clipped B16G vs. unclipped 20G

[MitsuBoost]

what kind of characteristics would these 2 turbos have against one another? I am debating on these 2 turbos and will be purchasing my supporting mods in the very near future.

This will be for a daily driven 2g fwd btw

 

[1fast97gsx]

good question I'm wondering this myself. I think the 20g route would be better .. I heard clipping a big 16g kills spool up. Even if the 20g still spools slower I bet it'll make a lot more power compared to the b16g even with clipping.

 

[Nabyar]

It all depends on what times you want to hit. If you want to hit high to mid 12's all day, then get a big16. Because in the end it's going to be cheaper to install the big16g rather than the 20g. If you want to go faster, then go to a 20g, but even then, some of the 50 trims are similarly priced.

 

[KRAZYKOREAN]

unclipped 20G > clipped B16G

Both will have very similar spool up, then the 20G will take over after about 5k.

 

[L2RTSiAWD]

Who still clips turbo's anymore? There are so many choices you don't need to worry about that anymore.

 

[Spidey]

Originally posted by L2RTSiAWD
Who still clips turbo's anymore? There are so many choices you don't need to worry about that anymore.

Not all of us are AWD and want a fast or semi-fast spooling turbo. A clipped td06h 20g would be my choice as far as Mitsu turbos.

 

[KRAZYKOREAN]

Originally posted by Spidey
Not all of us are AWD and want a fast or semi-fast spooling turbo. A clipped td06h 20g would be my choice as far as Mitsu turbos.

nice flames.. in the sig

 

[Spidey]

Thanks, but the sig is 'chopped. I kinda wish I really didn't shoot flames, my damn bumper lip is burnt to hell

 

[DSMSpyder99]

Originally posted by Spidey
Not all of us are AWD and want a fast or semi-fast spooling turbo. A clipped td06h 20g would be my choice as far as Mitsu turbos.

nah i rather have a ported TD06H 20G than a clipped TD06H 20G anyday. In matter of fact thats what i am gonna get

 

[kpt4321]

I wouldn't even consider the clipped B16g, or even a B16g. I would be deciding between an EvoIII16g and a 20g if I were you.

Whoever suggested a clipped TDO6H 20g.... bad idea, very bad idea. The TDO6H hot side allows you to gain a good amount of flow, but you obviously will spool a little bit slower just because of that. Regardless of the drivetrain of the car, you don't want to sacrafice boost response.

Clipping the turbine wheel makes it less efficient, and capable of less.

 

[MitsuBoost]

Originally posted by L2RTSiAWD
Who still clips turbo's anymore? There are so many choices you don't need to worry about that anymore.

is clipping not that effective? Since this is for a street setup, how much more lag time with clipping as opposed to unclipped?

 

[painmaster]

So why were 20g's clipped then? What was the gain?

 

[Groomz]

Originally posted by kpt4321
Clipping the turbine wheel makes it less efficient, and capable of less.

From this thread: http://www.dsmtuners.com/forums/sho...ge=25&highlight=clipping clipped&pagenumber=2

Clipping is done to increase the flow through the turbine. It is generally
bad for turbine performance (from an efficiency standpoint). You're better
off to go to a larger trim turbine or a different A/R housing, but often in
the aftermarket, you've got to work with what you've got, so you clip. [/B]

This is the best explaination I've read so far. kpt4321: Can you explain a little more. I still do not understand it completely and would really like to know more. Thanks.

 

[crankbender]

Hmmmm... it seems that many don't know what clipping is.

Clipping is basically where they make the turbine wheel smaller by cutting it (I believe anyway i could just be plum dumb today). This has the obvious drawback of longer spool up times. However at high RPMs if you have an improperly sized turbo (too small) the exhaust gasses will back up and your exhaust pressure will rise. This robs you of power. To correct this they "clip" the turbine so that it interferes witht he air less.

The best way to really solve this problem is to get a turbo that will run in the RPM range you like (this is why serious drag racers don't worry about spool up untill 4K).

Several years ago this had to be done because we didn't have easy access to all these turbos at the prices they are today.

This explain why it was done?

 

[painmaster]

Thanks for the info crankbender?

 

[kpt4321]

Originally posted by painmaster
So why were 20g's clipped then? What was the gain?

When they first started running 20g compressor wheels, there were using them with the same turbine side as the 16g. With the extra airflow of the 20g, you needed a freer flowing exhaust side. Since at that point, it seems as though nobody knew about the TDO6H, they only had one choice: clipping.

The clipping basically decreases the size of the turbine housing, so that more exhaust gases can flow past it without having to exert a force on it.

On the other hand, with less turbine area, you have less force that can be exert to spool up the turbo.

Additionally, turbine design is very very difficult. Simply chopping some metal off an existing wheel is not going to be a replacement for a properly sized wheel.

 

[painmaster]

How could I or anybody else tell if a turbo is clipped? Is it obvious, or do you have to see a picture to compare to?

 

[coltboostin]

20g all day. It will be more efficient than the 16g at all boost levels. So if you run lower boost, it will be better, and if you want over 20 psi, it will be ready to deliver

 

[4g63eclipseman]

hey have you guys conserderd a 25g from hahns? they claim with there high flow manifold oor other manifold that it will hit full boost by 4k. the high flow version 4500. thats not bad for a 700 turbo. than again you get a gt35r and it full boost by 2500!! but its about 400 more! it all in what you wanna do really. you can the 25g for 850-950 shipped with all the litte goodies to go with it. OR you can go buck wild and ive seen and slaop a greddy t78-33d or t88 on you car. i know gus that run the t78 on there 240's and they gfull boost at about 4k. as for the 50trim there a guy i come across every now and then and he says hes getting full boost around 3900? does that sound a littl high to you guys for a turbo thats the size of a 20g?

 

[kpt4321]

Originally posted by 4g63eclipseman
hey have you guys conserderd a 25g from hahns? they claim with there high flow manifold oor other manifold that it will hit full boost by 4k. the high flow version 4500. thats not bad for a 700 turbo. than again you get a gt35r and it full boost by 2500!! but its about 400 more! it all in what you wanna do really. you can the 25g for 850-950 shipped with all the litte goodies to go with it. OR you can go buck wild and ive seen and slaop a greddy t78-33d or t88 on you car. i know gus that run the t78 on there 240's and they gfull boost at about 4k. as for the 50trim there a guy i come across every now and then and he says hes getting full boost around 3900? does that sound a littl high to you guys for a turbo thats the size of a 20g?

Ok, there is a whole lot of stuff wrong with this.

First of all, a GT35R will NOT spool by 2500. No freaking way.

You sure as hell do not want to "slap a T78 ot T88" on your car. Not unless you have plans of making 600+ whp right now, with a powerband that sure as hell is not very streetable.

The 50 trim is not the size of a 20g.

 

[painmaster]

Is the 20g larger than a 50 trim?

 

[candela]

INd/Exd. 20G 50 trim
2.07/2.68 2.12/3.00

20g all day. It will be more efficient than the 16g at all boost levels

Want to explain this?

When they first started running 20g compressor wheels, there were using them with the same turbine side as the 16g.

Still are... people seem to do ok with them. Though I would never clip any of my turbos...

You must be logged in to view this image or video.

 

[KRAZYKOREAN]

Originally posted by candela
INd/Exd. 20G 50 trim
2.07/2.68 2.12/3.00




Still are... people seem to do ok with them. Though I would never clip any of my turbos...

Never would clip or you probably meant would not ever have one clipped again..

 

[KRAZYKOREAN]

Originally posted by candela
I have never had a clipped turbo

i dont care

 

[candela]