kab-pro Posted May 12, 2015 Author Report Share Posted May 12, 2015 LOL mate I didn't met you there Quote Link to comment Share on other sites More sharing options...
kab-pro Posted June 29, 2015 Author Report Share Posted June 29, 2015 Weapon after its first battle at professional league Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted July 2, 2015 Report Share Posted July 2, 2015 Dude, what did you do to that piece of art?? Now after racing, do you have a better feel for any Power-gains your porting and butterfly-mods made?? I wonder what exactly the rule for more CRF-topend is!?! Quote Link to comment Share on other sites More sharing options...
kab-pro Posted July 3, 2015 Author Report Share Posted July 3, 2015 (edited) I raced it, just like what its born for Yeah the throttle body mods did give it a little more everywhere. And so did the heat wrapping on the header. Its not phenomenal, but definitely feelable. Well I can put top end for you this way, at high RPMs air and exhaust both want to move through the engine in very large quantities and speeds. Any restriction that is present in the system wants to suppress this, like a speed limit sign. So in order to get the most out of top-end you must get rid all the restrictions i.e. mismatched transitions on intake and exhaust side, steps, gaps, bottle necks, backfire screens, suffocating air filters etc. Everything must be smooth and big enough. And then theres the mapping to match all of that. That should pretty much give you a very good top-end, but in most cases it comes with a trade-off which is low-end. Nothing is free, but not always though Edited July 3, 2015 by kab-pro Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted July 3, 2015 Report Share Posted July 3, 2015 That should pretty much give you a very good top-end, but in most cases it comes with a trade-off which is low-end. Nothing is free, but not always though Yeah, that's the prob: I pretty much like the grunt down the rew-range and how controllable it is in stock trim. Would'nt want to change that. The stock powerband like it is, is not a bad application, especially for Supermoto. There just that bid of "early signing off" that I like to get rid of. No big changes just tweaking a bit on the right side. I'll contact you after next weekends round, want to try the bike without BF-screen this season, so I'll have an idea how much forward this goes. Interesting stuff what you bring up here. Keep on Mate!! Quote Link to comment Share on other sites More sharing options...
kab-pro Posted July 3, 2015 Author Report Share Posted July 3, 2015 Getting rid of BF screens and matching the transitions on intake and exhaust side, grinding down unnecessary sharp edges or steps - these will most likely help both low and top end. Its the tampering with intake and exhaust runner diameters and lengths (new pipe, TB overboring) and extensive head porting that will introduce a trade-off. Thanks! Quote Link to comment Share on other sites More sharing options...
Ben Posted July 3, 2015 Report Share Posted July 3, 2015 So basically there´s not much you can do yourself as a home mechanic. Someone once said "the power lies in the head" - which stays true (for four strokes) as it seems. The undertaking will be expensive if you want to do it properly. Blueprinting, head modification for intake and exhaust, then exhaust system modifications and lastly ignition and fuel tuning. That trade off you´re referring to - that would be shifting the power band up the revs and sacrificing low end torque I suppose. Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted July 3, 2015 Report Share Posted July 3, 2015 (edited) So basically there´s not much you can do yourself as a home mechanic. Someone once said "the power lies in the head" - which stays true (for four strokes) as it seems. The undertaking will be expensive if you want to do it properly. Blueprinting, head modification for intake and exhaust, then exhaust system modifications and lastly ignition and fuel tuning.That trade off you´re referring to - that would be shifting the power band up the revs and sacrificing low end torque I suppose. Ben: Your Saying ("the power lies in the head") is true, when there is an insufficient port-design, but latest Models have very good designs as stock, what makes it more complex. What I read so far is, that the 13's CRF stock port-design isn't bad at all. Even if some tuners claim different, there are some approaches that show no real advantages. Saying that, port-design isn't port-design!! Changing Diameters in the floor of a port will lower the flow-Velocity, which surely will shift the power in the band upwards. So it's all about finding the "right combination" for your Engine and Application. Porting nowdays isn't a Question of making some beautiful grinding, but matching all components together and refining what the constructor was after intentionally. What Andis did so far is just tweaking the Edges what isn't hard at all (also for a home mechanic, how you call it) I just wonder if these changes will be good enough to give a "Slow-mo-Rider" like me the results I'm asking for!?! Yes: Porting will cost a bit, as will a Big-Bore Topend for a Twostroke, to get into the Game. Wether the Bike is in need of it or not is something I really want to know. Then there are still these blue Bikes running around, having power as stock and making me really nervous..... Life is hard..!! Edited July 3, 2015 by Connader Quote Link to comment Share on other sites More sharing options...
Ben Posted July 3, 2015 Report Share Posted July 3, 2015 Life is full of choices. Isnt that a wonderful thing? Quote Link to comment Share on other sites More sharing options...
kab-pro Posted July 6, 2015 Author Report Share Posted July 6, 2015 So it's all about finding the "right combination" for your Engine and Application. Golden words, my friend.. Golden words. Then there are still these blue Bikes running around, having power as stock and making me really nervous..... Those blue bikes are not all that more powerful as everyone thinks. Sure, they are more powerful in stock trim, but I think I am on the edge of unlocking all of their secrets which seem to be very simple actually. So far, my 13' CRF can keep up with them on straight runs with no problem. Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted July 6, 2015 Report Share Posted July 6, 2015 Those blue bikes are not all that more powerful as everyone thinks. Sure, they are more powerful in stock trim, but I think I am on the edge of unlocking all of their secrets which seem to be very simple actually. So far, my 13' CRF can keep up with them on straight runs with no problem. I was surprised this last weekend how good I could follow one TM on the straight!! It was a fast rider being in the top 5 of the whole grid, so it was not about the rider. But before the straight there is a chicane and you would need drive out of that one, so this would make up for pure acceleration. The Honda comes good from down low, don't know about the TM's. I still like both brands but I think the Honda is the easier bike to go fast. A good rider will be with the TM but lets be serious: We're all chicken, aren't we?? Quote Link to comment Share on other sites More sharing options...
kab-pro Posted February 11, 2016 Author Report Share Posted February 11, 2016 (edited) Short video from last summer fun race event [video=youtube;2Hwg2DOYXxo] Edited February 13, 2016 by kab-pro Quote Link to comment Share on other sites More sharing options...
Tom#79 Posted February 11, 2016 Report Share Posted February 11, 2016 Was that you? Quote Link to comment Share on other sites More sharing options...
kab-pro Posted February 11, 2016 Author Report Share Posted February 11, 2016 Yesss !!! Quote Link to comment Share on other sites More sharing options...
Ben Posted February 11, 2016 Report Share Posted February 11, 2016 Wouldn´t have happened with a few go fast stickers on the bike Karlis! Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted February 12, 2016 Report Share Posted February 12, 2016 Looked like a lot of fun....!!! Any progress in Bike Development done? Quote Link to comment Share on other sites More sharing options...
kab-pro Posted February 13, 2016 Author Report Share Posted February 13, 2016 You can join to us with friends upcoming summer if want too. Everyone is welcome!! Development in process and it will be described here later as well as results. Dali, how your rebuilding is going on? Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted February 13, 2016 Report Share Posted February 13, 2016 I stuck a bit, waiting for parts: One sent me the wrong Bearings, the other has 4 weeks of delivery for the piston and my head hasn't found it's way to the U.S. yet. But 3 days ago I finally got the Bearings, so tomorrow I planned on going into the Garage and start the build-up of the low-end. Spring is coming faster each day, get kind of scared I might not make it early enough. We'll see.... Quote Link to comment Share on other sites More sharing options...
kab-pro Posted June 28, 2016 Author Report Share Posted June 28, 2016 Hi guys, I am finally back with some more pics to show from my CRF450R project bike. Last year we left this topic as the cylinder head and camshaft were pulled off and brought to a laser scanning office. The goal of this research was to modify every component of the gas exchange system in order to deliver more power at the top end of the rev range. Enjoy. This screenshot shows the overlap between the scanned .STL file and the CAD recreation of the ports and combustion chamber. Mean deviation ~ 0.03 mm. At this moment enough material has been accumulated to perform a flow simulation and determine the volume flow rate of the ports. The CFD simulation will be carried out using a flow bench standard of 12" H2O pressure drop. The result is 143 CFM. For comparison, a standard 2013 head flows 128 CFM @ 12" of H2O. The manually ported head trumps OEM variant by 11% To be continued... Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted June 28, 2016 Report Share Posted June 28, 2016 Nice work Mate!! The result is 143 CFM. For comparison, a standard 2013 head flows 128 CFM @ 12" of H2O.The manually ported head trumps OEM variant by 11% You're talking about your ports as you got the bike or your "theoretical goal"? 11% sounds like a lot more, regarding the fact you optimize here, only through grinding off material!! Nice!! Quote Link to comment Share on other sites More sharing options...
kab-pro Posted June 28, 2016 Author Report Share Posted June 28, 2016 Everything is going according to plan, be patient and keep following up this thread. There is a lot more to come Quote Link to comment Share on other sites More sharing options...
kab-pro Posted June 29, 2016 Author Report Share Posted June 29, 2016 The long road to perfection. Optimization process of the port shape involves dynamic stretch and skew + CFD simulation to evaluate the results. Truthfully, the results are like waves. Ups and downs. Main conclusion - the changes that visually seem most appealing are definitely the wrong idea. Just like an optical illusion. Try 80th.The result is as shown below. Visualisation of the CFD results. And, of course, a comparison. OEM - 128 CFM Previous owner - 143 CFM Long road to perfection - 187 CFM = + 46% vs OEM or + 31% vs previous owner. An overlap plot of the scanned facet body (red) and the freshly dveloped intake port (grey). The red spots point out to areas where welding will be necessary. Quote Link to comment Share on other sites More sharing options...
Throttle_Jockey Posted June 29, 2016 Report Share Posted June 29, 2016 Very interesting thread! I'm excited to see if the real results will match the theoretical ones Maybe the question was already answered but what kind of program do you use for the CAD stuff? Quote Link to comment Share on other sites More sharing options...
kab-pro Posted June 29, 2016 Author Report Share Posted June 29, 2016 Maybe the question was already answered but what kind of program do you use for the CAD stuff? This was a major problem because the requirements for such things are very demanding on the capabilities of the software. I had tried several high end CAD systems but eventually ended up using NX. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 29, 2016 Report Share Posted June 29, 2016 Very cool info you crazy guys! Quote Link to comment Share on other sites More sharing options...
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