your forgot to add that you know what your are doing...

beers

 

This will be nowhere near 3k when complete.

Just the engine is 500, then you have to factor in custom motor mounts and tranny mounts. A custom drive shaft to go from the 240 trans to rx8 diff (read very expensive). An ECU to run the KA and custom wiring to have both the car and engine in sync. Not to mention custom AC lines, Radiator, and all the other creature comforts like trying to get abs and DSC to work. Then you want to add a turbo to the KA! This will be upwards of 10k if not more. Just doesn't seem worth it to me. Especially if all you want is gas mileage.

EDIT, just read you want to use the RX8 trans, which is much more custom work.

 

Well, I'm not going to discount that the OP might as well.
I have found that there are plenty of folks out there that my seem misinformed that are actually quite capable.
Unfortunately, these sort of people are far less in evidence than those that seem like they know what they are doing when, in fact, they do not.
YMMV.

 

You are allowed to post pictures as your avatar again MM? Nice. Anyways I thought this person seemed familiar. I agree with swoope. You, no offense, seem not completely able to do this task due to all the questions you asked but what do I know? Try it out. It seems your really into doing this. But I do not understand why your are using the Rx-8. Seems kinda... mundane.

 

The admin and I, once again, achieved a concordance. All is good in the world.

 

Hmmm... I had the idea that trying to bolt in the RX-8 trans to the KA24DE would be cheaper than fabbing a custom drive shaft.

ECU shouldn't be an issue on RUNNING the KA since it'll all be stock. But the issue will be at making the RX-8 gauges and non essential electrical components work. Such as A/C, lights, Headlight adjustments, Door sensor.

ABS, DSC, TSC, TPS are not an issue. I will be removing them.
Radiator hoses are the easy part. Electric fan will be removed since KA has a clutch fan for radiator.
A/C Pump, Power Steering pump, Alternator, Starter are all built around the KA and pop right in with the engine.
Biggest issues are the trans and the steering.

this whole project is going to be taken one step at a time. Right now I'm getting a Miata to put the 240SX in the garage.
First step will be to rebuild a KA24DE engine and test it on the 240SX.
I'm not going to buy a KA24DE, rebuild parts, buy an RX-8, Pull out the RENESIS and try to figure out what goes where all at one time.

 

Never tackled anything this big, but I would look into both options and price out exactly what would need to be done for both. I think the driveshaft would be easier for you but also more expensive since it will have to be custom made. Mating the 8's tranny to the KA would be pretty hard to do but cheaper if you can do the work yourself. Either way, I don't think that this will be a 2-3k swap. There is going to be alot of custom stuff that you wouldn't think would need to be done that is going to show its head when the project is underway.

 

Wow, no offence here but. if you call this project an "experiment*, fine.

but if you're doing all these stuff just to try to get a few more mpg. You're wasting your time, totally.

if you use 3000 bux to buy gas for your 8, Premium cost about 3.5 per gallon in nyc, 857 gallon of gas , 15 mpg = 12855 miles / 15 miles per day = 857 days = 2.34 years of gas.

I mean, is it really that worth it just to save maybe a buck the most 3 a day ? Im pretty sure you've spent more than those 2-3 bux on other useless crap every day.

You're talking about replacing pretty much 70% of the car's stuff. actually, more like 80%, cuz you will have to strip most of the eletronic Stuff outa the car. Yes, it will be lighter, probably few more mpg, and maybe a bit faster (cuz its lighter). but, if MPG is your main reason to *try* this swap. I guess you should just forget about it. Its just not worth the time (and money)

Not to mention, if 7 bux a day extra (compare to maybe 4 bux if you're on KA), will affect your life. I guess you should start looking for a higher pay job (or try to cut your other spending).

I spent more than 10 bux a day just to commute ... and Im ok with it. but thats just me, you might have your own problems I understand. but ... doing this swap for mpg just dont .... work for me.

 

Why would you remove ABS!?!?

 

The ABS drives me nuts. Maybe it was the worn Yokohama ES100 tires but the whole ABS kicks in thing trhows off my braking. You see, all my cars never had ABS before.

And yes, the experiment also comes with the fact that I like the KA24DE engine. I have 200K miles on mine and the only thing replaced are the oil seals and gaskets.

 

All due respect, but it is quite obvious to me that you are not on a track to success with this.
Hopefully I am wrong, but you clearly have some grave misunderstandings for what it takes for a swap of this scale.
Certainly to believe that the fabrication debit for mounting the Y16M-D to the KA would be less than simply having a drive shaft made is ludicrous.

 

11 MPG for a car that cant get 250 HP? If you really want to play get a fast car and get your gas monies worth. Otherwise we should be happy with a 4 seat sports car that looks good.

 

No turbo? So after all this you'll only be getting 157 horsepower?

This is such a bad idea. You're trying to turn an RX8 into an economy car and destroying any semblance of sportiness in the process. Why don't you just buy a cheap economy car?

 

There are many places that can make custom driveshafts. This is usually much easier. And in the V8 world Mcleod makes a modular bellhousing that allows just about any classic and late model rwd trans to mate with most V8's. Maybe there is something similiar in the import world?

If you go through with this make sure you do all your research. Talk to people who have done something similiar to this. And only do it if this is really what you want, not to save gas.

 

I nominate this the worse thread of 2007. It's really that bad. Spending thousands to get less power! Woo.

 

While I can certainly understand the need for better fuel milage this is classic case of wanting your cake and eating it too.

If you need a daily driver that gets good gas mileage, bite the bullet and buy something that gets 25-35 MPG. The Mazda 3, while FWD, is right in your price range and an excellent vehicle of which will provide you with a warranty and 30-34 MPG.

As MM said, engine swaps are full of unexpected expenses and no doubt you'll run into issues with the parts themselves needing a rebuild or replacement. Despite that, using it as a daily driver is rolling the dice when it comes to reliability.

Point and fact, if it's not broken don't fix it.

Respectfully, if you can't afford the gas then don't buy the car. I certainly budgeted gas into the equation when I looked at the RX8.

Anyway, I understand what the OP is trying to accomplish and from a project car standpoint I'd say go for it. However if your end goal is to save $$ then doing any kind of modifications to a vehicle isn't for you. The only return you get is the excitement from driving it.

 

if I want a Muscle car I would've got myself a "R"ustang

Not to mention our *11mpg car that cant get 250 hp* can kick those *over 250 hp* car on the track without too much effort. So tell me. who is better bang for buck ?

Did I mention that I am getting around 16-19 mpg right now? (mixed with city/hw) Im happy with it

 

and make it completely un-resalable.

 

You drive hard enough to engage the ABS on a normal basis? Worn tires or not...better put that $2/day savings into brakes.

I'm thinking you may be WAY in over your head.

 

uh, maybe thats why gas mileage is such an issue for him.

here's how to save a few mpg a day. shift before 3k rpm.

cant you buy the int-x and tune for less hp and better mpg?

 

Turboed 8's on ebay get bids and sell. You'd have a much tougher job trying to unload a hack-and-slash, unpowered, 4-cylinder project car.

 

That's not a bad idea, actually. Clearly the OP is content with less power, so here's a de-tune that actually will cost him ~$1000. When he gets sick of it, he can take it off, sell it, and get most of his money back without hurting the resale value of the car or voiding the warranty. It may not get 35mpg but it's a much smarter choice than swapping the engine. Brilliant!

 

Like I said, get a REAL SPORTS CAR cause that R stang thing dont cut it either.

 

You can restore a turbocharged RX-8 to stock in a single day. Besides a few minor underhood plastic bits that might have to be cut up a bit, you should be able to go 100% stock in a short period of time.

I hope you're not suggesting that putting a lower power engine in the RX-8 would increase it's resale value.

lol

 

Sorry Mr. Corvette troll, we're not all loaded. Some of us have to make due with RX8s.