I'm no engineer, but I don't think they necessarily failed. Yes theres been a handful of cars that had problems with the BMW metal guibo, but I think it's a case of "the loud minority out-screams the silent majority" - it's not like every 1M had to have their guibo replaced and from what I've seen in the failure posts it was usually people who dropped the metal guibo into their pretty heavily upgraded and tuned x35, and we dont know if they DIY'd it, had a buddy help, went to the cheapest local shop or if they actually had a reputable shop do it with proper alignments and procedures. Id be willing to bet most of the broken ones were just put on like a regular rubber guibo.
Take a look at the aluminum & poly guibos offered by Revshift. They require a very very strict tolerance rating during installation (thousands of an inch iirc - that's .001's), and require that everything is measured and aligned along the DS and drivetrain before putting even putting the guibo in place, before checking it all during installation multiple times. They require a 100% perfectly balanced and aligned driveshaft before even starting, then tightening two bolts in a certain order, recheck tolerance, tighten the opposite bolts, recheck tolerance again for both directions, tighten all bolts and recheck tolerance of the guibo yet again, and then check the alignment of the entire driveline, and then the guibo once again if anything else in the driveline is touched after checking the DS alignment and balancing - and if you dont install it that way or any evidence is found that you were .001" off then your lifetime warranty is voided. BMW designed their metal guibos to hold (and more importantly instantly put down
) ~300hp and they probably still used the entire process above too, if not more.
I think a properly built, sturdy guibo with whatever bushings it needs (whether that's soft rubber, harder rubber than stock, poly, UHMW, etc.) could certainly be made for our cars for those dedicated enough to want it and take it to the right place. Anything driveshaft related should be treated just as if you were getting an engine or transmission (re)build done. But it seems like lots of people see it's easy to get to that stuff so assume it must be easier to do too.
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Anyway,
@martymil I think something very realistic, easy to mass produce, likely would sell a very decent amount and shockingly isn't available on this platform is a racing or "off-road" midpipe/catless midpipe/"test pipes"/secondary cat delete exhaust section (
meaning mid pipes only, nothing axle-back)that's as plug and play as possible - i.e. bolts to twin downpipes (you avoid any hassle of ST owners thanks to most kits offering a 1-to-2 outlet Y'd dp) and bolts to the stock location mufflers so it fits plenty of aftermarket axle-backs too.
Some aluminum or similar weight pipes that mimic the stock exhaust routing so you can drop a little extra weight, save R&D time, and build them quick enough to keep on the shelf would be excellent imo. You could offer them in either straight pipe form or keep the stock e92/sport pkg tiny x pipe. Eventually or even at launch since it's a relatively simple design, you could have drop or check boxes to offer them in different sizes, offer a single pipe version that maintains stock connections or possibly even one for adding a resonator.
I know there's the PE mod and that many people go have the cat replaced with a resonator at an exhaust shop for cheap, but one requires a decent amount of time dropping, disassembling, cutting and welding several parts of the exhaust and the other requires you to sit around for hours waiting for your turn to have 12" of pipe clamped on while being charged for welding instead of clamps and you're still stuck with the rest of the weight. Personally I'd rather have an OTS option that doesnt require me to remove any other exhaust components and that I can do in my driveway in an hour.
This is the first car I've owned where there aren't *any* midpipe product options. If you look at any LS platform car, 5.0, or even older BMW gens theres multiple options. I know the VRSF exhaust is similar to what I'm asking for, but it includes an axle back system and is $750-800 which is slightly overpriced for 5 Chinese exhaust parts. Borla used to offer a midpipe-only section of exhaust for our cars as well, but it was priced at $700 for two seperated straight pipes (which probably cost them $80 including labor to make) and was advertised as for the Borla axle-back so who knows how it fit. I know getting a semi-custom exhaust fabbed isnt the most expensive thing in the world but still, its a bit of a hassle imo and few hobbyist wrench turners can do it themselves.
Have it in stock, advertise it as making your car capable of shooting fire, x% weight loss, reduced back pressure or x less WGDC, maybe even a 5hp bump if you're feeling adventurous, price it between 130-300 depending on the options you have and I think youd sell a good amount. Not to mention if you copy how the stock exhaust runs, you could develop this in a few days while working on your bigger projects.
