ZRXDean
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posted June 02, 2009 09:07 AM
Defeating the purpose: cam for torque.
Hey folks, I bought a second 2006 ZX10 that I'm using as a streetbike / commuter. It was a low-side wreck, and I fitted it with handlebars and a single headlight. Stock motor with Kerry Bryant's half-system.
I sold the KLR this bike replaced, and I'm still getting used to the quadrupled power and chassis stiffness. Once the footpegs are lowered, I'll be about happy. I'm not a knee-dragger. Someday I'd like a Versys, but I'll try this for a while.
One thing I miss is low-rpm torque. The bike is not slow by any means, but it doesn't come alive until 6K. I plan to install a stock exhaust and regain use of the back-pressure valve, but I have another idea. I have a set of stock cams, what if I installed a stock exhaust cam on the intake side? It has 8 degrees less duration, and .024 less lift. Think it would make much difference?
The stock lobe centers are at 104/102, any suggestions? 100/100?
Thanks,
Dean
  
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Shane661
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posted June 02, 2009 09:10 AM
 Edited By: Shane661 on 2 Jun 2009 17:11
I can' t help on the cam stuff, but have you thought about giving it a little gear? The gearing is ridiculously tall in 1st gear, as you know.
What is the setup on the newest Z1000? Is that based on the 10R now? Perhaps it has smaller throttle bodies?
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ZRXDean
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posted June 02, 2009 10:00 AM
Yes, I forgot to mention that I will try a 15T front sprocket, good point. The Z1000 is no more, but was based on the ZX9 mill. I don't want to get too crazy with mods, but a cam swap would be pretty easy, and free. But if 8 deg/24 thou won't make much difference, it's not worth it.
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SteddyTeddy
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posted June 02, 2009 10:09 AM
If you want low end TQ get another ZRX.
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Y2KZX12R
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posted June 02, 2009 10:32 AM
Dean, I think a stroker crank and bigger pistons with more compression would help... 
Is that "too crazy"? I don't know, I have a distorted sense of what crazy is.
You zx10 guys need to check (or better yet replace) the valve spring retainers on those zx10s.
They break quite often. We have an 06 zx10 head here that has two split in half retainers in it.
THE BIKE RAN 100% PERFECT LIKE THAT!!!!
The springs were on the bucket. He just wanted to check the valve lash at 16,000 miles and he had zero lash on those two valves.!!!
He got very very lucky.
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TRNorBRN6001
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posted June 02, 2009 10:32 AM
Edited By: TRNorBRN6001 on 2 Jun 2009 19:27
Maybe bump the compression a touch, epoxy ports.
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ZRXDean
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posted June 02, 2009 10:48 AM
A bit too crazy Jim. If it involves cracking the cases (or my wallet), I can live without it for now 
I'll recheck the retainers in a few weeks on the race bike. I've been lucky, haven't seen one break yet. I'm not sure Carpenter produces the Ti replacements anymore, I can't find them. I think KHI changed them in 2006?
But Jim, do you think 8 degrees less duration would make a seat-of-the-pants difference? Tighter lobe centers?
(I do miss the ZRX Ted, but not the extra 150 lbs)
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SteddyTeddy
Pro
Posts: 1664
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posted June 02, 2009 11:23 AM
I hear ya. If I could knock off even another 50lbs I'd have a whole different bike. I had a couple people at the ZRX rally this passed weekend asking if I knew what you were up to these days.
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tcchin
Zone Head
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posted June 02, 2009 11:42 AM
Stock cams, 100/105 LC as a starting point. Maybe consider a kit head gasket or skimming the block and head for more CR.
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shiphteey
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posted June 02, 2009 03:38 PM
+1 on the gearing change. Why not -1 and +1..should be about the same wheelbase.
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tcchin
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posted June 02, 2009 05:13 PM
When I convert my race bikes to street duty, I often leave the race gearing on. We're currently running 15/44 gears, which is -2/+2 compared with stock, and still good for ~180 mph. That's equivalent to a 16% increase in torque. Yee-haw.
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2000redrocket
Pro
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posted June 02, 2009 06:48 PM
advancing the cams to 99/100 has to give more low and mid range plus should help cranking compression. u will loose top end.
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ZRXDean
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posted June 02, 2009 07:02 PM
Cool, I will regear and see how I like it, then try cam timing. I definitely don't need to go too fast on the street, I can get my fix at Maxton.
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tcchin
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posted June 02, 2009 07:19 PM
Going from 102 to 100 on the exhaust is actually retarding the timing, which is the wrong way to go. Going larger on the exhaust will reduce overlap and increase cranking compression. Of course, you will need to verify PTV on the intake side.
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krexken
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posted June 02, 2009 07:24 PM
I'm about to pull the head on a friends zx10 and change out his ti retainers for newer, lighter ti retainers. Interested in his old ones? I think he said his new ones were kibblewhites. I'll know for sure in a couple of weeks when I get the bike. I'm gonna change the exhaust cam with something custom he had made and send the head off for a valve job and maybe thinner head gasket. These zx10 guys... LOL
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krexken
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posted June 02, 2009 07:26 PM
Your new bike looks awesome, BTW. I think you'll get used to the lack of lowend. Hell, I got used to not having a bike that actually runs.
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dougmeyer
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moderated
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posted June 02, 2009 08:15 PM
Spread the lobe centers - reduce overlap as Tim suggests.
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oldkawboy
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posted June 02, 2009 08:39 PM
Edited By: oldkawboy on 3 Jun 2009 04:41
Dean,
That is a great looking streetfighter ZX10, you done good.
As for a Versys........I got one a while back and it's the best every day streetbike I've ever owned. Been doing some mods on it and now have a great light duty sport touring bike.
Dan
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entropy
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posted June 02, 2009 08:51 PM
Dean,
I really like yr nekkid black bike and am thinking that if you just ride it a bunch you'll get used to it pwr curve.
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ZRXDean
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posted June 02, 2009 09:12 PM
Hey Ken, I'll take the Ti retainers for sure, thanks. fullcolorbrain - at - yahoo.
Thanks Tim and Doug, I always get the cam direction / degree r'ship reversed. 100/105 it is.
Dan, beautiful Versys! How did you get a black one? Someday, green for me.
Karl, you are probably right, I know there is plenty of torque there, it's just a curve shape thing that makes it feel somewhat doggy. But really it hauls ass at any rpm.
Thanks folks.
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ZRXDean
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posted June 02, 2009 09:21 PM
Dan I see now that you swapped out some plastic on a red one, very clever. Nice job, looks great.
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Y2KZX12R
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posted June 03, 2009 03:37 AM
Like Tim said... go ahead and advance the intake cam as far as you can. You will run out of P to V clearance at some point, I'm guessing about 100-98....? 105-107 should be good on exhaust. Short stroke engines are more sensitive to exhaust cam timing changes vs say a stroker busa engine. But in general exhaust cam timing changes don't have nearly as much effect as intake cam timing changes do.
On my zx12 I fly cut the intake valve reliefs in the stock pistons back in 2000 and ran as low as 100 and it increased the torque right up threw 9000 rpm with just a few hp loss above that to redline. Good for the street.
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shiphteey
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posted June 04, 2009 03:51 AM
quote:
When I convert my race bikes to street duty, I often leave the race gearing on. We're currently running 15/44 gears, which is -2/+2 compared with stock, and still good for ~180 mph. That's equivalent to a 16% increase in torque. Yee-haw.
180 mph ACTUAL gearing with that extreme gearing? ZX10 or 12 I can't see happening unless you made other changes that would compensate.
A.
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tcchin
Zone Head
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posted June 04, 2009 06:41 AM
Edited By: tcchin on 4 Jun 2009 14:45
~180, or 176 with Karl's Korrection Factor. GSX-R1000's are geared really tall.
Regardless, anything over 160 on the street is wasted. And it's not going to be like riding an FZR400 that turns 10k on the freeway - it'll run more like 5k on the freeway.
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ZRXDean
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Posts: 2225
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posted June 04, 2009 07:39 AM
I installed 15/41 gears on it last night, big difference. This will be fine, I'm getting more used to it every day.
Found some footpeg plates, and will soften the suspension a bit, and call it good. This thing hauls ass, power wheelies in 3rd.
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