Will an 02 dump, eliminate the need for clipping on a big16?

[MLSCrow]

I'm looking into a big16G, but I don't want the extra lag from clipping. If clipping it is to allow the increased air from the larger compressor wheel to work through the engine and flow out of the same TD05 exhaust side as the small 16G, couldn't I just not clip and dump the 02 housing? I mean, I will be able to keep the quicker spool, and at WOT when the gate opens, any extra exhaust that the big wheel is trying to push through the Td05 exhaust side will be going out the gate. In theory, does this work?

 

[larryd]

ive never heard of a dump tube doing the same thing as clipping the turbo.. clipping it will increase your top end and make it spool a lil slower.. a dump tube will just keep it from boost creeping..

 

[MLSCrow]

The 02 dump will do alot more than just control boost creep, it will increase the flow of the turbo, and provide less backpressure type restriction to the exhaust flow. Without an 02 dump, you are trying to cram, all of the exhaust, including the wastegate's "waste", through a small 02 housing opening. If you dump the 02, its only the exhaust from the turbine wheel going through the DP, and the wastegate "waste" will be venting freely to the atmosphere. In some cases, people have picked up about 15-20whp from dumping the o2 housing, and thats on a 14B.

What I'm wondering is, if an 02 dump will eliminate the "need" to clip the exhaust wheel of a 7cm housed Big16G, as its taking some of the exhaust away from having to be pushed through the wheel.

 

[stompk]

I agree with your post. What I am wondering is does a 2.5" exhaust ( test pipe, 3" catback ) with a 40mm tial with dump tube release enough backpressure from the exhaust to make a 3" exhaust upgrade still worth upgrading to ?

if I am dumping enough exhaust out the wastegate and dump tube to not have the 2.5" downpipe a restriction, why bother with a 3" exhaust ?

ps. I have a 20g and run 22lbs boost.

thansk !