If you’re diving into some serious engine work or just need to upgrade your cooling system, check out this HPS 3" to 4" silicone reducer coupler hose. It’s not just any hose; this bad boy is built to last with a 4-ply reinforced design that can handle some serious heat—up to 350°F, to be exact. So, whether you're pushing your rig hard on the trails or cruising on the water, this hose has got your back.
What I really appreciate about this coupler is its versatility. It's perfect for custom turbo setups, intercooler piping, or even your DIY intake projects. The 3" to 4" diameter range (that’s about 76mm to 102mm for those who prefer metric) means it fits a ton of applications. Plus, with a wall thickness of around 4.5mm, you know it’s not going to crumple under pressure.
Another thing worth mentioning is that it's UV and ozone resistant, so you won’t have to worry about it degrading over time if you’re using it in outdoor setups. Just keep in mind, this silicone hose isn’t compatible with fuel or oil, so save it for your cooling system or air intake.
In terms of specs, the outside diameter ranges from 3.39" to 4.41" (86mm to 112mm), and it measures a solid 4" long. It really ticks all the boxes for a high-performance silicone hose, and it meets the SAEJ20 industry standards, which is a big deal if you care about quality. If you’re looking to up your game in the engine bay or just need a reliable coupler for your next project, this HPS hose is definitely worth a look.
Features:
⚠ WARNING:
Cancer and Reproductive Harm
https://www.P65Warnings.ca.gov

HPS Performance Products is a leading manufacturer of aftermarket performance parts, fabrication components, and silicone hoses. HPS serves a number of different industries, including automotive, aerospace, construction, commercial truck/bus, marine, agricultural, turbo diesel, off-road, performance racing, general manufacturing, and water treatment. The company’s ability to fabricate custom-shaped multiply silicone hoses make it ideal for a wide range of applications. The multiply carcass makes HPS’ hose perfect for coolant and turbocharged pressure applications while the fluoro-silicone-lined hoses make it safe to be used with petroleum-based oil and fuel.
HPS Performance Products is committed to meeting its original goals of producing quality parts at competitive pricing and providing customer service responses in a personal, timely manner. All HPS products have been thoroughly tested on the dyno and track, and meet or exceed SAEJ20 standards. The HPS staff has solid expertise in the silicone hose department, which allows them to deliver standard size silicone hoses with same-day shipping. HPS’ highly skilled and knowledgeable team, paired with the latest state-of-the-art technology, ensures the brand’s continued success and reputation as a premier manufacturer in the industry
HPS Quality Silicone HosesHPS Performance Products specializes in and is best known for manufacturing multi-application silicone hoses. HPS silicone hoses are carefully crafted from only the highest quality 4-ply reinforced high-temperature material. The hoses are available in the following varieties: straight coupler, 1-foot tube, 3-foot coolant tube, charge air cooler hose (CAC), hump coupler, reducer couple her, 45-degree elbow coupler and reducer, and 90-degree elbow coupler and reducer.
HPS Performance Products also carries performance silicone vacuum hoses and silicone heater hoses. You can choose silicone hoses in both standard inch and hard-to-find metric sizes. Stainless steel T-bolt clamps are available to match with the silicone hoses as well. In order to meet the high demand and shorten the turnaround time for its silicone hoses, up to 90 percent of the product is already in stock and ready to ship or pick up from HPS authorized dealers like Vivid Racing.
HPS Performance Products at Vivid RacingVivid Racing carries a comprehensive lineup of HPS Performance Products for a number of different makes, models, and applications. Our extensive inventory of HPS parts includes aluminum tubing, cold air and short ram intakes, vacuum lines, hoses and clamps, intercooler pipes, radiator caps, and much more! If you have any questions regarding the items listed above or have fitment concerns, please contact our expert sales team at (480) 966-3040. We are here to help you through the entire purchase process and make it a pleasant experience.