Leafy

iTrader: (1)

If companies that arent asshats start doing power stuff for them. A buddy of mine just paid like 3k for a 2.5 swap. Which consisted of re-ringging a $350 junk yard motor, putting a $130 NC oil pan on it, and using a $24 special tool to put an NC crank pulley on it. They might have maybe bored the NC intake spacer out for the mondo mega porntastic 2.5 liter ports and supplied a custom gasket maybe.

cordycord

iTrader: (2)

A 300hp (whp?) J35 that weighs 9lbs more than stock and 90lbs less than a turbo/Rotrex checks at least one box for me.

I messed around with an MZR MazdaSpeed turbo long enough to know that you need a confirmed electronic package (or big $) to deal with direct injection. Maybe SkyActiv too. A 2.5 MZR that bolts right up to a 5/6 speed --and has an ECU solution, could be interesting. Taller engine though.

Leafy

iTrader: (1)

Yeah **** the Mazda DI motors, but now the ecoboost, those motors are basically the same and do have big tuning options, any swap kit that would work mechanically with a normal MZR/Duratec would work with an ecoboost. But any of the DI options for that swap would require cutting a hole in the firewall to clear the pump.

Efini~FC3S

iTrader: (4)

A Catfish with a J35?

I'd seriously consider selling a kidney for that.



DO IT DO IT DO IT DO IT DO IT
















Do it...

concealer404

iTrader: (3)

The DISI has plenty of aftermarket... They're making power we dream of.

gorillazfan1023

iTrader: (1)

I've got nothing to add to this discussion. I just want to say that like 7 years ago (when I was a super noob) I asked about doing this swap on m.net. They said it was impossible that the engine spun the wrong way to use the stock transmission....So suck it m.net.

Full_Tilt_Boogie

iTrader: (1)

So I keep noticing everybody talking about the J35. You guys do know that the J35 is the more modern eco-turd V6 with the exhust ports cast into the head right?
If you really want to do a J35 that doesnt suck you have to do a J32/J35 hybrid to get good cylinder heads. So essentially you have to find 2 engines. Either that or just stick with the 3.2 liter.

Just some food for thought.

Sparetire

Yeah, M.net is for old guys who like to regurgitate things they heard elsewhere. Its cute, sort of like a time warp to about 10-15 years ago.

IIRC Hondas engines have spun the right way for like 20 years now. The last one that did not was the B series.

Besides, that 9lbs on the nose of the car will ruin the balance when you take a corner at 3.2 MPH past the posted limit on all-seasons. I was worried about how my Nardi wood shifter **** would affect the balance too, but it sits low and in the middle of the car and adds so much to the experience of driving that I am risking it. Because that's what the open road is all about. plus I put the luggage rack on to balance it all out.

hornetball

iTrader: (4)

Old guys rule!

OGRacing

iTrader: (1)

till it blows the stock miata tranny...

ctdrftna

iTrader: (1)

Why is this swap still being talked about. If you want a better 4 cyl you have the K swap. If you want more the you need drivetrain anyway. Thus you have the LS swap. Thats all thats needed.

I saw a supercharged j32 swaped CRX at the strip last year. Big pile of ****- end of cool story bro's

cordycord

iTrader: (2)

Isn't that the same for the LSX? on the other side of the coin, that gives more room in the engine bay.

I've read that the J32/35 (most) are the same blocks, although head efficiency differs. A J32 block with a J37 crank makes a nasty J36 swap with low tech electronics, which are easier to tweak. The sand rail guys break open the ecu and disable the immobilizer, while Hondata and AEM are the higher priced alternatives.

cordycord

iTrader: (2)

What do you guys consider the HP/TQ cutoff for using the stock transmission? This is assuming no drifting or obscene hooning.

ctdrftna

iTrader: (1)

Well I think it's been pretty well documented, after 300-350 ftlbs a 6 speed is on borrowed time.

Now that's a pretty intensely built BP or a K24 with 10-12 psi

Next level of power and money will get you a LS swap.

jakeordie

I did some searching, and there's guys blowing up 5spds at ~280-300 lb-ft.....but that's with seriously turbo'd 4s, a V6 will deliver the same numbers with less impact on the drivetrain. So for keeping the stock drivetrain, it makes sense to start with a flat torque curve of 240-260 lb-ft and gradually tune it for a little more if things are holding up.

The K swap makes way more sense for high-rpm power, but what would it cost (money, weight, reliability) to get 250-300 lb-ft out of a K24? And we already know what it costs (money, weight) to get that & more out of a Chevy kit.

ctdrftna

iTrader: (1)

All the defense for this swap would make sense if it was a quality swap, but its not. the parts are crap.

turbofan

iTrader: (1)

It all depends on the weight of the vehicle and the manner with which it is driven.

Many break even around or below 300 lb ft with track use.


5-speeds tend to kaboom with less torque than that, again depending on driving. With 230 lb ft the trans in Lazarus popped on it's second or third track day. That's a 2000 lb car, but track use. A heavier car on the track would likely have gone even sooner. A same-weight car on the street would put up with more, unless you drive it like an ***, which I'd assume most of us do.

Much over 200 lb ft with aggressive driving and your 5-speed isn't going to live all that long.

18psi

iTrader: (76)

5sp on my 00 popped at 280tq on a street car that wasn't beat on that often.

cordycord

iTrader: (2)

I think a realistic TQ number will be 260, with under 300whp. This swap falls in the middle, which is why it's getting so much push back IMO. The othe big issue is always going to be the electronics. If you're not ready to tackle that, then a turbo or Rotrex makes much, much more sense.

Again, same weight, more mass centralized, 100 more ft/lbs and whp, and I kinda gloss over the other stuff.

I see the numbers the Rossion is putting out with the turbo 3.0 EcoTec V6 and a Hydra, and the bench racer in me starts to percolate.

codrus

My 5-speed popped at Laguna making around 260 ft-lbs, but it had done a lot of previous track days. ~ 50K miles while boosted, probably a dozen boosted track days (plus a bunch more NA).

It seems to be somewhat hard to predict -- I've read that the tolerances on the 5-speeds vary quite a bit, some of them have the gears lined up perfectly, others they're a bit misaligned, and since there's less tooth engagement there's less strength.

--Ian