900/1000 dogs compared to 650/750?

hocbj23 wrote:

Damn I wish I could post pics....

Going step by step ---

1. Is the photo already in a file on your computer?

2. Does your computer use a Windows operating system?

Patton wrote:

hocbj23 wrote:

Damn I wish I could post pics....

2. Does your computer use a Windows operating system?

Can't believe you using such curse words on KZR!

XXXdows? How dare you!! The evil monopoly! Evil incarnate!


Since this thread is pretty well worn out, let's go to the chi chat forum and argue xxxdows vs Linux! That' always good for a spirited discussion! :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:

Oh goodee.Does yours rattle like Hell when idling?Mine does and I cant figure out whats causing it.bj

No not at all, Mine idles really smooth actually. but it does have a parisidic drain that keeps draining the battery. I havent worked it out yet.

Do you know if there are any forums for radians? i havent been able to find one.

-luke

Bad ground or short in wiring,try rear light harness-I found a couple bare wires there when I was restoring mine.So far found no Radian sites at all.bj

Vintage 5

Pre 1983 2-stroke factory road racers up to 500cc.

Pre 1983 Production based 2-stroke up to 750cc.

Pre 1983 4-stroke push rod unlimited displacement.

Pre 1983 OHC Twins to 1200cc.

Pre 1983 OHC 2 valves per cylinder to 1200cc.

Pre 1983 OHC 4 valves per cylinder to 1025cc.

Among the eligible V5 machines are the following: Ducati F1A and F1B, 750cc limit; Honda CB750F, CBX, CB900F, pre-1986 Honda VF500, VF700, and VF750; Kawasaki KZ750, KZ1000, Z1, GPZ 550/750, and EX500 without restrictions and regardless of year; Suzuki GS1000, Seeley Suzuki 750, pre-1986 Suzuki GS 750 (no hybrids, i.e., Suzuki GS 1000 motor in a 1985 mono-shock frame), GS 500 (no restrictions); Yamaha FZ600, Seca 550, Seca 750, Virago 980, TZ 750 (steel frame, twin shock). RZ 350 with maximum displacement of 450[/i]

I was part of the MAMBA team that raced a 550 at year before last's Mid-Ohio Vintage races and they left wishing they had picked a 650 as their platform because of the lack of performance alternatives. Stock 22mm Tekei carbs and stock cams with 12:1 compression pistons in a big bore kit don't make for a super fast bike...
wiredgeorge
Texas Hill Country

Like George mentioned, the MOMBA guys were ok with how the 550 did, but it has limitations because of it's cc class. GPz parts swaps are about the only real options available for an old bike like that. I spoke with the guys via email quite a bit after the article came out and they argreed that jumping up to a larger cc bike would be the better financial idea for more speed & power. So I ditched my 550 in favor of my now current 750.
Jason Rymell

Re: Anybody Race a GPZ550 ?
by WFO100 on Fri Sep 10, 2010 11:48 pm

We (team Momba) built a 1982 monoshock GPz550 that Andy Mauk is riding in middleweight superbike. He is also current #1 plate holder for the class and was undefeated last year. I rode the same bike at a couple of WERA events and Mid-O.

Ours is heavily modified, but works very well. Needs a little more weight on the front end to be perfect, I think we could probably raise rear ride height to get there but our shock is maxed out at the moment. We tried running a 6mm over 676cc engine a few years ago but it wouldn't keep base and head gaskets in it for more than a few practice sessions. The engines have puny 6mm studs and start pulling apart at the power level the 676 was capable of. The 676 bottom end is out of the bike and we are putting 8mm studs from a KZ650 to see if we can get it to hold together. The bike has had a 3mm over 615cc engine with a completely stock bottom end in it for two years now and has been trouble free. Besides the small studs, the rest of the motor is built like a brick shithouse. I have heard rods can be a weak point but no problems on our side, but we only rev to 10,500. 6 speed tranny was back cut by fast by gast and is the nicest shifting transmission i have ever ridden. lots of potential in the engine, but you are limited by exhaust valve size. The bike is definitely a good basis for a race bike.

Andy and I are driving down to Barber and he will be running it down there if you want to check it out.

WesWes Orloff
BOT #100
AHRMA #74




Under current rules the 550 and 750 are faster on most tracks in vintage racing than the 900/1000 with out frame work or a rickman frame. I have emails and waiting on info on more track times road course, 1/8 mile and 1/4.
Vorbeck

Mark Wing wrote:

My hopped up KZ650 would take my friends KZ1000 with a Yosh header and 28's by 1/2 second every time down the 1/4 mile. That was when it was just 716cc's with head work Yosh cams smoothboars and a Yosh header now my bike is 810cc's. I remember out at the road races a KZ650 was in second place overall after 4 hours in a 6 hour race. Don't sell the little guys short.

Mark

Half a second :ohmy: That 1000 must have been absolutely whipped. I find that dam hard to believe.

hocbj23 wrote:

Vorbeck wrote:

sorry it took a day to get it on here hocbj23.

Thanks. I know Jamups and the scooter store.Havent heard from Griffiths in a long time-thought they were out of business.Never been to rumors,but know where it is.Another place or two for u to visit--Rose Kawisaki down on Rossville Blvd and R/T Cycle further down the Blvd. R/T has a whole big-ass building FULL of vintage iron--nostalgia all over the place.My bud Jerry (Batman) at That Motorcyle Shop is a good wrench and a world of knowledge about bikes as well.Hwy 58 area.Rides an old Goldwing with his Boston bulldog in the passenger seat.bj

Rose had some parts I needed so I got to know them a few years ago. That Motorcyle Shop I think it is closed, was it the one with the dyno? I us to got to Honda of chatt on glass street before they moved to 58hwy. At the time I was riding a 78Honda with a 79 engine in it. I thoguht a 750 was a 750 but had to cut the frame and weld it to get it to work out, but I was young and learning so it was fun.

PLUMMEN wrote:

how about we settle it this way,i spend $5000.00 building a 900/1000 and you spend $5000.00 building a 650 and we compare notes at track midway for both of us?
we can do just like the magazines do compare them on the road,on the drag strip and roadcourse track

If I had $5,000 I could build a bike or buy a bike in any class that would be a winner. The point was dollars per horse power or performance. Throwing money at a bike was NOT the point. Do you throw money at every thing to make up for lack of skill and ability or are you just lazy and want an easy but costly answer?

stonemaster wrote:

I wanna be the bookie, I wanna be the bookie :lol:

What is your cut and are you planning to fix it?

lemo32 wrote:

mjg15 wrote:

This thread is kinda funny because it is very unlikely that anybody has bought an air-cooled Kawasaki for it's performance in atleast 25 years.

Bout sums up all that needs to said :laugh:

Not true. People get them every day for vintage and bracket racing. What planet are you from?

andy9802gt wrote:

PLUMMEN wrote:

turboguzzi wrote:

back to a bit of science.... shooting this at Larry
C as he stated elsewhere that he has seen Rainey in action on the GPZ750, but if anyone has answer to the next question he's welcome to shed some light:

What was the difference in lap times in AMA superbike racing when the switch was made from 1000cc to 750cc in 1983? Kawasaki won back to back in 82' with eddy on the KZ1000 based bike and in 83' with Wayne on the GPZ750 based bike, so which one was faster on pure lap times, (on same circuits of course)?

TG

and to make it really fair,how much faster was was eddie lawson on a 750 than a 1000 of the same year?

So I'm starting to get confused. I spent about $3000 on my big motor to make it faster and I could have just bought a 650? I guess the entire racing world has had it wrong for 50 years, there IS a replacement for displacement.

Written by David Reher

Looking back at the 2004 season, I can attribute much of the performance improvement in Pro Stock to faster engine speeds. It’s difficult to believe that 500cid Pro Stock engines now routinely turn 10,000 rpm, but the truth is plain to see on the data recorders and on the time slips.

The trend toward higher and higher engine speeds was also evident in NASCAR stock car racing until the rulemakers applied the brakes with new restrictions on rearend and transmission gear ratios. Now the growing interest in fast bracket racing, Top Sportsman, and Top Comp eliminators is bringing this same high-rpm technology to sportsman drag racers.

Why does turning an engine higher make a race car run faster? This is my final column of the year, so I’ll offer my ideas and hope that they give racers something to think about over the winter break.

The simple explanation is that raising rpm effectively increases an engine’s displacement. This might seem nonsensical because the volume displaced by the pistons doesn’t change, but consider the effects of filling and emptying the cylinders faster in real time. An internal combustion engine is an air pump, and if we turn that pump faster, we can theoretically burn more fuel in a given amount of time and consequently produce more power. For example, an eight-cylinder engine running at 6,000 rpm fires its cylinders 24,000 times in one minute (assuming perfect combustion). Increase the engine’s speed to 8,000 rpm and it will fire 32,000 times per minute, a 33 percent increase. The volume of air and fuel that moves through the engine is now equivalent to an engine with a much larger displacement. There are also 8,000 additional power pulses per minute transmitted to the crankshaft that can be harnessed to turn the wheels and accelerate the car.

Raising engine speed is analogous to supercharging or turbocharging a motor; the goal is to increase the volume of air and fuel that moves through the engine. The airflow is increased with a forced induction system by pressurizing the intake system; in a naturally aspirated engine, the airflow is increased by raising rpm. If done correctly, both approaches will increase power.

A higher revving engine also permits the use of a numerically higher gear ratio to multiply the engine’s torque all the way down the drag strip. Let’s say an engine that produces 1,000 horsepower at 7,000 rpm is paired with a 4.56:1 rearend gear ratio. If this engine is then modified to produce 1,000 horsepower at 8,000 rpm, it can now pull a 4.88:1 or 5:14:1 rearend gear without running out of rpm before reaching the finish line. The numerically higher gear ratio gives the engine a mechanical advantage by multiplying its torque by a greater number to accelerate the car faster – in effect, it has a longer lever to move the mass.

I learned this lesson many years ago when I started drag racing. I raced my little 302cid Camaro against 426 Hemis and 440cid Max Wedge Mopars. The big-inch engines had thunderous low-end power, but my high-revving 302 with a 4.88:1 rear gear would just kill them because they were all done at 5,800 rpm. My small-block had much less torque and horsepower, but I could multiply the power it had with a steeper gear ratio. The same principle applies to racing a Pro Stock or a Top Sportsman dragster. By turning more rpm, we can use a greater gear ratio to produce more mechanical advantage to accelerate the car.

There are limits to engine speed, of course. Higher rpm increases parasitic losses from friction and windage. The stability of the valvetrain also restricts engine rpm. However, with the technology developed in NASCAR and in Pro Stock, racers are learning how to build engines that operate reliably at high rpm. Research and development on valve materials, springs, rocker arms, and pushrods are now being applied to serious sportsman drag racing engines. In fact, I wish that I had some of the parts that we now install in our high-horsepower sportsman engines for our Pro Stock program a few years ago!

While increasing rpm is generally a good thing for a racing engine, it also puts more responsibility on the owner. A high-rpm combination requires more vigilance and more maintenance than a low-rpm motor. It’s important to check the valve lash frequently and to look for early warning signs such as weak or broken valve springs. Neglecting these parts in a high-rpm racing engine can produce some very expensive problems.

Raising an engine’s operating range also requires complementary changes in the drivetrain and chassis. A high-rpm sportsman engine really needs a high-stall torque converter to realize its potential. With an automatic transmission, the engine speed should ideally drop 1,000 to 1,300 rpm after a gear change. For example, if the converter stalls at 6,700 rpm, the engine should be shifted at around 8,000 rpm. Shifting this engine at 7,000 rpm would simply put the engine back on the converter, causing the converter to operate inefficiently and wasting horsepower by heating the transmission fluid.

I’m excited about the emerging trend toward fast sportsman drag racing. I enjoy working with customers who want to go fast because it gives me an opportunity to deliver the benefits of our Pro Stock R&D to other racers. Not every racer wants or needs a high-rpm engine, but if the goal is to have a fast car, raising the redline is a proven approach

Vorbeck wrote:

PLUMMEN wrote:

how about we settle it this way,i spend $5000.00 building a 900/1000 and you spend $5000.00 building a 650 and we compare notes at track midway for both of us?
we can do just like the magazines do compare them on the road,on the drag strip and roadcourse track

If I had $5,000 I could build a bike or buy a bike in any class that would be a winner. The point was dollars per horse power or performance. Throwing money at a bike was NOT the point. Do you throw money at every thing to make up for lack of skill and ability or are you just lazy and want an easy but costly answer?

lazy,lack of skills? so how much do you have into your bike including buying it,tires/wheels/motor work and everything else involved in building it?
$5,000.00 isnt a whole lot of money into any kind of race bike.

now for the lack of skills part :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: