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-   -   Do remapped cars have louder turbos? (https://www.team-bhp.com/forum/technical-stuff/164666-do-remapped-cars-have-louder-turbos.html)

Hello Friends,

I recently bought a used Getz crdi which has run around 1,10,000km and which has been remapped to 154bhp by a leading tuner ( not taking names), I also got partial free flows done by another tuner. The latter told me, my turbo is weak and hence he's not going in for a full free flow exhaust. He said the loud whistling is a sign that its on its last legs. Although, I'd love to get a nice Garrett turbo for this car and lower the suspension and do many other nice things I am short on time and money for such adventures at the moment. Reliability is a big thing for me.

Will a remapped car make a louder turbo whistle? or is my turbo really on its last legs?

Thanks!

Remapping with just change the way power is delivered and torque is generated at the RPM band as required by the driver.

It will not effect the turbo noise.

Check if the turbo plumbing is fine and tight. I guess it is air that is leaking out.

It depends on what remap and other associated mods. Turbo whistle increases, but that is due to early spool and higher pressure if you fiddle with waste gate.

How did the assumption that turbo was failing reached at? Is there a power lag? 1.1 Lakh kms is a high reading and yes turbo's can get weak.

Back when i was looking into buying a used turbo powered car, one of the signs of turbo problems was that it would rattle. Though it was specific to BMWs, it probably won't hurt to keep that in mind.

If the remap includes more diesel volume, and hence more combustion, hence more power, and more exhaust gases, then YES, there will be a louder and sweet turbo whistle.

A turbo whistle doesn't mean a turbo is shot.

Signs of a bad turbo are:

• Lot of oil in the intake plumbing, and consequent whitish/blueish smoke.
• If you notice more oil consumption. (Can also be due to engine)
• If turbo shaft is shaking kat-kat, then bush is gone.
• If engine in stock form gives out more black smoke, and you have power loss and mileage loss, then turbo isnt giving out required boost, and impellers might be damaged.

I'll post more as and when I remember.

EDIT: There is also a sound when the turbo bush is really at its end. That is different from the sweet turbo whistle, its more of a whine. High pitched metal rubbing sound.

A seemingly stupid query: where to put the ear to find this turbo-shot-noise? Near the turbo or it manifests in the exhaust or somewhere?

What exactly do you mean by early spool? The turbo kicks in at 2000rpm and shuts off at 4000 rpm as it should. The person who did up the free flows said he used a diagnostic tool to check the vehicle and said the engine was in good condition but he found the turbo to be weak. He didn't specify, should I get this checked at Hyundai? I'm not sure if the previous owner has increased the turbo boost and fiddled with the waste gate.

There is no rattling sound, it is a whistle around 1600rpm onwards, which becomes louder until about 3000 rpm when it is drowned out by the engine noise. There is plenty of black smoke, I'm sure the car is running rich because it is remapped and also the cat con has been removed. But I ran an emission check 3 days ago and it turned out normal. I've not driven the car in stock condition. After installing the partial free flows, the power delivery is linear, the punch of the turbo is lesser.

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Near the turbo. There will be no rattling sound in the turbo.
These seldom work.

Meanwhile, what is your problem? The turbo whistle doesnt mean turbo is shot, & check my post above for usual bad turbo symptoms.

Noise of rotating machines like turbines / pumps increases with speed. Turbo has both turbine and pump. Turbo speed will increase if the exhaust gases flow faster. And for a faster exhaust gas flow rate, the engine needs to tun faster.

For a given engine rpm (say 2000 rpm) , if you have louder noise after re-map, then its the bearing problem IMO. If, as dhanushs says, the engine is revving higher after re-map (due to richer air fuel mixture), then that could be the reason behind louder noise.

Open the air inlet and try to move the blower impeller lightly by hand. You will notice a play if the bearing is worn. The wear is not all over 360 degrees in the bush; it is localized. So check the play in all directions.

Actually, after remap, if there is more diesel volume, then yes, at a particular rpm, for a given engine load, there will be a louder turbo whistle. Its not a turbo problem. Its just turbo spinning faster than before, because of more exhaust gases. [Its a diesel engine]

Thanks Dhanush for the inputs. I too thought there's nothing wrong with the turbo but when the tuner said it, I figured he's a guy who knows this stuff. After reading your inputs I'm confident of getting the full free flow done.

Are you sure the tuner said turbo is weak just because of the whistling sound? I dont think so, I am not getting the current condition of the car before remap too from this thread. What did you ask the tuner when you went for the remap? Normally any knowledgeable tuner will never push the map to its limits of the car unless there is a pressure from the customer, but they usually inform the customer about the consequences of going for a "non-compatible aggressive map". BTW, a good tuned car will not have continuous smoke unless the map is pushed to its limits else there is some prior issue with the car related to engine / turbo. Now-a-days, the smoke issue is seen only with the boxes or very bad maps. I would suggest take it to another tuner and check his opinion.

As far as I know thick blue grey smoke and loud whining noise from the turbo (than the normal sound) esp from the engine side are some of the symptoms of a weak turbo or in its last stage.

Isn't the engine consuming oil if one notices bluish - white smoke?

May be the turbo boost is only aggravating it.

Thats the reason why I was telling unless we know the condition of the car esp before tuning, nobody can say anything on this.
These are definitely the symptoms of a poor turbo, but at the same time these can happen due to other factors also. The OP said thick black smoke, not towards white. Better get a second opinion. If it is indeed the turbo issue, then a thorough checkup of the car may be required as there may be other related issues too due to the mileage.

Best bet is to get the stock map flashed by the tuner and check the behaviour for few days.

That should help you identify if there is any real problem with the turbo or its the tuning which is on the aggressive side.