mitchell_2kSiR

Running a B16 with forged internals 440cc injectors t3/t4 turbonetics turbo tuned on 8psi running through a rev hard log manifold and a shop made down pipe.

i put on about 7000 km's since downpipe was new and the minute muffler and another muffler shop both told my my exhaust is crystalizing. . and that my exhaust from the turbo is making my down pipe too hot. .

i HAD stock exhaust with cat and straight trough muffler, now i have the 3 inch mandrel bent kteller exhaust with cat delete for about 2000km's

my downpipe is made up of 2.5 inch 13 gauge piping with a crush bend
and after that its mandrel 2.5 to my oil pan back 3 inch

i have a couple cracks on the crush bent corner three inches from turbo

any reccomendations besides heting a new 5 bolt t3 flange and getting slim rad fan to fit a mandrel bend for the first bend

mitchell_2kSiR

why would my exahust be getting so hot that its over heating my DP causing it to "crystalize"



Modified by mitchell_2kSiR at 9:00 PM 11/13/2008

mitchell_2kSiR

bump please

red_crx

iTrader: (2)

PICS?

mitchell_2kSiR

one shop said its due to crystalization and getting too hot. . its 13 gauge pipe


another shop looked further back and my resonator has a couple scrapes and nice dings on it and they sait it just broke under impact. . makes sense cuz it BELIEVE happened after draging car on gravel road crown

CRXdan

hahahahaha sick
post it on homemadeturbo.com

LShatchie

its because your using really SHITTY pipe looks like galvanized pipe, you need some thick stainless or REALLY good flex in DP

HiProfile

I'd guess it was from impacts, especially if you don't have a flexpipe in the system somewhere. If no flexpipe, and the other flanges are not the flexable donut type, its also due to constant stress when your motor torques (which is with any throttle change with stock mounts).

As for your IAT's, I find it VERY hard to believe you had IAT's only 10F above ambeint after several boosted pulls. Most NA Hondas with CAI's will get past 100F due to natural heatsoak from the head. You have an uncovered/coated manifold, turbine, and exhaust that impact IAT's. The only way this could be the case is to have a Garrett/Spearco/Precision type of core ($$$), and a 2.5" crushbent DP tells me that's unlikely.

One thing the muff shops said may be right. Excessive heat could cause carbide precipitation, but that's usually around/in the weld (1/16" or closer to welds). I forget the exact temps, but constant heat above a certain point will cause the steel to harden, which will make it more brittle. I'd guess you have a very safe tune, which means very conservative timing. Conservative timing means higher EGT's, meaning more heat put into the exhaust. A small pipe will get hotter than a large pipe when flowing the same amount of hot gases.


All things combined probably helped crack that pipe, not just one.