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Cat-less Exhaust. Why?


Guest thedrunknmastr

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Guest thedrunknmastr

Seen some posts regarding people installing cat-less exhausts. What is the advantage of doing such a thing? Noticable performance difference? I'm always looking for something to tinker on my bike and was trying to figure out why and what would be diff, knowing I have LV cans installed.

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I think the performance improvement is mininal at best, I don't know for sure though. Others here may have concrete evidence.

It will be lighter though! (Main reason I'd like to switch. Cost is pretty steep though.)

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Catless exhaust has two main advantages: 1. Horsepower, though it's not a huge gain, it's probably the only real way to add horsepower to a 2000+ VFR short of a Torocharger or porting and polishing the heads, etc.

This is debatable, but I think people have gained from 0-4 horsepower. The headers for 1998 and 1999 models were catless and 2 mm wider, which means they should theoretically flow better, possibly at a loss of torque, however. If you want a bike that's faster, changing your sprockets would be more bang for your buck.

2. Sound. An unrestricted exhaust really brings out that V4 rumble.

And yes, they weigh less, but I'm not sure how much, a pound or two?

Why do people do it? Like you, we like to tinker with our bikes and get every last pony out of them! You will need a Power Commander to add more fuel if you do this.

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Not being a master tuner by any stretch...

When I looked into it a few years back (the motard SS header) the very helpful Chicago disp- rep. confideded that for the bucks spent, the flow was not any better than oem (for the motards).(the old group buy thread is in search somewhere)

I am happy with the current Staintune sound w/oem headers, PCIII set-up and didn't feel the need for the a 5lbs weight loss. We not talking R/R bikes here. So the $6hundy savings went straight to the suspension up-ticks and would go that way every time.

I mean if you've got all those other high end mods already covered, suspension, brakes, lighter wheels, your favorite stickers, than have at it, I guess.

Kinda sounds like the the best gains for such systems apply to the 4th and older Gens- a Hot Rod Tuners Delight! my .02's

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Not being a master tuner by any stretch...

When I looked into it a few years back (the motard SS header) the very helpful Chicago disp- rep. confideded that for the bucks spent, the flow was not any better than oem (for the motards).(the old group buy thread is in search somewhere)

I am happy with the current Staintune sound w/oem headers, PCIII set-up and didn't feel the need for the a 5lbs weight loss. We not talking R/R bikes here. So the $6hundy savings went straight to the suspension up-ticks and would go that way every time.

I mean if you've got all those other high end mods already covered, suspension, brakes, lighter wheels, your favorite stickers, than have at it, I guess.

Kinda sounds like the the best gains for such systems apply to the 4th and older Gens- a Hot Rod Tuners Delight! my .02's

Is it really a 5 lbs weight loss?

And the 4th and older gens all came with Catless headers stock.

If you do want them, you have a few options: Used 98 or 99 headers, Delkevic (cheap, but potential fitment issues), Motad (expensive, with slightly less potential fitment issues). As far as used goes, Veefer Madness is selling a set for cheap over in the classifieds. For $210 you can try it, and if you don't like it, turn around and sell them for $200 or a little less. Though you'll be buying new gaskets each time, which adds up.

I'm tempted to buy a set of Delkevic headers and add another thorough write up! There is one on here saying that the fitment is awful, but I had installed 99 headers on my old 6th gen and would be able to compare to that...

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Is it really a 5 lbs weight loss?

And the 4th and older gens all came with Catless headers stock.

Don't know about 5lbs. ( the thing looks like balast down there and if you've ever lifted a cat can, you know)

On the older cat-free Gens, I was meaning that with a proposed air flow increases, Rodders would have an easier time playing with Air, Fuel, whatever combos.

When I first looked into it, I was hoping that the SS would be polished as shown but later learned that they were not...

gallery_13109_4094_247818.jpg

D8HR-Motad.jpg

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I sold my catless headers. The reason? The 4th gens are steel; 6th gens are stainless. Ergo, GUT THE CAT! :blink:

Don't know about weight, power loss/gain(haven't done a dyno), maybe a little more rumble but, I gutted the Lasers too! :lurk: I'ts really not that hard if I can do it and just like gold jewelry, people are paying $$ for Platinum too! :blush:

Some pics: Thanks Trace as well for some..... :goofy:

DSCF0402.jpg

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DSCF0426.jpg

CatShieldOff.jpg

Cat-Empty.jpg

DSCF1769.jpg

DSCF1771.jpg

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I sold my catless headers. The reason? The 4th gens are steel; 6th gens are stainless. Ergo, GUT THE CAT! :blink:

Don't know about weight, power loss/gain(haven't done a dyno), maybe a little more rumble but, I gutted the Lasers too! :blush: I'ts really not that hard if I can do it and just like gold jewelry, people are paying $$ for Platinum too! :lurk:

Some pics: Thanks Trace as well for some..... :blush:

personally i dont know if my motads gained me any power, but there is a definite weight savings and the sound is awesome. there is this resonance that occurs as you pass through the 4-5 grand area that sound amazing just like a mini v8! :goofy:

oh and those coated headers look cool too, like they belong on some kinda heavy duty catapillar equipment!

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Is it really a 5 lbs weight loss?

And the 4th and older gens all came with Catless headers stock.

If you do want them, you have a few options: Used 98 or 99 headers, Delkevic (cheap, but potential fitment issues), Motad (expensive, with slightly less potential fitment issues). As far as used goes, Veefer Madness is selling a set for cheap over in the classifieds. For $210 you can try it, and if you don't like it, turn around and sell them for $200 or a little less. Though you'll be buying new gaskets each time, which adds up.

I'm tempted to buy a set of Delkevic headers and add another thorough write up! There is one on here saying that the fitment is awful, but I had installed 99 headers on my old 6th gen and would be able to compare to that...

I don't know about the weight loss, but I do know that the the fitment issues are related to the piped not being for a Vtec bike.

The last one I saw on the delkevic's the pipes were for a 99 and the guy was fitting them to a vtec. He outright admitted that was where he had the issues.

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I don't know about the weight loss, but I do know that the the fitment issues are related to the piped not being for a Vtec bike.

The last one I saw on the delkevic's the pipes were for a 99 and the guy was fitting them to a vtec. He outright admitted that was where he had the issues.

Isn't the header fitment the exact same for the 5th and 6th gens?

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Is it really a 5 lbs weight loss?

And the 4th and older gens all came with Catless headers stock.

If you do want them, you have a few options: Used 98 or 99 headers, Delkevic (cheap, but potential fitment issues), Motad (expensive, with slightly less potential fitment issues). As far as used goes, Veefer Madness is selling a set for cheap over in the classifieds. For $210 you can try it, and if you don't like it, turn around and sell them for $200 or a little less. Though you'll be buying new gaskets each time, which adds up.

I'm tempted to buy a set of Delkevic headers and add another thorough write up! There is one on here saying that the fitment is awful, but I had installed 99 headers on my old 6th gen and would be able to compare to that...

I don't know about the weight loss, but I do know that the the fitment issues are related to the piped not being for a Vtec bike.

The last one I saw on the delkevic's the pipes were for a 99 and the guy was fitting them to a vtec. He outright admitted that was where he had the issues.

Isn't the header fitment the exact same for the 5th and 6th gens?

Yes, the only difference being that one crosses the front tubes and that there is no center stand tab. That's basically it.

I have 98 headers on my 04 now, bolted right up!!! :pissed:

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As the discoverer of this mod, I thought the louder exhaust note and quicker rev'ing engine were positive signs of better flow. How much? I never found out as there aren't any dyno's near me. But IIRC, one 6gen owner put his on the dyno and with a PC3 tuned map got 111hp or thereabouts. Anyone remember this or who it was?

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To answer the OP's question, the cat causes some restriction in the exhaust flow. By removing it the engine can breathe better and in conjunction with a filter, PC III or V, and good map, produce more power. I put on a set of the Delkevic headers and there is a noticeable improvement. You lose a small amount of torque on the bottom end but the motor winds up quicker and has more pull on the top end.

As far as fitting the Delkevic headers - I helped a friend put a set of 98 headers on a 04 (same year as mine). They bolted right on with absolutely no problem so it was not unreasonable to expect the Delkevics to do the same. I did have some trouble getting them to fit but, I've also head a couple of people having the same trouble with Motads. They only problem I still have with mine is the right rear down pipe is not bent quite right. It works fine but it touches the seat pan and doesn't seat all the way down into the header (it doesn't leak). They have a one year warranty and I'm still trying to decide if it's worth the trouble to replace it.

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gallery_13109_4094_247818.jpg

D8HR-Motad.jpg

You would think that shiny things would automatically produce more HP.

Boy, there sure are a lot more welded joints in those headers than in OEM Honda 98/99 headers. All of those pipe in pipe connections and welding do add on the lbs.

I have 98 headers on mine. I'm in the process of ceramic coating them now. And being the overly anal engineer that I am, I even brazed a tab onto mine so it still bolts up to the underside of the engine like the catalytic headers do.

I know, I know, I know. There are no records of headers falling off a 5th Gen VFR. It just made me happy to have a little extra insurance and it makes installation a lot easier. Kinda like having an extra hand.

I have been diagnosed by doctors with OOD - Obsessive Overkill Disorder. I'm an engineer! That's why I'm on my third year of remodeling our home.

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As the discoverer of this mod, I thought the louder exhaust note and quicker rev'ing engine were positive signs of better flow. How much? I never found out as there aren't any dyno's near me. But IIRC, one 6gen owner put his on the dyno and with a PC3 tuned map got 111hp or thereabouts. Anyone remember this or who it was?

Pretty sure that was tinyminds, but dyno's and tuners can very wildly IMO. He got 110 hp. :pissed:

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As the discoverer of this mod, I thought the louder exhaust note and quicker rev'ing engine were positive signs of better flow. How much? I never found out as there aren't any dyno's near me. But IIRC, one 6gen owner put his on the dyno and with a PC3 tuned map got 111hp or thereabouts. Anyone remember this or who it was?

Pretty sure that was tinyminds, but dyno's and tuners can very wildly IMO. He got 110 hp. :pissed:

But more importantly, Jason did a dyno run before and got 99hp, then did a run after install and got that 110!!

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As the discoverer of this mod, I thought the louder exhaust note and quicker rev'ing engine were positive signs of better flow. How much? I never found out as there aren't any dyno's near me. But IIRC, one 6gen owner put his on the dyno and with a PC3 tuned map got 111hp or thereabouts. Anyone remember this or who it was?

Pretty sure that was tinyminds, but dyno's and tuners can very wildly IMO. He got 110 hp. :blush:

But more importantly, Jason did a dyno run before and got 99hp, then did a run after install and got that 110!!

So it was an 11hp gain as I remembered. That's why I was thinking 111hp. As 100hp is the typical stock hp thrown about.

NOTE: this is with aftermarket mufflers not stock (obviously).

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As the discoverer of this mod, I thought the louder exhaust note and quicker rev'ing engine were positive signs of better flow. How much? I never found out as there aren't any dyno's near me. But IIRC, one 6gen owner put his on the dyno and with a PC3 tuned map got 111hp or thereabouts. Anyone remember this or who it was?

Pretty sure that was tinyminds, but dyno's and tuners can very wildly IMO. He got 110 hp. :blush:

But more importantly, Jason did a dyno run before and got 99hp, then did a run after install and got that 110!!

So it was an 11hp gain as I remembered. That's why I was thinking 111hp. As 100hp is the typical stock hp thrown about.

NOTE: this is with aftermarket mufflers not stock (obviously).

Yes, he had the Best numbers I've seen, but many others for whatever reason had little gains in pure numbers but all said the engine puller harder and freer.

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I don't know about the weight loss, but I do know that the the fitment issues are related to the piped not being for a Vtec bike.

The last one I saw on the delkevic's the pipes were for a 99 and the guy was fitting them to a vtec. He outright admitted that was where he had the issues.

Isn't the header fitment the exact same for the 5th and 6th gens?

No, Honda doesn't list anything in the fiche about the headers fitting multiple machines (like they do for other bits) and the 6th gen is a totally different part number (not just a finish code).

also look at the differences in the headers, the six gens cross the front pipes and the rear pipes where as the motads and delkevic's don't

I'd have to see a picture of the 5th gen cat headers to see what they do, but I don't remember the fronts crossing.

That means that exhaust pulse scavenging is quite different in the 6th generations pipes as compared to the delkevic's and the motads.

Is it better or worse I don't know I just can see that it is going to be different.

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I think he has his map from the dyno tune available here on the site, I believe it has the mods listed.

Yep, it's in our download area and just been downloaded into my vtec track pig today! :blush:

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Seen some posts regarding people installing cat-less exhausts. What is the advantage of doing such a thing? Noticable performance difference? I'm always looking for something to tinker on my bike and was trying to figure out why and what would be diff, knowing I have LV cans installed.

There's a weight and power difference but it cost a lot. I'm running Motad head pipes, jet hot coated. The Motad's are much larger than the stock Honda pipes; I think the Honda pipe would fit inside the Motad. But beware nothing fits as well the stock Honda pipes. I had my bike custom tuned by a friend that really know his business (High Performance Cycles, Lake City Fl.) on the stock head pipes and my Erion back half and of course a PCIII and a KN&N air filter (snorkel removed), 96 hp and 54 fp of torque, ok but not great. Same bike with the Motad and it hit 112 a couple times but we where working on a balance of horsepower and torque, the final # was 104 and 57. So up 8 hp and 3fp of torque but the cost is a lot full exhaust change, PCIII and tuning = $$$$$.

There's also a weight difference, I put everything on a scale and the stock Honda head pipes 14 pounds, Motad 10 pounds. Stock Honda muffler back half 19.2 pounds and just incase your wondering the center stand and it's hardware 4 pounds. Yes I'm a little OCD.

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This is really approaching a point where I have to make a decision as my 5th gen pipes are reaching the critical point.

I highly doubt that they can survive another winter of commuting on the salted roads of the area.

The fact that Honda screwed up and used mild steel instead of SS on bikes tells me two things.

1. Honda expected every owner to replace his headers with something aftermarket, and when that did not happen, they had to change the 6ht gens to stainless.

2. Honda expected a lot of issues and failures with the cats and wanted to keep their replacement costs down. Now that would fall in line with them expecting the US to start actually testing the functionality of the Cat like they do with cars.

But now at this point, I either need to plan on pulling my pipes, having a friend patch them and then powder coat them.

or buying either the motad's or the delkevic's.

I keep pestering Toro to crank up some TI headers and tucked in high pipe, but it hasn't happened yet.

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