TOPIC:

Some things are best-resolved by trial and error.

1 or 2 hp might be closer (only guessing of course) but even then it would be worth that to me....... you make a good point too flovanus.......... a few of my friends always thought I was wasting my time removing weight..... only 1 and a 1/4 lbs to drill the front disc etc but when you added that to the turn signals, kicker, header, a little drilling, air box vs pods, smooth bores 2 and 1/2 lbs over stock carbs, a diet (never was good at that) running 1 gal of gas instead of 3 etc it equals 3-4 or more bike lengths (which they found out).

It's all relative. 5 hp for most our
bikes depending on the engine is in the neighborhood of 5% gain which ain't too shabby for less than $100 if you factor in any extras parts you need for tuning.

I saw a show on velocity that involved an original Fiat 500. The mechanic was all up about tricking the out engine (12 hp iirc) and spending more than half the budget doing it for a net gain of 6ish hp. The rest of the show had the boss whining about how they'd spent so much money only to get 6, maybe 8 hp I can't quite remember power gain. I kept yelling at the TV "Dude! That's a 50% power gain!" The Abarth "only" got like 30 hp or less back then.

I'm not going to rush this mod, I'm probably going to wait until the end of season since its running well enough. I'll do it in conjunction with my muzzy muffler install, etc. Besides, I have a shaftie to get running and a SAAB to finish up.

JaFlo wrote: I totaly agree that there are better "bang for the buck modifications", but the original question in this thread was essentially "How can I get more performance from a stock air box?", not "How should I spend my money?".

I believe the best way to get more performance from a stock air box is to do a full, proper tune-up of the engine to ensure it is running up to the original specs. Many folks overlook this obvious step when searching for more power. If a full tune-up is performed and the bike is producing approximately the same power as when it was new I suspect that most folks would be pretty impressed with the stock setup. If that does not provide enough ooomph at least it sets a baseline that may be used to measure the affects of any modifications.

Right out of the box the 1982 GPZ750 produced 78 hp, would run the 1/4 mile in just over 12 seconds, and had a top speed of 135 mph. That's a pretty quick bike for 1982, and 34 years later it is still plenty of performance for the street. Will it outrun a 2016 sport bike? No, but the amount of money involved in making that possible is greater than the amount of money required to buy the 2016 sport bike. So if that is one's objective perhaps other options should be considered. Ed

In my case I'm using 33 mm carbs in a box designed for 28's. If I can get more air flow without the drawbacks of using pods, I will give it a try. Nothing wrong in having something good and making it better.
Steve

Very true, Ed. I would assume that anyone looking for more power has already taken care of any maintenance and the engine is running strong. There would be no point otherwise.

Personally, I own a 2016 Ducati in addition to my KZ750. I don't expect the Kz to ever perform at the Ducati's level. That being said, it won't stop me from extracting more performance from the Kz in all categories. Why? Because it's just what I like to do. A good day wrenching is just as enjoyable as a good day riding. There is something euphoric about increasing the level of performance of anything. Some people just don't get that because they're not into it, and that's ok.

Shit, we're just hot rodding. MOST of us, like modern hot rodders (or tuners, builders, etc.) are doing more show than go. We're happy to have something that runs and looks better than when we got it. If performance increases at the same time, especially over stock, that's gravy. Usually it's only in one or two categories and not overall. At least we haven't given then up for scrap. We all need some kind of hobby.

KZB2 650 wrote: 1 or 2 hp might be closer (only guessing of course) but even then it would be worth that to me....... you make a good point too flovanus.......... a few of my friends always thought I was wasting my time removing weight..... only 1 and a 1/4 lbs to drill the front disc etc but when you added that to the turn signals, kicker, header, a little drilling, air box vs pods, smooth bores 2 and 1/2 lbs over stock carbs, a diet (never was good at that) running 1 gal of gas instead of 3 etc it equals 3-4 or more bike lengths (which they found out).

All I'm saying is that a light fork brake, ditch the heavy bars, modern sticky compound tires, proper gearing for the application a good single disc setup ( big rotor and ex250 caliper) are going to be a lot more noticeable that fiddling with carbs first.

Take a car with a 305 chevy engine and 2.54 rear gears. If we dump a holley 750 carb on it, it's a turd with a big flashy carb on it. Drop some 3.73 gears in it instead and a 350, you're going to be a lot better off.

GPzMOD750 wrote: Shit, we're just hot rodding. MOST of us, like modern hot rodders (or tuners, builders, etc.) are doing more show than go. We're happy to have something that runs and looks better than when we got it. If performance increases at the same time, especially over stock, that's gravy. Usually it's only in one or two categories and not overall. At least we haven't given then up for scrap. We all need some kind of hobby.

And most HP gains are made at the upper end of the power band which sacrifices low end grunt, a 650 or 750 doesn't have the greatest amount of torque, most kzs are peaky little motors, great for passing on the highway or short bursts down the dragstrip, not a lot to gain over a stock bore stock tune with stock carbs, guaranteed you will make better more noticeable gains with gears, tires, shocks and brakes than dealing with carbs, detonation and pinging. How many members have we seen come in asking about carb tube and end up turning into a never ending saga? Anytime I see a couple hundred bucks being tossed at a stock engine for a minor gain it gets amusing. The engine power of the kz line isn't dramatically out of line with more contemporary bikes, BUT the things I say are a much better focus are much more outdated.

swest wrote: $10 for 5 HP is a good deal to me. Not a lot of useable room on my box. I might be able to use 4.
Steve

Steve, do you know where that 5 hp, for poking holes in the air box, came from?
I'd like to see some proof of that!!
LOL!
That would be a home run with basses loaded in the real world of bolt on HP tweaks!!

I was being facetious.
Steve

All I am hoping for is a little better performance at WOT. There may be little to gain with a stock configuration.
Steve