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I bought an 07 is350 a couple months back and its a great car, however it feels like the car would be perfect with an extra 30-50hp. I am not 100% sure I'll actually follow through but I am hoping to run ~5psi or whatever within about $2000. I have a few leftover parts from when I supercharged my mustang years back and I can make/machine some of what I need at work. Plan is to see if I can get a good deal on a vortech v2 as its supposed to be one of my quieter options. I hope to get this done by the end of summer, but it mostly depends on how well I can find everything within what I want to spend.
Right now I have a spare crank pulley and a bracket to use a procharger. I think I can figure out the pulley situation with these, and use the bracket as a starting point in making a bracket for whichever blower I actually end up with.
Slight update. I was able to get an unused v2 sci for 1145. I set the bracket for the procharger on it and there is no way I can adapt it. I kind of expected this so it's no big deal. Not sure when I'll be able to get around to making the bracket but it shouldn't be too hard. I'll move forward with purchasing an intercooler and piping once I have a bracket made with the blower mounted. I haven't looked yet, I'm not even sure how it will fit.
Hopefully I am reading the compressor chart properly. It looks like spinning it around 30k should get me what I want. The pulley I'm going to piggy back onto the crank pulley is 4.72" and according to vortech www.vortechsuperchargers.com/page.php?id=33511 the 3.8" pulley is a good starting point.
show us your math.
Guys who have used the rotrex had issues with belt slippage. I think they maxed out at 5.25" 8 rib crank pulley. If I were you, I'd start there and see what size pulley that would require at the S/C.
Or were you just able to source a 120mm crank pulley and already have it?
My math below. If anyone here actually knows this stuff, id be very grateful for any input or advice.
I assume the fuel system is good for 350hp which seems like plenty of power for a DD. I did some probably poor math to see what I would need for that. The CFM for the engine with an assumed 90% ve rounds to 355cfm at 6500rpm. Average stock power rounds to 260 wheel hp, so 355/260 = 1.37. poor math for cfm needed for the 350hp is 1.37*350 = 479.5. Eyeballing the compressor map it appears that ~480cfm at 5 psi happens at 30,000rpm. This 5psi gets me in the mid 300hp range fits pretty closely with the few examples boosted is350s I could find online. So I found an underdrive pulley for an is300 or something online for ~35 bucks. I would prefer a larger pulley but the holes for a puller or whatever line up just the same as the spare is350 crank pulley it looks like I can machine the back down so it fits flush on the crank pulley. The pulley is right at the same size as a CD, so that rounds to a 4.72 drive pulley for the supercharger. Vortech supplies the online calculator posted above for calculating impeller speed. According to their online calculator, with a 3.8" pulley the impeller will close enough to that 30,000rpm range at 6600rpm. I am sure the actual math is bit more complex but hopefully this gets me a close enough starting point. Realistically ill likely be happy with another 50hp so if my poor math fails me I should still be good.
As far as the belt slip thing goes I have no idea what problems I will run into but ill try what I can to keep it to a minimum.
If you check those threads that are linked by mike33, I think you'll find Mike and Stew were able to run around 7psi of boost before they got too lean. That would give you a pressure ratio of 1.5. the v2 sci can run up to 53k rpm so 30k you are talking about is pretty low. Even if you switched to a 5.25" crank pulley, that would only spin the S/C at 33.4k rpm, would it not?
I don't know enough about superchargers, but don't you run the risk of not having much boost at low rpm? I mean isn't it possible the v2 is oversized for your application? OTOH, you already have it, it was not too expensive, so even if it doesn't kick in much until higher rpm, I guess you can't complain.
I'll be following this. I'm hoping this works out well for you.
What am I chop liver and don't forget about Adam (HeyArms)! I just installed a 2.15" procharger pulley yesterday from a 2.55". Going to test her out today. It took me about 6 months and $5k to S/C but its all worth it. I wish you luck!
If you check those threads that are linked by mike33, I think you'll find Mike and Stew were able to run around 7psi of boost before they got too lean. That would give you a pressure ratio of 1.5. the v2 sci can run up to 53k rpm so 30k you are talking about is pretty low. Even if you switched to a 5.25" crank pulley, that would only spin the S/C at 33.4k rpm, would it not?
I don't know enough about superchargers, but don't you run the risk of not having much boost at low rpm? I mean isn't it possible the v2 is oversized for your application? OTOH, you already have it, it was not too expensive, so even if it doesn't kick in much until higher rpm, I guess you can't complain.
I'll be following this. I'm hoping this works out well for you.
Yes others have gone further, however I am not so sure I can squeeze in a methanol kit within my $2000 budget. Yes this is taking it easy on the blower, I don't expect it to add too much power below 3k which is fine by me. I am not looking to create any traction problems and the steep gearing offers enough acceleration as is anyway. I ended up ordering a 3.6" pulley anyway, its not too much more than the 3.8" and I found it cheaper on ebay than a 3.8" pulley. I also started working on the bracket, I have a piece of plastic I am going to make a test bracket out of. I ordered an idler pulley and a spring loaded tensioner. Once I receive these pulleys I can finish the bracket and test fit the vortech.
I am currently undecided about the intercooler. I already have a few parts to do an air to water setup but for a DD I like the simplicity of an air to air intercooler. I am also not looking forward to the boost/afr gauge situation. I need to find a spot on the exhaust I can mount the wideband sensor and a non intrusive spot to mount the gauges. Ideally id like to make sure everything runs fine then keep them to be out of sight.
Glovebox gauges? There's a member who's parting out his car who has a nice hideaway nitrous controller and gauge in his glovebox. looked nice and clean.
I think I am going to go with an Innovate PSB-1 for a gauge, it is everything I think I will need. I added up what I spent and I am $1445.09 into this. I still need to buy the intercooler gauge and piping which add up to $486.20 if I buy what I am looking at. It is looking like I will be close to pulling this off in my $2000 budget. If I can do it cheap enough I will consider trying some trunk mounted meth kit. I need to do some more reading but I am feeling fairly confident in this.
07-11-15, 02:30 PM
slowly supercharging my is350
and don't forget about Adam (HeyArms)! I just installed a 2.15" procharger pulley yesterday from a 2.55". Going to test her out today. It took me about 6 months and $5k to S/C but its all worth it. I wish you luck!
