Being retired I have lots of time on my hands so usually hit up the FB and Craigslist autoparts sections on a regular basis. I came across a Lysholm 1200AX that appeared to be too good to be true but I bought it with Paypal so that if I was scammed I could get my money back. It appears the unit was never used as the magic marker date is still on the rotors that matches the dremeled serial number/date on the case. Guy told me he won it in a raffle at a local speed shop that went out of business. I think I can get it mounted to my Thumper Performance TP-1.8 engine that has forged internals. The boost should be up over 20 PSI even with the larger engine displacement but I have a tuner that uses MPPS on the Facelift Siemens and can reset the TMAP scales accordingly.
I am using Smoothflow.com pulleys on my M62 and I reached out to Nate the Owner to see if he could fabricate a 2.625 pulley for me. I can send him my Lysholm pulley and then he can use a Cobalt/Mini pulley blank, milling the special receiver I need and also match the bolt/screw spacing. He confirmed he could and I told him I would send him something off in a couple of weeks. From some initial mock ups I know that a spacer is going to be required of about 3/4" as the Lysholm/Whipple snout will not clear the timing chain cover. I am in the middle of a clutch upgrade this week and should start bracket fabrication next week. Going to use some 3x5x1/4 steel angle.
I cobbled up some hangers with pieces of wood to determine if I really could make this thing work. Once I had it close to where I needed it I then went out and bought an 1/8" angle and a 3/4" tube to make metal hangers. I have the pulley center lines very similar to what the M45 snout provides. The hangers align the 1200AX with the horizontal axis of the engine while also maintaining that the long axis of the 1200AX is parallel with the engine.
Might have it on the car next week. At 14,500 rpms it will provide about the same amount of air as a TVS900 does with 18,500 rpms and require about 10 hp less to spin..
You may find this interesting it is from a post on lotus talk. If you would like to read the thread it is here https://www.lotustalk.com/threads/lessons-learned-after-7-months-of-exige-ownership.479031/ Getting that out of the car I got one more surprise. Actually I kind of was onto it early on in the removal process when I noticed that several parts did not look OEM. This is what I found: It is a TVS 900 supercharger (offered on the new Katana kits) rather than the MP62 and employs a slightly different method to mount the pulley. It also runs at a different RPM and boost ratio compared to the stocker so the pulley diameters will differ depending on the required boost. Further, the rotor design is different and is more efficient vs the MP62 and, thus, generates less heat under boost comparatively. Yay, good news for a change. MP62 at 8.5 PSI boost is on the 60-62% efficiency island TVS 900 at 8.5 PSI is on the 70% efficiency island As a side, using the above compressor maps, my calculations show about a 17 degree lower charge temp vs the MP 62 at 8.5 PSI boost (assuming 2 PSI pressure loss across the IC/manifold, 80 degree F ambient, and sea level). I found a source for TVS gaskets, replaced with new and reinstalled. Once It was back up and running, I found another PSI of boost, (9) and the car simply runs great. Now I’ve been focusing on other items like additional IC cooling (though not likely needed since I won’t track the car), upgrading interior bits, and having fun driving the darn car!!!
All in all not a bad hack job considering I used no special tools or measuring devices. The baby Lysholm/Whipple does not require the radiator or radiator shroud to be cut up or moved toward the front further. Used some brass plumbing fittings to connect up the PCV, brake booster and MAP lines. A PVC pipe coupler with some heat shrink tubing worked on the inlet tubing. The Lysholm uses 5w/50 synthetic oil with a 30k change interval. Used some more brass fittings to make the supercharger dipstick tube. For the engine oil dipstick tube, I cut a junk yard tube that I then used rubber heater hose to reconnect to traverse the tighter turns. A Cravenspeed dipstick works fine as it is able to travel around the tighter bends. I measured up the amount that the OEM extends into the oil pan and compared to the Cravenspeed. My dipstick tube is little longer so now the Cravenspeed correct oil level is in the middle of their drilled tip instead of being at the top. The Twin Screw has a lower "whine" tone than the Eaton and as noted above consumes less power than the TVS900 at the boost range I am pushing, which I swear I can feel with my Butt Dyno. My 2nd gear WOT times are faster by almost 1 second so I am quite pleased. I am aware of two IHI 1.6 Tritecs "over the pond" and RMW had a TVS 1320 but I am not aware of anybody else doing a 1.2 liter Lysholm/Whipple that requires allot less work to pull off than these others.
I did find an old post from Over the Pond where a shop had a Lysholm/Whipple 1200AX installed so apparently I am the second to have one on a MINI. Been putting some miles on with no issues and decided to have a 60 mm idler pulley made. The OEM tensioner is 65 mm and has a C3 bearing but I could not get the 2.875 pulley to fit. I have been using a 2" flangeless pulley on the tensioner but it will over spin the rating at higher rpms. I did a lot of searching but could not find a smaller idler pulley that would work on the oem tensioner without some major modifications. I have stopped tweaking the tune as I am going to change out the Thumper TPR2 head for his TPR2R that has larger valves and a higher rev limit. With the smaller valved TPR2 on a stock 1.6 engine I had 213 lbs of torque (4870 rpms), and, 268 whp (6716 rpms) with 17.3 PSI of boost. I have never seen a TPR2 head make that amount of power. Getting larger injectors to go with the TPR2R head as well.