I have a manifold that is a pretty nasty boost creeper, it has shitty wastegate placement and I would like to get rid of it, but I am not selling someone a manifold that creeps so I am going to do my best to fix it.

Picture 1 at the bottom is the manifold as I got it........ looks like a 38ish mm hole with a 44mm flange on it huh? I was creeping from 15 to 20psi on the dyno using a 13lb spring, never realized the manifold was like this.

Over the summer I bored out the extra material and I was holding 16lb off the gate pretty steady.

Now that winter is back I am creeping again off the wastegate, from 16 to 22psi on a 13lb spring.


So with that being said I am going to cut off the existing 44mm flange and extension and I plan on taking a 90 bend and cutting it to a tear drop shape, and then cut the manifold in the shape of the bend I just cut, is this the direction I should be going or do any of you have another suggestion? I drew red lines on the 3rd picture to give a general idea of the area I was planning on cutting and welding on a new elbow...... yay or nay?

Any suggestions appreciated

Do any of you have a picture of a bend like I mentioned cut and ready to weld on? I keep picturing it in my head but when I look at the bends I have it doesnt seem to work out correctly.

 

we just did this on a mustang with a 90mm turbo. what we did was cut a 90* bend at an angle like you have drawn on there. turned out perfect and is more directed with respect to the flow of the exhaust.

we did this but its so much simpler to make it out of one piece instead of three or whatever it is like you see here

 

thats what I like to hear, thanks bro

anybody else?

 

your welcome, have fun

 

do you have a picture of the inside of the collector?

 

the picture is not mine, i got that from lovefab website. i didnt even know he was making his ramhorns like that. ours is the same way, just like you drew on your manifold and like i said we just cut a 90* tube at an angle that would give us that shap of an end.

 

cool thanks

 

Does that have any negative effect on what we try to achieve when making a nice collector? I mean, does the new added space cause any turbulence or anything like that?

Nice looking design I must say.

 

I would imagine it has an effect, just not sure if it is negative or not. I know what kind of boost my car build and at what rpm so I am going to note any losses, I am only hoping to gain some boost control as mine is way out of control right now, if I wasnt running E85 I would be in big trouble...........

 

if you are running really high boost, i'd suggest getting a whole new manifold that is wastegate priority.

 

Not super high boost right now, just 21-22psi, as far as I am concerned wastgate priority isnt that much of an issue if I was running 30psi because I am not bleeding off as much through the WG at that boost pressure, but I want to try to get the boost down to a steady 14-15psi in 1st and 2nd gear, and have the ability to ramp it as I see fit.

Either way I have to fix this because I am not going to sell someone a junk manifold, I am confident I can make it hold boost.