cordycord

iTrader: (2)

I just scaled my car and found out some interesting information. The weight for the engine and transmission is 460lbs.

6 speed transmission
stock flywheel
happy meal clutch
engine
stock intake
FM turbo exhaust manifold
2560 turbo
alternator
no PS
no AC
trans oil, engine oil, radiator water
driveshaft

So if you're going to swap out an engine and transmission, this is your baseline weight to get 250whp. Of course, you'll need to go through the same game if you're swapping differentials and half shafts.

Leafy

iTrader: (1)

**** thats heavy dropping 80-100 lbs with the right motor in front of a T5 shouldnt be terribly hard.

cordycord

iTrader: (2)

**** just got real yo!

I think the J35 might even be lighter than a 1.8 with turbo or Rotrex. The LFX might be lighter too? Maybe not with the transmission and other upgrades, but with the tradeoff being a more bulletproof drivetrain.

Midtenn

iTrader: (15)

Not to mention moving the center of mass back into chassis and lower.

Corey

I feel like I started posting this a long time ago, but never did it. It's a J-series S2000 swap, but the mounts are what matters.

Turbo J32A2 S2000 build thread - S2KI Honda S2000 Forums

Edit: Got them uploaded:

paNX2K&SE-R

iTrader: (8)

That's a lot better. Now it just needs an oil pan solution that keeps the Miata rack in the stock location.

Savington

iTrader: (31)

Yep. No stock steering rack location, no care.

TurboTim

iTrader: (9)

Where is the starter in that s2000 swap?

williams805

iTrader: (2)

They made a cutout in the oil pan. Still on the bottom.

viperormiata

iTrader: (24)

Somebody put a big roots style blower on one of these.

soviet

iTrader: (10)

Wait, the J series is SOHC?

cordycord

iTrader: (2)

Yep. SOHC. And 4 valves per cylinder. And VTEC.

soviet

iTrader: (10)

Honestly in my mind, the SOHC alone makes this infinitely inferior to LFX swap.

Corey

I don't see why a rear sump pan and pickup can't be made to allow the use of the stock rack and stock location. Obviously that would require moving the starter to a more traditional spot, though. I don't see why one couldn't place the starter on a stand-off mount like what Claire and the other KLDE/KLZE guys are using.

The engine design is at least 10 years older. Base engine against base engine it may be inferior, but the market for tuning the j-series is huge. All that said, I really like the idea of the LFX swap. Using all OEM stuff is nice.

Efini~FC3S

iTrader: (4)

SOHC makes the engine package as a whole smaller = easier to fit in your tight space.

SOHC (and belt drive) gives the engine very low friction characteristics = good cruising mpgs

SOHC makes the engine lighter



On paper, the J series is a pretty simple, almost archaic engine. In the real world you drive a J powered car and the last thing on your mind is "Man, this thing would be soooo much better if it was DOHC!" The engine as a whole package is excellent, can make great, reliable power NA and make crazy numbers when adding boost.

Obviously the merits of DOHC are well known and there's a reason the J engine seemed to top out around 300hp in OEM (vs ~350 of a VQ) but please don't discount this engine solely on the fact that it's SOHC, that's just ignorant.

karter74

iTrader: (4)

I find it humorous people discount an engine because its "only" SOHC. People haven't seemed to mind too much about the whole pushrod/2 valve thing in the LSx swaps.....

Thats the equivalent of complaining about the LSx and going with a DOHC mod motor because its DOHC.

jakeordie

Yeah, it's a trickle-down version of the NSX engine;

Honda C engine - Wikipedia, the free encyclopedia

Simpler, lighter, cheaper.....better for 99% of users. Comparing this swap to the LSx is missing the point, different strokes for different folks.

18psi

iTrader: (76)

don't get carried away ladies, this doesn't even come close to touching the LS

.... and many of us are still not impressed at all when comparing this to the K's, which are making serious progress and showing impressive potential...but that's off topic so I'll just leave it at that

KMiata

Our thoughts exactly. I never want to knock a competitor's product, but I do think you get what you pay for with swaps like this. There sure are some strange design choices with this J kit.

Anyone actually finish the swap? Any track footage (from the manufacturer or a customer)?

cordycord

iTrader: (2)

One of the hallmarks of a good bench racing BS session is that you should not have all the information. Conjecture and misinformation only makes the discussion more fun.

So on that note I apologize for contacting SuperFastMinis to get more information about the steering and oil pan. Norm at SuperFast said,

"The oil pan in the V6 Miata is approx .700" below the bottom of the stock K member. You will drag the bolt heads on the cross brace of a stock NB frame before you get to the oil pan. I can decrease the capacity of the pan from 6 to 5 qts., raising it .690", but I would rather have the capacity over the clearance. I have a Touge Run chin spoiler on one car that is one inch below the oil pan.

The rack and pinion is lowered approx .625" and has minimal bump steer in a firm stock height setup. Lowering the car considerably amplifies it somewhat. I have developed a rack offset kit that eliminates bump steer and actually be adjusted to give better steer characteristics in lowered cars. I will eventually add it to the kit."

Now since I would be considering an engine swap for a Catfish rather than a Miata, it means that I have more options than a Miata to move the engine in the bay--I may be able to keep the stock steering rack location, for example. Also, since the car is considerably lighter than a stock Miata, it also means that there's less stress on a stock drivetrain--I need to worry less about grenading a transmission or pumpkiin.

The difference between the LFX and J35 -- besides horsepower -- seems to be weight and robustness. The LFX will weigh more, but will have a stout transmission that can handle the ponies. I assume that a pumpkin change and driveline upgrade would be in the cards too.