asostre

This isn't a thread asking the cost or anything like that. Rather a discussion.

13B-REW TT swap into RX8 or buying an FD and keeping the RX8 as a DD.

In your opinion, which is better? Please take into account things like insurance cost, maintenance, general fun, which chassis is better, and also practicality.

Personally I lean toward the FD.

The way I see it, I can then turn my RX8 into a DD and the RX7 as a weekend/track car. (PRO)

Insurance rate will go up though with a second car. (CON)

I'd have two very fun cars. (PRO)

FD weighs less. (PRO)

I could gut the interior, set up a roll cage, and in general set up the FD as a proper race car. (PRO)

I'd have a backup car if one is in the shop. (PRO)

Also, if I'm correct my insurance policy won't cover the upgraded engine. (CON) In which case if the RX8 is totaled that is 10-15K down the drain, but please correct me if I'm wrong about this.

However on the other side I've been told that the RX8 is an easier, more enjoyable drive due to the wider wheelbase. Also, I've been told that the SE3P chassis is (arguably) better than the FD. Also, owning two cars requires the space to do so. A lot of FD's are older and could have hidden issues. FD reliability is worse than the RX8.

With that said, can people with engine swapped RX8's and people with FD's chime in? It'd be great if someone has driven/owned both.

bryan4140

iTrader: (2)

If you have the space and money for two cars I would add an FD to the collection, especially if you need a reliable daily. Swapping the REW in to the the 8 is going to cost a good amount of money but more importantly time and know how. Having both cars will allow you to build each (or just the FD) to suit your needs better as well.

poacherinthezoo

2 rotary cars is better than 1.

FD's are getting harder and harder to come by, especially in unmolested condition. If you've always wanted an FD it might be better to get one now - as their numbers will only continue to drop over time. That said, I am not well versed, or versed at all really, in the cost to insure an FD.

xexok

I drove a 330 whp fd with stock twin turbos and a good amount of other upgrades and I would trade my rx8 for that thing without a second thought. I love my rx8 but compared to that fd it is almost a joke. That was a modified fd though and I can't speak about a comparison to a stock one which is very likely significantly different. It was not a practical car at all and was kind of a bitch to get in and out of. Once you got in it fit you like a glove it was almost like wearing the car.

I think the fd looks better than the rx8, it was way ahead of its time. I'm not saying the rx8 looks bad at all I like how my car looks but the fd is just great looking. I'll post some pictures of this fd I drove in a minute when I'm back at my computer. I'm not sure I'd trade my car for a stock fd but this one I sure would have.

It wasn't my car so I couldn't really throw it around really hard but I was able to go through the gears a bit and it was a lot of fun.

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Karack

if you dont need 4 seats and want to go faster then buy the FD, even a swapped 8 won't be the same.

as well they were never produced in the same numbers so the FD is appreciating in value where most 8's still have not bottomed out. not that an FD is something you buy as an investment, but it will not lose value.

comebackqid

iTrader: (13)

most probably never experienced an rx8 with a 13brew. other than that FD looks better (IMO,8 still looks cool tho.) 8 is more practical, which chassis is better? biased ppl (most, here or there) will say the FD irregardless of chassis knowledge or technology that went into building each model (not like I know any better) I'd take either.

RIWWP

iTrader: (2)

Talk to firecran, he should be able to give you the perspective you are looking for, as he has an REW swapped 8, and I think I remember him saying he had an FD at one point too.

Personally, after driving 2 different FDs, one single turbo one overhauled stock twins, I'd take the 8 with a Renny hands down for anything but a drag strip.

A brand new FD might tempt me enough, but part of the problem is the simple age of FDs. Both in the actual wear in the chassis structure as well as in chassis technology.

Brettus

iTrader: (2)

You forgot about a turbo Renesis which is what I have............ and wouldn't swap for either of those options .

9krpmrx8

iTrader: (46)

+1, 90% of the FD's on the road are turds. I love them when done right but sadly they are just getting so old that you rarely see well running ones. .

asostre

@Brettus I did not include a turbo or supercharged Renesis, because I am afraid of the loss of reliability. Everyone tells me horror stories about boosted renesis, so I guess I'm a little paranoid about it. How many miles/years have you driven yours while boosted?

@9krpmrx8 The handful of FD's I've seen down here are quite nice. And we have a few for sale that are crazy. I'm talking only 10-15k on the odometer and completely stock, garage kept.

@RIWWP Can you elaborate as to why you'd choose the 8? Also, is the chassis really that much better? Or is it somewhat negligible if you find one without much wear?

@Xexok That FD is nice. I'm curious as to how tall you are. I'm about 6'1 1/2 but always hope I'll grow just a little bit more haha.

Thanks for the replies so far.

Brettus

iTrader: (2)

The horror stories abound because so few people get it right . You could say the same about the FD swap except the calibre/knowledge of people doing that is generally higher than those just fitting a turbo so the success rate is higher for that reason alone.
Done properly the Renesis is quick , reliable and suffers no compromises .

I have 100,000 turbo kilometers on my car but there have been a few engines killed because i pushed the limits on a platform that few people understood so I had to learn the hard way.
I like to think I'm on top of reliability these days - certainly it's there at low boost (<10) .

asostre

How much HP are you getting?

Brettus

iTrader: (2)

My last (optimistic) dyno was 362whp and it now makes about 40 more than that so 400 on that dyno ... Maybe 360 realistically though.

xexok

I'm 6'1" as well. That fd also had recaro confetti seats which made it a bit more difficult to get in as the owner was very strict about not rubbing/leaning on the sides as you got in and out. It had a removable steering wheel which I had to take out if I wanted even a chance of getting in there lol. I have sat in a stock fd drivers seat and it was much easier to get in an out of. That fd was also rhd so that may be tainting my comparison a bit just because it felt a bit more special to drive it. That probably sounds silly to some people but it is not every day you get a chance to drive a car that isn't even allowed to be legally imported for another 6 years(it was a '95). I don't want this to be taken the wrong way so I will just say being rhd does not make it a better car, I know that, THAT would be silly.

The rx8 is a really great car but I don't have to tell you that. For me it is just an issue of power. If some day I have the financial means of risking blowing the engine I would love to turbo this car but that is out of my reach right now. I think with more power I would definitely be much happier with my 8 as it is a lot more practical than the rx7 I drove. The rx7 just had a more raw driving experience while the rx8 is just a smooth and easy ride, the difference is really tough to describe. I would still love to get an fd at some point.

asostre

What do you mean RHD doesn't make the car faster?! I suppose now your going to tell me that Red RX8's don't have 15 more horsepower. :p

Being serious though thanks for the info. I guess I'll see if I can find anyone local to show me an Rx7 and an RX8 with a 13Brew or a boosted renesis.

RIWWP

iTrader: (2)

Many reasons. Please note that these are my personal opinions only, and I fully expect that there will be some people replying that utterly disagree with me on some or all points. That's fine, and it wouldn't change my opinion. It's nice that we all have opinions, right?


1) Compression. I like high compression engines far better than low compression. Yes, I still like and approve of the benefits that turbocharging brings, however on public roads you will spend more time out of boost than in boost. And out of boost, the RX-7 is slower and more sluggish than the 8 is. Stick a big single turbo on an FD, and it gets even worse. The big single turbo FD I drove was slower than my wife's 100hp Mazda2 until the boost started rolling in. Seriously. The one with the stock twins was significantly better, but still not up to the response level of the Renesis. I disagree with the "reduce compression and increase boost" line of thought completely. High compression low boost is preferrable to me in every way. Both of the turbo 8s I've driven still had great engine response and usability when out of boost.

2) Age. Even a low mileage FD is still attacked by time. In both FDs I drove, the structural creaks, chassis flex, and wear on the car was incredibly apparent. Even in the 60,000 mile one that had a completely overhauled interior and freshly painted body.

3) Technology. I love new technology. I am not nostalgic in the least. I don't find myself wishing for something from my past. For example I loved the Ferarri 360, until the 430 came out. Then I loved that, until the 458 came out. Advancing technology appeals to me greatly, and I don't just mean cool tech features like the GT-R has. A huge one to me is how far suspension development has come, and I don't mean the shock/spring tech. The FD would be a far better car if Mazda was able to develop it with the suspension design that they gave the RX-8. I fully expect that the next rotary sports car will be yet another suspension advancement that will be clearly superior to the 8's. The chassis feels so much better. Just one example. I value technology advancement in every area. Engine design, turbo design, aerodynamics, interior refinement, weight reduction, safety, etc... A 20 year old car just can't compete on those playing fields any more. Even my MSM uses chassis technology that is essentially from 1999, and engine technology that is essentially from the 1980s, and my biggest complaints with the car are sourced from those basic facts.

4) Reliability. A completely stock FD has a worse reliability than a completely stock RX-8 in my opinion. Not just the engine, but everything. "Rats nest" is what they call the 70 some vacuum lines in the engine bay that get baked by engine heat and eroded by time. At 20 years old, even long life stuff is going to keep breaking. Sure, call it maintenance that you are replacing stuff before it breaks, but it's a rather long list at this point.

5) Ease of work. The RX-8 is far easier to work on. This is somewhat subjective I think, as I have never actually worked on an FD, but from everything I've read about and picked up on talking to owners, there are lots of pain points. The RX-8 on the other hand, is ridiculously easy for all maintenance items, and many other major items beyond. I had no reservations about tackling any project on the 8 all by myself.

6) Cost of parts. The RX-8 still has a supply chain of parts, the FD's supply chain is slowly drying up. On top of the reduction in availability, the FD was originally a $40,000 car, vs the RX-8's $25,000. The original MSRP has a huge impact in how much replacement parts cost, regardless of what you bought the car for.



ymmv

Karack

i agree with you on all but these points.

taking the engine technology and compression versus boost that is subjective to every person. more power means less low end response, more low end power means less high end. that's up to each person to decide what they want.

the FD is lighter already, giving it one major advantage. the drawback is the suspension is less enhanced and sitting on likely old rubber, upgrading those components easily puts the weight advantage back into major play.

i also wholeheartedly disagree with the reliability of the FD 'engine' versus the majority of the 13B-MSPs on the road(series 1s). most FDs made it on average to 125k, it is only now that you're seeing original cars with coolant seal failures in the 50-60k mile ranges, that's due to age of the seals. the main thing that fails on the FD is simple electronic controls on the engine, failed hoses or solenoids causing erratic boost problems. yes the cars with under 125k now that are failing is bringing the average down but age is still a major factor with these engines, something the renesis has to play catch up with.

when it comes to working on the engine both are equals in my opinion. the fact that the RX8 shrouds half the engine makes it more of a headache to do simple work than is necessary. even pulling the engine out requires a shoehorn compared to the FD unless you have a fully equipped shop to drop it out the bottom, which can also be done on the FD but for the average DIYer i find them close to equally matched once you know what you are dealing with. the FDs rats nest is intimidating to anyone, until you have worked on it before and realize it basically all comes out as a complete unit and can be worked on outside of the car in less than an hour.


the major drawbacks that never really drew me to love an FD as some have is the fact that the interior and rear suspension rattle, the interior plastics are as cheaply designed as humanly possible, even zip tying them to the car would have resulted in a better interior feel/sound. IMO the REW is the BEST engine mazda ever produced, the issue with the FD is the complex twin system which realistically couldn't have been refined further due to the amount of actuators and emissions systems necessary for the car. to most it is a nightmare under the manifold, to me it is a marvel that it works as well as it did for how long they did. even the RX8 has solenoid failures regularly in the same mileage range that the FD had issues with the twin system, p0661? yep.

the last statement is subjective, depending if you like feeling boost or more linear power from the bottom up. it may not take off from a dead stop like an 8 but it certainly will pass the 8 in no time. i wouldn't buy an FD to mainly drive it on city streets, i would buy it to drive it in the canyons where it was meant to live. the RX8 is a more city friendly car, something i would much rather drive around town or take on a long drive compared to the FD which gives me arm cramps after an hour.

stock for stock, to each their own. the FD was quicker all around but of course it lacked space and new technology/comforts of the 8.

firecran

iTrader: (3)

I've had a FD and now have a swapped 8.

My vote is if you can afford it go with a REW RX-8

I wouldn't own a RX-8 with a Renesis, but that's just me.



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Brettus

iTrader: (2)

Would love to do a side by side comparison between mine and a well setup 400whp REW . Performance in all rev ranges , driveability , fuel comsumption , longevity... the works .

My feeling is the renesis would come out on top ... but I know it's never going to happen so you and i will always have something to argue about

firecran

iTrader: (3)

No arguing here...
Your car is set up well and has lasted.
Did you find the Renny holy gain??

I'm at just under 30k miles on this engine and been running between 12-16 psi.

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Brettus

iTrader: (2)

did you mean 'holy grail ' ?
No , I just learned how to make the best out of what I had to work with . Turbo rennys are getting more and more reliable as we realise what it takes to achieve that.

Your car would be a great one to do a direct comparison with because it is still within the range of what can reliably be done with a Renesis . Start talking about more power than that and we can't get there ....yet.

asostre

Interesting points RIWWP. If only they resurrected the Rx7. That would make things so much easier. Lol.

Karack

again, to each their own.

the REW is actually the best compromise in compression versus boost that was ever put into a rotary engine at 9.0:1.

even with simple water injection the compression ratio allows for in excess of 30psi with simple pump gas, allowing it a rather easy ceiling of 800+WHP without any crazy bells or whistles.

to see much of anything to note with a renesis you need a huge turbo limited to low boost, which still compromises response.. or run E85, race gas or mixes of fuel to increase octane.

firecran

iTrader: (3)

Also...

The REW looks way cooler in the engine bay than a renny.






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I8yourv8

What car came with the "REW" engine guys? Sorry, im totally new to the rotary side of the world