83 gs750e build thread

[tarzanscot]

Thats my plan ill take 2 gps's with me and they both can record the max speed traveled,
also will have a video.

[cyclefvr2]

the tscc is still used today , same design motors, so whats the differance in the gs16v and gsxr16v motors?? cams, compression,tranny,is a lil diff, but for performance where is all the power gained in the 00-09 models??
compression,cams,valve springs
you can make up speed by different sprockets, smaller front ,and smaller rear will make a big differance

[posplayr]

The difference between 131 and 150 is huge. Personally, I think you're underestimating the challenge, but by all means give it a try.

We wont mention that 150 mph requires 50% higher hp than 131 mph; I'm sure he will get there if he adds some pods, maybe a Dyna S will get him there; Couple that with the 1/4 throttle mod he will do it for sure

[jwhelan65]

We wont mention that 150 mph requires 50% higher hp than 131 mph; I'm sure he will get there if he adds some pods, maybe a Dyna S will get him there; Couple that with the 1/4 throttle mod he will do it for sure

It also requires some big kahonies on bias tires..

[Roger P.]

Ninja 900 would break 150mph with 113hp at the crank. On bias tires.

Getting that kind of power out of a GS750 will require some lumpy cams and carb work, but it might be possible. It might not be very streetable though.

[posplayr]

Ninja 900 would break 150mph with 113hp at the crank. On bias tires.

Getting that kind of power out of a GS750 will require some lumpy cams and carb work, but it might be possible. It might not be very streetable though.

It is really about aerodynamics not hp at these speeds. If you want to take a stock GS750 from 131 to 150 the easiest way is to put on a full fairing. As an example, to drop the drag coefficient from 0.8 down to 0.53 would compensate for the 50% increase in horsepower otherwise required. With the 1/1.5 reduction in drag, there are no other changes to the engine required.

On the other hand, tires might start to become an issue.

[Griffin]

the tscc is still used today , same design motors, so whats the differance in the gs16v and gsxr16v motors?? cams, compression,tranny,is a lil diff, but for performance where is all the power gained in the 00-09 models??
compression,cams,valve springs
you can make up speed by different sprockets, smaller front ,and smaller rear will make a big differance

First of all, modern GSXR engines have nothing in common with the GS700 engine, other than they are inline fours made by Suzuki. After that, the similarities end.

thanks glad u like , well i raced a eclipse gst (turbo) , and i was stock before i started any
work on it and i was holding 140-45 give or take (dont know how accurate the spedo is but it held that speed and you could'nt give it anymore there was just no more power. i will be taking a video soon either on here or a link to you tube.

Secondly, if you wanna go 150 mph on a GS700, you've got a lot of work to do, and you'll spend thousands of dollars to do it.

This GS700 -


Made 102 BHP at the rear wheel, and topped out at about 150-155mph with a 155 lb rider.

It also was notorious for eating up transmissions, and the entire engine needed to be torn down and rebuilt after every race.

Good luck.....


Edit: One other thing about your 140 mph claim on a stock GS750 - no way. With stock gearing, you'd have to be spinning about 12,800 rpm in 5th gear. Can't be done. Period. No way, no how, nope.

[reddirtrider]

It is really about aerodynamics not hp at these speeds. If you want to take a stock GS750 from 131 to 150 the easiest way is to put on a full fairing. As an example, to drop the drag coefficient from 0.8 down to 0.53 would compensate for the 50% increase in horsepower otherwise required. With the 1/1.5 reduction in drag, there are no other changes to the engine required.

On the other hand, tires might start to become an issue.

This is it in a nutshell. In an earlier post I mentioned that the wall of air you're pushing at 150 is tremendous. I had my ZRX1200R near 150 (my speedo said 155) and shut it down as it was getting too dangerous on some South Dakota backroads. It might have gone a bit faster, but not too much. It has pods, jetting, pipe, and a few other mods mostly cosmetic and it'll rip any GS750's wing off. Yea, I know blasphamy but I've ridden some and built one so I'm speaking from experience.

I also estimated you'll need 110 - 120 hp to get to 50 on the 750. I think you're also in the ballpark on your figure Pos.

[reddirtrider]

the tscc is still used today , same design motors, so whats the differance in the gs16v and gsxr16v motors?? cams, compression,tranny,is a lil diff, but for performance where is all the power gained in the 00-09 models??
compression,cams,valve springs
you can make up speed by different sprockets, smaller front ,and smaller rear will make a big differance

The only thing you wanna do with sprockets is figure out at what RPM you're making the most HP and gear the bike so you do it at your maximum speed. There is a minimum size for the front, I'm not sure what it is for the 750, but if you go too low the chain must pivot too much and that ain't good at speed.

Lots of differences, from combustion chamber to head port angles to cam timing. The entire motor has been reworked. Some subtle changes, some not so. They all add up to a big difference.

[posplayr]

This is it in a nutshell. In an earlier post I mentioned that the wall of air you're pushing at 150 is tremendous. I had my ZRX1200R near 150 (my speedo said 155) and shut it down as it was getting too dangerous on some South Dakota backroads. It might have gone a bit faster, but not too much. It has pods, jetting, pipe, and a few other mods mostly cosmetic and it'll rip any GS750's wing off. Yea, I know blasphamy but I've ridden some and built one so I'm speaking from experience.

I also estimated you'll need 110 - 120 hp to get to 50 on the 750. I think you're also in the ballpark on your figure Pos.

The estimate is a little on the high side, as it represents the increase in hp required due to frontal area drag. Frontal area drag required hp that increases to the 3rd power of velocity. Any internal drag terms such as engine drag or to the extent that rolling resistance do not increase to the square of velocity then all drag components do not contribute to the 3rd power rule.

Hp = Force x velocity
C x V^2 x V = C x V^3

However it was interesting that Chef and I were BSing one day and used the formula to estimate the horsepower and top speed of the world record holding busa and then related that to KrisV's nitors/turbo 1150. I don't have the figures but the conclusion was that the model worked well to predict top speed/hp requirements. It ignores gearing and RPM obviously.

[reddirtrider]

The estimate is a little on the high side, as it represents the increase in hp required due to frontal area drag. Frontal area drag required hp that increases to the 3rd power of velocity. Any internal drag terms such as engine drag or to the extent that rolling resistance do not increase to the square of velocity then all drag components do not contribute to the 3rd power rule.

Hp = Force x velocity
C x V^2 x V = C x V^3

However it was interesting that Chef and I were BSing one day and used the formula to estimate the horsepower and top speed of the world record holding busa and then related that to KrisV's nitors/turbo 1150. I don't have the figures but the conclusion was that the model worked well to predict top speed/hp requirements. It ignores gearing and RPM obviously.

It may be a little high, but I estimated by taking a bit off what the Kawasaki makes thinking it can go a bit faster yet. Interesting though that frontal area drag is related to velocity cubed. I guess that explains why incremental increases in speed once you get past 120 are not trivial. I'll make a note of that.

You gotta be slippery - that's the real key to speed.

[posplayr]

It may be a little high, but I estimated by taking a bit off what the Kawasaki makes thinking it can go a bit faster yet. Interesting though that frontal area drag is related to velocity cubed. I guess that explains why incremental increases in speed once you get past 120 are not trivial. I'll make a note of that.

You gotta be slippery - that's the real key to speed.

Red

Drag is proportional to Vel ^2

HP = Force (e.g. Drag force) times Velocity

Hence Horse power is proportional to Vel^3

Horsepower is a measure of ability to perform work which is applying a given force at a specificed velocity. Example pushing against 100 lbs at 10 ft/sec.

http://www.howstuffworks.com/horsepower.htm

[reddirtrider]

Red

Drag is proportional to Vel ^2

HP = Force (e.g. Drag force) times Velocity

Hence Horse power is proportional to Vel^3

Horsepower is a measure of ability to perform work which is applying a given force at a specificed velocity. Example pushing against 100 lbs at 10 ft/sec.

http://www.howstuffworks.com/horsepower.htm

Dude, my mind is full I'm not going to read articles on stuff I'll never use in a theoritical sense. I have more than enough problems keeping up with work.

Anyway, thanks for the clarification. I was thinking drag was related to the square of the velocity in the first place but misread your post and just went with it.

[posplayr]

Dude, my mind is full I'm not going to read articles on stuff I'll never use in a theoritical sense. I have more than enough problems keeping up with work.

Anyway, thanks for the clarification. I was thinking drag was related to the square of the velocity in the first place but misread your post and just went with it.

Red,
Most of the time when I post I know you either know it or just forgot about it and so it is partially a memory jog as well as for anybody else that might read my post and start asking even more questions.
Jim

[reddirtrider]

Red,
Most of the time when I post I know you either know it or just forgot about it and so it is partially a memory jog as well as for anybody else that might read my post and start asking even more questions.
Jim

I know you're giving me a hard time, but when I look back at some of the mathematical problems we had to solve in school I just scratch my head and wonder who did that - it sure looks like my hand writing.

You won't believe how many times I set my glasses down when working on bikes and 2 minutes later wonder where I put them. Dazed and confused.