KW V3 Arrived

My new KW V3 coilovers arrived while I was out of town. I came home to a fancy box. Looking forward to unpacking and going through everything in preparation for a possible install as early as this weekend. Thanks to Dynosty for getting them here so quickly and at such a great price.


I’m purchasing a new set of KW V3 coilovers this week. This is going to be a nice upgrade from the K-Sport Kontrol coilovers. I will be posting a nice review of the new set, and snap a few pics of the installation as well for a simple write-up.

What’s an Oil Catch Can?

So now that you have a performance motor you’re hearing about Oil Catch Cans and probably wondering what this is all about? Or maybe you know what they are but you’re not sure how to hook it up? No worries. This is a pretty common question and an easy one to answer.

On a car straight from the factory, they tend to re-route a lot of plumbing for environmental purposes, but this is not always the most efficient thing for the performance of your car. One of the things they reroute is the breather hose from your crank case. Inside the engine gases and sometimes a little oil will blow past a piston into the head of the engine. If this was not ventilated in some fashion, there would be a lot of pressure with nowhere to go. That’s not good. The factory solution routes these hoses using a one-way check valve back into the intake of your engine. So you’re feeding dirty, warmer air back into the engine. To make matters worse, there could be some oil residue in there and that’s going to gunk up things.

The aftermarket solution is to route those breather hoses to a catch can. The can itself can then be routed back into the intake, to atmosphere, or to your exhaust pipe to be sucked out. In a perfect world, you want some vacuum on the breather hoses to pull air and oil blowby out of the crankcase. So if you use a catch can and re-route it to the intake or to the exhaust then you achieve this result. However, it’s completely fine to just run both breather hoses to a catch can and then put a little air filter on the catch can and vent to atmosphere.

Oh, and in case you didn’t figure it out yet – the catch can accumulates the oil so that it doesn’t go back into the intake.

So here is the catch (no pun intended), you want to make sure that if you do re-route the catch can in some fashion that you are using one way check valves and that your catch can is baffled so that oil doesn’t go out once it has gone in. And remember, you’ll need to periodically empty the catch can. Once a month is usually about right for most builds, and it won’t be full.

Simple Catch Can
Nylon Braided Breather Hoses

Track Days

If you really want to have fun in your car once your swap is completed, you need to do some track events. There are four types of events (that I’m aware of) for you to participate in:

  1. Autocross
  2. HPDE (High Performance Drivers Education) Track Days
  3. Drag Racing (at the track, not on public roads!)
  4. Drift Events

I’ve actually yet to do a proper drag racing event or a drift event, but I’ve done 3 years of autocross and HPDE events. I recommend starting with autox to get a good idea of how your car handles with the new power and balance. Then once you are comfortable you absolutely need to do an HPDE event. This was the most fun I’ve ever had with my car. My theory is, learn to handle your car, then handle it under speed. Now when you feel confident in your driving ability go do a drag event. That’s my plan at least. This way, if your car gets loose on the drag strip you have a better chance of bringing it under control instead of crashing into the walls.

If you haven’t checked out this site, go do it now. It will tell you about most of the track events in your area.

Trying to hit the Apexes at Putnam Park

The Right Turbo

Most of the manufacturers producing turbos do a pretty good job. Your choice of turbo should not be decided based on one manufacturer over another just because you like their brand or the name better. What really matters is which turbo is best suited for your engine. I’ll give you an example. When I first built my RB25DET I was using a Bullseye Power (Borg Warner) S362 Turbo with a .85 a/r. This same turbo was producing 650hp on a Toyota Supra, but it was maybe hitting 400hp on a good day. When the turbo seals blew I went with a .70 a/r and had a bit better spool but still only about 421hp. So I started looking at compressor maps a little more closely and with a little help from a friend and some additional reading I determined that a smaller turbo like a GTX3076R by Garrett would be better matched with the RB25DET engine based on the math. Sure enough, the planning paid off because I hit 534hp with a SMALLER turbo that was spooling quicker.

So the key here is that a bigger turbo does not always automatically mean more power. Yes, if I would have continued to push the limits of my Bullseye Power turbo with race fuel and tons of boost, it would eventually make more power than the smaller Garrett. But that is just not practical for a street/track car hybrid and that power is not in the usable RPM range.

Be smart when selecting your turbo.  I highly recommend reading this book and running the numbers yourself. Maximum Boost

GT35R Knockoff, GTX3076R, Bullseye S362

Turbo Exhaust Manifold and Downpipe

If you’re working with a stock setup then you can probably find a downpipe for sale somewhere to bolt up for your swap. But if you’re working with a more custom setup then the downpipe is going to have to be custom fabricated to ensure a proper fit with your exhaust. The reason is because you’re going to want a custom exhaust manifold for the turbo application, and if you’re like me you’ll probably end up with a top mount turbo exhaust manifold.

There are a few things to keep in mind when selecting a turbo manifold:

  1. Never buy a generic EBay Manifold. You are asking for trouble. These are cheaply made, probably won’t support the weight of your turbo, and have a higher chance of cracking. Why take the risk of damaging your new swap?
  2. When planning for the manifold, be sure to take into consideration the downpipe placement with your steering column. There is not a lot of room for the downpipe or an external wastegate, but it can definitely be done.
  3. Not all manifolds will allow for the AC Compressor to be installed. If you want to keep your AC then you will need to make sure the exhaust manifold is built for that purpose.

You can spend a lot of money on manifolds, but the result can be worth it. Besides reliability, proper manifold design will allow for the maximum efficiency in airflow to your turbo. This means quicker spool and more power. Without going into a ton of detail, the main difference between a tubular, equal length manifold and a factory cast iron manifold is that you’re allowing the cylinder exhaust of each port to work in harmony to power the turbo. Otherwise you’re shoving air through the same area from different sources and those sources can fight each other, robbing you of power.

Here is an example of an Ebay manifold vs. two quality manifolds:

Cheaper EBay Manifold
McKinney Motorsports Manifold
Custom Built Lovefab Manifold

Engine Mounts

When doing a swap one of the first things you’ll need to tackle is how to mount the new engine in the vehicle. Fortunately, for common swaps there are usually several choices for engine mounts.

This is also true with the RB in the S14. Even though I had access to an R32 crossmember when doing my first RB20DET swap, I opted to go with the McKinney Motorsports engine and transmission mounts and retained the S14 crossmember. This allowed everything to mount up perfectly in the vehicle, including the shifter.

When it came time to install the RB25DET I ordered another set of mounts from McKinney and was equally as pleased. They really do a great job and they make the installation a breeze.

Used McKinney RB20DET Mounts

Carbon Fiber Hood

People have often asked whether or not a carbon fiber hood is a good upgrade. My opinion is that for a swapped motor in the 240sx it makes a difference in two areas:

  1. It helps with adjusting the weight distribution since you are adding in more engine and engine components in the front of the car. The carbon fiber hood weighs quite a bit less than the factory hood. At the end of the day you’ll want to corner balance the car anyways, but this does help. People laugh at me for saying it, but I can feel it when driving the car.
  2. I prefer a vented hood because it’s going to let some of that heat escape the engine bay. Remember, you’re stuffing a bigger engine in the car and you are generating more heat with performance additions, such as the turbo.

I have a Seibon hood with the vents in front of the engine and after the radiator. This allows the air passing over the hood to pull air through the vent. So the air is pulled off of the radiator and out through the vent instead of blowing additional hot air from the radiator onto the engine itself. This also means that the vents are not directly above sensitive electronic equipment, like the coilpacks.

I think it’s a great, practical upgrade, and it’s not something I did for the looks.

Just remember to install your hood pins to keep it from flying off at high speeds. I didn’t have them when this picture was taken, but I went with the Sparco hood pins for ease of installation. I still have a set of Aero Catch waiting to be installed. Maybe someday…

LS2 Truck Coil Pack Swap for S2 RB25DET

The factory coil packs, and the various generic replacements, have problems with higher hp applications. The problem seems to occur around 17psi and higher. The coil packs don’t generate enough spark for a good burn, and the only way to get your spark plugs to stay lit is to gap them extremely small. This, of course, reduces the quality of the burn and the overall performance of the vehicle can be compromised. Some solutions, including putting tape or liquid tape around the coil packs to prevent arcing do not solve this problem, as those are not true solutions for high HP applications. Instead of putting my faith in other replacement coil packs, such as the split fires, I have decided to upgrade to a significantly better coil pack… The LS2 Truck Coil.

Click Continue Reading to see the full write-up.

Continue reading LS2 Truck Coil Pack Swap for S2 RB25DET

New Site

Rad's S14 240sx

I’ve created a new website / blog for sharing information about my fairly lengthy and elaborate RB25DET powered S14 240sx project car. I’ll be adding regular updates on the build and tips that you’ll hopefully find useful.