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Dump pipe problems

nizmokid

By nizmokid,
in Engines & Forced Induction

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nizmokid Mentor

nizmokid

Posted
Posted

Hi guys I just fitted a bigger dump pipe to my R33 and the dump has a split pipe on it, so on high boost the the car feels like the power hits then stops then hits again and stops like it is choaking or something any ideas on this problem!

standard boost is fine but highboost is running like a dog! this wasn't doing this before I placed the new dump pipe on the car.

any help with this problem would be great!

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https://www.sau.com.au/forums/topic/41794-dump-pipe-problems/
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Mcboost Enthusiast

Mcboost

Posted
Posted
Hi guys I just fitted a bigger dump pipe to my R33 and the dump has a split pipe on it, so on high boost the the car feels like the power hits then stops then hits again and stops  like it is choaking or something any ideas on this problem!

standard boost is fine but highboost is running like a dog! this wasn't doing this before I placed the new dump pipe on the car.

 

any help with this problem would be great!

maybe your o2 sensor?? that would have been bolted into your old dump, maybe it got damaged during the move??

raist60 Community Regular

raist60

Posted
Posted

Cars dont give two shits about o2 at full load.

Id say now your flowing more your hitting the standard 4800-5000rpm ECU flatspot. ECU see's too much airflow gets a little worried and pulls the timing back pretty severly. If it is that then there is no way to fix short of putting a new ECU in.

blind_elk Grand Master

blind_elk

Posted
Posted

Sounds pretty much like compressor surge. The new dump pipe is allowing the engine to exhale lots of gas. As a result, it wants to inhale more air, but the turbo is inefficient at the (higher) boost levels you are running - on low boost, the turbo is still within its efficiency range.

Abo Bob Grand Master

Abo Bob

Posted
Posted

I don't know if I'm helping or hindering by posting in this thread but a mechanic thought mine was hitting boost cut but later said it wasn't. Dyno graph says it's not. Timing might be being pulled (my opinion) or I need a bigger intercooler (his opinion).

ps feel free to tell me shut up if I'm just confusing things.

raist60 Community Regular

raist60

Posted
Posted

I believe there are 2 seperate things that the 33 ECU does

1. Is when there is excessive airflow it retards the timing and increases fuel

2. When boost gets very high its causes an extremely violent ECU fuel cut that almost throws you through the front window when it hits

I believe in this case its no. 1 fixable as i said with an ecu

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