I devoted last Saturday to the PS13 header system, read on to see how it came together.
As you may have read in my previous post i teamed up with Martyn from VE to design my header system, developed in conjunction with Tomei Japan i needed to get this right, just cutting some tubes and “winging it” wasn’t going to do. I wanted to be able to replicate this exhaust accurately and have confidence in it being millimeter perfect in both fitment and internal dimensions
It started with a heap of SS 304 1 3/4 mandrel bends i imported from America, while these look great we soon found out they weren’t. The design is a 4-2-1 with a rise in diameter after each step.
I also had some exhaust flanges imported from the US, these are also 304 stainless and looked great apon first inspection, but after some consideration to the design and fitment i will be designing and producing my own in the future.
With the garage all clean it was time to get to work, theres nothing better than starting the day knowing excactly where all your tools are.
The morning was spent building a jig for each individual exhaust runner and collector, why go to such extremes? Well its all in the name of repeat-ability, having these jigs and also the drawing’s with specific dimensions and angles for each cut makes building an exhaust an exact science, no guess work and garenteed 100% perfect fitment each and every time.
At this point you would be thinking that its all a bit professional, well not really, without a bandsaw Martyn and i struggled along with an angle grinder and a linisher. With patiance we got the fitment pretty spot on. The issue with the “mandrel bends” was that they were not 100% round in the bend radius and specifically at the start of the radius, this crushing of the pipe led to some very minor miss alignments. This will be a big factor in purchasing tube in the future, we think we have this problem sorted and will be able to supply you with the proper tube for the job.
With the addition of the last runner it finally took shape, please note that its only tacked and i still have to break it apart, match the ports and then match each pipes alignment to each other.
With the 4 tubes now running into two collectors im going to hold off on doing the next part till i find a factory SR20DE header to get the stock position on the factory flange, i will match this position with my new header so those of you who already have a nice “header back” exhaust wont have to change it to fit this.
As is the case with everything i do i spend a lot of time making performnce and looks work together, i mean its always been my dream to have an SR20 engine with quad throttles and a “formula atlantic” style header system, of course the internal dimensions could have been achieved with a simpler design but thats just not what the aim was.
I have to say a big thank you to Martyn for his help with this, to be honest without the time he spent on design this would still be a pipe dream (sorry for the pun haha), with SR20DE parts like this being very rare i hope i can change this and offer a solution to many peoples problems. With our quad throttle system still in the works and not far away from reality the perfect SR20DE is only months away.
Although this motor is still stock im looking forward to building up a bottom end, adding some angry cams, CNC porting a head, screwing the whole package together with some pretty neat new parts i have in the works and bolting it down on the engine dyno to see if we can get some big torque and power out of the motor. What happens after that? Well im keen to get this PS13 on the track and really stretch its legs, after all this work what else would you want to do!