MR2 Owners Club Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
Looking for learned opinions - What are the pros and cons of swapping a Gen 2 [email protected] to either a 3.5L V52GRFE vs to a Honda K20, K24z type of engine?

Thank you
 

·
Registered
Joined
·
621 Posts
2GR will always have a boatload more torque. You are around 280ish rwhp in a basic swapped 2GR. That takes a lot of work and $$$ to get there with a K24. K20 will never get there and be streetable.

2GR can make 300-320 rwhp when modded some, which few have done. Still stock bottom end. K24 is going to be at the ragged edge to get there. I’ve seen multiple 300 rwhp “reliable” K24s blow up on track in just a few events, which kinda proves out if you’re going to push 8.5-8.8k rpm or so on a long stroke engine like that, it should be more street/drag and is generally on borrowed time even with built bottom end.
 

·
Premium Member
Joined
·
13,048 Posts
Playing devils advocate (I am of course a huge 2GR fan), the K series is quite a bit lighter weight, or so I hear. Probably it's only real advantage in my opinion.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #5
Thank you. Good comparison.
Follow-up question - I will probably go the 2GR transplant route. Can the stock MR2 turbo be added to the 2GR or do you have to upgrade to a more robust turbo? if so, what is the recommended turbo? In the alternative, is adding a Supercharger the better way to go? And again, if so, which Supercharger??

Thank you
 

·
Registered
Joined
·
621 Posts
Well, the stock MR2 Turbo from the US (CT26) can support about 250 rwhp, so it would actually choke down a 2GR at full tilt.

IMO, you don’t just “add” a turbo or SC. It’s magnitudes more complex than that, and gets much much more expensive if you’re paying a shop to do the work vs a straightforward off the shelf engine swap where you can buy all the pieces and LEGO it together.
 

·
Registered
Joined
·
180 Posts
I was on LotusTalk, a thread about the K20 and asked why they spend $20K to swap a 2zz to a K20 with only 200 more cc's while being heavier and not use a 2gr. They went on about weight and how wonderful the K series is. Whatever, they all have street cars. For the street, torque is king and the area under the curve is what matters on the street. I've had 3 cars with different discplacement engines with 4-5 lbs /hp and have learned that small motors and high boost are not as fun as larger motors with low boost. Even if the K24 could make 500hp turbo'd on stock internals, it would never be as fun as a 3.5 liter making 400hp.
 

·
Registered
Joined
·
180 Posts
Thank you. Good comparison.
Can the stock MR2 turbo be added to the 2GR or do you have to upgrade to a more robust turbo? if so, what is the recommended turbo? In the alternative, is adding a Supercharger the better way to go? And again, if so, which Supercharger??

Thank you
If you can weld then turbo is easy, if not supercharge. I'm running a GT3584 non RS wheel with a .82 hotside. GT3582 would work too. The problem with a smaller turbo is that you won't be running much boost for the volume. Look at a compressor map and you will see that 5-7 psi runs it off the map on most turbos that would other wise easily support 4-500 hp but at say 15 -20 psi.
 

·
Registered
Joined
·
9,198 Posts
K series is physically smaller and lighter. After market is massive for the K series. If you want a turbo the K series would be easier, packaging wise, to add a turbo. To make stock 2GR power with a K series you will have to run boost. There is some debate on how much power the stock Honda transmission will hold in a mid engine chassis if drag launched. The Stock MR2 turbo trans is quite strong.
 

·
Registered
Joined
·
621 Posts
You can actually make 300 whp through a K24 with nothing but off the shelf parts. That said, piston speeds are very aggressive, so it isn’t going to take abuse like a stock 2GR with bolt ons will.
 

·
Registered
Joined
·
690 Posts
You can actually make 300 whp through a K24 with nothing but off the shelf parts. That said, piston speeds are very aggressive, so it isn’t going to take abuse like a stock 2GR with bolt ons will.
Also the torque will be quite lower with K24 vs 2GR so both being at 300whp I would say you would enjoy 2GR much more.
 

·
Registered
Joined
·
17 Posts
If you're still in the planning phase of your project, I suggest going with the 2GR. It's much easier and cheaper to get a low-mileage 2GR-FE that's never been beaten on it it's life. 2GRs are going to be a much more usable powerband, and keeping it Toyota and Toyota allows you to enter the car in lower class racing groups, if you ever choose too. Also, if you ever felt the need to turbo a 2GR, you'd have stupid power. Plus, a 2GR swap is (comparatively) quite easy. I personally would choose the 2GR any day, but it's really up to you.
 

·
Registered
Joined
·
146 Posts
I wonder what the response in the kswap section would look like? lol. The pros for the kswap is aftermarket support for the k engines. However, 2gr support is slowly but surely growing. Check Harrop for supercharger, check MWR for tons of engine options including full engine builds. There others too but these two are well established companies that likely won't disappear over night. Then you have Alex and Marc who've been in the game from the beginning and brought interest back to this "killer" platform. Also, if you are looking for exclusivity then you can't go wrong with either because they have almost complete support for the swaps but are so cost prohibitive that most shy away from them. Please forgive my lack of provision of kswap resources, but due to my bias I can't bring myself to support them. I see a lot of people throwing Honda engines in Toyotas but I don't see the the opposite ever. Aaaaand there is my Toyota Pride! I'm out!
 

·
Registered
Joined
·
17 Posts
I think (hope) that one day, the 2GR-FE will have a higher power ceiling. Right now, however, we just simply don't know enough about it. The thing is that I've only seen 2GR-FEs being used recently, as the 2GR is a relatively new engine compared to the K24. People've been beating K-series motors for time immemorial, and they've been in almost every Japanese car, so people know what makes them tick. I'd love to one day (if I had infinite funds) put the same amount of time that's gone into K-swap design over the years into the 2GR. It's in my opinion the more modern and sophisticated engine than the K20s.
 
1 - 17 of 17 Posts
Top