7/8/2023 0 Comments Thumper racingWe will need the Cam specs and the rev intentions to insure the heads are at your needs. If the revs are to be at the 4500 and higher range on full boost and yet still need power out of the turns, then we offer our performance “Big Valve Head”. We do know that there are racers out there, and we do also make a head for the track and seriously aggressive drivers. And if the “off boost” is where we drive 70% of the time, then the higher flow numbers of a “larger valve” head means slower moving air and a low to mid range loss where we don’t want to lose it. We keep the stock valve size with a 5 angle performance valve job (flow cut on the valve) to maintain the good street manners, and yet with the correct port work in the runners, bowls and throat, it will pull hard till you reach the red line when on boost! Velocity is the key to a small displacement engine, as we are NOT on boost all the time. Our Stage 1 Street Performance Heads are modified to work with the basic mods used by most MCS drivers - the pulley, exhaust and CAI, yet still allow more power when a camshaft or other future modifications are added. Keep the low to mid range for the stop light to stop light drive and still have all the additional power needed for the higher rev aggressive driving we all love on the occasional Track Day. Power to keep the daily commutes fun and exciting. Our Ported Cylinder Heads reflect this idea. Our intentions are NOT to try everything, but to try and decide the best bang our buck! However, we will try to be a little bit different, as we will share all the data we have noted on those items, from OUR own cars, with actual road tests (SOP meter) and the Dyno sheets. When we find a procedure or an item that will increase the torque and the power levels, we will offer it up. in street conditions, where the airflow is poor.Īlthough we are primarily interested in Performance Cylinder Head Modifications, we will look into other mods also. The cooling fans at the dyno are primarily to cool the engine and NOT used to super cool the I/C, which will give an incorrect “actual” H.P. We try to keep it as real to the actual driving conditions as possible. The gains of power are proven on the Dyno. You can count on the products you see on this site to have been tested and installed on our own cars. So, I'll follow up when I can get it WFO, till then, a few more hours of limited throttle.We are dedicated to increase the performance of our MC and MCS through expanding new ideas and prior experience from our own engine building and racing experience. I'll be doing MX and scramble racing, enduros, trails and street/ parking lot super moto-ing it too. I fell for my Husaberg 570's power, hated the heat/electrical/design for wrenching. Both kits are said to really improve the low and mid range. The Athena kit is 290cc but uses a heavier piston and does increase vibration. Reliability is possibly better due to its extra piston ring compared to the Athena kit. Well, why KTM hasn't been building these as a 570 or 610cc is a mystery for the ages! The 280cc Thumper Racing kit is said to have the same vibration as stock as piston weights are very close. It was fast, it did what I asked, but lots of flywheel, not very exciting. I loved my 530 but always felt it lacked the sizzle. Still keeping it under 1/2 throttle but as smooth as stock, or better, the instant torque is right there and it'll knock the front wheel up just by thinking about it. It lit up on the first touch of the button and was idling like it had never been apart! I primed it with bursts of starter while holding down the kill switch. I've finished the heat cycles and first light break in ride and can't knock the stupid grin off my face. The install requires a case split and machine work to the base gasket area to fit the bigger cylinder, so a good time for a new crank and merged oil sumps too. I sent my previously big bored Thumper Racing 570 kitted 530 EXC engine to Travis at Thumper for a full blown 610 conversion and single sump modification.
0 Comments
Leave a Reply. |