big gun Eco exhaust
1 - 16 of 16 Posts
On a stock motor and bike no, but you'll see no more power than stock exhaust. Possibly less power... a slip on is a frivolous addon expense in many/most cases. Is yours rotted out or broken or something? You'll need that $220 elsewhere to maintain/fix your bike real soon... Have fun!
Joined
·
7,087 Posts
Yes you ALWAYS need a tuner when you add an exhaust or any other power mods to an EFI machine, they are all tuned on the lean side to start with to meet emissions and adding an exhaust only makes it worse. Throw a tuner on it even a cheap one, it will save your engine in the long run and keep it running much cooler.
Some guys say the exhaust isn’t worth the money but your looking at a 10-15% increase in RWHP typically, so I would say that’s worth it !
Sent from my iPhone using Tapatalk
Some guys say the exhaust isn’t worth the money but your looking at a 10-15% increase in RWHP typically, so I would say that’s worth it !
Sent from my iPhone using Tapatalk
Joined
·
5,072 Posts
Your in CanAm mode Mac, 10-15% more power on a Rene is worth it, on a Honda.... It’s negligible.
A cam with tuner would be the ideal way forward IMO.
Joined
·
7,087 Posts
10-15% more power is a good improvement no matter what your talking about. Look at the first and 2nd gen 300’s there is only about 9% power difference there.
Sent from my iPhone using Tapatalk
Joined
·
7,087 Posts
Exhaust, filter, retune is always the first 3 mods. 475cc top end or 455cc high comp piston are options but you have to go into the motor, not really bolt ons, nobody sells an off the shelf cam. PCV will also control timing, so there is that as well.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
Joined
·
7,087 Posts
Allowing an engine to breathe better will ALWAYS increase performance. It doesn't matter if it's been bored or stroked or whatever. Of course if you took a 420cc stock engine and added an exhaust and high flow filter to it, it's not going to respond the same as a 420 engine that has been punched out to say, 550cc. But the fact remains that there is a 10-15% power increase when adding an aftermarket pipe and tuner to a STOCK engine. No other mods. Once you start doing big bore kits and stroker cranks you'll find that there is airflow restrictions elsewhere, and you'll see guys doing head porting, bigger valves, larger throttle bodies, custom airboxes...stuff that really wouldn't be needed on a stock engine with a few bolt ons.
As far as cams go like I said, there isn't much for the 420/500. Nobody has one off the shelf, Griffin Performance does if you don't mind buying parts from a convicted pedophile.....I think Hormell's may have one but I have no idea whether you have to buy an entire package from them to get it or what's the case, if the price on that is anything like their GR prices it's probably ridiculous too. Also if your going to replace the cam you might as well do at least a 500 top end at the same time, because these pushrod engines need to have the head removed to change the cam. So suddenly you go from buying a pipe and tuner for $400~ to buying an entire assortment of performance parts for $1500+ and add to that a TON of extra labour, not even going to get into the cost of a port and polish job or any other custom stuff.
Yes no replacement for displacement, but there is plenty of cases where guys can make MORE power with a stock bore engine than other guys will with a big bore or stroker just because there is more to it than just slapping a bigger piston in it and calling it a day.
As far as cams go like I said, there isn't much for the 420/500. Nobody has one off the shelf, Griffin Performance does if you don't mind buying parts from a convicted pedophile.....I think Hormell's may have one but I have no idea whether you have to buy an entire package from them to get it or what's the case, if the price on that is anything like their GR prices it's probably ridiculous too. Also if your going to replace the cam you might as well do at least a 500 top end at the same time, because these pushrod engines need to have the head removed to change the cam. So suddenly you go from buying a pipe and tuner for $400~ to buying an entire assortment of performance parts for $1500+ and add to that a TON of extra labour, not even going to get into the cost of a port and polish job or any other custom stuff.
Yes no replacement for displacement, but there is plenty of cases where guys can make MORE power with a stock bore engine than other guys will with a big bore or stroker just because there is more to it than just slapping a bigger piston in it and calling it a day.
Joined
·
5,072 Posts
You’ll get away with a back box/muffler for sound, to alter the airflow I assume you mean induction, to do so you’ll still need a tuner. More air requires more fuel.
The basic idea of an exhaust is to create negative back pressure, IMO you’ll not create enough back pressure with a tuner to need to replace or modify your stock exhaust. I’m only giving my opinion of course, you do what you feel is necessary and what makes you happy
A claim of a 10-15% RWHP increase from only a slip-on and tuner is misleading. Any observed multiple percentage point power increase is a result of the tuner, not the slip-on. The exhaust is tuned & matched to the motor by two parameters: Header pipe diameter and header pipe length. Implying that the stock slip-on muffler destroys an otherwise decent exhaust tune match (a choke killing off double digit percentages HP?) on a stock motor is a stretch.
Little improvements can be made to a stock motor to optimize torque output & throttle response under the rev limiter, but the REV limiter built into the ECM prevents anyone from observing multiple percentage points of observed horsepower on all stock Honda ATV motors.
Little improvements can be made to a stock motor to optimize torque output & throttle response under the rev limiter, but the REV limiter built into the ECM prevents anyone from observing multiple percentage points of observed horsepower on all stock Honda ATV motors.
^^^^THIS!^^^^
Raising the valve curtains and optimizing valve event timing by putting in a custom ground camshaft is the single most cost effective mod you can make for a bone stock motor. You can leave the stock exhaust alone on most motors too, and still get a considerable percentage increase in torque and tractible power below the rev limiter.
Why the camshaft? Because the camshaft controls the Dynamic compression ratio, increases Volumetric efficiency and greatly improves brake-specific fuel consumption (HP per pound of fuel consumed) which is a key indicator of overall engine fuel conversion-to-power efficiency.
Generated Cylinder pressures are what creates torque and power under the limiter. I'm talking about acceleration and power you can feel in the seat of your pants and actually put on the ground to do work. Way more bang for the buck than any other mod if done right!
The exhaust system is optimized last by the designer as Sam noted, because its job is to carry the volume of oxidized gases away to meet the demands of the gas exchange process defined by the physical constraints, the type of fuel, loads and RPMs of the motor. It is critical that the exhaust is designed well on a heavily modified motor.
Save your money... you'll need it soon for other routine repairs & maintenance on your Rancher. Honda don't make 'em like they used to...
1 - 16 of 16 Posts
