Custom Fabbing a Honda Prelude Downpipe (Video)
This 1997 Prelude downpipe/turbo combo has all the right ingredients to be our next favorite YouTube budget build.
How many of us have custom fabricated a Prelude downpipe? Not too many. Now how many of us did it while we still had peach fuzz? Youtuber Nate Lee, did just that for his 1997 Honda Prelude Type SH budget build. Lee recently slapped an eBay turbo onto his clean H22A4 engine. So what’s the logical next step? Make it purr.
Off-camera, Lee sources a 1-2/2 ft section of downpipe from a Hyundai Genesis. He also welds on a bung for the Prelude’s O2 sensor. And with that, it’s time to get to work.
Cutting the Prelude Downpipe
“At the very bottom, it needs to be angled,” explains Lee “So what I’m gonna do is… cut a little pie out of it, bend it. And hopefully, when Vasily gets here with his welder, he’s gonna be able to weld it up for me.”
Lee starts off by using a pie-cut technique to find a proper angle. After several cuts, the pipe comes apart. Afterward, Lee decides he’ll try again and that the angle also needs to be higher for proper fitment.
With this second attempt, Lee decides to use a new cutting technique. Lee makes a cut, then pinches the two halves together for the following cut. With each cut, Lee explains he’s able to remove a millimeter at a time to ensure perfect fitment. After several more cuts, Lee tapes up his work, tests the angle, and viola. A perfect Prelude downpipe.
Welding the Prelude Downpipe
After a short break, Lee’s friend Vasily finally shows up to help with the welding. To prep, Lee creates a smooth mating surface for the downpipe using 60 grit sandpaper.
“You don’t want to weld on concrete,” Vasily warns “But in this situation, it’s gonna be fine.” Honestly, who didn’t ignore standard safety procedures at that age? Vasily drops his visor and immediately gets to work on welding the downpipe.
Vasily tacks together the cuts made to the downpipe and then tacks the pipe to the exhaust flange. Next, the guys weld up the rest of the cuts Lee made earlier. The camera dies, so we’re left without video for a short portion, but afterward, we see the finished product.
Finishing Touches
The end result is an impressive DIY Prelude downpipe. “These welds look really good,” says Lee “Even though he used a flux core welder, they turned out really nice.”
The guys spray down the downpipe with a coat of paint and call it a night. Unfortunately, we don’t get to hear that H22A4 sing. But we’ll be keeping our eyes peeled for that next video. What these two did was nothing short of impressive, and we hope to see more.