Hey, man, I plan on getting the supercharger, too, and I’ve been following your buildup. I was wondering if you’ve actually put the 3.25” pulley on your blower yet. In your quest to make really big power, I want to suggest a couple of other things you might want to do. First of all, have you done the “Hobb’s switch” trick (leaving the vacuum line unplugged so the T-Rex pump runs all the time, not just under boost). Search the forum for more info on that if you need to. Keep in mind that your stock fuel injectors will only allow you to make a certain amount of horsepower. You may want to talk to RC Engineering about upgrading your injectors. See the May issue of Sport Compact Car p. 302 for the formula used to calculate the maximum horsepower you can make given the flow rate of the injectors you’re using. BTW, do you know if our injectors are the Peak and Hold or Saturated style?

I would recommend you get an air/fuel ratio meter (about $50) to see if you’re running lean, which is a very real possibility if you’re pumping 10 psi of boost w/the stock injectors. An Apex Super AFC (air fuel controller) will let you adjust the air/fuel ratio so you can get everything set correctly if you get new injectors (preferably while on a dyno). Your sig says that you got an intercooler. Which one did you get? From what I understand, there is about a 3 psi pressure drop going through an intercooler, so you may need to compensate for that somehow (smaller pulley?). A boost gauge would help in determining that (you would want to locate the gauge after the intercooler).

You’ll probably want to get the Quaife differential to help put that power to the ground, too. It should be out within a couple of months. Also, by then Stillen should have an aluminum flywheel available for the 5th gen Maxima. May as well replace the clutch you’ve already purchased, flywheel, and differential at the same time.

With the 3” exhaust, do you notice a loss of torque at low rpm/off boost situations? What did you do for a muffler?

Let me know if you incorporate any of these ideas and keep us posted on your progress.

 

Yes I already have the 3.25" pulley installed.
The following are not installed yet (will be installed Mon.)
* 3" exhaust
* Centerforce Dual Friction clutch
* Autometer Boost & AFR gauge
* Intercooler (prob. wont install till running over 10psi)
To reply to your suggestions:
1) The Hobbs switch was never hooked up.
2) I already spoke to RC Engineering & they do not make any injectors for my application. I am currently researching which injectors to use along with either an APEX'i S-AFC or a Fields Hyper-R fuel controller...since nobody is currently able to re-program the ECU...
3) I remember seeing a post that someone lost 3 psi with the installation of an intercooler. I find that hard to beleive although if i remember correctly it was a water-air intercooler & that could be possible. Typical pressure drop w/ an Air-Air intercooler is usually less than 1psi to about 1.5psi MAX....unless you do a HORRIBLE job with the I/C piping.
4) With regards to my boost gauge...I dont think you quite understand how that works....you don't "locate it after the intercooler"...the gauge simply taps into a vaccuum line off of the intake manifold.
5) With forced induction applications (Turbo/S.C.) BIGGER is always BETTER....it's completely different than with a naturally aspirated car....the more flow the better...PERIOD. There will be no loss in low end power/torque with 3" exhaust...Backpressure is your enemy when running forced induction.

I will keep everyone informed during my build up.
Dyno runs, tuning, E.T.'s & mods will all be posted as they come.

 

Thanks for the reply. I got the “3 psi pressure drop though an intercooler” info from ATI Prochargers website (http://www.procharger.com/). In the “Head to Head Dyno Test” section, comparing a non-intercooled Vortech blower to an intercooled Procharger on a Mustang, the Vortech had 9 psi at the blower outlet and 8.2 psi intake manifold pressure. The Procharger had 11.2 psi at the blower outlet and 8.2 psi intake manifold pressure, hence a 3 psi drop through the air-to-air intercooler. Since you’re interested in intercooling, check out their page on that (Technology>Intercooled Supercharging).

Also, have you considered getting colder spark plugs? They will help prevent detonation. In the owner’s manual, under engine specificatins, it says that heat range 6 spark plugs are a “service option” (5 is standard). If you’re interested in Denso iridium plugs, stock NGK5 equals Denso IK16, and NGK6 equals Denso IK20. If you want info on that, call Denso at 1.888.511.4312 ext. 3008.

When I get my supercharger, hopefully around the end of summer, I’m mulling over the idea of getting the Unorthodox Racing underdrive pulley and the 2.62” blower pulley, which is the equivalent to the 3.33” pulley w/the stock crank pulley. The UR pulley is such a nice piece, and combined w/the aluminum flywheel (which should be out by then) reciprocating mass will be reduced by a significant amount.

Anyway, good luck with your buildup!

 

That seems like a good idea. How'd you figure out that setup is the same as the 3.33" pulley?

 

Well, I had a picture of the stock and UR pulley side by side. I measured the 2 on my computer screen in millimeters. I then divided the the size of the UR pulley by the size of the stock one and got the percent reduction in size (stock 70mm; UR 55mm on my screen; 55/70 = .79 or 79% as big). It doesn’t matter that I measured them on my screen; it’s the difference between the 2 that does. Since you have both pulleys, you could actually measure the 2 and then use this formula, but the percent will be the same. Anyway, I looked at Vortech’s website for all of the pulley sizes available (it’s the 6-rib style). The smallest one is 2.62”, and if you take 3.33 x .79, you get 2.63, a near perfect match. In other words, it’s the ratio between the 2, not the actual size, that counts. Simple, no?

 

OH...you're comparing the pressure drop as the difference between the pressure at the blower compared to the pressure at the intake manifold....OK....then 3psi is probably accurate....but you must realize that even WITHOUT an intercooler you will see pressure drop between the two.... it is inevitable...especially considering the large amount of piping in the 2K maxima kit...I'm talking about the difference in boost at the intake manifold after the intercooler is installed (compared to w/o the intercooler) and that shouldnt be more than 1-1.5psi.

Yes I do plan on getting some plugs with a colder heat range...just not looking forward to swapping them out since it looks like a huge pain in the anus.