What power gains with 4 into 1?

Hi, '83 KZ1100 Spectre, 100 hp stock I believe. Was looking at buying a Delkevic 4 into 1 stainless exhaust system for it. After jetting, what sort of power gains could I expect, otherwise stock motor. Also, am running 125 main jets on the stock BS34 carbs and these seem about right, What would be the recommended jet with the new exhaust? Thanks.

A header, a set of real K&N pod filters, and a Dynojet jet kit will net you something like 5-7% (maybe). Depends on how good the header is. The chart below was made with data from an article Joe Minton did back in the day.

Another Joe Minton test... (BTW, the title should say GS1100...)

I don't think anybody here has put a Delkevic equipped bike on a dyno. A well designed system might net you 5 or so hp up top without sacrificing midrange. A poorly designed one can cost power in the mid range, or even all over. With a stock engine, the biggest gain is likely to be weight loss.

Dang Nessism, that was quick!

No eBay APP ID and/or Cert ID defined in Kunena configurationThe header I was looking at is this
Pretty good value I think. So around 5 HP maybe. I might swap the collector out for a real race type one, guessing the one on that is an open type. One other question, how loud would that pipe be? The stock Kawasaki exhaust is VERY quiet, I do like that for stealth, but would rather be heard just a little for safety.

They come with a pretty loud baffle.

But if you think someone in a car, radio on windows up and heat/air blowing will hear you approach, you're a little off on your thinking, I ONLY hear bikes when I'm driving when they go flying by, or when they get right next to you (travelling in what is specifically labelled a "no zone" in driver's ed classes, your blindspot) I've never bought into the 'loud for safety" line

In fact I just read this thread kzrider.com/forum/13-bike-related/590854...4into-1?limitstart=0 the other day, the posts by bountyHunter are quite good

Hmm. My XV750 has a cafe type reverse cone muffler with a 1.75" core and not a lot of room for packing so I have to redo it maybe twice a season. I like the sound, but a little quieter wound be ok, when it's freshly packed its nice. It has one of the coolest exhaust notes I have ever heard. An inline four isn't that nice sounding I think, a bit buzzy, so quieter is nicer. I don't consider ALL drivers in cars would hear you, but if 50% of them do, well that's 50% more that took the time to look in their mirrors maybe.

Doppler effect limits any safety advantage of loud pipes. The sound us all behind you. Besides no pipe is louder than the wind decibels. Wear plugs if you like your hearing. I will say the Delkevic pipe with the baffle was quiet at low speeds but still had a bark up high. The upswept exhaust made it seem louder to me. But having it rest ridden by a few folks it's really not a loud pipe. R

floivanus wrote: They come with a pretty loud baffle.

But if you think someone in a car, radio on windows up and heat/air blowing will hear you approach, you're a little off on your thinking, I ONLY hear bikes when I'm driving when they go flying by, or when they get right next to you

That's because the sound pressure wave is coming off the BACK, not the front. :laugh:

In my life, I have been astonished at how many people missed that point.....

Exhaust only... Don't expect much in a way that you would truly notice.....

Case in point, street racer Toyota, Nissan etc... with Cherry bomb exhaust... Eeeewww, sounds bad ass but still a dog turd in acceleration, torque, power.....

Now throw a set of mid to whacked performance cams in their, ported head and some racing carbs (BS- 34's :whistle:) along with that 4-1 exhaust and you'll definitely feel the difference....

Hell if nothing else, some CR's 29/31 or Mukini's 34's alone with a good exhaust will approx. get you 5 - 10% increase.

Just sayin.....

Old Man Rock wrote: Case in point, street racer Toyota, Nissan etc... with Cherry bomb exhaust... Eeeewww, sounds bad ass but still a dog turd in acceleration, torque, power..... .

Amen! Some folks believe dB = hp, but they are only fooling themselves. Ed