KB front mount limits......
Oct 1, 2008 | 10:51 AM
#21
You're running 19psi of boost, but what is your exhaust back pressure? That has more to do with why the hot parts failed. If you have a tiny exhaust housing on there with a restrictive exhuast post turbo (dp, tailpipe, muffler etc), it will cause a ton of backpressure. I'm wondering if you need more of a flex joint in there to allow for the amount of heat you're throwing at it. The way it broke looks like it was loaded and not from internal pressure. Its hard to say though from the pic.
Oct 1, 2008 | 10:53 AM
#22
You're running 19psi of boost, but what is your exhaust back pressure? That has more to do with why the hot parts failed. If you have a tiny exhaust housing on there with a restrictive exhuast post turbo (dp, tailpipe, muffler etc), it will cause a ton of backpressure. I'm wondering if you need more of a flex joint in there to allow for the amount of heat you're throwing at it. The way it broke looks like it was loaded and not from internal pressure. Its hard to say though from the pic.
Oct 1, 2008 | 10:54 AM
#23
you can still have backpressure bud...what AR is that turbo and what size again?
Oct 1, 2008 | 10:58 AM
#24
He did contact me before he posted and I offered to build him a new stainless crossover for only the cost of materials. The only down side is that the crossover needs to be fitted to the manifold that it was built for so the V-band will line up. Every kit is a little bit different and fit on a V-band is important for sealing.
My speculation on what happened, is at 19 lbs of boost on this type of setup is probable some where in the neighborhood of 3 to1 back pressure meaning there is some where around 60psi in that pipe and generates a TON of heat very quickly. The area where is failed is especially a hot spot coming right off the manifolds and probable turns bight red in a hurry. That's just more stress then the steel can handle I would have to guess.
I'm running the EXACT same crossover on my truck for over a year not and have ran up to 15 psi and it's still hold fine.
My speculation on what happened, is at 19 lbs of boost on this type of setup is probable some where in the neighborhood of 3 to1 back pressure meaning there is some where around 60psi in that pipe and generates a TON of heat very quickly. The area where is failed is especially a hot spot coming right off the manifolds and probable turns bight red in a hurry. That's just more stress then the steel can handle I would have to guess.
I'm running the EXACT same crossover on my truck for over a year not and have ran up to 15 psi and it's still hold fine.
Oct 1, 2008 | 10:59 AM
#25
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It's less psi on the dyno, 19psi on the street. For some reason, we just couldn't load the dyno enough to get full boost, so HP is more than 612hp, that's just what we recorded. I think it was somewhere around 12psi at peak rpm and max of 16psi midrange.
Oct 1, 2008 | 11:03 AM
#26
http://www.racetep.com/tnetgtk.html
Oct 1, 2008 | 11:10 AM
#27
I appreciate the offer, but if im going to have to fit it up anyway I figured I would go ahead and just build it all. I say 19 psi is max, running around 90 percent of the time the controller is off and on 15 psi. But again, I had no idea that I couldnt run high boost with it. Thanks again
Edit: Mic is pushing these a lot harder them most will ever do, and when you push things to the limit, you find the weakest links. All I can do it to build it stronger and see what fails next. That's the name of the game in High HP applications.
Last edited by kbracing96; Oct 1, 2008 at 11:20 AM.
Oct 1, 2008 | 11:13 AM
#28
here are the turbo specs, I have the gtk850 on there now, and have a new gtk1000 thats going on when it goes back together. again, this is my first turbo project, i never claimed it was a perfect kit. and the 612 hp was at 16 psi, and i have 22s that weigh over 100 lbs each. they rob alot of power.
http://www.racetep.com/tnetgtk.html
http://www.racetep.com/tnetgtk.html
Oct 1, 2008 | 11:18 AM
#29
Seriously, we have no idea as to the limits of this kit, because the only thing that was measured was boost. HP numbers weren't even measured either. I'm willing to bet he has a small A/R housing stuffed on there in an effort to build as much boost on the street as possible with a manual trans.
