On a V8 with a single turbo, does it matter if the wastegate is placed on one side of the exhaust prior to the pipes being y'd into the turbo? Or does it have to be placed in the pipe after the two exhaust banks are merged? MP T70 going on a 4.8. Thanks.

 

I have built MANY turbo kits with the waste gate mounted in the crossover like this...

 

So what happens when the wastegate opens? Seems like the log primaries sweep towards the turbo some, so do they actually backflow to the wastegate or it the only side vented the driver bank?

 

Running it like Kyle has it is slightly less efficient than having it after the pipes merge, but it still works (many people including myself have his kits), and is much easier and cleaner to pipe.

I would be curious to know the exhaust velocity on the hot pipes though since Ive always thought of it more as a low velocity, high pressure, high temperature flow.

 

When the gate opens, it allows enough exhaust to escape pre-turbo to keep the turbo from spooling more and increasing boost. I would imagine the vast majority of exhaust that escapes comes from the driver side bank, as the velocity of the exhaust gasses are pretty high when the gate opens, relatively speaking. The pressures that build up pre-turbine will vary with each setup though.

 

So has anyone built a kit with the wg after the log? If so is there a noticeable difference in spooldown characteristics or not?

 

I relocated mine on kbs kit to the last elbow before the turbo on the log manifold, ive had problems keeping boost down only because i didnt make it straight into the path of the exhaust flow here is a recent pic of what i just did to hopefully correct this.... In a perfect application you want your exhaust gasses hitting your turbo and waste gate with the same volume and speed to my knowledge so keep in mind dont put it on a flat surface right after a elbow... back pressure has alot to do with it also, ill post up some results when i run it again.... When i went from a t4 medium frame pt88 to a large frame 91mm t-6 it changed backpressure tremedously. You can notice how i had it before just stuck straight off with a 2" pipe before and exhaust gas was going right by it into the turbo whether the waste gate was open or not!

 

so on a normal kit it is also coming off an a backwards oblique angle. Anyone else experience boost creep with the normal setup pulling off the crossover?

 

No, 99% of the turbo trucks on this site run the gate as shown by KBRacing. If you try to use a 38mm gate and are chasing real big numbers, you might have issues.

 

im having serioius boost creep problems with mine. I have the KB kit. 44mm. My spring should be around 10 or 11 psi. Im hitting 15-16 pds is 2nd gear and up. please someone help with a way to solve this.