Please keep us posted. This is the first time I've ever heard of anyone reporting actual efficiency on a VP converter setup. Devon
I picked up a SP TH400 core last week if you decide to go that way I have the parts. I spoke to Jim at PAE a couple of weeks ago. Super nice guy.:TU:
I have not found a spot to do a wot pass in the city to see how the sp converter is on high stall mode. But here is a neat calculator, maybe some of you guys can get some data from your cars and see what numbers you get at 55 mph or so. http://www.wallaceracing.com/converter-slip.php
Norbs...how do you like it compared to a reg hi stall fixed pitch??? Do it leave just as hard out of the hole??? Overall are you happy with it?? Are you running a GV?? Thanks
I really can't say right now until i get some hard data. I am ordering a driveshaft speed sensor that goes on the diff. Once i have it set up i will be able to log everything and see what exactly is going on in the slippage area
I'm still waiting on my speed sensor, my logger is in but, still no good without a speed input. This is where i got my sensor from. This is the accel new wideband/datalogger i will be using. http://motorsportsinnovations.com/wb_Speed.htm
Does anyone have any 55 mph rpm numbers with a fixed pitch converter? Just need your tire diameter and gear ratio in the car, and we can come up with some idea's on slippage.ou:
Norbs here is some info on my my current converter.....its a 10" BTE thats rated 3400-3800 stall. On the highway at 60mph with the GV engaged its turned right at 2475 on flat ground. I have 26.1" tall tires and 3.55 gears. Tranny is a TH400. What size converter are you running?? An custom 11" or 12". I remember you saying it was an 2000/4400 I think. I have herd great things about the 1400/4000 if yours is to loose on low stall maybe you could switch to that one???
You are correct, however if its rated for 2000 rpm stall on the low and im driving above that point, i should have minium slippage. It is a custom 11" unit, as you can't go bigger using the JW bell. I may have to go with a 1500/3500 unit, but that would take weeks of waiting as the cores are getting harder to find. From you rpm it looks like your at 11% slip, which is almost identical what i am getting, provided my numbers are not off a bit. The problem is i can;t have a dramatic rpm change from high to low, on a turbo car it will just bog , i have to find the best mph to change from high to low stall, good thing my datalogger has a ouput based on mph/rpm/boost or thr combination of all 3!
With 3.55 gears and the Gear Vendors, final drive is 3.55 X .78 = 2.77........RPM@ 60MPH with 26.1" tires would be 336/26.1 X 2.77 X 60 = 2139 RPM (no slip) 2475 - 2139 = 336 additional RPM, 336/2139 X 100 = 15.7% slip. At least that's how I'm figuring it. Someone correct me if I'm wrong.
Ya Larry i was doing it wrong, i was taking the (higher rpm/lower rpm)/100 to convert it to %. But your way is correct as the tci caculator shows. http://www.tciauto.com/Products/TechInfo/Calculators.asp#4 So that means 6d9 and i are slipping worse than we thought:error:
Norbs...Yeah I knew I was slipping quite but it was expected with a 10" 3400-3800 stall and 2.77's! Larry...I know you have posted it before but with yours in low stall whats your slip at cruise?? Also whats your slip going thru the lights?? Thanks Ron
Anyone else with some data? MY datalogging stuff is still in the mail. I bet Larry is out there getting us some good data tonight!
Finally i got some logging going on. On very small accel in overdrive its 15.7%at 70 mph low stall mode. On cruise on flat road no accel at all its about 7-9% slippage, at 18 psi boost in drive not overdrive its 24% heavy accel at 80 mph. My speed sensor is a bit shakey so im not sure how accurate but its with in +/-2 mph i hope
Damn...24% slippage! Thats a ton. I know Larry's was much tighter from what I remeber him saying. Maybe he will chime in again. I would call PAE back and let him know whats going on. 24% in low stall is just not acceptable in my book.
I've PM'd Norbs several times. My converter doesn't slip anywhere near that much. At a steady 60 MPH cruise, on flat ground, in low stall, my observed RPM (Autometer Tach) is no more than 100-150 RPM above the calculated RPM with 0 slip. I have 27" tires and 3.73 gears 336/27 X 3.73 X 60 = 2785 RPM (0 slip), Observed RPM is 2800-2900. That is without the GV. With the GV my final drive is 2.84 336/27 X 2.84 X 60 = 2113 RPM, Observed RPM is 2250.
Right on thanks larry...hey what about under wide open throttle thru the lights. have you had a chance to check it like that?? Thanks
