mysql101

We had a group buy not too long ago. I picked up gram lights 57F for $250 shipped per rim. They are supposed to weight 17.8 lbs for 18x8.5. The website you listed show them at 20 lbs each though.

I've heard there are two manufacturers of the OEM rims. One was 22 lbs, the other is 25 lbs.

Soravia

I started with the idea of a Piston swap because the cheap KA24DE engine had more torque at mid RPM range than a RENESIS.

A lot of people look at wheel horse power (peak) but for fuel economy I'm considering how much torque can be delivered into use at any given amount of fuel. Basically Fuel-to-Torque ratio, which is Miles per gallon.

I'm considering replacing CAT with a mid pipe, replacing the muffler, using lighter and smaller wheels (because wheel is not the only thing that has weight, tires weight too), have Interceptor on top of it to make the car run lean at cruise and map it to use with only High octane.

There are other ideas like attemping to make the intake temp cooler but that's for later.

mysql101

Now you're making sense But unless you make some drastic weight loss and move to skinny tires, I don't know if you'll get much further than 22 mpg range.

V Vette

iTrader: (-1)

e *****? Dont be a dick..Also, C6's are plastic not fiberglas. Maybe an Elise now...

mysql101

Nice. Did you know Saturns have had plastic for a while now?

Soravia

I AM looking for 22MPG range. The RX-8 I had before got like 15MPG or 17MPG at best and on the 15 miles trip to work I drove like 11 miles on highway.

I don't plan to pay a lot for wheels. Last time I checked the stock 18" weighted 22LB same as Dodge 18" but the Dodge wheels were 7.5" instead of 8".

I'm thinking 16" if I can get it down that much. 17" if not. One inch in wheel and a bit more in tire could count for something.
Does the lighter fly wheel accounts for anything? Or is it just as much as a Cat-less exhaust?

I have a HKS 4" steel pipe on my 240sx. It sounds glorious with a low growl (I've heard enough Mustangs, 350Z, G35, Civic Type-R, WRX to say this).
But the frikking thing is heavy and expensive. The only reason I have it is because it came with the shell. Will a cheaper and lighter 3" straight pipe sound like crap (Civic with fart can) on an RX-8?

V Vette

iTrader: (-1)

and your point is? Lets get this crap off the tread as I am sure it is childish..PM me if you need to discuss further.

Rootski

iTrader: (1)

And what do you think "Fiberglas" is? AKA "GRP," glass-reinforced plastic.

kersh4w

iTrader: (3)

more info on the intercepter x. (also note: its mazsport, not greddy. greddy has the e-manage ultimate)

http://www.mazsport.net/store/index....uct_detail&p=7

4me2

Fiberglass is cheaper crap, cracks and rattles.

swoope

iTrader: (5)

you are going to hate this, but the last tank of gas driving home from the mid atlantic... 23.45 mpg...

you really really need to read more and post less... really..

this should make my point...

https://www.rx8club.com/showpost.php...80&postcount=7

and to answer the ? in another thread... if you get one or two more mpg with the ceptor x on a na car, it will never pay for itself...

beers

Rootski

iTrader: (1)

I've worked extensively in fiberglass. Not only can be it be very strong and durable, but it can also get pricey as well.

ghlewis

The point of this question seems to have gone over a lot of peoples heads. The car looks fantastic but the engine is thirsty, lacks torque and reliability is an issue. The right engine will give 30+mpg 250k miles+ easy, rebuild proof driveability and maintenance, 180lbft torque and 190 bhp. The rotary engine has two strengths and many weaknesses, if mazda had built the car with a better engine they would have sold five times as many. The fact that you can buy an excellent example with a knackered engine for £500 ($750) is all the proof anyone without rose tinted specs needs.
Obvious candidate is the Honda s2000 engine (same gearbox I think) but it also lacks torque and costs £2000 ($3000) upwards. My choice would be a 2.5 BMW engine & gearbox, a cheap, bullet proof, superbly smooth straight six, not too big & really cheap. (£500 or thereabouts) ($750) can easily be chipped to over 200 bhp and 200lb/ft. It shouldnt affect the handling much and its rock solid proven german engineering. Has anyone had a go at this?

RIWWP

iTrader: (2)

Thanks for bumping this from the grave to let us know that it belongs over in the engine swap subforum.

Zuhalter Vati

Holy Necro Thread Batman!

alnielsen

iTrader: (4)

If it wasn't for there being a rotary engine in this car, I wouldn't have bought this car new and would be driving a BMW today.

ghlewis

It may be less of an issue in America but in the UK where petrol is $10+ a gallon a car that does 15mpg is a disaster. Add in the lack of torque and reliability issues and the continued use of a rotary engine in any future production car must be questionable.
I re-raised the issue because there doesnt seem to be a definitive answer or anything close to one. Maybe the answer it to install a 325 bmw engine myself and report back

ghlewis

Most people bought it for the looks and put up with the engine. Drive a straight six BMW and you will realise the rotary engine has no virtues that the bmw cant equal and it has none of the vices, its a no brainer,.

RIWWP

iTrader: (2)

Answer for what question? Piston swaps have been done, this is in a subforum dedicated to the after all. The engine doesn't really matter. The Daab turbo engine swap has the same challenges as the Izuzu swap and every LS swap.

If you feel strongly, then take action on it.

Posted From RX8Club.com Android App

ghlewis

I cant find the subforum, I love the site but the indexing of subjects and the ease of use needs a tidy up. My point is that Ive seen a lot of conjecture about this subject but the engine choices seem ill considered at best. An engine thats not too difficult a fit, has the same smooth revving and power to weight that the rotary does but with added benefits of torque, easy maintenance and double the fuel economy. If its practical I`ll have a go, I think its by far the best engin e choice.

New Yorker

Actually, I bought it for the engine and am lukewarm about its looks. And, like most enthusiasts who appreciate this car, I didn't buy it for the engine, per se, but rather for the remarkable handling the little engine makes possible. No automotive journalist ranks a straight six BMW's handling ahead of the 8s. And swapping in a larger, heavier engine would negate the 8s handling advantage. That's just basic physics.

RIWWP

iTrader: (2)

If you scroll to the top of this page, you will see this line:
RX8Club.com > Frankenstein RX-8s > Frankenstein RX-8s

This is the breadcrumb string for where the thread is located.

This thread is IN the subforum for engine swaps: Frankenstein RX-8s.

My point about the engines wasn't the engine choices. Everyone has different engine likes and dislikes. My point was is that it doesn't matter WHICH engine you pick, the challenges will still be the same across the board. The cost and difficulty of swapping a BMW I6 is going to be pretty much the same as swapping an Mazda 20b, a GM V8, a Ford V8, an Izuzu V6, a Saab Turbo I4, a Porsche Flat 6, or a Harley V-Twin.

They ALL have the same challenges to deal with. Picking a different engine isn't suddenly easier. The ONLY engine that could be considered to be "easy" is the peripheral port 13b from the RX-7, but that is still around a $12k-$15k (USD) project, consisting of some fabrication requirements, many ECU and wiring difficulties, and exhaust, cooling, and oiling customization. And that's for an engine that is fundamentally the exact same size!

It's possible that the 2.0L MRZ from the 2006+ Miata would be "easy" to swap as well, since that car shares the same subframe and most of the same body electronics modules as the RX-8. You can bolt the front and rear subframes of the RX-8 to an NC Miata after all, the reverse is clearly true as well. But I've only heard of someone pursuing that once, and I heard no more about it. It's a far weaker engine anyway, and not much more fuel efficient.


BTW, I can't seem to find a BMW straight 6 engine that would be "double the mileage" of the 8 without also being a diesel and/or a hybrid.

You need a City rating of around 32mpg and a highway rating of at least 44mpg in order to classify as "double". And you have to consider that a portion of mileage calculations is the aerodynamics which will NOT be transfered from that BMW to the RX-8. An RX-8 that isn't hitting 16mpg city and 22mpg highway is an RX-8 that has something broken. Might be parts or it might be the driver, but it doesn't change that fact.

I also don't see you pitching a fit over vehicles that get significantly worse mileage... If mileage is such a big concern, get a car with better and be done with it.

You may also want to consider that even assuming you find an engine that allows "double the mileage", doing a swap that costs you even 6,000 quid is going to take a very long time to break even on the fuel costs vs swap costs.

ghlewis

The RX8 has a better drag coefficient than the 3 or 5 series BMW, assuming the engine will fit without changing the bonnet line its figures will improve slightly. My mates 325i will return close to 45mpg on a run and 28 overall, I think this is close enough to warrant the experiment. I plan to do all the work myself except the electrics where i have some help. There are no cars for the common man in the UK with worse mileage so the point is irrelevant.
My plan is to buy the RX8, recon the rotary and sell it to fund the change. It would appear from this forum that custom garage service hourly rates in America are very high compared with Europe.

ghlewis

Youre in a very small minority if you did. Mazda are continuing the mistake by putting a rotary in the next generation. If it offered a choice of engines the rotary wouldnt make 10%.

RIWWP

iTrader: (2)

No one here thinks the rotary is a mass market engine. It's a niche engine for sure. Your 10% is way way way too high.

If you want to swap and think you can do it easily, then just go ahead and do it. We know the drawbacks of the engine and most of us love it anyway. No need to continue bemoaning the topic. You aren't going to suddenly convince us of anything we didn't already know.

My attempts were only to try to get you to understand that it won't be as easy as you think it is, but I have no stake in that so... have fun...