Author Topic: What is the most valuable power boost? (Read 6077 times)

banditcilik · « **on:** March 24, 2006, 05:17:42 AM »

Hi I wonder what has the most bang for the buck in the term of engine mods.
- Replacing stock filter with open type such as K&N and rejet
- Replacing stock exhaust with free-flow type and rejet
- Replacing stock coil and plugwire with racing type
- Replacing camshaft
- Replacing pistons with hi-dome type
- Bore up job
- etc ?

Also are those listed above can be separately done without having other item influenced i.e. could we do a bore-up without replacing exhaust system?

chupacabra · « **Reply #1 on:** March 24, 2006, 07:14:23 AM »

Most bang for the buck, I would go with replacing stock exhaust with free-flow type and good jet kit and better flowing filter! Some jet kits come with good filters.
I always do engine mods in stages. First thing is to open up the air flow.

kedeg_97B12 · « **Reply #2 on:** March 24, 2006, 10:10:01 AM »

Quote from: "chupacabra"

Most bang for the buck, I would go with replacing stock exhaust with free-flow type and good jet kit and better flowing filter! Some jet kits come with good filters.
I always do engine mods in stages. First thing is to open up the air flow.

Word.

A good jet kit WITH needles or shims, a good aftermarket exhaust and mid pipe will add a good 15 hp. Also it will be under $500.

The next 15-30 hp get expensive. Big bore makes a great differance but not as much as originally opening the exhaust.

tacoman · « **Reply #3 on:** March 24, 2006, 02:15:46 PM »

What kind of budget do you have and how mechanical are you? The most bang for the buck as the others state is jetting and a new can. A kit like the Holeshot has the ignition advancer, i would take this over a KN filter. Lots of posts for and against the KN. Jetting is cheap and makes a huge difference. A good aftermarket silencer has 2 benefits, freer flowing for more power and a big weight loss over stock. Have fun!

banditcilik · « **Reply #4 on:** March 25, 2006, 04:54:01 AM »

Budget is off course tight. However actually I was thinking of putting exhaust mod lowest in the list. I really really hate loud noise. So I was also thinking bout changing to hi-voltage coil and better wire plug but a discussion with friend concluded that it is not going to give much gain.
Does it make sense to replace only the jets and filters but not the exhaust? I just love the stock sound.

chupacabra · « **Reply #5 on:** March 25, 2006, 07:12:15 AM »

I haven't seen or heard one but HoleShot has a 21" street can.
I bet you'd love it.

Red01 · « **Reply #6 on:** March 25, 2006, 12:31:17 PM »

Quote from: "banditcilik"

Budget is off course tight. However actually I was thinking of putting exhaust mod lowest in the list. I really really hate loud noise. So I was also thinking bout changing to hi-voltage coil and better wire plug but a discussion with friend concluded that it is not going to give much gain.
Does it make sense to replace only the jets and filters but not the exhaust? I just love the stock sound.

If you like the stock sound, just shim the needles, remove the EPA plugs from the pilot screws and set them to ~2.75. Do the poor man's ignition advancer as shown on Fast Larry's site and call it good. You can do this for a couple bucks in washers and a little time. (Figuring you have access to a drill and a few drill bits.)

The weakest points in the Bandit's stock state of tune are the lean factory carb settings and the restrictive exhaust. Curing these two issues will give you the most bang for the buck. Expect a 15-20 hosepower gain with a smoother power curve and no sacrifice of low or mid range power.

I don't think you'll see any apreciable gains in high output ignition on one of these motors until you're up into the higher levels of tune. If money is tight, this would probably be the last place I'd spend the money. Putting in new pistons or cams isn't exactly cheap either. If you like the power curve of the bike now, but wanted more across the board, higher comperssion pistons (stock or big bore) will give it to you. Hotter cams will give more power, too, but make the engine peakier and really work best with the higher compression slugs. These mods could be done with the stock exhaust, but you'd be holding it back with the restrictive exhaust. Any of these changes should have you checking out and adjusting your jetting.

rider123 · « **Reply #7 on:** March 25, 2006, 10:57:20 PM »

I concur with what RED01 says. I'm in the middle of fine tuning shimming my carbs and installed a Muzzy slip on system. After removing just the snorkle, shimming the carbs, installing the muzzy and adjusting the screws, my bike constantly wants to wheelie! I think I broke it!

Even when I just adjusted the super grim stock jetting by the mixture screws it improved the bike alot. I used 1 1mm (.040) shim under my needles and it's running a tad rich on the needle so I'm going to 1 .5mm (.020) shim tomorrow and see if that makes it better. Right now I'm compensating with the pilots for the rich mid-range so I have a bit of popping. I'm hoping dropping the needle then readjusting the pilots back up will make everything hunky dory. My bike ironically ran a little rich from the factory so I'm thinking I only need 1 shim.

You can get the shims you need from Radio Shack(part#?) or a hardware store. You need #4 washers. Be sure when you install them that the needles seat properly. Mark and measure the needle with the stock "donut" and then put a shim between circlip and donut and measure again. Make sure the needle is only lifting what you're shimming. If it lifts more than what you're shimming you need to file down the outer diameter of the shim untill it's the same size of smaller than the circlip.

Total costs:
Muzzy Slip on - $240
Shims: $1.99
Getting rid of grim stock jetting and insta-wheelies: priceless

The sound of the muzzy especially at lower RPM's is not that much louder than stock. In fact, at idle it's slighly quieter as it has a bigger hole to exhaust to. Don't feel you need to keep the horrid stock exhaust. It's heavy and very restrictive. Removing the exhaust and putting on the muzzy probably saved me 15-20 pounds. Trust us it's grim!! If you are concerned with noise than I suggest the Holeshot 21" can. However any at least 17" exhaust like mine and Other, Yoshimura RS-3, Zyclone, etc. Will not be that much louder than stock, it only really gets loud at full throttle acceleration where you probably aren't noticing anyway. Just driving normally around the city is only slightly louder but it's usually a deeper sound so it's hard to notice as much.

If you like you can PM me you're address and I'll send you the proper shims if you're worried about getting the wrong ones.

jeepskate99 · « **Reply #8 on:** March 26, 2006, 08:37:15 AM »

+1 for jetting and pipe. If you aren't in a huge hurry just look for deals. Nothing wrong with used stuff especially from these guys. I found a Yosh RS-3 slip-on with mid-pipe and an Ivans jet kit on here and they both came to less than one cheap Holeshot pipe. And I must thank Fritobandito and zoombic again for the parts. They were flawless!!! And that Yosh really sounds beautiful to me. (with the obligitory earplugs)

banditcilik · « **Reply #9 on:** March 26, 2006, 11:38:41 AM »

I must be born in other planet. Is the carb shimming same as placing small washer on the carb needle?

kedeg_97B12 · « **Reply #10 on:** March 26, 2006, 12:44:31 PM »

Quote from: "banditcilik"

I must be born in other planet. Is the carb shimming same as placing small washer on the carb needle?

Welcome to our planet. We are earthlings. Here we may call it shimming, raising or lowering the needle with a washer. That food over there is called corn or you may call it maize. Those are clouds and that is water.

Sorry I had to.

Bob Holland · « **Reply #11 on:** March 26, 2006, 02:22:49 PM »

Quote from: "banditcilik"

So I was also thinking bout changing to hi-voltage coil and better wire plug but a discussion with friend concluded that it is not going to give much gain.

Changing the coils and plug wires is probably the least effective mod. I have run stock and aftermarket coils and wires, and I have yet to see any gain by changing coils. Now if your stock coils and wires are bad, it would be cheaper to go with after market coils and wires than to buy stock ones.

tacoman · « **Reply #12 on:** March 27, 2006, 01:30:37 PM »

Have you priced some of the coils and wires out there? Big bucks, you can buy a top of the line exhaust for what these things run. I'm with the other post on the exhaust, you don't have to spend big bucks. Watch ebay, there's guys selling Supertrapps for under $100. You can adjust the sound with the discs, they're light, and look pretty good. They are a direct bolt on, no mods needed, so you can always put the stock exhaust back on.

CWO4GUNNER · « **Reply #13 on:** April 14, 2006, 11:12:43 PM »

rider123 · « **Reply #14 on:** April 17, 2006, 05:26:54 PM »

I could sell you my Muzzy Slip on for $100000 then you can say my Slip on is the most "valuable" power boost ever!!