{"id":819976,"date":"2026-10-18T16:49:51","date_gmt":"2026-10-18T16:49:51","guid":{"rendered":"https:\/\/tunerscapital.si\/product\/bull-x-downpipe-121-101-mm-za-audi-rs4-rs5-b9-quattro-450-km\/"},"modified":"2026-10-18T16:50:00","modified_gmt":"2026-10-18T16:50:00","slug":"bull-x-downpipe-121-101-mm-za-audi-rs4-rs5-b9-quattro-450-km","status":"publish","type":"product","link":"https:\/\/tunerscapital.eu\/en\/product\/bull-x-downpipe-121-101-mm-za-audi-rs4-rs5-b9-quattro-450-km\/","title":{"rendered":"Bull-X 121\u2013101 mm downpipe for Audi RS4\/RS5 B9 quattro 450 PS"},"content":{"rendered":"<p>These Bull-X downpipes can be exchanged 1:1 for the standard downpipes. The available catalytic converters provide increased exhaust gas flow and reduced back pressure, helping to increase power, lower exhaust gas temperatures and reduce the load on the turbochargers. This is further supported by the enlarged pipe diameter of 121\u2013101 mm and removal of the second catalytic converter. The downpipes run from the original turbocharger flange at 121 mm, continue at 101 mm and are only reduced to 76 mm directly before the original flange. They are also suitable for vehicles with increased power. A noticeable change in sound is achieved after installation, particularly in combination with a sports exhaust system.<\/p>\n<ul>\n<li>OEM downpipes each feature 2 catalytic converters, while the Bull-X downpipes are fitted with no more than one catalytic converter<\/li>\n<li>integrated heat insulation<\/li>\n<li>material: stainless steel<\/li>\n<li>fully TIG welded<\/li>\n<li>significantly enhanced sound, even with the OEM exhaust system<\/li>\n<li>with the HJS 200-cell Euro 6 catalytic converter option, no software calibration is required and no catalytic converter monitoring fault is displayed, but only on models without OPF<\/li>\n<\/ul>\n<p><strong>Note:<\/strong> For models with OPF, software calibration is required after installing the downpipes. Both the temperature sensors and differential pressure sensors must be disabled in the software. On pre-facelift models, the downpipes are supplied without sensor connections to avoid unnecessary costs.<\/p>\n<p><strong>Road use:<\/strong> For public-road use, only the version with the EG-approved HJS catalytic converter is permitted. All other catalytic converter versions and decat pipes without EG approval are intended exclusively for track use.<\/p>\n<p><strong>Suitable for:<\/strong> Audi RS4 V (B9), Audi RS5 II (F5).<\/p>\n<h3>Manufacturer\u2019s vehicle data<\/h3>\n<ul>\n<li>Bull-X Downpipes Audi RS4\/RS5 B9 quattro 450PS<\/li>\n<\/ul>\n<p><em>Original product name by HG Motorsport (\u00bbz.B.\u00ab = e.g.). Please check model, year and engine of your vehicle before ordering; if in doubt, contact us and we will check for you.<\/em><\/p>\n<h3>Approval<\/h3>\n<p><strong>Only the version marked \u201croad legal\u201d<\/strong> has a European <strong>ECE \/ EC<\/strong> approval (Bull-X Tronic controller with ECE or the HJS EC catalytic converter). Versions marked \u201cno ECE, track use only\u201d have no approval and are not permitted for road use. If in doubt about the version, contact us and we will check for you.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Bull-X downpipe for the Audi RS4\/RS5 B9 with larger-diameter piping, sports catalytic converters and a more pronounced exhaust note.<\/p>\n<p><strong>Suitable for:<\/strong> Audi RS4 V (B9), Audi RS5 II (F5).<\/p>\n","protected":false},"featured_media":819987,"comment_status":"open","ping_status":"closed","template":"","meta":{"ep_exclude_from_search":false},"product_brand":[146199],"product_cat":[109615],"product_tag":[],"class_list":["post-819976","product","type-product","status-publish","has-post-thumbnail","tc_lang-en","tc_lang-hr","product_brand-hg-motorsport","product_cat-downpipe-kiti","product_shipping_class-dostava-veliki-paketi","pa_proizvajalec-hg-motorsport","first","onbackorder","taxable","shipping-taxable","purchasable","product-type-variable"],"_links":{"self":[{"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/product\/819976","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/comments?post=819976"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/media\/819987"}],"wp:attachment":[{"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/media?parent=819976"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/product_brand?post=819976"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/product_cat?post=819976"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/tunerscapital.eu\/en\/wp-json\/wp\/v2\/product_tag?post=819976"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}