Tom-Guy

Yeah, I've tuned a couple SSAC turbos. Screaming != whistle.


Doubtful. I've tuned a couple hundred turbo cars, whereas you're asking basic questions.

Surge != imbalance.

I thought you claimed to know more than I do?

Obscene_CNN

Oh my the SCCA!! you mean you have worked on a car that someone autocrossed? Wow we all shudder at your greatness. LMAO!!!!

The only reason that I'm asking is my whine, whistle or screaming is more than twice as loud as it was. Seeing as its in the middle of winter with temps of 18 degrees F and I'm about 300 feet ASL I don't think its due to going from a T3 45 trim wheel to a 50 Trim wheel. I'm well to the right of the surge line on the map.

Surge can be induced by anything that disrupts the smooth flow of air in through the compressor, be it turbulent air flow at the intake, or a vibration of the compressor.

Tom-Guy

You have no idea what an SSAC turbo is, yet you've gone from asking n00b questions to master of all things turbocharged in a matter of days?

You are a silly, silly creature, and I pity your mother for getting drunk enough to let her brother ---- her and produce your ignorance

Hitchhikkr

What the ---- kind of turbo are you talking about

Im not 100% sure but I think that your only supposed to use a compressor wheel that has been balanced separate, with a turbine/shaft that has also been balanced separate.

SSAC=SS Auto Chrome

JD is ------- with you because you are a douche.

This is HMT, better come with your flame suit on.

HiProfile

Lets just cut throught the bullshit for a second, then you all may resume.

When you upgraded to the larger wheel, did you also upgrade to the proper housing machined to fit the 50 trim wheel? The 50 is marginally larger (0.079"), but in a 45 trim housing it will probably scrape just enough. If nothing else, its probably just close enough to the housing to produce a different version of JD's intake noises. I'm no expert in aerodynamics, but a fan's shroud has to have a certain clearance, which in this case, it is now lacking if its a 50 trim in a 45 trim housing.

And FYI, there is a form of screaming that *is* caused by imbalance, due to harmonics & it vibrating the turbo to hell. You can't tell me a turbo's airflow characteristics is what causes the whine, as the airflow doesn't change over time. Fucked up harmonics and resonation from a wobbling shaft will though. The whistle JD is thinking about is the from all the GT35's and GT42's he deals with in all those baller cars, ones that don't use the silencer cone. He probably just gets asked that a lot, as most of his customers probably just have him to all the work and ask stupid questions. No doubt they're puzzled about the [whistling] noises because they went from a loud NA setup they knew nothing about to a turbo setup they know nothing about.

I know JD will try to pwn me, thinking this is just some bullshit from an upstart n00b, so lemme introduce the harmonic dampener. A wonderful device on the nose of a Honda's crankshaft. Known to absorb/prevent oil pump-shattering harmonics from slight misbalance (among other thigns). Of course you can't hear the vibrations, as they're well masked by occational internal combustion, scraping rings, valves slapping shut, and the fact a crankshaft rotates *once* for every *twenty* times that little turbo spins around.

Tom-Guy

Holy ----, you do have a brain in your head.

The two SSAC turbos that came apart on me within 25 miles, and one that lasted a whole 275, ended up making a gravel/screech sound when spooling, before the bearings got slopped enough to acheive turbine-housing contact. Two of them were removed mid-tune to inspect. It most certainly is not whine/whistle.

HX35 (with silencer ring removed) and .60/.63 are louder, but again that's only some of them. Both intake and exhaust dynamics dictate if the turbo makes that screaming sound, and a turbo will sound different on two different cars if the manifold/etc has been changed.

HiProfile

JD there's that eirie howl sound big turbos make, then theres a weird scream quality, but worn out, turbos make. I'd bet the guys at the volvo/saab/chrapler garages would be able to better explain it. The one you hear all the time is from a pimp-*** monster turbo. The smaller ones I'm used to don't scream unless they're fucked. This sound you can hear through an intake tube, through a filter. Ordinarily, you just hear a whooshing/sucking sound.

I'm suprised you even hear sounds from those ssauto turbos. Usually they leak well before hand, giving the grinding surfaces just enough lube to stay quiet. Has anyone ever tried balancing one of those turbos that you know if? For a few bucks you could probably add garrett parts to give it a half-decent lifespan, assuming the chra brearings you replace don't have misaligned seats. Or that the shaft isn't out of round. Just a passing thought... :1

Tom-Guy

I tune three to four HMT-level cars for every baller car, I've seen plenty of OEM T3. Sometimes there's a little noise when there is turbine-housing contact, but usually not. I pulled a nicely trashed .50/.48 off my CRX that had been passing oil... and flakes of turbine wheel ground off against the housing. No appreciable noise.

The .60/.63 on my CRX screamed for the year it was on there, before it started passing oil, and it never made turbine-housing contact. It had the Ford bolt-on angled compressor entry and I used the stock black plastic flexy-hose to PVC routed to a remote airfilter in the bumper, car screamed like a Mack truck. Hitchhikkr remembers the car, and can attest to the fact it was loud.

The only SSAC I've sent off to BLAAST for rebuild was a T61, which is a wierd K26/K27 clone using a chinese made Garrett clone of a P-trim turbine on a T3 shaft, I have zero clue what the compressor wheel was copied from because it resembles nothing in Garrett land, and the bearings are made out of whole cloth. I understand the T04E/T3 clones are based on Garrett parts and have a good track record for rebuild, but *shrug* I've zero experience.

Obscene_CNN

Yes, I upgraded the housing too. Of course now that you mention it the compressor housing gasket seemed thicker than the one I pulled off. I figured that it was due to being mashed for 20 years. A thicker gasket could space the housing enough away from the wheel to cause the noise. I'll pull it a part this weekend and take a measurement. BTW A 50 trim wheel won't fit in a 45 trim housing. Thanks

This is a new install less than a week old and the much louder whine was there from when it first fired up. I figured it was just surge when we were free revving the engine because the stock compressor wheel did it to some extent until it was under load. Once I got it on the road and it didn't go away I knew it was a problem. The noise is definitely aero.

Obscene_CNN

My faux pah, I guess my mind couldn't imagine that someone would actually boast about working with a SSAC turbo so it read it as SCCA.

I guess your just to stupid to realize I was the master all along.

Now go ---- your mom some more and tell her a real man might stop by some day.