Cxracer

iTrader: (6)

I just got my Greddy kit installed and took a test ride yesterday. Right now I have the basic kit with the addition of a 2.5” down pipe of unknown origin and a FM 2.5” cat and exhaust.
I’m trying to do a quick shake down before I take it to the track this weekend. I’m going to be taking it easy since I just got the kit on and I’m not running a intercooler, blow-off valve or any band-aids other than the Vortec rising rate fuel regulator that came with the kit and a higher capacity Walbro fuel pump.
The car sounds good under acceleration but as I get off the throttle I hear a metallic noise. Almost like a heat shield rattle. If I’m coasting and showing hi vacuum numbers sound will be long and drawn out.
I’m assuming this is the waste gate? I just want to double check this isn’t possibly the sound of the turbo scraping the housing or something weird and bad like that (when I checked the turbo prior to install I didn’t feel any shaft play).
In the past I had a 2002 WRX wagon so I am familiar with wiring sound of the turbo but I never had a sound like this on deceleration.

curly

iTrader: (25)

God, that is not a trackable setup, good luck.

What are you using for a cross over pipe? If its the stock unit, you rip out that resonence box and clamp a dsm bov there. They're $25 all day on eBay. Put some zip ties in the cavities of the accordion piece to stop some of the expansion.

EO2K

iTrader: (37)

Get out the GoPro and let us listen!

I'm not a turbo guy so take this with a grain of salt... No BOV? maybe compressor surge?



If its surge, I *think* I've got a BOV the garage somewhere attached to some MSM intake plumbing. I've also got the Bosch PN for the recirculating unit on my rotrex. Its a stock part for a bunch of Audo and VW's so Napa might have it... Mounting it might be a challenge. I'll be hanging out with gesso (Geoff) tomorrow, let me know what you need and I'll see what I've got

EDIT: I didn't see a wideband on that list... I happen to have a spare LC1 & VEI gauge. I believe Geoff said you were running a LC1 but didn't mention if you had a gauge or not. I'd be willing to loan if you need to borrow one.

hustler

iTrader: (6)

This is compressor surge:

That light, overrun flutter shouldn't be worried about.

mankiew

It could be the wastegate actuator rod. As delivered on the Greddy kit it is loose and rattles. Sounds like a heatshield is loose. I never heard it on my kit since I had tightened mine before the install. When I sold it to a friend he loosened it up (didn't want too much boost) and was wondering "what the hell is this noise". It rattled on deceleration.

I hope it is something simple like this. Check it out and make sure to give everybody feedback.

Cxracer

iTrader: (6)

Thanks Gordon, I'll see you Friday night for the welcome dinner. You can have a listen then. Could you bring your MSM cross pipe if you find it? It would be good to borrow for the event and before I get a chance to install a proper intercooler. I'm running a LC-1 and gauge. That and my boost / vac gauge are working well. The digital temp gauge on the other hand is screwed up and shows 90F at operating temp so it's useless till I get it sorted after the event.

Cxracer

iTrader: (6)

I'll check that rod in the morning. As far as I rember it didn't feel loose but I didn't mess with it.

I guess the sound I'm hearing is a little similar to the first video (only happens on deceleration and not during boost). I'm in the car with the windows open and hood closed compaired to that video but mine sounds a little more metallic and whistlelly. Almost like I have a bad blow off valve that vents slowly and kind of vibrates. I'll try to get a sound recording if I get a chance.

Braineack

iTrader: (62)

lol at hustlers video. that turbo was like I'm making 300hp and that's it bitches.

hustler

iTrader: (6)

I've never understood how surge could occur on off-the-shelf stock turbochargers. I get how a 2554 cold side on a 76mm hot side will surge, but not something reasonable. Considering its a Synapse video, I'm sure it's some Chinese bullshit.

Cxracer

iTrader: (6)

OK, isolated the noise to the waist gate. I can make the sound by blipping the throttle while standing over the engine as it idles. Each time the engine slows the rattle can be heard. I can also get the noise a little if I put side load on the actuater arm so that's how I know it's the waste gate.

How have people fixed this?

mankiew

Did you try tightening the wastegate actuator rod a turn or two. This sound like the exact problem my friend was having. When his was stock tightness.

Give it a shot

curly

iTrader: (25)

This really isn't a question, It's a known problem* that's fixed with the above adjustment.

*Anything that's fixed by tightening a bolt two threads isn't really a problem.

9671111

iTrader: (10)

*

Cxracer

iTrader: (6)

Well, I tried the tightening trick but it didn't help the rattle. I had to pull the rod out about 3-4mm to get it back on the arm. Do I need a lot more tension than that?

If I do tighten it more what other problems will I cause?

curly

iTrader: (25)

Your wastegate won't open and you'll boost to infinity.

Technically, you're turning up the boost when you tighten it. But it's a fairly well known fact that out-of-the box greddy kits run at 4.5-5psi and they're safe to 5-5.5, which is what snugging the wastegate does. You've probably tightened past that, and are now boosting too high. If it's completely stock, with 1.6 injectors even, you need to turn it down until the arm of the wastegate is barely being held closed with the rod.

Cxracer

iTrader: (6)

So far I've only seen 3.8psi max on my gauge (it's got a nice recall function). Hopefully the tightening I've done is minimal but I'll bring the 10mm wrench to adjust if I need to.

So, if it can't be fixed with tightening the rod is there a rebuild to fix the rattle?

Bryce

iTrader: (24)

Don't just give it X more turns. Tighten it until the actuator arm no longer wiggles on the lever. Just the slightest amount of preload will fix the wastegate-related rattle.

There aren't any rebuilds for the wastegate flapper that I'm aware of. If the above doesn't solve the issue, I would possibly start looking elsewhere for your rattle.

Both of the videos in this thread are compressor surge.

mr.na

Mine does the same thing as in the first video if I give the engine a quick blip of throttle. The wastegate arm is adjusted just enough to fit on the actuator flat door.

Cxracer

iTrader: (6)

I took a couple quick videos with my iPhone of before and after the adjustment
Before: I also ended with a shot of Curly's trick of zip-tying the intake tube

After adjustment: Not that much of a change. I tried to show how I can flex the arm and get the rattle but it's a little hard to hear.

Cxracer

iTrader: (6)

Track day update: Turbo power is intoxicating! I finally feel like I'm going fast when I head up the straight after turn 11 at Laguna Seca.

I only hit a high of 3.9psi. I guess I could tighten the waste gate more to get rattle but I'm glad I didn't because after every session I had to loosen the T-bolt clamp and slide the intake pipe back firmly on the intake manifold. It moved about 5mm each time (dangerously close to the point where the splits in the end of the would start a leak). I tried the hairspray trick and changing to a T-bolt clamp but it still wants to work it's way off.

I guess I'll be waiting on this fix till I get the intercooler installed and I can replace all the stock parts in the intake tubing.