email protected] in the next little while and i'll try to help ya out..

Cheers.

[AZhitman]

Think I found my answer already...

http://www.gofastbits.com.au/i..._info

I have been dealing with this foul sound since mine was finished - I didn't think I'd need to do this modification but I now see that I do!!!

Also didn't realize I needed to open up the BOV and remove a spring - This is good news.

Bad news = My beautiful polished SS intake pipe will now need a larger port (or maybe I'll make a "tee" and just drill another port so the BOV charge enters the intake in 2 seperate places).

Guess I know what I'm working on this weekend!

[Florida240sx]

My vaccum feed is off the hotpipe...is this my problem?? It still reads pressure thought it wouldn't be an issue. I just spent 30 minutes trying to adjust it to no avail...

[klattr1]

yea its pressurized but the BOV wont open with the same pressure on top and below the spring...

you need it connected to somewhere after the TB so that vacuum is applied once you let off and the difference in pressure allows the BOV to open....

[Florida240sx]

Ahaha, then off to get a bolt to plug my hotpipe, and get another t fitting...

[darkforcejackal]

I used that port (on the IAP hotpipe) for my wastegate and it seems to work well...

[Florida240sx]

Yea it should work fine..... because the vaccum it sees is only 3" away from the bov.....No matter what setting I had it at it still flutters....any ideas??? No vaccum leak and the gasket is fine to the hotpipe...

[darkforcejackal]

No, no, I think you misunderstood me (I could be wrong).

Leave the nipple 3" from your BOV for a dedicated wastegate connection instead of for the BOV. That will open your external wastegate when it sees the boost. This is an important connection obviously so make sure it's secure!

Then, run a nice long vacuum line from your BOV all the way to your intake manifold vacuum source, preferrably fed off of the FPR.

That's how mine is set up, and that almost indefinitely will get your RS opening up happily.

Now with the above configuration, you may find both springs necessary to get it working. I did. With 1 spring in there was a large vacuum loss through the BOV's opening to atmosphere on idle. Basically, to vent, the BOV likes to be tight.

Let me know.

P.S. AZHitman -- Good luck on your project lol....let us know how it goes for ya for sure!

[Florida240sx]

Th bov is untouched so both spring should be inside...I'll go find a misc bolt and put it in my hotpipe. I got my wastegate running off my fpr.

[darkforcejackal]

Yeah that setup should be good.

I was only implying avoiding bolting the hotpipe tee to save time and prevent too many tee's on your FPR, but i'm sure it'll be fine.

Let us know..

[Florida240sx]

Nope still doesn't work...... Bolt in the hotpipe and now have a 5 way t of my fpr..... fpr line to fpr and then bov,wasteate and boost branch off..... It works best with NO spring load....is that right? I have the flutter at little boost but if I hit 10psi it opens nicely with a small skip in it.... Tired of this damn thing.....

[darkforcejackal]

If you're venting to the atmosphere, it seems to need MORE load on the spring(s), as in you might want to try tightening it all the way down (with both springs in, as sold), and backing it off from there.

The 5-tee thing might be suspect, make sure there are no vac leaks..

But man what a nuisance they can be until "just right" though....I feel your pain...hang in there, it's worth it!

[Florida240sx]

I tightened it almost all the way....right now it has a very small flutter but works 100x better.....