PassionRE

When air is forced into a cavity, the pressure inside increases. When the external force pushing the air into the cavity is removed, the higher-pressure air inside will flow out. However, this surge of air flowing out will tend to over-compensate, due to the inertia of the air in the neck, and the cavity will be left at a pressure slightly lower than the outside, causing air to be drawn back in. This process repeats with the magnitude of the pressure changes decreasing each time. IF you take the engines natural frequency at rated peak hp and match it to the natural tuned frequency of the manifold, you can retain more AF mixture for the engine to process. Basicly a supercharge effect if you will. This holds true from literally the air filters to the silencer. If all is matched, peak efficiency will occur. All engines designed for a certain drag coefficient ultimately will make only so much HP within reason. If you can reach max efficiency, you can make this engine produce this number at a lower rpm...making for a much more violent engine that will pull more gear and tire. In drag racing, 9500rpm is 9500rpm from engine to engine. The bike that has the more violent power delivery and pulls more tire and gear at 9500 rpm is going to win ,with everything else being the same as in rider ability,engine displacemnt, traction etc. etc. Resonance tuning allows port configurations to be designed to make the power you looking for at a higher effective displacement layout.Theres a lot more to it but thats the simple explanation. Bottom line, it's trick, it's fast, and it's coming your way....Jim

Forgot to add that the stinger tubes AND silencers will be resonance matched to the pipe...a industry first. At a later date we will offer resonance matched intakes for a variety of engine formats currently being used. Initial testing yielded 4% increase in HP on 421 cubs with just the intakes(no other changes) Ill post up the dyno results of the intakes when I get a chance. Unless you were a part of Yamaha or Aprilia road race team, nobody has had access to this level of technology until now....Jim

Rest assure the quality will be there. Instead of oxy/acetelene welding, all units will be tig welded for the purest, cleanest welds. We are currently building highly accurate jigs for pipe orientation upon assembly. Machine work etc. on silencers will be top knotch. Standard plating will be electroless nickle inside and out. Not the cheap flash plating. This plating is so hard that it can actually be machined. Pipe prep and proper etching will be done professionally. Gary is at least as anal as I am and that's saying a lot. We are trying to keep the prices down and as soon as we get bids back from our vendors, pricing info will be available. We are taking a lot of extra steps to insure quality so in the long haul the customer has made a good investment. No wham bam here ya' go stuff like most people are used to. Not only will they blow every pipe on the market away in performance, they will hold for the long haul...Jim

With the design of the Sniper Inframe complete, we have been going over some of our design files for our OOF drag pipe that we researched around 2 years ago in an effort to determine final design parameters. I meant to post up several files, but most of the file sizes were so small that they were hard to read. I have although posted up a sister pipe to the inframe design that I like very much personally. It made a little less peak hp, but did make an additional 7 lbs. torque over the inframe version, 61 ft. lbs to be exact, on one of my 421 Cub engines on GAS! Most high end methanol 421's will make around 62 ft. lbs. These tests were done against the Shearer OOF drag pipe and CPI. The reason Im doing this is that I would like some feedback from anyone reading this on power delivery preference. Big HP at high rpm vs. decent HP with off the charts torque at a earlier rpm ...your thoughts? We appreciate any input for we want to deliver what the people want. Interactive responses are important to us, and in a way, you get to be part of the fun...Jim A side note.....notice at 6500 rpm it makes 19 more HP than the Shearer or the CPI...not bad http://i57.photobucket.com/albums/g215/passionre/dyno12.jpg

NO NO, youv'e got it all wrong. The old saying goes "If it wont run, chrome it."

PV motors will only be limeted to the basic set-up at rated rpm just like any non PV motor. Typically a 421 PV for example will make around 10 more HP through the midrange than the non PV motor with the only difference being the PV's themselves. Lightening the spring load will give better upper mid-range vs. better lower midrange. All out HP should be the same at max rpm if the valves have been modded for a seamless ex port roof. PV's simply extend the powerstroke and reduce blowdown durations at lower rpm's. Thats where the bottom end hit comes from. A well ported PV will just be insane on these pipes...Jim

No problem here Andy, everybody has different thoughts on these engines. Ultimately these pipes only being better on my engines only would be a very short sighted goal. So far, from what we can tell, I feel these pipes will make every reputable well studied builder look better. That is much more beneficial to me personally. I touched on it earlier, possibly on the other site(not sure), but once were up and going if builders have preferences on power delivery etc. we can match the pipe in pre-production to best suit a builders preference. These stampings are made a little different in where we have a lot of options in the end result. We have no problem working with other builders to match up there designs to work at their best. New experiences and testing really get one's mind going and that is where new innovative performance increases come from. Im all about learning new things such as you are. Were always looking for more power,just like you, and in this case, we have no problem spreading it around. Im sure you will have the same results we've had, and were glad to help. Once weve verified meth capability and are happy with the results, I really would like to meet up with you and see what you can gain from it. Seriously, were excited and I think you will be too....Jim

Were anxious to see how the pipe does on several formats, not just the stock cast setups. From looking at the dyno sheet its only 12 horses down at 7000rpm compared to your 421 methanol dyno sheet in the dyno section, that sounds about right on a gas vs. methanol comparison, not sure where you got 20-30 hp difference in the midrange. I wasnt trying to showcase the motor, just showing how well the pipes did. But as you can personally attest to, my cubs run beyond hard. Were looking forward to more tests on different formats of our own and from different builders as well. Were certain of the outcome in advance, thats the beauty of real science. I'll keep you posted as the results start coming in...Jim

Yeah Andy I replied to this on the other forum, but huh, that thread is gone..go figure. This engine is a little high strung but its all we had access to on GAS at the time.The engine we actually developed this pipe on made 101.5HP on Shearers and GAS but it wasnt available on testing day. If you have a GAS bike to test them on in the 400+cc range, 90+ HP range on GAS feel free to contact me and we'll test them on your bike as well as some other test we want to do. We havnt made the meth runs yet and may need to tune the pipe further. We intend on offering GAS and Meth version if needed in the end. let me know...Jim yep yep

Thanks for the input on the silencers. We did the dyno runs using the same set of silencers on each set of pipes. We are going to use circlips with sparky capability. Were trying to cover all the bases...Jim

In the works...Jim

Alf, they are actually bigger in diameter than even a CPI...only out of the way..heres a different shot....Jim http://i57.photobucket.com/albums/g215/passionre/Photo0063_001-1.jpg

As a few of you may be aware ,of my great friend Gary Bilby of TST Engine Software an I have been working on a new inframe drag pipe for some time now. Gary and I are much alike in that we feel there is always more power to be had regardless of how pleased we are with results of our current set-ups. Honestly , we are diabolically driven by it. So driven, that Gary wrote his own pipe software just to develop this particular project. Some might say that pipe design is not Rocket Science, but it might as well be. It takes 4 minutes for a modern PC processor just to simulate a 1 second real time event...that’s a ton of data. Were all about data. If the data doesn’t support it, it wont happen...period. Goal: create the hardest hitting, max tq. and HP inframes for the CP Industries Cheetah Cub. These cylinders in stock form are by no doubt the most mathematically correct designs on the market. They have great potential for additional HP as well with extra porting and mods. All the version of it are similar and predictable when modified. In creating this pipe we needed a correct design to base it on. Good math in, good predictability of our pipe in the design phase. Not all engines run best with a certain pipe. But choose a category specific engine style in the design process, and the results are much better. Its also easier to tune the pipe for a certain engine type. Our pipe was designed on the 421 cc Cheetah Cub but will also run well on others as well up to around 600cc. Once we are fully tooled for production, I will place a port mapping guideline on my website for a tool for people to use to calculate a few things before contacting us to see if this pipe might work for them. We also have tunability of the pipe capability in pre-production to custom tune it for your engine based on you port mapping specs you provide based on the guidelines on my website. It will be offered in our standard form for gas and methanol, along with custom tuned versions discussed above. Some OEM cylinder porting designs will be able to use it as well. Im quite familiar with most of the major engine builders designs and some of them will fall into the correct engine specification needed for best results. Regardless, the mapping guidelines I will offer will be the last word...its that math thing again, you cant get around it. Real science makes real results. Our first stampings are finally in and I have a few pics and a dyno run against a very good pipe offered on the market currently. We hope to be in full production be end of summer. Special attention to physical design was based on input from my customers over the years. GOOD body english, no hitting the frame, head, carbs. You can run the stock air box, it clears the bigger cylinders. It has good plug access, and yes, it even clears a Pingle. Welcome to the new standard. Point em’ out, and take em’ down SNIPER PIPES....Jim Smart PASSION RACING ENGINES INTRODUCING....SNIPER INFRAMES http://i57.photobucket.com/albums/g215/passionre/Photo0064_001.jpg http://i57.photobucket.com/albums/g215/passionre/Photo0067_001.jpg http://i57.photobucket.com/albums/g215/passionre/Photo0062_001.jpg http://i57.photobucket.com/albums/g215/passionre/Photo0066.jpg http://i57.photobucket.com/albums/g215/passionre/sniper.jpg Dyno sheet is 421 CUB on gas, near stock port timing, 180psi, 40 mill Lectrons, VF3's 7 deg advance

What he said ^ Only 80hp if you want power everywhere...or less if you want. Better pick a strategy and go with it. A good trail motor is going to suck as a fast hillshooter bike. On the other hand, HP is so addictive that you better plan on getting a little more than a trail motor or you'll be spending more $$$$$$ over the long run......Jim

If your planning on a cub ,better bump the carbs to 39's or you'll be leaving 7 hp out of the picture. TZ drive bearing as well instead of maxload ....Jim

Have you checked your compression with a gauge? If your running a .020" base gasket with 795 series pistons on a 4 mill crank with 23cc total volume domes(flat plate) your pushing over 200 psi. The plugs coming loose is detonation, so is the pattern shown on the picture you posted. The oring condition is caused by extreme overheating...they are made of Viton and can stand alot of abuse...more investigation may be needed...Jim

Not to add fuel to any fire, I thought it might interest viewers to learn a few cold hard facts about reed valves. If nothing else it might give a few of you ideas in how to tune a little extra power out of your machine, regardless of what reeds you are currently using. First I'll address a few statements made throughout this post: 1) "No one reed design will be best in every engine configuration"...this is a cold hard fact. With all the options available in cylinder porting, monoblocks, stroker cranks etc. this is definately the case. 2)" The mathematical formula doesn't exist in reed design"..... not true. Like any machine that operates within the laws of physics on planet earth, with given properties and characteristics of those said properties, its performance capability can be calculated on any engine configuration with amazing accuracy. For broad rpm range efficiency it becomes a little tricky, but for all out performance as in drag race engines, it's alot easier. Tools do exist for this design process, some commercially available, some privately held. Certainly not rocket science, but it might seem so if your trying to develop or tune reeds without the use of them. Unlike mechanical valves as in 4 strokes, a reed valve is a interactive valve with a direct relationship to the engine its mounted to. In addition to this, its performance will also be affected by the expansion chamber and tuned resonance of the intake manifold between the reed tip and carb entrance as well. Generally speaking, the better the pipe, the better the reed will perform unless its extremely undersized in cage area or reed lift area. Also, if the reed configuration's natural frequency is out of range, high or low, performance will be deminished. If a reed's natural frequency falls well below the engines natural frequency at rated peak HP rpm bottom end power at lower rpm ranges can actually be improved, but at the cost of high rpm reed stability resulting in power loss at high rpm and almost certain reed damage. If the reeds natural frequency is too far out of range on the high side, bottom end power will suffer as a result and if even higher yet, top end power as well. A reeds natural frequency is determined by reed compostion material, thickness and stiffness of this material, and clamped length of the reed. In reed design a few questions have to be answered upfront. 1) What is the expected performance of the engine design itself? 2) At what rpm is this engine going to produce this level? 3) what displacement and primary compression ratio are we using? 4) Is my carb big enough for this goal? OK...the reed valve itself....the 3 must haves to get there. 1) cage area...has to be big enough to flow the required amount of air to meet the performance level. 2) reed lift area.... this is the interactive process at its finest. Will these reeds open up enough to allow the required air requirements for my engine design? 3)...And better yet, will they be operating at a natural frequency that wont cause tuning problems? HUGE importance, this is what seperates a good reed from a bad one. Other variables exist as well, but these are the big ones. You can mess up your design in other areas and still meet your goals, mess these up and you'll never get there. A flow bench can be a good tool to use if you know the max values of lift area a engine is capable of producing. But even then you are just testing the cage and cfm capability at a given reed lift area. If you've based your lift area on the actual value your good to go as long as you know the natural frequency of the reed and it matches your engines peak rated HP rpm, if not, all bets are off...this goes back to the no one reed is best on all engines statement I reffered to earlier. ALL OUT HP CAPABILITY... a subject a few of you might be interested in. Pay particular attention to REED LIFT AREA and NATURAL FREQUENCY. Most reed cages themselves are capable of more than you need unless your trying to exceed 85RWHP...even the stock Yamaha cages can do this, although the reed choice itself is just mathematically disasterous. For you guys with big stroker motors, Cubs, etc. Youll need more than 4 entrance ports per reed valve to massage out the power your looking for unless you are going to totally redesign any reed valve I'm aware of currently being marketed. Im not familiar with Chariots lift area or natural frequency capabilitys, but will be more than happy to calculate it if anyone will send me a few specs. A side note, VF3's are capable of 120RWHP, maybe more depending on the pipe effects due to the pipe design itself and how it reacts to the given transfer duration.....Jim

I always go NOSS personally. All my engines have my designs but David cuts them for me. The poor guy probably shreeks when he sees me on caller ID because he has seen me through years of R&D and has produced some pretty unorthodox designs for me. But he always delivers, doesn't try to second guess me, and does fantastic work. Thanks Dave!!!!...Jim

Only bore if needed, no need to waste bore sizes. Have the cylinders measured first to ck clearance. If the motor got pretty hot, just plan on a set of Wiseco pistons of the correct size. If your 02 hasnt been apart ever, or in the last couple of years, have the crank trued and welded and replace all the oil seals. Make certain to check the outer bearings while your at it. Youll be fresh to go for a few years if no mishaps come your way...Jim

Target temp should be 1250 deg F measured 12 inches from the piston side. This will get you real close. ET runs on a track will get you closer yet....Jim

In most cases PJ34's want DEK needles for best results..50P and 142-155 mains are common results......Jim

In need of RZ powervalves, just the valves themselves and the long allen bolts that hold them together. No servos or bushings needed ...call Jim 918-232-3950 thanks in advance

Small tracks require smooth power delivery if you want to run with well tuned 450's. Tracks that have room to stretch your legs.... a well built 4 mill on stock cylinders 75-80 RWHP will actually outrun 535 Cheetah's even on 1/2 miles. Big PV monoblock motors aka Cheetah's, T-rex etc. will have so much power loss due to lack of heat exchange that you'll be 25HP down by the 4th lap. There are exceptions to this, but it requires big changes in monoblock PV motors to get around it and it gets expensive. Proquad101 won the Nationals in Joplin 2 or three years ago on one of my long rod 370 strokers ( OPEN PRO CLASS ATVA). The biggest mistake made on short track motors is power delivery style. Too explosive and theres not enough room to make up for lost traction off the turn. To pipey of motor will not power off the turn and will not pull enough gear to give gearing options aproaching the turn in traffic. Flexability on gear choice while underway due to super flat torque curves and neverending top end rpm with smooth transition is what wins the BIG races....Jim

Any pressed crank that tries to seperate will always tend to do so. Welding can slow this down, but at a later date it will break the weld and seperate again. no big deal ,normal behaviour on some multi -piece crankshafts...Jim