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VFR750FL-P Exhaust System Modifications
[Although it has been recently updated, this page is still a work in progress. Please check back later for further updates...]
OEM and Replacement Systems
The exhaust systems found on Honda V-4 motorcycles when new are generally of good quality, though they are constructed of mild steel tubing with stainless steel in the cannisters. This means they are generally quite heavy and are prone to eventually rusting through. Like most factory exhaust systems, they also restrict the engine's performance to some degree and muffle the delectable sound produced by the V-4 engine. Factories fit such exhaust systems to their bikes in order to pass the various noise regulations in effect in the market where the bike was originally intended to be sold. But even Honda occasionally gets it wrong—one of the few modifications Honda made to the 1992 US-spec VFR750F, for example, was allegedly to increase the noise output of the exhaust cannister, because they had simply overshot the mark. (See the RC36 Differences page for more detailed information.)
One advantage of retaining the stock exhaust system, rather than replacing it with aftermarket parts, is that stock systems generally fit the bike very well and allow the use of all of the designed components. On VFR750FL-P models sold in the United States, the centerstand (standard equipment on "Rest of the World" (ROW) models) was an optional Hondaline accessory, but it did fit perfectly on all of the bikes (early magazine reports—and even current book statements—to the contrary notwithstanding). One of the typical "features" of aftermarket exhaust systems, for example, has been their characteristic incompatibility with centerstands and passenger footpegs. Due to the relatively few aftermarket exhaust system options for the VFR750FL-P models, there are few alternatives to the stock system for someone who wants to improve upon the stock system as well as retain the ability to perform routine maintenance with the bike on the centerstand.
But it is possible to fit an "aftermarket replacement" exhaust system made from stainless steel, which do not really enhance performance (indeed...), but should last the life of the bike. There are apparently only two ready-made options, both manufactured in the UK: The Motad stainless steel front pipes and collector system (which can be coupled with any aftermarket slip-on muffler such as a C-2 oval from Two Brothers Racing (TBR)—as shown on the official VSource.org RC36—and the uncanily-identical system sold by Predator Motorsport. However, the UK also boasts several custom exhaust fabricators that can build stainless steel full systems for VFRs, the most well-known of these being Gazelle and Zorstec.
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Another advantage of stock systems is that they also function just fine with the stock carburetor jetting and air filter. Although most aftermarket manufacturers will state that their slip-on does not require re-jetting, that just means that your bike won't likely burn its valves just because you installed their pipe. In order to make the most of the performance modification you've just installed, you need to have the carburetors re-jetted to work properly with it—and probably install a free-flowing air filter as well.
Aftermarket Full and Half Systems
There are still a couple of choices of aftermarket exhaust for the early RC36, but as this model ages, the number of choices available will certainly dwindle. At one time or another, aftermarket exhausts have been available in several configurations, including full systems, half-systems and slip-ons. This slightly-out-of-date page from the Texas VFR Garage gives an overview of what was available for the VFR750FL-P at one time. Neither the Two Brothers Racing stainless steel full system (discontinued?) nor the Holeshot full system (discontinued) allow for centerstand retention on '90-'93 VFR750s. It is not clear if the left-exit Sebring system (discontinued, but still occasionally appearing on German eBay) retains the center stand on FL-P models, but it may, as shown in this photo. Due to the bikes being very similar, full systems for '94-'97 FR-V RC36s will fit the earlier models, but the centerstand cannot (ordinarily, that is—see below) be retained. The Kerker "White Tip" left-exit slip-on (discontinued) and the Yoshimura right-exit system (discontinued) were essentially half-systems, as they replaced the stock collector box while utilizing the OEM front and rear downpipes; true "slip-ons" attach to the pivot point on the collector box.
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Underseat Systems
Although not a job for the inexperienced, Brandon Monnig managed to combine a Yoshimura half-system with a Wolf Racing underseat slip-on originally designed for a later RC36 to achieve a truly unique VFR750FP. (Note that he's also retained his bike's GiVi Wingrack mounts...) And, as demonstrated by the official VSource.org RC36, it is possible to use a TBR full system on a '90-'93 RC36 and retain the center stand, but this requires that the bike's rear ride height be increased substantially and the center stand bracket be lengthened or spaced downward by approximately 55mm (the side stand should also be lengthened to match). The VSource.org bike's Laser Xtreme underseat exhaust system was originally manufactured for a CBR600RR, but with the use of a custom stainless steel link pipe from [Predator], fits the RC36 underseat area quite easily. [Work in Progress!]
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![The VSource.org RC36 with Laser Xtreme underseats [work in progress]](Images/PB100001x.jpg) |
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Road-Legal Aftermarket Slip-ons
Interestingly, and unlike in general in the United States, whether or not a particular end-can is legal to use on the road in Europe depends upon whether it carries the appropriate markings—not necessarily upon how loud it is. In the UK, exhaust parts sold for road use have traditionally been "BS-marked", a reference to the relevant British Standard for exhaust noise, but with the increasing influence of the European Union's harmonization rules, the new mark is the "E-mark", valid throughout the EU. Enforcement of this and other "construction and use" regulations by traffic police varies greatly between countries, with the UK being one of the more dangerous countries to be found riding with an illegal end can (or number plate or headlight cover, etc.). Police in the UK can often be found making random (or not-so-random) checks at the roadside or even patrolling motorbike parking areas—not to mention what can happen if you should be stopped for an actual traffic offense.
Accordingly, being "road-legal" isn't necessarily about passing an annual inspection (MOT) or being polite to the neighbors... Fortunately, the 180-degree firing order of the RC36 sounds very good even when restricted by draconian sound emissions regulations!
Nearly all aftermarket exhausts made for the RC36 are right-side-exit, i.e., the same side as the stock exhaust exits. (Certain exceptions to this rule include the left-exit Two Brothers Racing stainless steel full system (discontinued?), the (discontinued) Wolf Racing underseat slip-on, the (discontinued) Yoshimura, Sebring and Kerker "White Tip" half-systems, all of which are (a) expensive or no longer available (except on eBay), (b) not road-legal and (c) require the removal of the bike's centerstand.) The original silencer used a spring-loaded exhaust flange pivot to allow rear wheel removal without the disassembly of the exhaust system. Very handy, but the OEM design unfortunately places the bulky exhaust can right in front of the VFR's unique single-sided rear wheel. But the main reason to install a high-mounted aftermarket exhaust is aesthetic, of course!
The following is a description of most (if not all) of the high-level road-legal aftermarket exhausts available for the early RC36. (In general, the later RC36 has many more exhaust choices still available, whether race or road legal.)
BSM "Future" stainless ("titanium-look") w/connector (length x diameter: 40cm x 10cm; weight: 2.0kg) £187.55 + VAT (~$350) @ David Silver Spares [BSM high mount connector pipe (only) £95.88 + VAT]
BSM (NL)
David Silver Spares (UK)
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The French-made Nikko "Strada" is available in aluminum or carbon, round w/connector, approx. 42cm long €460-510 @ Metisse. [The US importer is Wild Hair Accessories, who apparently offer the race version for $460-490, but the road-legal version is probably the same price, if they do import it.]
Nikko Racing (FR)
Metisse (DE)
Wild Hair Accessories (AZ)
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Another French compnay, MIG, make a round silencer in aluminum, carbon, carbon/kevlar or texalu, which are all 12cm in diameter and a somewhat pricey £357 (~$575) @ Bullet Motorcycles (UK) (aluminum somewhat cheaper); ~$400-500 + shipping to the US @ Brian Law's Dynamo Humm in Canada.
MIG (FR)
Bullet Motorcycles (UK)
Dynamo Humm (CA)
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Harpoon is a Spanish company about which there is very little information on the Web, but which appears to have been re-named "Krieger". They made/make a rather TBR-esque oval end can with cast aluminum end caps in carbon, carbon/kevlar and aluminum in various colors. The photo below is of a high-mount carbon fiber slip-on mounted on an early RC36, which was, according to the "Way Back Machine", once available in a road-legal version in carbon fiber or aluminum. The current Krieger Web site includes an application chart that shows a high-level oval exhaust can available for the early RC36, but the only end can that is clearly road-legal is a round version that is not listed for this bike. There is a US importer, Centre Cycle Works (PA), but they do not inlcude this model in their application chart. Prices appear to range from $305-405, depending on finish and whether they can get them for this bike.
Krieger (ES)
Centre Cycle Works (PA)
Harpoon (ES) (Dead Link)
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Austrian company Remus has the round "Innovation" and the oblong, twin-spout "Viper" in aluminum, carbon fiber and titanium available for the early RC36 £248-344 (~$395-625) @ JB Racing. The Innovation is 11cm in diameter, and the Viper is 11cm on the sides and 13cm top-to-bottom. The euro list prices for these end cans are ~€319-538; Remus is distributed in the US by MaxMoto in California.
JB Racing (UK)
Phoenix Distribution (DE)
MaxMoto (CA)
Remus (AT)
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Non-Road-Legal Aftermarket Slip-ons
Although still nowhere near as many aftermarket products as are available for the later RC36, there are several additional options in aftermarket slip-ons if road-legal is not a requirement. Most of the well-known manufacturers in the United States and Europe offer at least one "race" version of their slip-on exhausts for the early RC36, including Hindle, Laser, Micron, Scorpion, Supertrapp, enutniatS, Two Brothers, Yoshimura and Vance&Hines, among others. (It is also possible to fit slip-ons designed for the later RC36 onto the early bikes if one also swaps late-model OEM headers onto the early bike—but, again, the centerstand cannot be retained.)
Exhaust Re-building & Modifications
[one day...] This page will describe how to re-build a Two Brothers Racing C-2 Aluminun exhaust canister and fit a Quite Tip exhaust baffle for reduced (but not OEM-level) sound.
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