A Nissan Sentra Forum banner

1 - 13 of 13 Posts

1,109 Posts
Discussion Starter #1 (Edited)
Some of you have known my build since it was conceived in 2013 - and I figure it is time to do a write up of some pros and cons plus some tricks/tips on what it actually takes to Procharge the QR25DE in the Sentra SER and/or Spec V.


The Pros are very simple:

-Boost when you want it. The thing makes little to no boost until you hammer the accelerator pedal or get up to a load where vacuum dissipates and boost is finally created
-The cool jet engine noises under idle and partial throttle
-The bypass valve venting out on wide open throttle shifts is a wicked sound
-Rarity and uniqueness
-Being able to say you HAVE a Procharger and watch people's head cock to the side like a confused dog
-It's very, very, very fun. Just enough power to daily drive and spank a few cars on the road in your 2700LB car
-The noise turns heads on the street and cocks heads at car meets and shows due to the unique pipe routing
-People mistake it for a turbo, and you'll have to explain to them that it is indeed not (humorous if the person inquiring is new to cars or obviously doesn't know cars)
-It's loud - a 4 cylinder supercharged engine, I mean.
-If you have a Revolution Auto kit, well, you've just hit unicorn status (mine was apparently one of the original prototype kits and proof was in it's lack of finesse)

The cons are also simple:

-Cost (if you research the price of the C1A headunit they are ~2700USD or $3400 CAD currently)
-Prochargers are a "sensitive" type of blower - I'll get into that later
-Prochargers are a wearable item and eventually will need a rebuild
-Procharger oil changes become a part of your maintenance routine; blower comes off, drain, fill, blower goes back on.
-You have to understand the internals of how they work relating to the above points (learn from my mistakes)
-The C1A is not a commonly sold blower anymore and they are getting harder to track down
-If you end up in a bind, it is nearly IMPOSSIBLE to get any information regarding the internals of the headunit direct from Procharger (bearing sizes, seal part #'s etc.) I will provide a listing of parts that I have first hand documented while in the middle of the "COVID19 Pandemic" and couldn't ship mine out
-People mistake it for a turbo, and you'll have to explain to them that it is indeed not (it gets really annoying)
-It's loud - a 4 cylinder supercharged engine, I mean. Loud enough that you will have to learn to love it in comparison to a turbocharged engine. Your neighbors will hate you.
-The kits are RARE to find, so expect to need some brackets fabricated
-Your supercharger pulley determines your engine red-line. Larger pulley = extended red-line capability, smaller pulley = more boost but lower red-line capability due to the C1A internal RPM limits. If you need some help with that math, look here: ProCharger C1: pulley sizes and rpm limits

Now, I have to say. I LOVE my Procharger and everything that comes with it.

To start it all off, you need to acquire the blower or find one of few kits in existence. I'm going to go out on a limb and say that you haven't been able to find an OG RevAuto kit. Once you have the blower, you'll need some mounting brackets. Unless you have the RevAuto kit, you'll need to have a set fabricated. I have given out my tracings to Caleb Warren once upon a time who has sold a few sets; and a good friend of mine is creating a new-and-improved bracket made with a press-braked piece with 3 head mounting holes instead of the original welded 2-piece bracket with 2 head mounting holes.


Once you have the Procharger and brackets, the intercooler plumbing is fairly simple. And yes, you will need an intercooler. Don't you dare buy some cheap eBay special on an intercooler. The Procharger needs to be able to breath, and you want the most boost and least amount of lost boost pressure, yeah? Good. Get a decent intercooler. NO BDSO eBay intercoolers.

This next part is pretty cringy. You'll need to use a 3" hole saw to cut a hole through the engine by right next to the frame rail in order to route your intercooler hot-side piping. We did it right on the first try, and I hope you all do as well. My advice and what we did was mount the blower with the first coupler attached with some white paint marker or chalk on the coupler lip and traced it out.

I started my first kit off with some hacked up intercooler piping attached to an AEM intake with a blow off valve flange welded in. It was gross and crude. This eventually evolved into some minimalist hot side piping (2X 90 degree bends) and minimalist cold side piping (1X 90 degree bend, 1X 45 degree coupler, and a 2J Racing cold air intake with a bypass valve flange welded in).



You will need to upgrade the fuel system. Because I am running the 2.25" pulley, it is good for ~14-16 PSI at 6800RPM heat soak pending. The larger pulleys (2.55" or 11ish PSI or 2.80" os 9ish PSI at ~6300RPM ) With any boosted car should also have an aftermarket set of injectors. I'm running a Walboro 255LPH fuel pump and Bosch 900CC injectors.

So now you have your belt-driven-spinny-boy blowing positive pressure - read this carefully. DO NOT UNDER ANY CIRCUMSTANCE USE A NORMAL ADJUSTABLE BLOW OFF VALVE. For example, the original RevAuto kit had come with a Greddy RS blow off valve. It's internal spring is far too tight to run a centrifugal blower, and sits at somewhere like 16-17 inHG. Meaning, it does not vent (if any) in vacuum. Great for a turbo application, sure, but not with a centri blower. Yes, I messed with mine a few times to loosen it up but the solution is easy - get the right valve. You'll need a bypass valve or a "static" blow off valve with a mega light spring. Tial offers a ~2 inHG spring in their Q50 http://www.tialsport.com/documents/w3_tial_qqr_sp.pdf and TurboSmart offers a 4inHG spring in their Raceport bypass valve for a blower setup https://www.turbosmart.com/product-category/products/blow-off-valve/50mm_raceport_blow_off_valves/ . Or if you have deep pockets, go with "Big Red" from Procharger themselves Details . The "why" I'll explain below 馃憞

Referring to my comment about Prochargers being "sensitive"; A Procharger is not a turbo. At idle the headunit pushes a ton of air. All the time. Idle, partial throttle, deceleration; it is ALWAYS pushing compressed air. You honestly wouldn't believe how much air is moving at idle alone or how much vents out. Due to the nature of a normal blow off valve like the Greddy RS, that compressed air has no where to go and will cause a constant surge because that blow off valve will NOT vent it out and that is what the centrifugal unit needs. Surge totally sounds cool, but it's not in the case of a Procharger. The backup of compressed air itself and surge will cause premature wear of the bearings and seals and eventually will be the demise of your expensive blower. As compressed air is hot, this can also damage the blower internals from excessive and long periods of constant heat. Not only that, but it will degrade you intake-air-temps. From one of my local Procharger specialists, "anything over 9PSI with a tight blow-off valve will cause internal damage to the headunit after time whether that be 5 cycles in boost or 5000". Well. No longer news to me, the Greddy RS played a big role in killing my C1A. If you have one already, get it off there and read below. One of the quirks of the OG RevAuto kit is that it did indeed come with a Greddy RS BOV, unfortunately that wasn't very well thought of (in my opinion).

You'll need a bypass valve built for a supercharged car. Tial Q50 (supercharged spring of ~2-3inHG), TurboSmart RacePort (supercharged spring of 4inHG), or a Procharger branded bypass valve will all have a much lighter spring that will vent the excess air when at idle, partial throttle or deceleration and then will hammer shut as soon as it's time to party. You'll get cool noises from constant venting and massive bursts of air when you let off out of boost all while keeping the blower happy. Procharger stresses that you do not use a direct vacuum port on the engine to connect the bypass valve to - you'll want some form of a vacuum block positioned between the brake booster and the intake manifold.



So now we have discussed the blower, charge piping, bypass valve and fuel system to get air in, now you'll need to get air out of the engine.

Currently I am running a Nismo exhaust manifold, a 3" Stromung midpipe and 3" Stromung exhaust. With any boosted application it goes without saying that you'll need to upgrade your exhaust system size. You'll want to explore the likes of a good flowing header such as the Nismo, Stillen (if you can find one) AEBS (once again if you can find one) or the Armonic Nismo replica. No bottle-necked exhaust. Keep it consistent from the header flange to the muffler. As I'd mentioned, you will always have air being fed into the engine at all times, so get used to a loud car after the installation. As I'd mentioned for an intercooler, I'll say it for the exhaust. NO BDSO exhaust manifolds!


With boost comes the necessity of a catch can for blow-by. You'll want to refer to Karl Smith (MisterNuts)'s diagram and thread. You'll need to cap off the air intake piping PCV nipple as well as the port on the top of the intake manifold. You'll run one line from the back of the valve cover to the catch can, and the line out of the catch can into the PCV port on the driver's side of the valve cover. This is PCV line routing is unique only to the Procharged B15's. The turbo routing or naturally aspirated routing will not suffice. You can read about that here: How to correctly set up your PCV system and/or catch can Currently I'm running a massive Vibrant Performance baffled catch can. It does the job well, and if you have your battery relocated you can bolt VIbrant's provided bracket to the two bolt holes above the driver side headlight (near like a glove, just needs a slight ovaling to fit one of the holes). You can find that here: Vibrant Performance Universal Catch Cans 12695 or go with one of the Saiku Michi cans.


To make all of this happen you'll need a tuning solution; UpRev has done some really cool stuff lately with the RealTimeTuning and as we all know, 5 maps on a stock ECU is pretty nifty for what is available to the QR25DE. You'll want a competent tuner that understands the way a Procharged engine operates, and obviously a tuner how understands the engine itself.
The rest of my engine has been built with a bunch of stuff. JWT S1 cams, a Cometic headgasket, ARP head studs, JE forged pistons, K1 H-beam rods with ARP hardware, ACL bearings etc. etc. I don't want to re-kindle old flames with my sore spot about some certain rods but having a tired old OE engine will not suffice for long. Get at least your bottom end built with some reputable rods/pistons and upgrade your head as you wish with a good headgasket and head studs.

One thing most overlooked things is the air filter itself. A lot of your well known branded air filters are in.. well.. the same factory. AEM, K&N, AirRaid, etc. are universally the same but in different quality and marketing. The small cone filter provided in the RevAuto kit was puny. I would't hesitate to call that cone filter a "restriction". Having a larger volume air filter is always a plus. Because that puny filter isn't doing much for the breath-ability of the blower, I recommend building a 3.5" air intake of sorts. I currently have mine in what would be the wheel-well area, but for a period of time ran my air intake for the blower right up into the foglight hole. It sounded neat, but I got tired of having to clean the filter so often from bugs and road debris. Only use an air filter that doesn't have a stepped cap - IE: an air filter that doesn't have any risk of separating and being ingested. I'd learned that lesson from a friend who had a Spectre air filter with a stepped cap destroy his Precision 6262 and consequently his engine. K&N footed the bill 馃檭



-get a proper bypass valve
-you can utilize the old washer fluid reservoir area for a cold air feed for the blower (if you're good with a ball-peen hammer) as it's a 3.5" air inlet.
-the boost is addicting and you'll likely burn through fuel fast just to hear the "PHHSSSHHHT"

I know, the Procharger will never be as fast as some of the turbo cars, but it's honestly a fun time and fun driving experience. 355WHP/318WTQ has been more than enough for me, and this round coming up in 2 weeks we hope to see 385WHP/340WTQ. I'll update this thread after with photos and videos.


Super Moderator
5,588 Posts
I read bits and chunks, only cause I'm going to use a rotrex unit, but will re-read later.

Interesting info on the bov, it reminded me of a 'one off" for some reason where a s/c build used waste gates instead of bov... I'll see if I can find it again.
  • Like
Reactions: Tritton

377 Posts
Did you think of or explore a recirculating valve like they have on the Eaton superchargers instead of the lightly-sprung BOV to solve the overboost on idle ?

1,109 Posts
Discussion Starter #5
Did you think of or explore a recirculating valve like they have on the Eaton superchargers instead of the lightly-sprung BOV to solve the overboost on idle ?
I'd looked at that, but in my mind it would be "just another thing" added into the mix and use up unnecessary space in that area behind the bumper/frame rail, inside-bumper shape to route around etc.

The issue isn't really with or without a re-circulation valve but with having almost all of that compressed air venting out of the charge system when in vacuum. Keeping a regular hard spring BOV with a recirc wouldn't accomplish the job other than muffling the explosion of air between shifts (however if using a similar valve to the Eaton, I think they are 10 inHG which is better).

It's far simpler and cleaner to just vent to atmosphere (y) The same vent-to-atmosphere approach is used still by the Camaro, Mustang, Corvette guys. Some kits come with a recirc valve but from what I have seen most guys ditch it for a VTA system anyways 馃し鈥嶁檪锔

Good Q, Kev.

377 Posts
What did you have to do with the power drive belt ?
I guess you had to use a longer one and how did you get it to wrap around the Procharger pulley and the Alternator tight enough with them so close together ?

5,167 Posts
Interesting read and awesome build. I knew something was in the works.

Doesnt the pulley bolt to the alt or something?

5,167 Posts
The actual pulley to the supercharger.

1,109 Posts
Discussion Starter #13
What did you have to do with the power drive belt ?
I guess you had to use a longer one and how did you get it to wrap around the Procharger pulley and the Alternator tight enough with them so close together ?
The belt hasn't had any issues - the belt size took some trial and error, but with the stock tensioner, it's routed off the idler pulley, over and above the blower pulley and back down onto the alternator pulley back to the AC (or AC delete in my case)

Haven't had any slip with the GatorBack. I think it was a 96" belt iirc, could be wrong.
1 - 13 of 13 Posts