SR20 Motor Options

The first step is to determine which SR20DET you will want to swap into your chassis. There are a few different options from different model years.

• S13 Redtop – offered from 1991-1994, this came in S13′s. It’s your base SR20DET motor with a T25 turbocharged at 7PSI clocking in at 205hp and 203tq.
• S13 Blacktop – offered from 1995-1998, these are almost exactly the same as the Redtop S13′s, except for a few small changes in the ECU, o2 sensors and wiring harness. The real benefit of the blacktop over the redtop is that in general they have less mileage.
• S14 Notchtop – offered in S14′s from 1995-1998, this version has a few upgrades over the S13 variants. It comes with a slightly larger, ball-bearing (Japanese spec) T28 turbocharger and variable valve timing on the intake cam. At 7PSI this motor comes in around 217hp and 203tq.
• S15 Notchtop – Some more changes here including larger injectors and a redesigned intake manifold let this monster put down 245hp and 202tq.

When considering which motor to go with, ask yourself “how far do I want to go?”. If you’re just looking to increase your horsepower with a stock SR20 swap, an S15 blacktop might not be a bad investment for the extra power over the redtop. Conversely, if you’re planning a full build, consisting of new camshafts, a sleeved block and forged internals, the extra spent on an S15 blacktop will be a waste.

Emissions Considerations
Anytime you’re performing a swap you’ll need to understand how emissions testing can come into play. To generalize the different laws, there are three “levels” of emissions.

1. Easiest – States such as Florida have no emissions laws. Swap what you want, any motor, any year, any model. Essentially there are no restrictions against swaps.
2. Middle of the Road – States like Connecticut and Rhode Island have emissions testing. However, it’s not quite as strict as CARB certification states. Using Connecticut as the example, any car that is more at least 25 years old is exempt. So, as of writing this, all S13′s are required to pass emissions. Since S13′s never came as OBDII, you’ll be subject to a “tailpipe sniffer test”. You’ll have to hit certain o2 and NOX limits. This usually means a good catalytic converter is necessary.
3. Hardest – Without a doubt, CARB certification states are the hardest. I won’t try to delve into the details of getting a swapped car to pass BAR and CARB certification. Though I will say going through legal channels can be an annoying and lengthy process.

Keep in mind this is a simple list and the laws vary, state to state. It’s generally always difficult if you live in a state that requires emissions testing. Most states have websites dedicated to their emissions process that can be of some help.

Stock Parts List

• SR20DET complete wiring harness
• SR20DET igniter chip
• SR20DET aftermarket radiator
• SR20DET SOHC MAF
• SR20DET downpipe
• SR20DET ECU
• Don’t forget the complete motor and transmission

You’ll need to consider other non-stock parts such as a front mount or side mount intercooler, although there are stock options available for those parts. As with any motor swap guide that we write, it’s smart to consider replacing the clutch, pressure plate and flywheel with a stronger, aftermarket unit. The same goes for the water and oil pump. Also consider placing the battery in the trunk with a quality relocation kit, or buying a smaller size battery. It’ll save space and generally better distribute the weight.

To Clip or Not to Clip?

It’s common with S13 swaps to simply buy what’s called a “front clip”. A front clip is essentially a shell, chopped at the a-pillar. You’ll receive the whole motor swap, ECU, harness and all the accessories unharmed. It’s a great route to go if you have no spare parts laying around. The cost difference between a longblock and a clip is usually $400-$500. If someone asked my opinion, I would go with the clip, it saves a lot of headaches. Keep in mind, once you’re done with the clip, it will have to go to the junkyard.

SR20DET S13 Swap

I won’t go into the whole process of doing an SR20DET swap, step by step, since it’s been done over and over. Browse through these sites for some really nice walkthroughs of the whole process.

• Zilvia has a great post on the necessary items for the swap.
• Need a DIY wiring harness guide for your swap? FRSport published a great one.
• ninja323 published a nice, simple guide for S13 swappers.
• SuperStreet has a walkthrough with some photos available.
• Tune2Win published what I would consider the best SR20DET swap guide yet, definitely worth a look.

S13 SR20DET Swap Kits

There’s plenty of aftermarket support for the S13 swaps. However, since there isn’t a need for custom mounts or crossmembers, there aren’t any “kits” available. There are wiring harnesses available that will make your swap go by that much easier though.

Photo compliments of mike_tseng

One reason why it is important to have a good machinist is that by changing the angles and size of the valve contact patches, you can change the “agressivenes” of the valve job. A more drastic valve job will have higher gains, but at a cost. Valves dissipate heat during their closed state. When the valve is closed, it is in contact with the cylinder head, and the heat is transfered. This issue with heat transfer is why titanium valves were introduced. Titanium valves provide ultimate thermal protection, and decreased maliability under stress.

Another thing to consider when doing any kind of cylinder head modifications is that entire valve train is designed to work as a system. The tolerances, valve lashes, spring tensions, etc, are all designed so that everything runs on harmony. When changing any part, you need to be careful and make sure that everything is compatible. I personally recommend the all or nothing approach. Many street cars will be just fine with stock head work. If you’ve got a spare head, and want to bring your car to the next level, i say go for it. But you can’t just throw in super aggressive cams, or get a 3 angle valve job by itself.

The best thing to do is make friends with a local machine shop. They will have more knowledge than you will know what to do with!

The Hardware
The unit itself is built quite well. It fits into your hand nicely, the OBD-II cable is plenty long enough to reach even the back seat if need be. The display is easy to read in all kinds of lighting. The only problem I ever had with my unit was the sheathing began to come off the OBD-II cable where it entered the device. Other than that, it’s well built and you can throw it in your backseat without worrying it’ll break.

How Does it Work?
Most Predator units come with multiple tunes for stock cars or slightly modified cars. For example, the 300C version of the Predator comes with tunes for:

• 93 Octane Performance Tune
• 91 Octane Performance Tune
• 93 Octane Performance CAI Tune
• 91 Octane Performance CAI Tune

These tunes when properly used are good for an instant 20-25rwhp on the 6.1L SRT-8, and 20rwhp on the 5.7L RT. Both get between 20-25rwtq from the Performance Tune. In addition to these tunes, often referred to as “canned” tunes, there are other customization options on the Predator. Using the 300C again as the benchmark, here are some options:

• Axle Ratio
• Idle RPM Drive/Neutral
• WOT Fuel 1k-3.8k / 4k-5k / 5k-7k
• Rev Limit Drive/Neutral
• WOT Spark 1k-3.8k / 4k-5k / 5k-7k
• Cooling Fan adjustment
• Tire Size
• Shift Points
• Shift firmness
• Autostick auto upshift enable/disable
• ESP enable/disable
• MDS enable/disable
• TCM adaptive reset
• Speed limit
• Read/Write time is approx 60 seconds
• Clear codes supported

Once you’ve made the proper changes to the options above you’ll flash the tune to your PCM (or ECU) through the OBD-II port. It’s a very simple process that takes about 60 seconds.

My SRT-4 Diablosport Predator Experience

When I bought my 2003 SRT-4, it was a mostly stock SRT-4, besides a Mopar Stage 3 turbo kit as well as a Modern Performance 3″, catted, turbo-back exhaust. This setup served me well, that is, until I rode in a 50 trim SRT-4. I knew I had to go big turbo. My setup consisted of a CTI tubular manifold, on a completely stock motor, with a .63a/r Borg Warner S256.

For anyone interested, note that the Borg Warner version of the .63 S256 exhaust housing will have issues hitting the wastegate flange on the CTI manifold. You’ll need the .63a/r S256 exhaust housing from AGP Turbo

I originally used an AEM F/IC on this setup. However, after having some issues with it, I started looking at at the Diablosport Predator Tuner. It was relatively new, but I decided to give it a shot. I contacted Nigel at Tru Dyno Sports.

Nigel sent me back a tune which I downloaded to the Predator tuner. I did some highway testing that night. He mentioned it would be very rich to be safe in the beginning. Then when I sent feedback, he would reply with a tune that was slightly leaner. This is a quick video of that tune. As you can see it needed some serious fuel removed once full boost hit. Multiple emails back and forth and we had it running really well. I’ve since sold the car, but Nigel’s tune was good enough to make a hair over 400whp and around 420wtq.

I was amazed the difference bewteen my AEM FIC tune and the first Diablosport Predator tune. I was experiencing stumbles and difficulties tuning with the FIC. After flashing the first tune Nigel sent me I thought it had failed and went back to a stock tune, it was that good. It drove without stumbles or hiccups.

Meet the GT-R Alpha 12. Putting down an incredible 1318 horsepower to the wheels is no easy feat. It’s the first 8 second R35 GT-R on the planet. If you’ve got deep pockets, an insatiable need for speed and a spare GT-R, send it to AMS and then call me for a test drive.

Motor Choices

• K20A Japanese Spec – this is the most powerful at 220hp and hitting redline at 8600rpm. Consequently, it’s also the most expensive option.
• K20A European Spec – second in line comes the European version of the K20A. Clocking in at 200hp it’s still plenty fast, just not quite as fast. You’ll hit redline just a bit sooner at 8100rpms.
• K20A2 – a K series from the US RSX Type-S. Very similar in power levels to the Euro Spec Type-R motor. 200hp and a 8100rpm redline. These are getting cheaper now since you can get them inside the US.
• K20A3 – The A3 series comes from the non Type-S RSX and EP3 Civic. Coming in at 160hp around 6500rpm, it’s definitely less exciting, but far cheaper, only you’ll be able to decide if the trade off is right for your project.
• K24A2 – Finally we come to the K24 options. This coming from a USDM TSX. It’s a wonderfully fun motor, featuring 166tq at 4600rpm. In other words, it doesn’t need to be strung out to have some fun.
• K24A – Last but not least, we have the USDM CRV. While lacking with a scant 160hp, it makes up for that with 162tq; for that extra bit of “torquey” fun.

Use the table below to sort by different options such as motor code, horsepower, torque, redline and compression ratio.

K20/K24 Parts List

Mounts
First you’re going to need a good set of mounts.  There’s a lot of quality mounts on the market.  Hybrid Racing makes a great set of K20 mounts.  Currently they’re only available in billet, but they may be offered in steel soon.  They have a lot of bushing options as well, from street to solid.

Axles
Stock axles have to go too, so we’re going to need a replacement, unfortunately no stock axles will swap over.  Hybrid Racing offers five different levels of axles.  The first K20 axles are suited for a stock K20 motor.  The options above the stock replacement are supplied by Drive Shaft Shop, with axles rated for 1000hp, they have something for every setup.

Clutch Line
The stock clutch line from your EK master cylinder, unfortunately, won’t match up to your new K20/K24 transmission. You can make your own, or pick up one from Hybrid Racing, their clutch line kit has pre bent ends and will bolt right up to any 1992-2000 Civic.

Throttle Cable
Up next is the throttle cable. On EK cars it should be long enough. I emphasize should because the word is out on whether or not the EK cable will work all the time. K-Tuned manufacturers a K Swap throttle cable which is supplied with its own throttle bracket.

Cooling System
There are some stock options available here. If you don’t care about keeping AC in the car simply switch the EK radiator over to the drivers side and plug the condenser hole. If you do want to keep AC, check out Modified Magazines’s K swap article, they have all the information you’ll need. If you like the aftermarket route, Hybrid Racing offers both full-size and half-size radiators. These units include ports for a coolant temperature sensor as well as a fan switch.

Shifter and Cables
Once again, there are some stock options here. A shifter arm and base from a 90-97 Accord will work fine when paired with the K series cables. This sounds too good to be true and it is. The transmission hump in the EK is too tall, your console cover won’t fit back on. You’ll have to mount it below the floor. You’ll need to make sure to encase it as well, so it doesn’t get beat up by the elements. For the ones with deep pockets there are a couple of options. For a true bolt in solution look no further than the Hybrid Racing short shifter. So much thought and design has gone into this shifter it’s amazing. It’s extremely well thought out and has options I’ve never seen before. You can use the stock RSX shifter cables (or possibly EP3 cables) for ease of use, but Hybrid Racing also has aftermarket k swap shifter cable options.

Fuel System
There’s two issues we need to correct here. First, the EK chassis uses a return fuel system, the K series does not. Secondly, the EK’s fuel system fluctuated with changes in vacuum. Any K series motor will run off a static fuel pressure, set by a regulator. The changes are really quite simple. First you’ll need an adjustable regulator, like an Aeromotive. Mount that somewhere in your engine bay. Set your fuel pressure to the manual’s specs. Next, hook up the return line on the EK to the return port on the regulator. Make sure to leave the vacuum line disconnected on the regulator, you’ll have serious issues if you hook it up. There are k swap fuel line kits available if you want to make this go smooth as possible.

Intake / Exhaust
No stock intake or exhaust header will work on this swap. The intake shouldn’t be too hard to fabricate. You’ll just need a straight coupler, a few inches of correctly sized aluminum pipe and a filter. This however will place the intake directly in the engine bay. Your best bet is to get it over into the drivers side wheel well for some cold air. Karcepts makes a nice k swap cold air intake that sits in the fender well. AEM also supplies a cold air intake for k20 swaps.

Since the exhaust has now swapped from the radiator side to the firewall side, we need a new header as well. None of the stock headers from a K equipped car will fit, so your options are limited to an aftermarket option. There are a lot out there, i’ll cover a few quickly. If you’re looking for a cheap, budget header, the DC Sports K Swap header is a great choice. If you’re looking to make a little more NA power, Hybrid Racing makes a race K swap header. And if you’re looking to extract every last ounce of naturally aspirated power, check out the K-Tuned K20 Ram Header, it adds 7hp and 5tq over their own race header!

K20/K24 Swap Wiring

Now comes the really fun stuff. If you’re crazy enough to do this by hand you’re going to need both engine harnesses, the charging harness from the K series and wiring diagrams for both cars. There are lots of little things to look out for and if you’re seriously interested in doing the wiring by hand, check out Hondata’s K20 wiring page. For those of us with more money than time, look no further than these K20 and K24 wiring harnesses.

• HASport K20 Wiring Harness – there’s not much information or any photos at all, but I would bet it’s comparable to the other two available.
• K Tuned Wiring Harness – A beautiful harness using mil-spec OEM colored wiring. It’s 99% plug and play and comes with a unique wire cutter / stripper and instructions.
• Hybrid Racing K20 Swap Harness – very similar to the K tuned harness above, this uses OEM connectors for a quality fit. It’s $20 more expensive than the K Tuned harness and I can’t find any serious advantages.

ECU options
Because of Honda’s use of immobilizers in cars with K motors there are some issues with simply swapping over the ECU from your K car. The easiest method is to get a Type-R ECU, which doesn’t have an immobilizer. This is usually the most expensive option since they are quite rare. There are K series immobilizer bypasses called “Mobilizer-K“. Your last two options are to go standalone. The first is Hondata K-Pro. Hondata will flash your K series ECU and send it back to you. You will have full control of your ECU and the ability to disable the immobilizer.

If you’re using the HASport Mount kit, you need these two PDF files. Even if you’re not using the HASport Mount kit, you can still use these PDF’s to guide you through the swap.

• EKK1.pdf
• EKK2.pdf

photo provided by Omar Echeverria

photo provided by Brandon Perdeck

• M50 – a 24 valve inline six. Introduced in 1992, it made 189hp and 181tq
• M52 – the replacement to the M50, introduced in 1996 as an OBD-II motor. Most swappers opt for the 2.8L version, at 191hp and 203tq. These are great forced induction motors if you’re planning on turbocharging your swap later.
• S50 – This comes from an M3, specifically the 1995 OBD-I M3. It’s power figures, 240hp and 225tq, make it a popular swap.

There are other swaps available. This is just the quick and simple list. If you’ve got a big wallet and technical know how, look at the S62B50 from the E39 M5.

E30 Swap Guides

Since most of the parts needed to do this swap are OEM, I won’t be talking too much about “kits” here. But there are a lot of great resources available out there for people interested in this swap.

• E30 Swap and Wiring Information – RM European has posted an excellent guide including engine installation and wiring.
• If you’re interested in this swap there’s really only one resource you’ll need: the E30 DOHC wiki.
• Here’s a quick and dirty E30 M50 swap parts list

E30 M50 Swap Parts

• If you’ve got large pockets and want things done right and easily, Project Orca by Zionsville Auto, is a complete E30 M50 swap kit
• AKG Motorsports has created a few products for the E30 swap. They have motor mounts and a plug and play wiring harness adapter to make things go smoothly.
• Treehouse Racing also manufactures E30 swap parts, such as a modified brake booster and swap harness.

If you need any more of a reason to start buying parts for this swap, consider this:

photo provided by DigitalK

There are also some other options availabe if you need a little more power to start.

• LS6 – In 2001 the LS6 made 385hp and 385tq. In 2002 the LS6 was modified to produce 405hp and 400tq. This motor was used in the C5 Z06 and the Cadillac CTS-V
• LS2 – This is the stock engine for 2005+ base model Corvettes and 2005-2006 GTO. In factory form it makes 400hp and 400tq
• LS3 – The 2008 and up Corvette engine which puts out 430hp and 424tq. You’re starting to get into rare and expensive territory here
• LS7 – Tough to find and cost prohibitive to afford (though not impossible), this came in the 2006+ Z06. Forget traction with this, you’ll be making 500hp and 470tq.

E36 LS1 Swap Kits and Mounts

There’s quite a few swap kits available on the market. Some offerings are more complete, while others are more of a do it yourself setup. Competition is good though, and any kit will work well.

• Nash E36 LS1 kit
• Vorshlag E36 LS1 swap kit
• Samberg E36 LS1 kit
• New Age Hot Rods E36 LS1 swap kit
• Jags That Run e36 swap parts

E36 LS1 Swap Guides

Since the E36 LS1 swap is still fairly new, there’s not a ton of great, easy to read information out there.  But i’ve done what I can.  Nash, who also makes a complete swap kit, wrote up this three part guide to swapping in an LS1 into your E36.  It’s the most complete guide i’ve been able to find.

• Part 1 - prepping the LS1 for the install
• Part 2 - prepping the E36 for the LS1
• Part 3 - installing the LS1 into the E36

Jags That Run, while not offering a complete “kit” for sale, has a few parts for sale. They also have been publishing their findings on doing an LS1 E36 swap. There’s lots of good information below the parts for sale.

If you’re intimidated by this swap, check out our E30 S50/M50 swap guide. It’s far more simple. If you’re not deterred yet, here’s some motivation for you to get your ass in gear and start swapping!

Here are some specs from the car’s build:

Motor setup:

• GRP aluminum rods
• Wiseco HD pistons
• HKS 280 cams
• Kiggly behive springs
• Stock size stainless steel valves
• Stock port
• O-ringed head by Shep

Turbo setup:

• Borg Warner S374
• Custom turbo manifold made by Roberts Imports
• PWR water to air intercooler
• 150 shot of nitrous

The drivetrain consists of a transmission and torque converter by ITP. The car is tuned on AEM EMS on C16 race fuel.

Keep up the good work in 2011 yellowrs!