exhaust leak cause artifical AFR's?
May 14, 2008, 06:57 PM
#16
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exhaust pulses, with very high pressures and high temperatures. Yes, it will push some exhaust out while the system is forcing the exhaust out of the cylinders, and that is then followed by a strong suction. this is where the error comes from.
May 15, 2008, 05:01 AM
#18
Alright so looking at my logs tells me this: lol it ruins my reading. Basically if I'm not "on it" for a good 3-4 run then my AFR reading is crap. It was erratically jumping from 10-20 and flatlining at both extremes. Idle said 20:1. This must mean that air must be getting sucked in at idle and low/no throttle. At wide open it seems I got "good" readings. My AFR was in the 11.6ish range which is where it was supposed to be... but then again I'm not going to simply believe that since so much of the rest of the data was corrupt. It seems if you have a leak at the turbo gasket you should know by erratic AFR fluctuations. My AFR graph looks nothing like normal. I was at Carolilna Motorsports Park. In-Car
so... anyone know where to get a replacement turbo gasket for cheap?
so... anyone know where to get a replacement turbo gasket for cheap?
May 15, 2008, 07:29 AM
#21
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The gasket I blew is the one between the turbo and the manifold. Half of it went missing when the bolts loosened up on me. I pulled off the manifold, took out the gasket, bolted it back up metal on metal and did 6 more 20 min lapping sessions holding about 20 psi with the boost controller maxxed out and my artificial afr,s all over the place. Was pretty happy with myself that I salvaged the situation.
May 19, 2008, 07:04 AM
#24
K, so just pulled off the manifold/hotside.... I melted the tips of my turbine. lol... isn't it inconel? Guess that's why I melted my starter, etc. Time to invest in an EGT sensor for my ECU+. So now I'm looking for gaskets and a new turbo... wish I could afford to upgrade now...
May 19, 2008, 08:51 AM
#26
Late timing, rich fueling (mixed with air leak from gasket meltage equals fire) and prolonged high boost. This all likely started when my water/alcahol pump kicked off likely due to an internal overheat switch. That probably sent my EGTs sky high which melted the gasket which let air in and caused flames, which increased EGTs more, which melted the turbine and other various things.
Thats my theory at least.
Lessons learned:
Run between 11-11.5 AFR
Never run less that 1 degree timing
Run cooling ducts to the water/alcahol pump
Run 25psi or less on the stock turbo
Don't use exhaust wrap on the manifold any more.
Thats my theory at least.
Lessons learned:
Run between 11-11.5 AFR
Never run less that 1 degree timing
Run cooling ducts to the water/alcahol pump
Run 25psi or less on the stock turbo
Don't use exhaust wrap on the manifold any more.
Last edited by honki24; May 19, 2008 at 08:53 AM.
May 19, 2008, 04:33 PM
#27
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running the turbo at 11.6 when you already saw messed up AFR's probly didnt contribute in a positive way either...good news is i should be able to post up later tonight about it since im finally putting new gaskets in...with alot of copper spray
May 20, 2008, 07:13 PM
#28
Late timing, rich fueling (mixed with air leak from gasket meltage equals fire) and prolonged high boost. This all likely started when my water/alcahol pump kicked off likely due to an internal overheat switch. That probably sent my EGTs sky high which melted the gasket which let air in and caused flames, which increased EGTs more, which melted the turbine and other various things.
Thats my theory at least.
Lessons learned:
Run between 11-11.5 AFR
Never run less that 1 degree timing
Run cooling ducts to the water/alcahol pump
Run 25psi or less on the stock turbo
Don't use exhaust wrap on the manifold any more.
Thats my theory at least.
Lessons learned:
Run between 11-11.5 AFR
Never run less that 1 degree timing
Run cooling ducts to the water/alcahol pump
Run 25psi or less on the stock turbo
Don't use exhaust wrap on the manifold any more.
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