Turbocharged sleepers ... popping noise?

[CG]

So I just watched about an hours worth of turbo charged sleepers stomping all over high dollar super type cars.

What is that popping noise they make when revving and shifting? Sounds like they are going to blow. Makes me cringe a little, but sure fun to watch.

['63GENIII]

Originally Posted by CG

So I just watched about an hours worth of turbo charged sleepers stomping all over high dollar super type cars.

What is that popping noise they make when revving and shifting? Sounds like they are going to blow. Makes me cringe a little, but sure fun to watch.

Pretty sure that would be the waste gate.

Where'd ya watch them? Track? So long as its fast, the sleepier the better!

[CG]

No just got sidetracked on youtube, next thing you know I lost an hour somewhere =)

[special-K]

Probably rev limiter. Guys these days rely on those instead of gaining great driving skills. Turbos cause a quicker rev.

[mongocanfly]

my guess would be waste gate as well...

[ct67_72]

That would be the rev limiter, cutting spark to limit rpm. As said above, turbo cars come on power fast and with a lack of traction especially, hit max RPM far before you have time to react to it.

[CG]

Well I guess if its something that helps you to not grenade your engine its a good sound even though it doesnt sound that way.

[68C15]

I had one built in the MSD 6AL ignition box of my 80 K20. It saved my engine many times.

[Dieselwrencher]

This sound could also be the blow off valve (BOV) to allow the boost to escape during sudden RPM drops to keep from fatiguing the turbo.

[61_FL_Apache]

Here is all the above sounds.

https://www.youtube.com/watch?v=-jzuvAsfzJA

[theastronaut]

It's probably some sort of no lift shift feature built into the ecu. The ignition is cut/limited when the clutch is in but you hold the throttle open so there is no loss of air flow through the engine, or loss of boost. Clutch comes out, ignition comes back in, and the unburnt air/fuel in the exhaust burns, making a lot of noise!

A turbo car doesn't like the throttle being closed (like when shifting) if it doesn't have a blow off valve. The pressure in the intake backs up against the compressor wheel and slows the turbo down, reducing boost, and it has to re-spool once you're back on the gas. A blow off valve releases pressure in the intake system between the turbo and throttle plate so the pressure doesn't back up against the compressor wheel so the turbo can build boost a lot quicker once you're back on the gas. No lift shift allows you to keep the throttle open so there's no loss of boost or a reduction of the intake charge into the engine.

I had a mostly stock turbo Conquest TSi that I raced against a Nissan 350z from a third gear roll. We were dead even through third, but I lost a full car length during the 3-4 shift from it losing and having to rebuild boost. If the car had been set up with no lift shift I wouldn't have fallen behind.


Here's a really good video that explains it well and shows how to set it up with Megasquirt on a turbo Miata that runs 13.0's.

Shooting Flames! Launch Control & Flat Foot...

[special-K]

It's all about performance but it sure sounds trashy. Something new for the tuners to get off on, same as truckers with jake brakes.