Cool project!

 

Id really love to see what this makes in the end. Question though why arent you changing the snout pulley to smaller one? Just curious

 

Good job on the custom work, I have a soft spot for PD superchargers

 

Smallest that will fit the new drive, its fatter. The inner diameter of the pulley is nearly scraping the outside of the drive so I have to run a 160mm crank to drive the blower to its limits.

Fell in love with it yesterday. The computer is getting the fuel sorted out and it is so smooth, responsive and quiet I went from buyers remorse and pissed off at the hassle to loving it. The engine loves the cooler temps. People with the old SOT kit and an AP2 would love this thing. I would guess they could get to 380whp on it if they maxed it out. When I first drove it with the fuel ratios way off and the bypass stuck partially open I felt like a total moron for spending the money and thinking "this is it? Even with the new pulley it is not going to be very impressive." I changed my mind. I thought I loved the rough, loud brashness of the MP62, I found this far better.

I don't have a way to measure inlet temp, but the guy who was swapping these in and making kits on the Elise board went from inlet temps at 12 psi from 240 degrees on the MP62 to 185 at the same boost pressure one the TVS900. You have to spin it faster but the max speed is higher and they really did a nice job with the efficiency. Given that I am not spinning it close to the max yet, my inlet temps are probably way down from the old SC. Although from the graphs I saw, even running it to it max speed will not increas the temp much from where they are now. I did not have an idea of what 20-24% more efficient would mean, but it seem to be impressive. If SOT was still making kits and using this blower, it would be such a nice option for people just looking for the ~350 whp range.

Huge power people would still be disappointed you can't make turbo numbers, but good lord is it smooth. I am still running the same timing curve as the hotter blower, and it is probably making quite a bit less power but I really had fun with it yesterday and can't wait for the new pulley. Even with the lower power I went from lusting after a Cayman to wanting to keep the car a few more years, I like it that much. The computer is sorting out the fueling after having run it NA for a few days, and it is getting more and more responsive.

To the guy who wants to do a TVS 1320 coldside kit, godspeed. I can't imagine how much fun that would be. To anybody with an old SOT kit (especially AP2) I'd say it was worth the time and money and I am probably down 40 hp or so from where I was until the pulley comes in. The new version of the blower was a nice leap forward. There is a size in between to TVS 900 and the 1320 that nobody is making right now that would have probably been great to try too, but oh well. If somebody wants to take the plunge and see if Magnussen, Harrop or another Eaton maker will machine one for you I bet 400 whp would easily be possible on an AP2. It is a TVS 1080 and nobody is cranking them out even though Eaton has designed the rotor assembly. I would seriously consider spending ANOTHER $2k if somebody made one and the size was close enough to fit to my existing kit.

I never thought the old blower was rough or coarse until I tried the new one. The Elise thread I was following he got 12% power and torque just dropping it in and changing the pulley to get the same boost, and this was before retuning to add more timing due to the cooler temps. I don't expect miracles from a retune, but just the nature of the car from the cooler temps and right now NA responsiveness is night and day at 80 degrees outside. Happy so far. Although, you guys would laugh at how ugly my finished bracket looks after they welded on the bushings. Super ghetto looking, but I don't really care. The welds are HUGE and rough looking for the $25 I paid. The bracket is double coyote ugly.

WOW Neema, I just saw the power numbers in your sig. You'd be disappointed in this blower. I am going to take it to Full Blown for the retune, but I just watched you drag vid and feel pretty dumb about talking up this blower right now. HO-LEE CRAP that looks fast. 143mph. WOW. 143mph. speechless.

 

Haha thanks! They are different beasts and I can definitely appreciate what you have set up for your car. I love the linear powerband of positive displacement blowers and the efficiency if twin screw. I wish SOS had made a kit using the blower they had on the NSX, would have been perfect for our cars.

 

Since these are positive displacement rotary lobe blowers, the 1.035 and 0.9 liters refers to the liters of air displaced per revolution of the blower. If you're spinning the blower 20,000 rpm, that's roughly 18,000 liters/minute of flow or approximately 635 cfm on a TVS 900. Note that this nominal displacement does not account for slippage. Since the TVS 900 is more efficient, I would expect the slippage (Qv) to be less and so in actual use, it probably flows about as much as a MP 62 while consuming less power and generating less heat.

Note that for a given speed (such as in a car with a fixed belt drive ratio), the blower will actually flow less at higher discharge pressure than at lower discharge pressure. The suction is the opposite. The higher the pressure at the suction of a blower, the more it is capable of flowing and the cooler the discharge temperature.


Tim

 

Updates?

 

Well, not yet. Both a loaner pulley courtesy of Kermdaddy, and then my original pulley at a local machine shop for a total of eight months and they made promises, lied, and never did ANY work on a new pulley for me. 8 months, and nothing. I gave them extra slack because the car was going to be down for the winter anyway. They also were going to charge me $350 to do a one off.

They refunded my deposit, and I sent my original to ASP Racing which was recommended by people on this board. They just recieved the pulley yesterday and I am told two weeks is typical turnaround but they only want $150.

The car sits without the pulley but when I have it, it will go back on the car ASAP and I will post some impressions from my car, still tuned with Emanage. The plan is to get a Haltech and retune at Full Blown but that depends on their schedule and my cash flow. Just have undertaken home improvement that was more expensive than I thought but hope to have the Haltech and tune by the end of June at the latest. I am getting anxious though to say the least.


EDIT* Just made a tune appointment for June 2nd.

 

Sorry to hear all the problems/delays. You are due for some good luck with the car.

Funny that you mention Kermdaddy, because I am about to sell him a diff (maybe tomorrow evening).

 

Wish I could make it down to full blown to see this thing on the dyno at that time, good luck!