I believe what's happening is you're making an air siren. We'd expect that turbo to be spinning 10-25,000 rpm just out of boost. If you have a 6 blades (3 pair) moving past 4 blocks (2 pair), it will 'chop' 12 times per rev. 10k rpm = 166.7 rev/sec, 25k rpm = 416.7 rev/sec. This is how many pulses happen per second: 10k rpm = 166.7 * 12 = 2000 Hz 25k rpm = 416.7 * 12 = 5000 Hz Now search for the video "20Hz to 20kHz (Human Audio Spectrum)" and play it from 2000 to 5000 Hz at 1.5x speed - sounds just like the car in this vid! The minor differences are likely resonances from the motor & the fact the turbo isn't making a sine wave sound. It sounds more like a square wave, since the blade & post edges are not parallel. If you do the math for 6 blades and 3 anti-surge posts, the frequency is cut in half. I suspect smaller/faster turbos would sound better with 3 anti-surge posts.
I machine parts and have been trying to figure this out scientifically and you literally hit the nail on the head, thank you! My 58mm turbo will be a air siren soon! Would angling the stationary block sides create different sounds, or create unnecessary turbulence.
@@aleksisalenius5103 I haven't decided wha5 groove width to go with either.. Turbolabs suggested anything wider than .200 would cause negative effects on power, but less than .100 would be too small to hear anything.
@@nesmio7378 well my compressor wheel had a good bit of material around it so rather than boring that whole part out like its typically done. I grabbed a hole saw and cut into the compressor housing around the wheel until i reached the start of the blades
Just installed this turbo with t51r mod(he351ve). I can confirm its very loud. I ended up putting my stock intake back on because with aftermarket aluminum tubing it was ridiculously loud. Sounds and preforms awesome though!
My HE34 with a K&N intake is already loud so, I'm wondering if there's much difference between the 34/35? Debating on doing this mod but, not sure if I want it that much louder lol
If you look at any real T51R, the trumpet in the inside is really then not so thick how companies be making them. The closes company i seen to get the real thing is Turbomod. Most companies, that do this mod fails to get the sound to carry, all the way up through the rev rang like the real thing most just get it low to mid rang. That gap, you was talking about is supposed to be way smaller not bigger like that dude said. Oh and i can't forget this 6 and 8 blade wheels, carries the sound way better 11 blades wheels. Good video tho keep it up glad you making videos about this. =)
You should have some turbos dynoed on the same engine. Identical brand and spec turbos but done with your t51r with the different clearances you’re talking about. So you can see when the clearances start to hurt or maybe help performance. Maybe send a couple to Richard Holdener, he lives for the dyno LOL.
Do you not think HKS has done all that testing already therefore HKS spec is probably the best. Products made for market got through rigorous testing!!
@@MrIrish1 This is Turbo Lab not HKS. He was talking about his T51r mods, again not HKS. He said “he’s not sure” and at other times he’s making educated guesses based on his experiences. Which is fine, it seems like he does great work. All I was saying is if he dynoed identical turbos but with different T51r specs he’d know what is too much and too little. It’s obvious in this video it hasn’t been done. Also don’t assume all products on market are thoroughly tested, especially in the aftermarket automotive industry. Their are way too many shit parts out there even from some well respected manufacturers.
It’s crazy that imo you still did not 100% explain how it makes a loud noise. I had to literally study and look at every cm, from what I can tell when you somehow drop in the cup housing, it has a small rectangular opening, so the air coming in creates a whistle because of the air coming in thru the rectangular shape opening, not once did you point this out, this information would be pleasing to someone who is new and has no idea about the terms you’re speaking about.
And Johnny spoke clearly to us. Exceptional video turbo!!! The things we have to learn to do and understand to actually go fast. And first learn how to drive them stock before you drive them fast.
Looks like originally HKS accidently made a small air raid siren when they designed the anti surge port. It defiantly will make it less efficient, which is why no other companies do it. But, it will make it loud obviously. look up air raid sirens and how they are made. That's what is making the noise IMO. Isn't there a more efficient and cheaper way to make the turbo "whine" more pronounced. Fumy shaped compressor nut, angled hole in the hub etc? Seems like a lot of effort for noise.
it’s slicing the air in half that’s why it’s so loud honestly my garrett screams why? because i’m spinning it into orbit. the spacing doesn’t matter i machine anti surge all my housing and everyone screams... even my little 1749 screams on my generator set.... figured out how to do the ihi and 3 k 2 piece housings ✌🏻
Have you noticed what changes the pitch of the whistle? Some modded ones do not sound very close to the T51R but a lot of lower toned whistle which isnt as nice. Is it the groove width or placement?
Would you be interested on trying to do this to a 3" housing? I have a Greddy td05 18G with a billet wheel that'd I'd like to use, unless there's not enough material which I could understand. Would it be possible to convert it to a 20G that had a larger compressor cover and do it to it instead?
Hey! I know this seems a far fetched but could you somehow do a custom housing (t51r mod) for a VF43 Turbo for an STI? Maybe increasing the port to a 3in could allow for the mod?
Hi Austin, which turbo was that EVO X in the beginning of the video running? Is it possible to do this T51R mod to a already Anti-surge turbo? For example a Gen 2 GTX3076R?
You would think that during some parts of the compressor map air would infact be flowing into the compressor via that groove I would think at hi flows not so high pressures
Hmmm. Anti-surge housings reduce your dose/flutter, though... So I'm wondering, how do you get loud whistle on a non-anti surge housing? And also, how do you effectively block off the anti-surge on anti-surge housings without fucking up flow or otherwise reducing performance?
more air too escape? no! more air in! boost is pulling in air from both sides. The groove width in the new Precision (nextGen) is larger, they state “more air through the larger AntiSurge” (further down-not up) air does not escap when in vacuume “the opposite happens” look at precision next gen schimetic
I have a question, and please forgive my agnorence. I'm planning to do a T51r mod in the future, and not sure if it's viable to install an air filter on the turbo? Is it going to fit? any changes to the sound? Thank you!!
It’s best to use a filter. I live in a construction zone, there is a lot of dirt in the air and rocks. The sound is still loud with the air filter, I have several video clips. I would not risk not using a filter.
I would like to do this to my 84 300sd mercedes turbo diesel my question is can any turbo get this mod? All I know that it has a garret turbo of that Era .
I think I know the guy you are talking about that had no noise, my buddy Devin. He took measurements off of my Boost Labs t51r that makes LOTS of noise. Things sounds like a supercharger lol.
I have a 2860 pulsar turbo on my miata with t51r mod from pulsar. Its ridiculously loud. I had no idea what this mod was 6 months ago. I was hesitant going with a pulsar turbo, even more so paying for the t51r mod. I am not disappointed at all. Sounds like a have a supercharger especially at lower boost pressure. My old turbo was basically silent compared to this one.
Have you ever done a velocity stack in a GT3782VA? I have probably 7 of them sitting around from various 6.0s. I'm wondering how silly a T51r modded GT3782VA with a 10 blade turbine wheel would sound.
@@turbolabamerica What is your email? I might be interested in doing a little work with you just to mess around with a GT3782 to maybe sell to people that are whistle junkies on 6.0s. I deal with quite a few on a daily basis.
I have an Australian ford falcon xr6 turbo, I love my turbo "flutter" I'm running no blow off valve, if I was to do this t51r mod would I lose the flutter?
@@jamesgasper8630 You'll never get them back...they've had mine for 2 years now. They don't respond to email or they're phone. GL. Great vids horrible customer service.
Have you actually Googled what MWI really means ? Translated Map With Inharsment, have a read and comp wheel design plays a big parts on induction noise
I sent my 3176 with this guyto get rebuilt and came back with the same worst play and box came half open look like it got ran over by a truck! won't reply back to me or even try to come with a solution on how to redo a turbo I payed for that never got fixed!! in short don't do business!!
How does this guy have his own company? Of course the clearance has to do with the turbo whistle. That’s basically how a dam whistle works. As for his horrible explanation the fucking word your looking for is BACK Pressure!!!
@@turbolabamerica I have a HE351VE that's off of my '14 Ram Cummins and has been sitting in storage collecting dust for a few years. If you want it, lmk.
