King Tut

Good luck. If you really want a worthwhile budget type track/daily car just go buy another damn S2000 or Evo. Leave the A/C in it. They will both get the job done very well. Now if gram points are more important then sure go ahead and byld a K24 RX7 and do your one track day a year to get IG pics and followers.

sleepycivichb

DavidNJ

The K24 is taller than a 2JZ...lower deck height and no rocker mechanism. It is longer and about 100lb heavier. But it can generate more power more easily.

You need to decide what your auto hobby is. Conversions? Track days? Racing? Vintage? Polishing paint and chrome? You are basically asking a marque site about marrying an antique engine to an antique chassis, where only the antique engine is even loosely related to the chassis.

If you read the posts of people tracking FI S2ks, many have had all sorts of teething problems that kept them off the track and under the car. Many times that was at the track when the expense of the track day was already incurred.

There is nothing magical about the combo you are proposing. An NA K24 weighs about the same as a turbo 13BREW. It may be a popular racing engine, but it is an antique. At best intake cam VVT + VTEC. No direct injection. No exhaust VVT. As an all aluminum NA engine from the factory, there is a lot of work to make it a strong turbo.

The 2JZ is popular because it can take tons of boost as is. It started as a turbo so already has the cams, pistons, etc. The block and heads have the necessary strength and cooling. For what it is it isn't that heavy. But it is still an antique. However, with E85, race gas, or water/methanol injection is can be a 1000hp-2000hp antique.

If you have the budget and skills to make a track worth FD3S conversion, you can make your own choices. But the result is neither an everyday street car nor killer track day or race car. It won't have high resale. It either qualifies for vintage plates or will soon.

For less/similar effort you could have 50% more power with a DCT or sequential gearbox by putting a 2JZ in an S2000, or even a FD3S.

Bullwings

just drop an LSx in the FD3 and be done with it. no need to get all fancy and complicated. that conversion is a proven reliable swap that should give much fewer problems if done by a reputable builder.

K24... LOL. K24 into an s2k was a lot of money and took quite a bit of fab and research to get it done right. I still don't think it has been perfected.

sleepycivichb

Now I remember why I left this site and never looked back for 10 years. As well versed as you are, your ideology is lackluster at best. I never cared about 800-1000whp or turboing it. If you think the K series motor is antique the I’d hate to hear what you think about the 30 year old technology F series motors and s2K chassis. To the LSx comment I’ve been there and down that, actually still have it. It’s far more expensive than a K-swap and I still understand the possibilities of the LS platform.

Chibo

If you want a RWD K motor'd car I would suggest you check out Miatas, as there is a pretty healthy community behind it and everything is well mapped out and generally available off the shelf. The RX8 is also another pretty popular platform these days as they are basically worth nothing, most Miata stuff can be adapted to them, they are incredibly capable chassis out of the box, and there is a TON of space inside of them with very large doors. Their downfall (other than stock power) is that the brake system does not work right if you remove the stock ABS unit, as it controls their brake bias, but solutions to retain it on swapped cars are pretty well known now.

DavidNJ

The S2k's engine is also an antique...even more so since it lacks VVT. You may have noticed things have changed since 1999. Then a Corvette had 300hp and the first Z06 had 385hp. In year two it went up to 405hp. In 1999 a BMW 528i has 192hp, a 523i 168hp.The new Porsche Boxster S had 250hp. VTEC was news.

Now, virtually every engine has direct injection and variable timing on intake and exhaust. Many have variable valve lift. Turbos are everywhere. A 2L 250hp turbo is a standard passenger car engine; you can get one on an Accord. Porsche and Nissan sell emissions legal 600hp 3.8L engines. Regular Camaros and Mustangs have 450+hp. 600hp 4L turbo V8s and some at 650hp or 700hp are readily available. Pump gas. Emissions legal.

The S2000 is a classic sports car, now 9 years out of production. The Supra, also a classic, hasn't been sold in the US for 20 years. The S2000 fell into a void between the Miata and the Boxster S. By the end of its life the Boxster S had passed it, but for a heavy price. Honda has had no subsequent RWD sports car.

The FD3S never gained a lot of traction when it was new. It was much lighter than the Supra, but the rotary had issues with emissions and never took off. It is attractive. And if you want to put a K24 in one that is certainly ok. But as already said, putting a K24 in an S2000, where the OEM engine is virtually identical is problematic. Most external K24 accessories don't fit. And many S2000 accessories don't either. It is just different enough to be expensive and problematic. First and foremost, the K24 was built as a transverse engine, in the S2000 is is longitudinal.

There is a current high-performance K-series, the K20C1. It has direct injection, VVT on the intake and exhaust plus VTEC on the intake. It comes factory turbocharged. Honda offers them through their HPD program, but they aren't generally available. A 306hp from 2L it is strong but not amazing.

What you are finding here is a general apathy to the Mazda RX-7 and not that much interest in the K24.

You might try K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum which is dedicated to the K-series and has members who have done a popular K-series to Lotus Elise conversion. I believe there are also K-series to 1st and 2nd generation MR2 conversions. In both, the K-series is mounted transversely.

DavidNJ

Here is detail on that swap: Mazda FD3s Honda Powered K20 Turbo RHD "RHONDA" - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum

It is basically a K24 to S2k swap stuffed into an FD3S RX-7. Lots of it was outsourced. It looks hyper expensive.

anorexicpoodle

I agree with the LS swap. In the world of power to dollar in a small package, the LS engines are unbeatable. However if you're going to LS Swap an FD, just buy a C5 or C6 corvette. Its literally almost the same car and works SHOCKINGLY well out of the box.

DavidNJ

https://www.sikky.com/product/mazda-...t-kit-stage-2/

Complete turn key FD RX7 LS engine swaps