I have a 93 gs.  Just installed drag bars.  Planning on doing the intake/exhaust but need to research more on rejetting.  What other mods do you recommend?  I really want to change out the front and rear turn signals because the stock ones are pretty ugly, just can't decide on which aftermarket ones I want.  Also was thinking of changing the seat and rear fender.  What rear ends would be an easy swap without subframe modification? 

the 3 best performance mods for cheap are:
1: 15t front sprocket cost $15-20 takes 30min or so to install
2: +5* timing advance cost is free if you have a drill and takes less than an hour.
3: adjust mix screws cost is free if you have a drill but it takes a few hours

The sprocket wont add power but it will noticeably improve acceleration and slightly increase top speed.

The timing will add 1whp and make low rpms smoother

adjusting the mix screws will add a little low end power, sharpen throttle response, smooth out low rpms, and decrease warm up time.

how will the sprocket improve accel AND improve top speed? i though it was one or the other

I'd recommend you strip the signals, lights, and mirrors off and take it to the track...

Seriously though, the first mods I'd do are springs, emulators, brace, and oil at the front, and a Katana 600 shock at the back. Install Stainless Steel brake lines and stintered pads up front. Bleed the old brake fluid out, and install super high temperature fluid. Bleed the rear, and consider replacing the line.

If emulators are a bit expensive for your taste, I'd still recommend the springs and oil.

Quote from: wakdady on May 26, 2010, 01:41:51 AM
how will the sprocket improve accel AND improve top speed? i though it was one or the other

Most(well really ALL) bikes are overgeared. If you hopped on a stock GS500 and tried to go as fast as you could you'd eventually hit a point in 6th gear when the wind was just stronger than the GS500 could handle. The bike would hit it's top speed before you actually hit the redline in 6th gear, so basically you've got wasted RPMs just hanging out. Technically the GS would have the ability to spin the rear wheel at around 125mph or so, but when you actually put it on the road and hit it with 100+ mph winds, it can only push it's way to 110-115mph. The reason they do this is to lower your rpms at cruising speed in 6th gear to make it more comfortable.

If you lower the gearing slightly, so instead of being able to spin the rear wheel at 125mph, it will now only spin the rear wheel to 120mph, but since you've lowered the gearing and 6th gear is a little stronger now, you can actually hit the redline, meaning your bike will actually do 120mph. So even though you lowered the mathmatic top gear from 125-120, you've increased your real world top speed from 110-115, to 120.

Make sense? Like I said the only downside is that your cruising rpms on the highway are now going to be about 1k rpm higher.

nhanxsolo: If you search for the words "tail" and "swap" under my name, I compiled a list of all the random build threads with tail swaps that i could find. The most common or yamaha R6 tails, first generation, followed by Ducati monster tails, first gen R1 tails, there's a Buell x1 tail, and a couple others. The only downside is that none of them fit perfectly with the normal subframe. The R6 and R1 tails can be made to fit the stock subframe, but on a bike that's as clean as yours is, you're never going to get as nice of a finish as what your bike has. I personally would love to put a Buell S1 tail on my bike, but it's technically my wife's, and I think it's an acquired taste and we'll probably end up selling this bike at some point, so I'll leave it with the tail I have on it now. I also think one of the 04-05 gsxr tails would look pretty alright on it, assuming you could fit it at the right angle. Someone was selling a tail, cowl, and taillight on craigslist for $50, which I kinda regret not picking up, but again, I think my wife likes the tail that's on it now, and I don't know if it would've fit as the subframe is now.

Quote from: black and silver twin on May 26, 2010, 12:34:19 AM
the 3 best performance mods for cheap are:
1: 15t front sprocket cost $15-20 takes 30min or so to install
2: +5* timing advance cost is free if you have a drill and takes less than an hour.
3: adjust mix screws cost is free if you have a drill but it takes a few hours

The sprocket wont add power but it will noticeably improve acceleration and slightly increase top speed.

The timing will add 1whp and make low rpms smoother

adjusting the mix screws will add a little low end power, sharpen throttle response, smooth out low rpms, and decrease warm up time.

Would any 15t sprocket work? Also how does the other two drill mods work? is there a write up on it?

Quote from: burning1 on May 26, 2010, 02:14:01 AM
I'd recommend you strip the signals, lights, and mirrors off and take it to the track...

Seriously though, the first mods I'd do are springs, emulators, brace, and oil at the front, and a Katana 600 shock at the back. Install Stainless Steel brake lines and stintered pads up front. Bleed the old brake fluid out, and install super high temperature fluid. Bleed the rear, and consider replacing the line.

If emulators are a bit expensive for your taste, I'd still recommend the springs and oil.

The PO just replaced the front fork springs, pretty sure they're stock.  What brand of fork braces do you recommend and do you really think they're that important? when you say oil at the front do you mean just in the forks?  and would any Kat 600 shock work in the rear or only certain gens?

Also how much does cartridge emulators usually run?

Quote from: tt_four on May 26, 2010, 05:35:43 AM

Quote from: wakdady on May 26, 2010, 01:41:51 AM

nhanxsolo: If you search for the words "tail" and "swap" under my name, I compiled a list of all the random build threads with tail swaps that i could find. The most common or yamaha R6 tails, first generation, followed by Ducati monster tails, first gen R1 tails, there's a Buell x1 tail, and a couple others. The only downside is that none of them fit perfectly with the normal subframe. The R6 and R1 tails can be made to fit the stock subframe, but on a bike that's as clean as yours is, you're never going to get as nice of a finish as what your bike has. I personally would love to put a Buell S1 tail on my bike, but it's technically my wife's, and I think it's an acquired taste and we'll probably end up selling this bike at some point, so I'll leave it with the tail I have on it now. I also think one of the 04-05 gsxr tails would look pretty alright on it, assuming you could fit it at the right angle. Someone was selling a tail, cowl, and taillight on craigslist for $50, which I kinda regret not picking up, but again, I think my wife likes the tail that's on it now, and I don't know if it would've fit as the subframe is now.

Thanks again for your help man.  I would love to see your bike! 

You shood get your seat covered in ostrich.  My brother did that and it is pimp
the lady put a whole in the middle.  That makes it easy to do stunts.

nhanxsolo,

Unless you're spending all your time on the racetrack or in the mountains, I'm going to offer a dissenting opinion on gearing changes. I wouldn't be willing to sacrifice freeway comfort and fuel economy for a small amount of acceleration off the line and a little top speed. In fact, I've ridden bikes that have gone the opposite way -- up 1 tooth in the front (on a Ninja 250 no less.)

When I say oil, I mean the fork oil. Changing the oil viscosity can stiffen or soften your damping. With emulators and the stock rebound ports, I run 20 weight oil.

The brace will help reduce flex of the front forks. The stock forks are fairly small, and the brace helps improve front end stability. The Buddha machines fork braces for the GS. It's an inexpensive part, so contact him.

Installing new springs is all about tuning the bike for you, the rider. Race-tech has a spring calculator that shows how stiff a spring you need for your weight. The OEM springs are WAY too soft. Unless you weigh 40lbs, you really should buy aftermarket springs.

Emulators cost around $120. If you are handy with a drill press and mechanically inclined, you can install them yourself easily enough. Otherwise, expect to spend $100-$200 for a full fork service (springs, and oil will be done as part of this service.) The emulators will help make the front suspension stiff under braking, but compliant over bumps. The stock suspension is stiff over bumps, but soft under braking.

Quote from: burning1 on May 26, 2010, 11:57:17 AM
nhanxsolo,

Unless you're spending all your time on the racetrack or in the mountains, I'm going to offer a dissenting opinion on gearing changes. I wouldn't be willing to sacrifice freeway comfort and fuel economy for a small amount of acceleration off the line and a little top speed. In fact, I've ridden bikes that have gone the opposite way -- up 1 tooth in the front (on a Ninja 250 no less.)

When I say oil, I mean the fork oil. Changing the oil viscosity can stiffen or soften your damping. With emulators and the stock rebound ports, I run 20 weight oil.

The brace will help reduce flex of the front forks. The stock forks are fairly small, and the brace helps improve front end stability. The Buddha machines fork braces for the GS. It's an inexpensive part, so contact him.

Installing new springs is all about tuning the bike for you, the rider. Race-tech has a spring calculator that shows how stiff a spring you need for your weight. The OEM springs are WAY too soft. Unless you weigh 40lbs, you really should buy aftermarket springs.

Emulators cost around $120. If you are handy with a drill press and mechanically inclined, you can install them yourself easily enough. Otherwise, expect to spend $100-$200 for a full fork service (springs, and oil will be done as part of this service.) The emulators will help make the front suspension stiff under braking, but compliant over bumps. The stock suspension is stiff over bumps, but soft under braking.

Thanks, I'll hit Buddha up for the brace.  Also I agree the rear suspension is wayy too soft, I feel like I have a flat tire sometimes going over bumps lol.  I looked at the race-tech website and it was confusing.  What do you suggest I do to find the right set up for the GS?  I weigh 150lbs.

Here's the link for your 93 GS500.

Racetech recommends 0.75 kg/mm springs for your weight, street use. You could probably go up to a .80 if you want a very firm suspension.

I run .85 kg/mm springs, but I race, and I weigh 180lbs.

A good starting place would be:

1. Stock fork oil level (140mm I believe?)
2. 15 weight oil
3. .75 or .80 kg/mm springs
4. Emulators.
5. Stock pre-load (you'll need to cut new preload spacers to use the Racetech springs. Racetech includes spacer material with their springs.)

While you're in there, replace your fork seals, and inspect your brushings.

Again, installation can be done at home, but requires disassembling the front end, and drilling the damper rods. This is a project for someone who performs their own valve adjustments. If you've never done one, take it to a shop.

A Katana 600 rear shock is a good starting point for your weight. The Katana 750 shock is better, but more difficult to install, and probably over-sprung for you.

Quote from: burning1 on May 26, 2010, 11:57:17 AM
nhanxsolo,

Unless you're spending all your time on the racetrack or in the mountains, I'm going to offer a dissenting opinion on gearing changes. I wouldn't be willing to sacrifice freeway comfort and fuel economy for a small amount of acceleration off the line and a little top speed. In fact, I've ridden bikes that have gone the opposite way -- up 1 tooth in the front (on a Ninja 250 no less.)

+1. I put a 17 tooth sprocket on mine. Now I get more relaxed cruising and better economy, and a higher top speed.Yes, you heard right. ttfour is right, the standard gearing is a little high for best top speed (with an unmodified bike), so now my 5th gear is about the same gearing as a bike with 15t tooth sprocket in 6th gear. I get my higher top speed in 5th,and have an 'overdrive' 6th for economy cruising. Yes, its slightly slower right off the line, but accelerates like a 15 tooth once you're moving, you're just in a gear lower at the same speed.

That's an interesting approach.

I was also gonna say I approve of not lowering your gearing too much. When I first got my bike back on the road it had -2+8(14/47), and it had really good low end for leaving redlights and everything in town, but as soon as I got on a road outside of the city where I wanted to go over 45mph it was awful. We did it 5 years ago just to play around on the bike, but now I've moved it back to 14/39, so I'm only down 2 in the front and stock on the rear. If I still had the stock front I'd probably put it back on. Someday if I have to replace it I'll either go with a 15t, or even just back to 16. The GS is just too small of a bike to want to mess with the gearing. It's a lot easier to gear down a 600 or larger bike that's geared to go 165+ mph, but this one doesn't really have as much give to it. Mine is ok now just about everywhere unless I want to cruise nicely on the highway. The RPMS are still a little higher than I care for leaving me with a decently buzzy ride on the highway.

Quote from: the mole on May 27, 2010, 10:23:08 AM
+1. I put a 17 tooth sprocket on mine. Now I get more relaxed cruising and better economy, and a higher top speed.Yes, you heard right. ttfour is right, the standard gearing is a little high for best top speed (with an unmodified bike), so now my 5th gear is about the same gearing as a bike with 15t tooth sprocket in 6th gear. I get my higher top speed in 5th,and have an 'overdrive' 6th for economy cruising. Yes, its slightly slower right off the line, but accelerates like a 15 tooth once you're moving, you're just in a gear lower at the same speed.

I never thought of that approach - gearing 5th for top speed - that's pretty awesome.

Your post perfectly illustrates the problem with extreme gearing. You do gain some grunt in first, but while each individual gear is lower, you have to shift earlier. So, you gain in some places, and lose in others.

Thanks, I've done the same thing on a lot of bikes I've owned (even my GS450 I had in '83). I recently replaced the 14" rims on my Mitsubishi L300 van with 16" to raise the gearing!

I had always thought it would make for a nice street bike if you had the first 5 gears that were normal, or even geared low, then a bit jump to the 6th gear. You could ride normal in 1-5th, and then when you were on the highway or wherever else you'd still be at a comfortable rpm.

They do something similar with some bicycles, mostly hybrids/cruisers. They're geared normal in the faster/taller gears, but then when you shift into the largest/easiest rear cog, it's a bigger jump, so easy hill climbing and things like that.

A few bikes do. I test rode the Kawasaki Vulcan Voyager. 6th gear was a almost too low for 65 mile per hour cruising. It's an excellent bike, by the way.

Keep in mind... Most bikes aren't meant for long distances on the freeway.

Quote from: burning1 on May 27, 2010, 10:09:09 AM
Here's the link for your 93 GS500.

Racetech recommends 0.75 kg/mm springs for your weight, street use. You could probably go up to a .80 if you want a very firm suspension.

I run .85 kg/mm springs, but I race, and I weigh 180lbs.

A good starting place would be:

1. Stock fork oil level (140mm I believe?)
2. 15 weight oil
3. .75 or .80 kg/mm springs
4. Emulators.
5. Stock pre-load (you'll need to cut new preload spacers to use the Racetech springs. Racetech includes spacer material with their springs.)

While you're in there, replace your fork seals, and inspect your brushings.

Again, installation can be done at home, but requires disassembling the front end, and drilling the damper rods. This is a project for someone who performs their own valve adjustments. If you've never done one, take it to a shop.

A Katana 600 rear shock is a good starting point for your weight. The Katana 750 shock is better, but more difficult to install, and probably over-sprung for you.

FRONT FORK SPRINGS
Recommended Fork Spring Rate for Street: 0.752 kg/mm (use closest available)
Stock Fork Spring Rate: .594 kg/mm (stock)
Available FRSP S2938 Series Springs are:

Part Number   
Description
Price       Select to Buy
FRSP S2938070   RT FRK SPR 29.0x377mm .70kg   $109.99       
FRSP S2938080   RT FRK SPR 29.0x377mm .80kg   $109.99       
FRSP S2938085   RT FRK SPR 29.0x377mm .85kg   $109.99       
FRSP S2938090   RT FRK SPR 29.0x377mm .90kg   $109.99       
FRSP S2938095   RT FRK SPR 29.0x377mm .95kg   $109.99       
   
REAR SHOCK SPRING
Please call for recommended rate.
Stock Shock Spring Rate: Call kg/mm (stock)
No Shock Spring Series currently specified for this model.
Please call Tech Support 951.279.6655 for help.

So they dont have the rear springs in stock, which is what I need correct?  the front fork springs were recently changed by the PO and I dont wanna change them quite yet. 

look online for a used katana 600 or 750 rear shock. the 600 bolts right in and the 750 probly needs a little bit of grinding. it's cheaper than buying new and it works very well.

Quote from: pandymai on May 27, 2010, 12:51:46 PM
look online for a used katana 600 or 750 rear shock. the 600 bolts right in and the 750 probly needs a little bit of grinding. it's cheaper than buying new and it works very well.

aren't they also adjustable much like coilovers on a car?  

Found a bunch of Katana 600 shocks with springs on eBay, does it matter what year it came off of?  I guess I should look for something newer so the shocks have less chance of being blown right?  Do I need to find one with the shock linkage attached? or will my gs shock linkage will work?

http://cgi.ebay.com/ebaymotors/06-SUZUKI-KATANA-600-STREETBIKE-REAR-SUSPENSION-SHOCK-_W0QQcmdZViewItemQQhashZitem2a0754e37dQQitemZ180511630205QQptZMotorcyclesQ5fPartsQ5fAccessories#ht_746wt_1167




Also I'm trying to research emulators and can't find much on them.  Can someone explain?  Thanks in advance!

look at rear shop swap info tab

http://pantablo500.tripod.com/

also, do you actually plan to track this bike? if so, emulators are decent investment. if youre not going pro with this bike, though, i'd suggest getting the thicker brace from buddha and gettin different oil/springs in the front.

or, if you really want, you can use the same money from emulators and be lucky to find a gsxr front end to swap over entirely, as others have done before.