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Boosted K20 into a SW20

54K views 61 replies 12 participants last post by  m5james 
#1 ·
Thanks for checking this thread out. This is a story about a MR2 going to the dark side, hahaha. I love the handling of the mid-engine lay out and would have loved an NSX but prices are out of my reach atm so for now I will play with my MR2.

I use to own a 1992 Prelude w/f22a that I swapped a jdm h22a and 5-speed lsd tranny back in 2004 and was my DD. I also install the SRV leather interior into it.



In late 2007, I ended up trading it in (sorry Prelude) for a Canadian spec 1993 MR2 turbo that needs some work, head gasket leak, paint was horrible, etc.



After a lot of upgrades throught the car, engine work (gen3 conversion+bigger turbo) and new paint job this what it looks like now. Got it tuned and dyno'd at 250 whp @ 18psi on 91 pump gas & meth injection. Not bad but it could be much, much better.





The stock seats were getting old and I found some S2000 seats. I had a buddy fab up some adapter brackets to install the s2000 seats and sliders. Looks very nice and much more comfortable, plus they are 11 lbs. lighter per seat than the stock seats bonus.



I haven't driven the MR2 a lot due to being a single dad raising a little girl and other life priorities. But when I do take it out, it puts a smile on my face. Anyways, a couple of weeks ago the head gasket starting to leak internally again and I got sick of putting any more money into it. I could have gone with the Toyota gen4 3sgte or 2gr swap but I remember how much fun I had with the h22a in the Prelude. So I picked up a 2003 k20a2 that I plan on boosting and using the MR2 turbo tranny (E153) with a adapter kit. More on this later.



This is the usual response I get when I say that I am going to use a k20 motor from the MR2 crowd.



To be continued...
 
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#2 · (Edited)
So my plan is to get 450-500 whp and 400 tq. @ 18-20psi on 93 pump gas or e85. I do a lot of twisty roads and maybe autoX next year so powering out of corners is where I want the k20 to be strong in, I can always change this set up down the road. The aftermarket support for the k20 is huge and much cheaper compared to the 3sgte. I have 95% of the parts needed, I would like to send a shout out to Ken for helping me get some of the parts. I know he is on this forum, but I don't know his screen name.

Here's the list:
-stock K20a2
-replace the valve springs with Supertech dual 95lbs., seats, TI retainers and valve stem seals (have)
-RBC IM with stock k20a2 TB (have)
-thermal gaskets for IM and TB (have)
-1000cc injectors and BWR fuel rail (have)
-BWR Lean exhaust manifold (have)
-meth injection for cooling (have)
-Ktuned goodies (tensioner, swivel water neck, p/s & a/c delete, etc.) (have)
-TracTuff oil baffle and oil pump baffle (have)
-Turbosmart BOV (have)
-5830 turbo (have)
-Southbend stage 2 clutch (have)
-Hux Kswap adapter kit (have)
-Turbosmart WG (have)
-A2W intercooler (have)

The only thing I need to do to the MR2 drive train is beef up the inner cv joints, so I bought a upgrade kit. The E153 tranny is built to handle high power from the factory so bonus again.

The welds on the manifold (T3, 44mm wg) are sexy and Tanner at BWR is very easy to communicate with. I purchased it during their labor day sale with free shipping, ya!





Test fitting the manifold on the k20, I picked up a wrinkle red valve cover from CL locally.
 
#5 ·
The Force is with him

This is a story about a MR2 going to the dark side, hahaha.
You bring it to the right sight :D

I love the handling of the mid-engine lay out and would have loved an NSX but prices are out of my reach atm so for now I will play with my MR2.
What about Lotus Elise/Exige? Anyway, I like the MR2 chassis, it was one of the first Siku cars I got when I was 6 years old :heart:

I haven't driven the MR2 a lot due to being a single dad raising a little girl and other life priorities. But when I do take it out, it puts a smile on my face.
Wow man, I raise my hat to you...great you do this project...big big respect!

This is the usual response I get when I say that I am going to use a k20 motor from the MR2 crowd.
LOL :D...they just don't know what they really miss :D

So my plan is to get 450-500 whp and 400 tq. @ 18-20psi on 93 pump gas or e85. I do a lot of twisty roads and maybe autoX next year so powering out of corners is where I want the k20 to be strong in, I can always change this set up down the road.
A more spontanouse load response of a SC'd engine setup for the Serpentines and AutoX wasn't on the table of idea's?

The aftermarket support for the k20 is huge and much cheaper compared to the 3sgte.
Yes indeed. One of the best high revving 4 cylinder inline engines combined with a great aftermarket makes that beauty of engineering art to a phantastic combination.

I am really looking forward to see more of your build.

May the Force be with you man :D

Markus
 
#8 ·
Re: The Force is with him

I picked up the turbo today from a turbo guru. It is a custom 5830 with BB center. It's built for torque and power to redline (8500rpms). The K20 is going to the shop for a couple of days to get Supertech valve springs installed this week. I would have install the springs but it would have taken me about a month to install them and I don't feel confident enough to do it. I will be doing the rest of the build, here is the pictures.







 
#12 ·
Thank you, I appreciate the comment. I'm excited to see the end result.

Nothing new to post, engine is at shop getting the valve springs replaced, head gasket and ARP studs installed. Soon the removal of the 3sgte will commence...
 
#13 · (Edited)
Just an update, been gathering parts for the swap. The old 3sgte comes out next month and I should have the k20 installed by the middle of March. The k20 is at a shop (Garage5) being built with supertech dual springs, valves, wiseco pistons, manley turbo rods, upgraded wrist pins, etc. I also wanted to add that I am going with South Bend clutch stage 2 endurance, a friends has one installed and he highly recommends it compared to the ACT tm1-hdss clutch.

K20 swap kit.










And a picture of a friend's MR2, my truck and my MR2.
 
#14 ·
I picked up the k20a2 from Garage5. The motor I picked up was on it's last legs so I'm happy that I got it built right the first time. Below are a few pictures from the builder, check out the stretched timing chain compared to the new one after 180,000kms, which after talking to the builder must be way more kms on it.

I will be updating the thread more often now that I have the motor back. here's a few pictures.









 
#15 ·
Started to install MR2 friendly parts for the swap. I broke the thermostat housing when transporting the engine to my house but installed the Ktuned swivel one.





Next up, I needed to install a coolant fill.







Nice shiny parts.



More to come...

 
#18 ·
I ran into a snag, I purchased a Tractuff oil pan baffle from maxim and a oil pump baffle straight from Tractuff. So to use both at the same time I'll need to trim the oil pan baffle which is no big deal.

The problem I discovered is the trap doors on the oil pump baffle are on the wrong side so instead of letting the oil drain away from the chain area it was trapping the oil which could have caused a big problem especially after paying big money to have the engine built. Below are pictures I took of the oil pump baffle.





When you compare it to the picture on Tractuff's website the trap doors need to be on the oil pump side.



Anyways, I contacted Robert at Tractuff and he apologized about the problem and offered either he can send me new doors and rivets or I can mail in the defective baffle and he would replace it. I opted to mail it in, I even paid for postage from Canada. I emailed him back and told him it would take 6-8 days to arrive to him and if he can send me the replacement so I can minimize down time because now I'm waiting. So far no reply from him, that is pretty sad to not reply to a customer when it was a defect on their part.
 
#20 ·
The Hux k20 swap kit comes with a mount for the engine and you use the other 3 stock MR2 mounts that mount to the tranny.

I purchased a set of poly inserts for the stock mounts so the engine doesn't move forward and back as much. I removed the front mount inserts and only have the rear mount inserted because it would vibrate a lot at idle and was annoying on the 3sgte and will be doing the same for the k20. I hope that makes sense.
 
#21 ·
I had to create a hole in the oil pan for the oil return fitting and it was fairly easy until the time came to start tapping the threads. I was nervous the tap would twist and damage the threads but it turned out great.







I also purchased the ktuned p/s delete kit. Going to make a brace to prevent the top alternator bolt from breaking off.
 
#22 ·
Going to make a brace to prevent the top alternator bolt from breaking off.
:up:

You don't weld a bold nut on to the oil pan for the fitting to drain the oil pan? Just from an engineering perspective:
  • the thread length is too short for the bore size and material-combination (Aluminum-Steel-combination!)
  • Vibrations likely loosen the thread tight and lead to leakage -> lack of oil supply = engine death!
I recommend you to revise the thread length by welding on a bolt nut to keep your nice engine safe.

:twocents:

Markus
 
#25 ·
So I am going to use the rbc intake manifold that I picked up locally for $200 cdn. The rbc intake has a water passage on the right side that needs to be removed for it to fit on the k20a2 head. I deleted the uncut intake picture by accident so here a generic internet picture.



And what it looks like after cutting it with an angle grinder and using a 60 grit flappy sanding disk to shape and smooth out the cut.









Next was installing the 1000cc injectors into a BWR fuel rail.







My MR2 didn't come with a/c or p/s so the k20 doesn't need it either. I got the Ktuned a/c & p/s delete kit.





After reading a thread on this forums that the ktuned supplied top alternator bolt sheers off in the block, I decided to not use it and get a oem bolt. I like to prevent anything that may cause me to have a bad day so I fabricated an alternator brace to alleviate the stress on the top bolt. I just need to find someone to weld the 2 pieces of the brace together.





What it looks like now. Exhaust manifold is next.

 
#26 ·
Adding a little bling. I test fitted the "lean" exhaust manifold and one of the runners was very close to the oil filter so I wrap the area with heat wrap and rechecked. Looks good.











The money shot.



The engine harness is next. I'm not going to post any picture of this because I'm just connecting it to the sensors. Bill at Indy will do the rewiring to work in the MR2.

 
#27 ·
For the k20a2 throttle body to work with the rbc im, I need to install an adapter. I also did a mini wire tuck to hide the fuel injector harness that you can see in the first picture.







Test fitting the tb and it all good.



I did a trim and shave on the throttle body.

IACV sensor - no way!
Evap sensor - hell no!
Map sensor relocate - that's what I talking about!
IACV delete plate - hooray!



















All torqued and almost ready to start installing the k20 swap kit parts.



Another side project, I had an aftermarket antenna on the MR2 that was plain ugly so I picked up a S2k antenna assembly and modified it to work with the MR2. (removed circuit board, rewired, drilled new opening and a short antenna)



 
#28 ·
I didn't like the service I got from Tractuff with the oil pump baffle so decided not to use their products. I instead installed the Clockwise Motion baffle into the oil pan. It just presses in between the fins inside the pan and has 5 trap doors so the oil pump is always submerged with oil. I had to order this from the UK and shipping was cheap and fast, surprisingly.
Then I JB weld the oil return fitting on the back and front side, it is locked in place solid. The oil pan back on and torqued it to specs and now is ready for the next step...









Up and out.



 
#29 ·
So I recently sent out my radiator to have it checked over to Richardson Radiators in Langley. The core was good and it has no problems but I wanted to be sure that it would do it's job with high boost and whp levels so after discussing it with them I had a thicker core installed. I recommend them, good service and price was good plus they have a 10% discount coupon on their website that you can use.





Next I put together a vacuum block to run lines from one source.



I also had to make another oil return opening. The first one (blue fitting) would have worked but the MR2 cv shafts are very large and it was blocking the opening so I tapped, plugged and jb weld the plug in place.





New oil return location.



Up next is the Hux k20 swap kit.
 
#34 ·
@1basdmr2
I would first like to say solid write up. I am actually going to do the same but I will be using the w30 chassis.

any update on your car? what numbers its making, how you addressed the concerns posted about oil temp?

Finally I want to ask you, are there any differences in the install for the w30 as opposed to you w20.

Thank in advance.

again dope car bro
 
#35 ·
Sorry everyone who is following this build. The MR2 is at the tuning shop now and life got very busy, anyways enjoy.

The Hux kit consists of these parts:



Carrier bearing housing installed.



Passenger side engine mount





Lay everything out



Flywheel adapter



Adapter plate



This cover needs to come off



 
#36 ·
This solid dowel needs to be removed, I tried but ended up grinding it off.





Lay out all the pieces



Installed





Now the joining



Had to drill through





The MR2 cv shafts are very large so this part of the k20 has to be shaved down





Next is the starter plug





Finally together. Wired in the starter.

 
#37 ·
This part of the k20 block was interfering with the clutch cylinder so need to shape it using these on a Demel and drill







You need to get this flywheel inspection cover from Honda ($13)





Ready to be installed









Being positioned



Installed



Passenger side coolant hose



Driver side was more challenging. All the hoses I tired would hit the shifter assembly, it took 2 days to figure out what combination worked.



Adapter to join the flex hose and reuse the Toyota passenger side coolant hose



Installed all the heater hoses and added coolant. There is air trapped in there so it will need to be bleed out.



A side project, new negative battery cable put together



Joe installed poly bushings in the rear control arms and rebuilt the cv shafts with the upgrade kit

 
#41 ·
The stock location for the starter on the MR2 is on the tranny and the Hux kit uses the 3sgte flywheel. I guess it was easier to just fab a flywheel adapter than using the k20 flywheel and clutch on the MR2 tranny.

I did the swap in 5 weeks, I was in the garage almost everyday for a few hours in the cold to get this done while dividing my time with my daughter. Thanks to my family for helping out when they could. I was exhausted at the end and wished I could have spread the swap over a few months.
 
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