ThruxTonUp
TT Racer
Ok I put the South Bay 813 cams in my Thrux yesterday, Fred had a pair laying around in the shop and Carlos has been after me to try them for a year now. My bike mods - bigger valves, cleaned up and matched ports, Mikuni 42mm HSR's, forged pistons with a 2 point bump in compression. Still an 865 motor, Predators and K&N's. Cranking compression is 230 PSI inthe left and 225 PSI in the right - THANK YOU Keith for those outstanding numbers! I put the new forged pistons in the stock bore with new Triumph rings - no honing per the race shop experts advice after examining the bore (18,000 at that point, 33000 miles now). Many on another forum said the bike would not make compression, the rings would not seal, Nik a sil sucks, you need iron bores, etc. Even Fred the guy tuning my bike is on the iron bore kick - nik a sil is for water cooled, no good for air cooled, and so on - man was he surprised when we did the test yesterday.
I WILL have dyno sheets for this bike and Scott's later BUT the damn printer was out of ink yesterday. The Short story is this - installed the cams, checked the lash and put her on the dyno. We did a base line dyno run last week for our starting point. Engine has to be cold to lash the valves. First run we made 5 RWHP <increase>. Jetting we did last week is now ALL out of whack with the new cams. Short story again, changed to 32 pilots, 155 mains, changed the needle clip, NEED the accelerator pumps Installed - but did not have. Synced the carbs, set the idle - about 12 dyno runs later we had made 10 more RWHP and 4 foot pounds of torque. Thats a 17 % HP increase and 8 % torque increase. The good news is (and you will see this on the Dyno chart latter) the power was ALL the way across the board and not spikes or peaks in comparision to the stock 865 cams. Needless to say being a cam skeptic for so long this really surprised me - I had just not seen anything out there to verify cam performance. The number surprised Carlos even more, he gave me a 5 RWHP increase estimate on the phone Friday. I'll get numbers posted this week. On Scott's bike we made 102 RWHP with the D&D 2 into 1 - 69 foot pounds on the torque yesterday. Still with the FCR 39's and the 813 cams. Dyno sheet on that monster to be posted this week too.
I WILL have dyno sheets for this bike and Scott's later BUT the damn printer was out of ink yesterday. The Short story is this - installed the cams, checked the lash and put her on the dyno. We did a base line dyno run last week for our starting point. Engine has to be cold to lash the valves. First run we made 5 RWHP <increase>. Jetting we did last week is now ALL out of whack with the new cams. Short story again, changed to 32 pilots, 155 mains, changed the needle clip, NEED the accelerator pumps Installed - but did not have. Synced the carbs, set the idle - about 12 dyno runs later we had made 10 more RWHP and 4 foot pounds of torque. Thats a 17 % HP increase and 8 % torque increase. The good news is (and you will see this on the Dyno chart latter) the power was ALL the way across the board and not spikes or peaks in comparision to the stock 865 cams. Needless to say being a cam skeptic for so long this really surprised me - I had just not seen anything out there to verify cam performance. The number surprised Carlos even more, he gave me a 5 RWHP increase estimate on the phone Friday. I'll get numbers posted this week. On Scott's bike we made 102 RWHP with the D&D 2 into 1 - 69 foot pounds on the torque yesterday. Still with the FCR 39's and the 813 cams. Dyno sheet on that monster to be posted this week too.