Another problem I inherited with my ’91 318i e30 is that exhaust wasn’t finished when the M50 was swapped in. The previous owner purchased Raceland “shorty” headers intended for an e36 325i, 328i, or M3 but the recommend headers for this swap are the longtube SuperSprint header clones commonly available on eBay. Neither set of headers is what I would call a direct fit, but the longtubes are much closer to fitting correctly. Because the Raceland shorties want to violate the control arm bushings, I decided to buy a new set of eBay longtubes for the grand total of $110 shipped to my door from the seller “SpeedDaddy”; below is a quick comparison.
First, the eBay headers I purchased have “1.75” outlets / collectors according to the auction listing. There is another version that has “2.00” inch outlets and costs a little extra. I measured 2″ on one collector and 1.75″ on the other where it necks down. My plans involve welding on a V-band so that 1.75″ section will get cut off anyway!
The Racelands fit on the car but clearly will not clear the lower control arm bushings. The treehouse racing “eyeball” control arm lollipops/bushings might clear, but they’re bloody expensive and I’m afraid they might ride harshly.
And one from the bottom
It’s hard to tell what’s going on in that picture because things are so crowded, but hopefully it gives some idea about how the Racelands fit. I was going to modify them to fit, but I thought it would be easier just to buy another set of eBay headers. So here they are!
As mentioned above, you can see that the end of the righthand header necks down. At the end, the header on the right measures 1.75″ in diameter whereas the lefthand header measures a 2″ diameter. Odd. Other than that, they certainly look nice.
Here are both sets of headers next to each other. I think these pictures speak for themselves – the Racelands are clearly better quality. Another telling sign is that the longtubes are the lighter set of headers, despite appearing much larger; the stainless steel used in the longtubes is much thinner!
And here’s a different angle. Note the O2 sensor placement differs.
Speaking of quality, look at how much thicker the Raceland flanges are! That and I’m pretty sure the eBay header flanges are not flat.
After a very long fight, I finally fit the longtubes to the M50. Where the racelands pop on and off quite painlessly, the longtubes require some serious fiddling to squeeze into place – from the bottom. The one header also needed some “adjustment” with a hammer to clear the passenger side floor. However, that process wasn’t too bad and the O2 sensor DID mount into place although it is a tight fit.
Finally, here’s the proof that the longtubes do indeed fit. Next up, V-bands and header back exhaust!