The Supersprint Header Design for a MINI Cooper S

Supersprint Header Oil Design for '02-'06 MINI Cooper and Cooper S www.bmpdesign.com What we are going to talk about today is Header design, specifically Supersprint Header design on a MINI Cooper or MINI Cooper S. When you purchase any kind of header, here's what you want to look for. Definitely stainless steel, it's pretty much the norm these days. But what you want to make sure that you are getting is at least 304 stainless steel. Another thing you want to look for is the flanges. Flanges have to be relatively thick. They have to be stable, so they don't warp. So you get a good seal for the duration of the system installed on the vehicle. What you are also wanting to see is that the tubing is all Mandrel Bent Tubing and that you have got nice wells and nice transitions where they meet the secondary collector. There's two kinds of headers on the market. You are going to find 4-1 header, that's one design, and then there's going to be 4-2-1. So basically what we are doing is we are taking 4 ports, each one shared. You will go into another, like a smaller collector. You will have the outside tube going into another collector, and then they join one more time. Now, the advantage of 4-1 header, this is 4 going on into 1 collector is typically, that will get you more horsepower gain at high rpm. That would be more of a strict road race in a situation. You are also going to lose a little bit of bottom end torque. You are going to lose your bottom end torque and horsepower, and typically what happens is the power comes on at a later time. Now, lengthening and shortening those pipes will put that power band in a different rpm band. But what Supersprint looks for is high horsepower, but not sacrificing torque. We are trying to keep the torque up there, because most high speed acceleration requires torque, especially on a small displacement engine, you can't afford to give up 15 horsepower in the midrange to gain 10 horsepower at the top end, you have got to get there first. On a 4-2-1, you are going to have a broader horsepower band, and depending on tubing diameter, select tubing diameter is what gets you your high torque all throughout the range. Now, a nice feature with the Supersprint exhaust is, the collector comes into a flex pipe on most header systems that you see on the market. This allows the motor to torque when you are accelerating, because the motor is obviously moving, and since it's a transverse engine, it fits sideways in the car, the motor is actually twisting backwards. So most headers on the market that I have seen, other headers, other than Supersprint, have one of these thermo expansion joints. It's basically a little accordion piece in there that has some braid on the outside, and what's happening there is all your motor torque is virtually being transmitted to this flex joint. This is not a good design. This unit was never designed to be torqued in flex, it was designed to expand and contract on a system where there might be two pipes riding parallel that have different expansion rates, because one is longer than the other. This system here, fairly inexpensive to put in, but not the optimum coupler. What Supersprint has developed is, at the base of the header here, there is a ball joint. It's basically a composite steel mesh type of seal that fits in there, and there's a bell. What's happening here is we torque these bolts down to a specific tension, to allow a little bit of tension on these springs, and that ball joint right there can move freely. So when that engine torques back and forth, you are basically sliding on that seal. It keeps a good seal, and it allows the motor to move, with very little wear. And when something does wear out here, you purchase a new seal, and the seal is a small ring, about 4 inches diameter on the outside, and it will basically slip right over the collar and then the ball. The ball socket will fit right over that point again. So that's what you need to know about headers. For more Tech Tips, Technical Videos and Product information please visit us online at www.bmpdesign.com