Mazda Rx8 vs Mazda Rx8 r3

Mazda Rx8 vs Mazda Rx8 r3

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Discussion

Rema2309

Original Poster:

3 posts

53 months

Wednesday 20th November 2019
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What’s the difference? and can you fit an rx8 engine in an rx8 r3?

Truckosaurus

11,275 posts

284 months

Wednesday 20th November 2019
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The R3 is the facelift model, looks nicer IMHO.

The R3 engine was updated to be more reliable but still needs semi-regular rebuilds.

I'm sure you could put the non-R3 engine in one, but I don't see why you would.

Rema2309

Original Poster:

3 posts

53 months

Wednesday 20th November 2019
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Thanks you have been a great help!

Nickp82

3,182 posts

93 months

Wednesday 20th November 2019
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You can’t fit the Series 1 RX-8 engine in to an R3 and get it working properly without uneconomical expense and as previously mentioned, it is a poor idea as the engine in the R3 is significantly more reliable.

R3s are worth a fair amount more than any other RX-8 model for this reason plus the fact they have Recaro Interior, 19 inch forged alloys, body kit, auto lights and wipers, Bluetooth , better suspension (though PZ and 40th Anniversary Series 1 models did have this too) etc etc

Rotary Potato

247 posts

96 months

Thursday 21st November 2019
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I'd agree with most of the above.

However, I'd not sure you could prove that the R3 engine is considerably more reliable than the S1 engine.

For starters, there are the numbers ... many thousands of S1s were sold, whereas only 800 R3s were ever sold in the UK. So as an observer listening to anecdotal evidence, you're going to hear about 20-30 S1 engines needing a rebuild for every 1 R3 engine (assuming they were roughly as reliable as each other), which is likely to make the observer feel that the S1 needs a rebuild a lot more often than the R3.

Then there's the age of the cars. The oldest of the S1s is over 15 years old, and the youngest of the R3s is still under 10 years old. That's obviously going to impact on the numbers of each engine needing a rebuild.

While there are lots of incremental changes across the car from the S1 to R3, the main ones impacting engine reliability would be the extra oil injector and the revised oil pressure regulator (I'm going by memory here - I'm certain they have an extra oil injector, but only 85% certain about the revised oil pressure regulator). Neither of these are a game changer, but both help slightly to mitigate the inherent design flaws in the engine.

If we were to consider budget, a decent R3 costs more than a decent S1 - by such a margin you could go to a specialist with a great reputation and get a full rebuild with an extended warranty and it still come in cheaper than the R3.

So to be a financially fair comparison, you need to compare an S1 with a fresh rebuild and a fairly bullet proof extended warranty against an R3 engine that's about 9-10 years old and done X thousand miles and who knows how it's been treated in that time. In that comparison, it all comes down to how much you value the additional R3 bits elsewhere on the car (seats, wheels, updated looks, suspension, etc.), as from a pure reliability point of view, I think I'd take the S1 with a fresh rebuild.

EDIT: And while most components are shared between the two engines, there's enough of a difference that you can't take an S1 engine and drop it straight into an R3 and it work. Depending on what broke on an R3 engine, it'd be possible (but not likely to be simple, quick or a good idea) to make a working R3 engine out of a broken R3 engine and a good S1 engine.

Edited by Rotary Potato on Thursday 21st November 09:26

CABC

5,575 posts

101 months

Wednesday 4th December 2019
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Rotary Potato said:
I'd agree with most of the above.

However, I'd not sure you could prove that the R3 engine is considerably more reliable than the S1 engine.

For starters, there are the numbers ... many thousands of S1s were sold, whereas only 800 R3s were ever sold in the UK. So as an observer listening to anecdotal evidence, you're going to hear about 20-30 S1 engines needing a rebuild for every 1 R3 engine (assuming they were roughly as reliable as each other), which is likely to make the observer feel that the S1 needs a rebuild a lot more often than the R3.

Then there's the age of the cars. The oldest of the S1s is over 15 years old, and the youngest of the R3s is still under 10 years old. That's obviously going to impact on the numbers of each engine needing a rebuild.

While there are lots of incremental changes across the car from the S1 to R3, the main ones impacting engine reliability would be the extra oil injector and the revised oil pressure regulator (I'm going by memory here - I'm certain they have an extra oil injector, but only 85% certain about the revised oil pressure regulator). Neither of these are a game changer, but both help slightly to mitigate the inherent design flaws in the engine.

If we were to consider budget, a decent R3 costs more than a decent S1 - by such a margin you could go to a specialist with a great reputation and get a full rebuild with an extended warranty and it still come in cheaper than the R3.

So to be a financially fair comparison, you need to compare an S1 with a fresh rebuild and a fairly bullet proof extended warranty against an R3 engine that's about 9-10 years old and done X thousand miles and who knows how it's been treated in that time. In that comparison, it all comes down to how much you value the additional R3 bits elsewhere on the car (seats, wheels, updated looks, suspension, etc.), as from a pure reliability point of view, I think I'd take the S1 with a fresh rebuild.

EDIT: And while most components are shared between the two engines, there's enough of a difference that you can't take an S1 engine and drop it straight into an R3 and it work. Depending on what broke on an R3 engine, it'd be possible (but not likely to be simple, quick or a good idea) to make a working R3 engine out of a broken R3 engine and a good S1 engine.

Edited by Rotary Potato on Thursday 21st November 09:26
very useful post.
i'm an RX8 noob. i'm looking for a new track/station car to cover less than 4k miles per year now my aged MX5 track car has died. I've tried a few fwd cars but they really don't do it for me. Coming round to RX8 and swallowing the fuel costs for such a low mileage biglaugh

i was thinking of R3 because of engine and suspension upgrades, but lack of R3s on sale and the logic you present are swinging me to earlier models. any specific tips you'd offer? PZ model could be a worthy model?


Rotary Potato

247 posts

96 months

Thursday 5th December 2019
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CABC said:
very useful post.
i'm an RX8 noob. i'm looking for a new track/station car to cover less than 4k miles per year now my aged MX5 track car has died. I've tried a few fwd cars but they really don't do it for me. Coming round to RX8 and swallowing the fuel costs for such a low mileage biglaugh

i was thinking of R3 because of engine and suspension upgrades, but lack of R3s on sale and the logic you present are swinging me to earlier models. any specific tips you'd offer? PZ model could be a worthy model?
How do you do those miles? If they are in several large chunks, then crack on. If it's lots of very short (sub-10 mile) journeys, then the RX8 might not be suitable for your usage.

They need to be regularly thrashed to stop them from coking up, and they need to be very much up to temp. before you thrash them. Therefore lots of short journeys with no opportunity to warm up are not good for the rotary. The fuel usage goes from very poor to absolutely tragic, as it dumps in loads of extra fuel while warming up. For this reason it's also possible to easily flood an RX8 if you switch it off cold ... but there are procedures detailed in the user manual (basically give it 10 seconds of constant 4k-ish - I forget exactly what it says in the manual - revs then pull the key out without moving your foot off the accelerator ... it pumps out any remaining fuel as it spins down) to mitigate the occasional cold switch off.

Assuming your usage profile suits a rotary, then we can look at which model. I've owned both a standard S1 (briefly - engine expired after 3 drives!!!) and a PZ (for about 18 months).

The standard suspension is pretty soft, but suits the car well on the road. It floated along back roads, while not rolling excessively and gripping well. It was only 3 drives, so didn't really get to bond with the car, but I was impressed enough to invest further and get a PZ.

The PZ was a much firmer ride, bordering on crashy on poor quality back roads ... however it came into it's own on the track. One thing I would say, the PZ exhaust backbox (I believe a rebadged Scorpion unit) weighs an absolute ton! If I were doing it again, I'd be swapping that out for an aftermarket exhaust.

If I were to do it again, my perfect world would be a rust free PZ, with recently refreshed shocks and springs, with very low compression and hot start problems (so moveable, but cheap to buy), with a high quality aftermarket backbox (cheap ones are LOUD and droney) and Ryan Rotary Performance ignition coils. I'd then drive it straight to Ryan Rotary Performance for a full rebuild (extra bells and whistles added depending on budget) and remap. However, finding all of those circumstances together is probably akin to finding hens teeth, coated in rocking horse poo, stuck to the horn of a unicorn!

Any particular questions you had about choice?

CABC

5,575 posts

101 months

Thursday 5th December 2019
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Rotary Potato said:
Any particular questions you had about choice?
lots as you're willing! and i'm sure many are reading this, esp after Car Throttle vids.

My needs are quite specific. A track car to replace a *very* focused mx5. But i'm now combining this into a 'station' car and occasional trip. the 'station' i'm referring to is an airport, not 2 miles away!. So, all my trips are 30 mins plus. i'm happy with discipline on starting/warm up/cool down. When parked at airport i disconnect battery - no problems on an older car like this i suspect (no stop/start). RX8 will be softer and heavier than the 5, but i'm happy with this as i'll also have the occasional hard core track outing in a lightweight. the upside is that i also get a car that can carry luggage and tour in comfort. so i'm an ideal 8 owner? low mileage via 40 days driving in total a year. 320 days parked, sometimes for 2 months.

R3s are coming up every now and then, and to me they offer latest improvements, reliability, better suspension and Recaros. i want the best seat for track as possible, so meaty bolsters and no leather. it's one problem upgrading to a mk3 MX5 - the seats are poor for track and have airbags so you can't (permanently) swap out for a bucket.

i'm thinking of running it out the box initially in case i move on after a year or so. That pushes me more towards R3.
Coilovers are probably a must on an older car, maybe later if i get an R3?

R3 is more expensive, but not so much difference as a few years ago obvs. i could *hopefully* get one of those (test for warm starts) and it'll be fine for quite a while. PZ has good mods already. a broken earlier car would be a great way of getting a new engine + bits all in for around 5k.

broken car = 1.5 + 3.5 full rebuild+ engine obvs good but rest of car older
R3 = 4k+ track out the box but uncertain engine risk. 2k contingency.

If a car warm starts ok after a thorough test run is that a good metric?

I see RRR are close to Snett, so they're convenient and you recommend them clearly.

I'm leaning towards R3 i think. at worst case it might be 1-2k more if it needs a rebuild, but if i do a few checks that risk can be mitigated, though still present. if i could buy on condition of inspection that would be ideal. With an R3 i'd be more likely to *invest* more too. I invested in my mx5 (don't ask), raw car was barely 1k. my lesson from that was to get a better base next time.

think i typed too much...

Nickp82

3,182 posts

93 months

Thursday 5th December 2019
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A good hot start is a good sign but should not be relied upon to judge the engine being in good condition. A rotary compression test is the best way to do this, as RP alludes to above, you are better buying a RX8 cheaply with a known low compression issue than buying one based on a good hot start for a normal price as it could still turn out to have low compression.

The R3 for example has the most powerful starter motor of all models so struggling to start hot is quite rare for them , an upgraded starter motor is something owners of older cars may fit to improve hot starting if they start to suffer with it (though for older models it is a wise upgrade as the starters were not good enough)

There are mobile specialists who can do compression tests for you if you find a car without one, going rate is circa £50.

Rotary Potato

247 posts

96 months

Friday 6th December 2019
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CABC said:
... My needs are quite specific. A track car to replace a *very* focused mx5. But i'm now combining this into a 'station' car and occasional trip. the 'station' i'm referring to is an airport, not 2 miles away!. So, all my trips are 30 mins plus. i'm happy with discipline on starting/warm up/cool down. When parked at airport i disconnect battery - no problems on an older car like this i suspect (no stop/start). RX8 will be softer and heavier than the 5, but i'm happy with this as i'll also have the occasional hard core track outing in a lightweight. the upside is that i also get a car that can carry luggage and tour in comfort. so i'm an ideal 8 owner? low mileage via 40 days driving in total a year. 320 days parked, sometimes for 2 months. ...
Your mileage usage is spot on ... but disconnecting the battery for any length of time (i.e. over a minute) does a number of annoying things. It causes the car to forget it's fuel trims, this can cause erratic idling, and possibly stalling, while the car relearns them. The most painless way to do this is to let the car idle for 10+ minutes when first restarted to allow it to relearn. Alternatively, if you just drive off, you'll need to keep a foot on the accelerator when coming to a halt to stop it stalling for the first 20-30 mins of driving, while it relearns. Less impacting on the driving experience (and quicker to fix) is that it causes the power steering to forget where centre is (a quick swing of the wheel from full lock to lock will fix that) and the 1-touch electric windows (push down button, hold it for 5-10 secs after window drops, then repeat with pushing up).


CABC said:
... R3s are coming up every now and then, and to me they offer latest improvements, reliability, better suspension and Recaros. i want the best seat for track as possible, so meaty bolsters and no leather. it's one problem upgrading to a mk3 MX5 - the seats are poor for track and have airbags so you can't (permanently) swap out for a bucket. ...
PZ suspension is considered superior to R3 suspension by those in the know ... especially for track work. I've not tried back to back, so can't personally comment. Some of those that say this had pretty tidy driving careers (British F3 for example), so I assume they know what they're talking about.


CABC said:
... i'm thinking of running it out the box initially in case i move on after a year or so. That pushes me more towards R3.
Coilovers are probably a must on an older car, maybe later if i get an R3? ...
The same people who say PZ suspension is better than R3 also say that you need to spend good money on some high quality coilovers in order to better what the PZ gives you. Something cheaper like an entry level Tein is considered inferior.


CABC said:
... R3 is more expensive, but not so much difference as a few years ago obvs. i could *hopefully* get one of those (test for warm starts) and it'll be fine for quite a while. PZ has good mods already. a broken earlier car would be a great way of getting a new engine + bits all in for around 5k.

broken car = 1.5 + 3.5 full rebuild+ engine obvs good but rest of car older
R3 = 4k+ track out the box but uncertain engine risk. 2k contingency.

If a car warm starts ok after a thorough test run is that a good metric?

I see RRR are close to Snett, so they're convenient and you recommend them clearly.

I'm leaning towards R3 i think. at worst case it might be 1-2k more if it needs a rebuild, but if i do a few checks that risk can be mitigated, though still present. if i could buy on condition of inspection that would be ideal. With an R3 i'd be more likely to *invest* more too. I invested in my mx5 (don't ask), raw car was barely 1k. my lesson from that was to get a better base next time.

think i typed too much...
It's your decision ... but a few things to consider ...

RRP do their engine rebuilds just down the road from me in Rugby. It's a pair of brothers, the one who does the mapping, develops new shiny bits, and runs the general sales is in East Anglia (Carl), the one who does the engine rebuilds is in Rugby (Scott). Last I was aware, there wasn't any crossover in responsibilities between their sites - but that might have changed.

I've never personally used them, when I had the PZ engine rebuilt, RRP were just starting off, and had no real reputation ... so I decided to play it safe and go with one of the established specialists. It was nothing but hassle, and felt very much to me like they're resting on their laurels and had stopped trying too hard as their established reputation meant they had a steady stream of customers (like me). RRP on the other hand felt (and still feel) like they are trying hard and really putting the customer at the heart of what they do. There were so many positive stories about them while I was sat there having issues with my established company. So if I had my time again, I know exactly where I'd be heading! smile

Many things impact how well a car starts warm. Quality of the ignition components, how free flowing the cat is, how beefy the starter is, what the compression of the engine is like. So a low compression engine can have it's hot starting problems masked by having all the other factors in tip top condition. If a car has a high quality fresh ignition system, a decat and a high power starter, the engine will be well past it's sell by date by the time it starts having hot start problems. Conversely, a car with a cheap aftermarket cat, poor quality ignition components and a worn out early S1 starter can struggle to start hot on an otherwise reasonably healthy engine that would give many thousands of miles of decent service once the other bits are swapped for something better

As said above, a £50ish compression check is probably worth its weight in gold. It's the only reliable test of engine health and means you can either walk away or offer appropriately based on the results. If a £5k R3 suddenly becomes a £4k R3 once the £50 compression test results are in, then far from costing you £50, it's saved you £950! Any specialist worth their salt will know this, but make sure the car is warm when tested, and to have any relevance, the results either need to be of the "X at Y rpm" variety, or of the "X corrected to 250rpm". You will receive 6 numbers, 3 for the front rotor and 3 for the back rotor (i.e. 1 for each chamber). As well as looking at the absolute, you're also looking for deviation between faces. So (to my eyes) 6.3, 6.3, 6.4 6.2, 6.1,6.2 would be a better set of results than 6.9, 6.8, 5.9 6.8, 6.0, 6.9. Even though the absolute averages are higher on the 2nd set, the fact that each rotor has a significantly lower value would make me worry that there was an impending issue with that face as it is wearing at a faster rate than the other faces in the same housing.

Any of that waffle help? smile

CABC

5,575 posts

101 months

Friday 6th December 2019
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Rotary Potato said:
Any of that waffle help? smile
yes a lot, many thanks.
i've learnt a lot from forums, but certainly didn't realise the PZ suspension was better. i guess the wheels are light too, which helps a lot.
i've seen a few of those with full leather seats, maybe they're standard? so that's one swap out that'll be needed.

Rotary Potato

247 posts

96 months

Saturday 7th December 2019
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There's a bunch of seat options for the S1 ... but to simplify lets boil them down to Leather and Cloth.

Leather seats were standard on the 231 and an option on the 192. They are heavy, especially the driver's seat! But they have electric adjustment (driver's seat only) and are heated (both seats). They sit quite high, so can be difficult to wear a helmet if you're tall/big bodied. I am 6 foot tall, and managed fine in a non-sunroof car ... but if any taller, or had a sunroof robbing an inch or so of headroom, then I might have struggled.

Cloth seats were standard on the 192. They are much lighter & grippier. They are manually adjusted and not heated. A popular mod is to take the base cushion cover off, cut out some of the foam and put the cover back on. Gives a little more headroom and grips your arse a little better under hard cornering.

I believe (but never investigated) you can flip the rear seat mount to drop the seat another inch. I'm sure a google would reveal more.

There are several different colour schemes and subtle differences between the leather seats in early & late S1s ... but the advice above applies to all.

CABC

5,575 posts

101 months

Sunday 8th December 2019
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ok, so a 192 seat replacement.

i'm familiar with ecu re-learning in that i've been disconnecting batteries for a long time on several cars (typically 2000-2014 vintage, not latest stop/start). for normal ICE this isn't a problem and barely noticeable. are you saying that rotaries are different and more sensitive on this? This car will be disconnected around 8+ a year, and then reconnected in all weathers.

many thanks for all the useful info.

Rotary Potato

247 posts

96 months

Monday 9th December 2019
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CABC said:
ok, so a 192 seat replacement.

i'm familiar with ecu re-learning in that i've been disconnecting batteries for a long time on several cars (typically 2000-2014 vintage, not latest stop/start). for normal ICE this isn't a problem and barely noticeable. are you saying that rotaries are different and more sensitive on this? This car will be disconnected around 8+ a year, and then reconnected in all weathers.

many thanks for all the useful info.
I can only speak from my experience. It'd idle between 1500 and 500 while relearning, and if you dropped the clutch on the approach to a junction, the car wouldn't catch the falling revs and it'd stall. This would happen for about 20 miles/30 minutes of back road driving. I learnt to just knock it in neutral on approach, left foot brake and right foot on the accelerator to keep it about 1000-1500rpm until it relearnt.

Maybe ask a specific question on the owners club forum and see if other people had the same experience as me, or if mine was a wrongun'! smile

Fishy Dave

1,026 posts

245 months

Tuesday 10th December 2019
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Rotary Potato said:
Leather seats were standard on the 231
Cloth was also available as standard on UK 231, I had them before building mine into an RX-8 Trophy race car. smile

350Matt

3,738 posts

279 months

Thursday 26th December 2019
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I run a 231 as a daily for my 16 mile commute

its generally great and has one of the best chassis I have ever owned and driven
admittedly the engine went pop within 3 weeks of buying it so I rebuilt it and am now at something like 32K in

probably going to go bang next week now...... wink

however they are so cheap I'd say you have very little to lose
if you were to do as Rotary potato suggests and find a solid car and immediately rebuild the engine you would have something quite unusual and very rewarding to drive for about 3.5 to 4K

yes the fuel consumption is bad but to be honest thats mainly because nearly everything else on the road these days is so good

even my mates 5.0ltr mustang averages about 28 mpg

but back in 2002 when these things came out an average of 20 mpg for a performance coupe wasn't too unreasonable
but in 2019 its very unreasonable - unless its matched with 600bhp.....

which is more of a mark of how far the industry has progressed and not really the cars fault