rear iron cracked
Thread Starter
Member
Joined: Apr 2006
Posts: 58
well i just broke my rear iron for the first time on sunday at the track and i know it had something to do with the boost spiking my t4 gasket was split open on its seem which led to the spike. i talked to one of the 8 second rotary racers and he told to let the motor warm up to 180. he runs his race car with a thermostat and since he made the change never had problems with breaking them. oh and he was breaking s6 motors which i thought was really hard to break. he is doing 30 to 35 psi.
Senior Member
Joined: Oct 2001
Posts: 10,906
From: Peoria, AZ
Blowing out an exhaust gasket will not cause a spike, it will slow down your boost response and threshold. Peak pressure will suffer considerably. Boost spikes are a malfunction of the wastegate, or its pressure signal. The high boost pressure isn't what cracked your iron, its being untuned for it that cracked it..
Thread Starter
Member
Joined: Apr 2006
Posts: 58
thats what i assumed as i havent tuned for anything passed 20psi. and my wastegate is getting a good signal same signal the microtech is getting. the spring i have in there is 12psi spring but sometimes it goes to 15 and sometimes 20. is that because of the gasket revvin?
Senior Member
Joined: Oct 2001
Posts: 10,906
From: Peoria, AZ
What size turbine wheel, turbine housing, exhaust manifold, and exhaust system?
The jump to 15psi could be a poorly designed exhaust manifold, or too small of a turbine housing for the wastegate. But jumping to 20psi is a serious problem. I would atleast move to a Tial 46mm wastegate, and depending on your turbine housing move up.
The jump to 15psi could be a poorly designed exhaust manifold, or too small of a turbine housing for the wastegate. But jumping to 20psi is a serious problem. I would atleast move to a Tial 46mm wastegate, and depending on your turbine housing move up.
Senior Member
Joined: May 2002
Posts: 22,465
From: California
Originally Posted by 1Revvin7' post='883402' date='Sep 24 2007, 05:37 PM
Hmm interesting... I would just try and move up to the Tial 46mm w/g and see if that fixes it after you get her up and running.
what el's trying to say, is that the spike and broken plate are symptoms of the problem, not the actual problem....