Finally got out this week-end to get some real seat time on the sled. Up until now most of the riding has been on our test track (1/2 mile at a time) to test various parts of the design. We shot a piece of welding rod through the turbine blades a few weeks ago after making a new exhaust system (though I'd cleaned the exhaust thouroughly inside, must have missed a piece).
Anyway, after some final wastegate adjustments we're showing a nice even 6lbs boost. The manual boost controller worked well also, 10lbs can easily be dialed up while still riding the sled. Doesn't look like we'll be needing 10lbs though... Even at 6lbs a setup that would barely pull 10k rpm pre-turbo is bouncing off the rev limiter almost immediately. The Pop-off valve seems to work well, and throttle response is excellent. Boost spools up pretty quick, and the 1.25 Ripsaw along with a Cat ZR skid underneath are doing a decent job of getting power to the ground. Didn't touch the skid this week-end, but it will need a little more ride-in, and a bit more pre-load on the front.
One of the problems we were having initially was oil getting past the seals in the turbo. Originally thought that 60+PSI was a little high for a turbo (and it is) so we'd been running a .045" restrictor in the supply line to bring oil pressure down to about 45PSI. That was working much better, but we still would occasionally get some oil in the exhaust/intake. We've since re-designed part of the oil return system and didn't see any signs of oil in either the exhaust or intake all week-end, and that was with the restrictor removed. I think this one is solved.
All of the electrical systems worked perfectly. The A/F guage shows the motor as a little lean down low, and progressively richer as boost comes on. Some quick adjustments with fuel pressure moved things in the right direction, but will probably require a little jetting as well. For now running fat is just fine with me. I have two LED's on the pod, one showing that the fuel pump is running, and the other hooked to a pressure switch that gets its air from the Fuel Pressure Regulator's boost line. When the motor sees 4LBS boost, the light comes on. If I see boost on the guage but no light to go with it, something bad is about to happen. I didn't like the idea of possibly smoking a motor because of a kinked hose or 20 cent clamp not doing it's job, and this seems like cheap insurance...
We took it fairly easy this week-end, starting boost off at 3 pounds then slowly adjusting it up to 6-7. Even with a poor clutch setup, the sled will walk up to 120 MPH indicated without effort. No question that with proper clutching and suspension set-up, the sled will see well in excess of 130 MPH on the speedo.
Overall, I would say the weekend was a success. Clutching this thing is going to be interesting, but I have a few ideas on where to start. The intercooler blew off once after coming off throttle, and the POV needs a quick tweak, but otherwise everything worked out really well.
Anyway, after some final wastegate adjustments we're showing a nice even 6lbs boost. The manual boost controller worked well also, 10lbs can easily be dialed up while still riding the sled. Doesn't look like we'll be needing 10lbs though... Even at 6lbs a setup that would barely pull 10k rpm pre-turbo is bouncing off the rev limiter almost immediately. The Pop-off valve seems to work well, and throttle response is excellent. Boost spools up pretty quick, and the 1.25 Ripsaw along with a Cat ZR skid underneath are doing a decent job of getting power to the ground. Didn't touch the skid this week-end, but it will need a little more ride-in, and a bit more pre-load on the front.
One of the problems we were having initially was oil getting past the seals in the turbo. Originally thought that 60+PSI was a little high for a turbo (and it is) so we'd been running a .045" restrictor in the supply line to bring oil pressure down to about 45PSI. That was working much better, but we still would occasionally get some oil in the exhaust/intake. We've since re-designed part of the oil return system and didn't see any signs of oil in either the exhaust or intake all week-end, and that was with the restrictor removed. I think this one is solved.
All of the electrical systems worked perfectly. The A/F guage shows the motor as a little lean down low, and progressively richer as boost comes on. Some quick adjustments with fuel pressure moved things in the right direction, but will probably require a little jetting as well. For now running fat is just fine with me. I have two LED's on the pod, one showing that the fuel pump is running, and the other hooked to a pressure switch that gets its air from the Fuel Pressure Regulator's boost line. When the motor sees 4LBS boost, the light comes on. If I see boost on the guage but no light to go with it, something bad is about to happen. I didn't like the idea of possibly smoking a motor because of a kinked hose or 20 cent clamp not doing it's job, and this seems like cheap insurance...
We took it fairly easy this week-end, starting boost off at 3 pounds then slowly adjusting it up to 6-7. Even with a poor clutch setup, the sled will walk up to 120 MPH indicated without effort. No question that with proper clutching and suspension set-up, the sled will see well in excess of 130 MPH on the speedo.
Overall, I would say the weekend was a success. Clutching this thing is going to be interesting, but I have a few ideas on where to start. The intercooler blew off once after coming off throttle, and the POV needs a quick tweak, but otherwise everything worked out really well.
LICKETY SPLIT
Extreme
turbo
Hi,I ran my mc express 200 miles this weekend with no problems at all,I did not have to touch anything under the hood,started out at 4 pounds of boost,That did not last long after running it at 12#boost,finally set boost at 9# for now,no one beat this sled at 9# yet,and there was some good running 1100 big bore cats,just picked up a blitz pop off valve,thinking about mounting it on the flat end ot the intercooler laying down above the clutch looks like a good spot for it and there is room.where did you mount your pop off and what kind is it?I am running stock primary clutch ramps and springs,with a 58/44 micro belmont helix,and silver spring in secondary set at 90 degrees,It run right to 10200 and stops at 10500 rpms engages at 3000.I have a boost controller mounter on the dash so i can change the boost,takes about 10 sec.see ya
Hi,I ran my mc express 200 miles this weekend with no problems at all,I did not have to touch anything under the hood,started out at 4 pounds of boost,That did not last long after running it at 12#boost,finally set boost at 9# for now,no one beat this sled at 9# yet,and there was some good running 1100 big bore cats,just picked up a blitz pop off valve,thinking about mounting it on the flat end ot the intercooler laying down above the clutch looks like a good spot for it and there is room.where did you mount your pop off and what kind is it?I am running stock primary clutch ramps and springs,with a 58/44 micro belmont helix,and silver spring in secondary set at 90 degrees,It run right to 10200 and stops at 10500 rpms engages at 3000.I have a boost controller mounter on the dash so i can change the boost,takes about 10 sec.see ya
With my turbo mounted in the rear, I have a charge tube that runs over the oil reservoir - the (Greddy) BOV is in that line. Works well, and kind of cool to hear the "whoosh" sound coming out of a sled.
Snow Fever
Expert
Lkracer, glad to hear your stylin. we went out on the weekend and it was above 0c and mine was running planty hot. Still ran good but I had to open the hood every time I stopped to keep it from melting everything. My dealer has a MC-Xpress rear model coming any day and if it works well and doesn't plug off the air from snow dust (Being in the back) in deep powder I may convert mine next year over like yours. Good luck talk to you later.
Fever - holy sh!t, does t his thing work well now! If you want to do anything about moving it to the back let me know. I have all the templates and measurements for the mounting brackets, exhaust, charge tubes etc. I could probably re-build my system in a week. You were a huge help on this project, so anything I have that might be helpful to you is yours if you want it.
Now, when do the two home-built sleds get to do a little head-to-head?
Now, when do the two home-built sleds get to do a little head-to-head?
snowbeast
TY 4 Stroke God
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Wow installed kong .460 round cat springs into my zr skid from the weaker square .405 springs i had,but now w/my new front torque arm on,it wont squat down and transfer very well right now,hopefully when they take set it will soften them some,but it takes the bumps nice. :twisted:
