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Discussion Starter #1
Any body know the best can and jet kit considerinf HP & tourqe not sound.
 

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Dirty Harry.... Moderator
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Tigger, I can't say what is the "best" combination, but I can say that I have installed the Yoshimura round race slip on, a dynojet jet kit and a K&N filter and am very happy with the results -- my ZR runs like a "scalded *** ape" and no problems yet (just over 2000 miles). Tom :D
 

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The Deer Slayer
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Hey Tom,

Runs like a "scalded *** ape," what is that exactly? Sounds like Gorillas in the steam bath. :rolleyes:
 

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Wheelie for Safety
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Hi Tigger,

The best can for torque is the stock can. The after-market race can actually reduces low end torque and doesn't add any power to the top end.

The only reason to buy a race can would be to make lots of noise and to reduce some power at the low end. Some claim it will also reduce vibration at 5,000 RPM, others say it doesn't.

One other thing, the race can will induce loud backfiring when you let off the gas. So you have to plug/modify the EGR emmissions. here is a link. http://www.zr-7.com/egr.htm

Still even with this information, some people will get a slip-on. Some who have tried the slip-on hated how loud it was when they rode their bike and ended up putting the stock can back on.

There is another option, that is to modify your stock can. It will make it a little noisier.

Regarding re-jetting the carbs. There is no free lunch. Yes you can gain about 1-3 HP (3 HP at 9,000 RPM), but you will loose gas mileage and have more carbon build up inside your engine.

If you have not re-adjusted your idle mixture screws, you should do that first. It will eliminate the off-idle hesitation.

Andy
 

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Dirty Harry.... Moderator
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Re: Hey Tom,

MedZR7Treker said:
Runs like a "scalded *** ape," what is that exactly? Sounds like Gorillas in the steam bath. :rolleyes:
I don't really know Tony, my Dad used to say that about my motocross bikes and any thing else that went fast. I always laughed when he said it, so I borrow his old expressions sometimes. He had a bunch of 'em. He had one that I didn't like to much because he said it all the time -- when I'd leave the house, and say "I'll be back later," he'd follow with "thanks for the warning." He was one crazy old man. Tom :D
 
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Discussion Starter #7
What about the Holeshot Can. They post an improvment with jet kit and can?
 

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Tom Droze had a good thread with dyno numbers before and after a jet kit and race can. see http://www.zr-7forums.com/showthread.php?s=&threadid=818

It doesn't make any difference what race can you get. They are all a straight shot through the canister. You can see right through them from end to end. The only differences are the sound tone, the appearance, the weight, and the cost. I have a Kerker, which are about the least expensive on the market, and I love it. Some have Yoshi's, Muzzy's, etc., which are about the most expensive, and they love them too.

I disagree with Andy (sorry dude) about the sound and the power. I think only one person, hmm, hmm, had a slip on and didn't like the sound. We won't mention any names.

And the jet kits are all about the same too. Different needles, some shims, and fiddling with some screws. No big deal. There are some good threads on how to do this too.

kelly
 

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The Commander
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Andy, you're out in left field dude. Kelly's right, I only remember one person who took their slip-on off because it was too loud for their tastes. The VAST majority of those of us with slip-ons are very happy with them. Please share the source of your information regarding how a slip-on reduces low end torque. It doesn't according to all of the dyno charts I've seen, including the holeshot one. But wait... there's more! ;) As far as reducing the stock bike's 4800-5200 rpm vibes, again the VAST majority of people with slip-ons who have reported vibes prior to the pipe have reported reduction or elimination of the vibes after the pipe. I can't recall a single person who had the vibes, got a pipe, and posted that the pipe did not improve the vibe situation.
 

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Wheelie for Safety
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Hi Jarel,

I appreciate your reply. I will be the first to admit that I have learned from you... so thanks.

First: if you look at the poll "How loud is perfect". You will see that 50% of the people thought the race can was not the best choice, they thought a little louder then stock would be best. I wonder what the other 275 people who joined this forum think. If you visit other forums out there, you will see that I'm not all alone in left field promoting the use of a stock can. Using loud cans makes the public (and your neighbors) very angry with motorcycle riders in general because of the noise pollution.

Second: the dyno charts do not show torque below 4,000 RPM. So it would be hard to measure. Look at most of the modern sportbikes and you will see they have a valve in the exhaust that almost completely closes (to create back pressure) at low RPMs. Why, to give more power/torque. So opening up the exhaust with a slip-on most likely reduces torque at low RPMs. Although I have no proof, so you are correct, I should not have said it like it was a fact.

Andy
 

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The Commander
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Hmmm.... I don't think so. Check out the Holeshot dyno run that I referenced, and it lists down to 2750 rpm, with the aftermarket pipe and jet kit higher in torque and HP at every rpm. The poll you mentioned also has no credibility since it included both people who have a slip-on and those who don't. I'd guess a lot of the voters in the poll have never heard the various slip-ons and have no basis for an opinion. Those of us who do have them are in a much better position to offer advice. Like I suggested previously, if you polled people who actually HAVE a slip-on, I believe the VAST majority will say they like it, based upon the posts I've seen on this board over the past two years. Also, I belive the Honda CBR and Yamaha R1 are the only two sportbikes that have the automatic exhaust restriction valve you mentioned to boost low-end torque, certianly not "most" modern sportbikes. Those are also MUCH higher compression engines that the ZR-7, so it's not a good comparison. I think you're on your own on this one. Particularly since tigger asked for the "best can and jet kit", I don't think he was looking for advice about why he should stick to the stock pipe.
 

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Wheelie for Safety
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Hi Jarel,

Suzuki also has an exhaust valve on their sportbikes. Maybe your correct, the engines on a sportbike maybe setup with cams that need the exhaust valve to gain power at low RPMs. Anyway, my main point to tigger was that the ZR does not gain power from a can. Only the jet kit adds power.

It is up to him to decide if he wants to add a can for the sake of being louder. Who knows, he may want a can, or maybe he will just go with a jet kit. All I wanted to do is share some of the knowledge we have learned on this forum.

Perhaps I am "on my own" on this one. :cool:

Andy
 

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Dirty Harry.... Moderator
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And I agree with Jarel on this point. And I wouldn't want Tigger to be dissuaded from installing an after market "slip on" or full system. The benefits are substantial in an aftermarket slip on. Loud is not the answer (i.e. Micron), performance is the goal. The gain may not be that "significant" but it is there. I have the Yoshimura round race slip on on my ZR, and I can say this much about it --- I don't want to put the stock can back on no matter how many holes I drill in that can -- it is not the same!! The jet kit also makes a big difference. So if you are really into some fast riding -- straights and twisties -- an aftermarket can will help. Let me add this: if you are an aggressive bike rider, the sound not only let's you hear your upshifts and downshifts, but instills confidence in what your'e doing. Otherwise, I'd trade my ZR for a Concours. Nice and quiet shaft drive. Tom :cool:
 

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Wheelie for Safety
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Hi Tom,

I have no problem hearing the engine with the stock can. So shifting is not a problem.

Here is Tom Droze's post regarding the aftermarket can:

"The jet kit did get rid of hesitation down low and the overall ridability is much improved--though I am still working on getting the choke to work right. Mark at Factory told me to expect a about a three horsepower increase with the jet kit. I was somewhat surprised when he told me that the increase in power from his testing came solely from the jet kit and not the slip-on muffler. I did remove the EGR valve and the fuel vapor recovery system.

I still think there is a horsepower or two still in there somewhere, I am just going to have to find it!"

Andy
 

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West Coast Moderator
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Face it men....we're all having the "wool pulled over our eyes"....all the race bikes that are running aftermarket cans are just doing it to make us think they're an improvement. It's just a wild conspiracy, so don't believe it. ;)
 

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Seems to me that Tom's quote (posted by Andy) shows the jet kit doing it all. But, Holeshot is saying with kit and can up to 7HP. Jarel, I think you posted that you have a Dynojet kit. If you haven't used that free dyno run coupon, why not use it to do a with and without aftermarket can dyno and post the results.

I am not going to say that an aftermarket can provides no performance increase, but on this bike with these carbs, it is very minimal. The carbs are the restrictive part of the fuel/exhaust system. The stock can is going to have no problems venting what the stock carbs can get into the engine, with 108's 110's or 112's.

When I talked to Dave Turner @ Muzzy he said that there really was no gain from their slip-on (maybe 1HP), maybe 2HP from a full system on the ZR. The max that they pulled out of it was 6HP and that was a full system WITH a jet size increase. His agreed that the carbs are too restrictive.

The bigger, true sport bikes running flatside carbs with accelerator pumps truly benefit from a slip-on because you can make significant jet changes/pump settings with these carbs that need the bigger/better/faster outflow.

I have a D&D exhaust on my bike right now. When I pull it out of storage in a few weeks I am going to put the stock can back on. Why? (1) I am tired of the noise, (2) the performance/driveability gains do not warrant the noise in my opinion.
 

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The Deer Slayer
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Hey Tom, my dad never said cool stuff like that, but he did have alot to say. like, " take all you want, but eat all you take, " and " elboes off the table." He also said things like, "Andy is tying to lull all of you into a hypnotic state. Listen to the sound of my voice. You are feeling very relaxed, very calm. Bring in down, waaaay down. Sleepy.......sleepy, your eyes are soooo heavy.....you just....want.....to.....sleep..................."

Now, when I count to three, you will all open yours eyes, very slowly. One...Two...Three....

Your after market pipe is bad. Take it off and mail it to Andy. He will be collecting them and .....re-using them for...... other purposes..... You do not go faster with that pipe on your bike. You are only louder...only louder. You will re-install your stock pipe. If you no longer have your stock pipe, you will order it from Andy. He has the stock pipe you need. Andy knows, listen to him. You can not go faster. You will only damage your engine.

Now on the count of three you will slowly awaken. You will do as you have been instructed, and remember nothing else.

One.....Two......... ........ Three
 

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Wheelie for Safety
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Andy knows, listen to him. You can not go faster. You will only damage your engine.
[/B]


Tony, you got it right except for one word... It should have been like this.

"Andy knows, listen to him. You can not go faster. You will only damage your hearing."

I love your sense of humor! :smilewink

Andy
 
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