Mega torque from my 1000?

larrycavan wrote:

Dave,

How about posting your latest dyno chart?

Jetting will make or break the graph. Same motor with some carb tuning before & after. Street ported head, throats opened up to 88%. Old VM29's with issues. 1075 with 110 grind Webs.

Larry, I have some dyno charts and will post them. If that graph is accurate, it's impressive. Midrange torque is a must on a street engine. The second run, while down a little in peak HP, has a lot more "usable" power. I have yet to see a 10.5:1 1075cc bike make 80lb-ft of rear wheel torque.

Here are a couple industry graphs for comparison:

www.sportrider.com/dyno/146_sportbike_dyno_charts/photo_13.html

www.sportrider.com/dyno/146_sportbike_dyno_charts/photo_06.html

Most of these are liquid cooled, 4V, 11.5:1 compression engines...

Getting 60+ lbft at 3000rpm on you second run is key. Is the only difference between the two runs jetting? Did you test with velocity stacks? Why do you think the torque curve shifted down (in rpm) with slightly less top end on the second run?

Also, Why on the second run is peak HP at 7200rpm? The stock cam makes peak power 8500. Seems like a web 110 cam with 0.395 lift/256 deg duration and a ported head would make peak power around 10,000rpm...

OK so let's say I choose to build a "budget" nitrous engine that's plenty strong. How's this sound?

1075cc 10.5 forged pistons
welded crank
clean up valves/seats but keep all stock head parts.
Nitrous- how much can it take?

I'm trying to buy the least amount of parts possible. Most "bang for the buck"

davel wrote:

Also, Why on the second run is peak HP at 7200rpm? The stock cam makes peak power 8500. Seems like a web 110 cam with 0.395 lift/256 deg duration and a ported head would make peak power around 10,000rpm...

Dave,

The dyno was having issues picking up the ignition signal. I have several the guy sent me from that motor when he was trying to dial in the 29's.

I'm wondering if those dyno charts you posted the link to are for KZ or the newer streetfighter liquid cooled 1000. One shows 66@8000RPM for z1000 and that seems about right for a stock KZ but the other shows 120 @10,250RPM. No detail on anything though...

Timebome,

I hear ya on the gearing and I won't disagree with that philosophy except I'd prefer a C/S larger than 14T with a 630 chain.

Nelson,

It's your pistons bud....spray 'em if you want to...

Everyone,

In case I don't get back to this place for a while, Have a Merry Christmas! Hope you all get some nice motorcycle parts & accessories under the tree!

larrycavan wrote:

66 @8000RPM for z1000 and that seems about right for a stock KZ

These numbers are for late model, liquid cooled,4V bikes with 11.5:1 compression
Numbers for a stock KZ1000 are 75hp @8000RPM and 52lbft @6500
motorbikearchives.com/Bike-Tests/Road-an...-KZ1000-ST-1979.html

larrycavan wrote:

The dyno was having issues picking up the ignition signal.

Consider this:
An engine making 100hp@7200rpm is producing 73 lbft of torque
An engine making 100hp@10,000rpm is producing 53 lbft of torque

53 lbft = 72% of 73 lbft
72% of 80 lbft(the peak on your dyno chart) = 58 lbft
Think about that.

No way a 0.395lift/256deg cam with ported head will make peak HP at 7,200rpm…
Web Camshafts lists the 110 grind as “Good mid and upper end performance for hot street”. Expect peak HP around 10,000 for that cam and head combination

larrycavan wrote:

I have several the guy sent me from that motor when he was trying to dial in the 29's.

The guy who dials in my carburetors is me. And I do it in-person at the dyno. Never have I experienced an RPM shift in the torque curve from jetting or ignition timing. A SLIGHT shift up or down in value is normal but never a shift left or right across the RPM scale. That’s why the large shift in the torque curve doesn’t make sense.

If you don’t know the exact rpm of the engine while measuring horsepower, you can’t accurately calculate torque. A dyno chart is only as useful as it is accurate.…and the dyno facility that posts the best results gets the most business…this leads to funny numbers and useless dyno charts like the one you posted.

All very interesting stuff. What I was thinking about is a much bigger shift in the way the engine works. Like 80 ft lbs torque at the expense of HP. Like lowering to maybe 60 - 70ish HP. Kinda like a big torquey V twin.

I'm thinking it's probably not possible because the design just isn't suited for that, but I'm not sure. Maybe a big difference in cam design/timing would do it. I'm not even sure If I'd like it I'm just curious about the idea.

I guess I'm spoiled because I had an SV1000 twin for a while... what an amazing motor on that thing! I know the KZ won't run like that tho.

Nelson wrote:

All very interesting stuff.

didn’t mean to get you caught in the crossfire…back on topic

I had an SV1000 twin for a while... what an amazing motor on that thing!

I included a dyno chart of the SV1000 in a previous post on this thread. Nice broad torque curve peaking at 70 lbft with 111HP. With a 1075 kit and stock cam in your KZ you can expect torque in the mid to upper 60s with 85-90 peak HP. These are very respectable numbers though unfortunately the KZ weighs about 130lbs more than the SV. Regardless, you’ll feel BIG difference - Night and day. I think you’ll be happy.

davel wrote:

Nelson wrote:

All very interesting stuff.

didn’t mean to get you caught in the crossfire…back on topic

I had an SV1000 twin for a while... what an amazing motor on that thing!

I included a dyno chart of the SV1000 in a previous post on this thread. Nice broad torque curve peaking at 70 lbft with 111HP. With a 1075 kit and stock cam in your KZ you can expect torque in the mid to upper 60s with 85-90 peak HP. These are very respectable numbers though unfortunately the KZ weighs about 130lbs more than the SV. Regardless, you’ll feel BIG difference - Night and day. I think you’ll be happy.

Oh...so there's crossfire :huh: Now I thought it was a discussion. My Mistake.

According to YOU, the motor should make PEAK HP at 10,000 RPM with those cams.

I'm not talking rev to 10,000 but make peak HP at 10,000RPM

Based on exactly what data have your derrived that conclusion? Web's advertisement of more top end power?


And where's those dyno charts for your bike anyway? I have an old one that was done in 06. As I recall you said that was with stock motor and RS34 Mikuni's. Is that correct? That's what you indicated in the email that the chart was sent with.

Interesting how you Install 34mm carbs and picked up nearly 20HP :ohmy:

larrycavan wrote:

Interesting how you Install 34mm carbs and picked up nearly 20HP

Wrong.
RS34, stock 1015 pistons, 0.365 drop in cam, 4-1 header with open megaphone. 60lbf@7200 and 93hp@9000

And where's those dyno charts for your bike anyway?

First we're going to get to the bottom of your funny numbers

larrycavan wrote:

According to YOU, the motor should make PEAK HP at 10,000 RPM with those cams.

Based on exactly what data have your derrived that conclusion?

here's the GPZ1100 chart you asked for
64 lbft torque and Peak HP @9000rpm. (similar lift and duration to my Web drop-in cam)

Your test engine has ported head and cam with more lift and 10 deg more duration...
like I said. peak HP around 10,000rpm

Larry, How is it possible that your 1075 makes peak HP at 7200rpm with 80+ lbf of torque???

im not sure if i am understanding davel's last couple posts???? Is he trying to say that Larry Cavanaugh doesn't know what he is talking about??? Is that like calling jesus selfish?

Seems to me, that the cheapest way to make torque is through added CC"s,and psi.
Go 1075 and keep the carbs, ports, cams, and pipe, small.
When u get the cases apart, don't forget to upgrade the springs in the clutch basket.
If u want a wheelie machine,shorten the swing arm, and lighten the front end.:woohoo:

A few final thoughts on dyno charts:

A dyno calculates horsepower from the RPM and torque applied to its inertia wheel and plots the results on a graph. In order for an associated ENGINE torque curve to be generated, the dyno MUST ACCURATELY read the engine RPM while measuring the HP. That said; there are some ways to trick the dyno into reading a lower engine RPM. Tricking the dyno into reading a 25% lower RPM will generate MORE than a 25% increase in the torque curve and whole curve will shift to the left on the RPM scale. The peak HP value will still be accurate but it will also shift down the RPM scale and the engine will appear to be a torque monster on the dyno chart.

Larry, It seems very unlikely for a 1075 w/10.5:1 pistons and Web 110 cams to make 100hp at 7200RPM with 80+lbft of torque. Tell your guy that next time he dyno tunes that bike to MAKE SURE the dyno ignition trigger is hooked up and operating properly and that the tachometer in the DynoJet software is in-synch with the tach on his bike. He might want to try a different dyno shop altogether and see how the numbers compare.

100 – 105 HP sounds right but it should be peaking between 9,500-10,000rpm with max torque in the 60’s.

IMO

I will post some dyno results in a new thread for comparison.