When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Have any of you had an engine with low compression? I have. It still had it's performance or at least enough for me to not be able to tell a significant difference. Many will say the same. It's just hot starts that become the first problem as it's the metal expanding when you turn the engine off for a few minutes that causes the seals to not make contact. Once the engine is going, performance is not greatly effected like you would think.
Why not just show me a few examples of R3s or S2s with these great readings you keep talking about? I can find a few but all in low 7s or even a high 6. Better than just calling me a bullshitter and making out these rebuilders don't know what they're talking about. I suppose it's easier to call names and make out I don't even know what the correct reading are than provide a bit of evidence to back up what you're saying.
Yes in 12 years I have had four engines (on my fourth) and have assisted in tearing apart around 6-7 failed Renny's and I have seen at least 20 compression tested with our tester. And in most, you know they are failing due to the loss of power and hot start issues can be masked by a good starter and battery. For example we put an S2 starter (popular upgrade) on a blown engine (cracked apex seal due to boost and a bad tune) and with the brand new S2 starter it would fire right up. The two low compression engines I had, had no issues with hot starts, only a major loss of power and intermittent stalling.
I explained to you already why there are no results listed publicly from S2 owners with no problems. I do have a R3 with 9000 miles on it in my garage, but there is no reason to compression test it.
Originally Posted by leetrx8
There's no point me going further with this as you're just discrediting the rebuilders and myself with insults rather then showing me examples of S2s or R3s with compression in the 8s.
The only reason I say R3s, as I've said, we only have R3s in the UK. No S2s so I can't comment on them.
Before a potential buyer gets the RX8, they often post compression results online to ask opinions before making the leap. These aren't cars with issues, they're cars for sale. I can find 3 such posts as this one for R3s and all of them are lower than 8s. It might be anecdotal evidence but backed up with what rebuilders say it proves my point so far.
Bring on more insults and your ad hominem arguments.
I'll just keep on eye this thread and see how long the OP takes to find a R3 with compression that you deem worthy (in the 8s).
You only have R3's? You should read more and post less because your point has not been proved at all and you have posted quite a bit of inaccurate information that is based only on what you have heard and honestly it is just downright silly to say than an engine in the 5's at 250RPM would run just fine, . Like I said, it's not magic and it doesn't have to be in the 8's to pass with a solid number either. These are tight tolerances we are talking about here, there is a fine line between running fine and not running very well at all.
We are still waiting for someone to post up a S2 compression test result with low miles... otherwise you're all talking sh*t.
be patient noob, when an SII owner actually has a problem and a reason to go get a compression test then they will post up. Otherwise don't hold your breath on someone with a healthy SII going in and paying for a compression test.
all r3 rx8s are s2 rx8s. there is no difference in the engine between them and not much difference from the s1 engine (3rd oil nozzle and engine mgmt being the biggest difference). sounds like your "builders" have no clue wtf they are talking about
Yes the engines are identical but, you guys are completely ignoring the gearing of the 2 models. Fact is all R3 engines WILL wear down sooner compared to the regular models because of the 4.7 rear end. The R3 engines will always be at a higher rpm in ANY gear when compared to the other models. Plain and simple. Lastly, the elevation where yhe compression check was done will also play a roll in compression. At 1900ft above sea level, I have never seen compression over 110 on any rotary I've ever rebuilt.
T-Von you are wrong. All Series 2 RX8s, including R3s have the same gearing. The R3s do not have different gearing ! R3s have suspension (Bilstein shock) mods, foam-filled members, and larger wheels and recaro seats and different trim. but they DO NOT have any different gearing from other Series 2s. The gear ratios changed between the Series 1 and Series 2 RX8s, but there is no change between any series 2 RX8s, including R3s. If someone or some dealer told you that, they were lying !
And the Series 2 engines won't wear down any sooner than a Series 1 engine if properly maintained, and properly driven.
Last edited by gwilliams6; 07-27-2015 at 01:41 PM.
Lastly, the elevation where yhe compression check was done will also play a roll in compression. At 1900ft above sea level, I have never seen compression over 110 on any rotary I've ever rebuilt.
This is one reason why I stated over and over to have the compression checker tested for accuracy.
FWIW, I am looking at another 2009 R3 — this one with 30,000 miles on it —*and it's also in the low 7s on the compression test.
My search continues.
Maybe their compression tester is broke or it was above sea level?
Originally Posted by 9krpmrx8
be patient noob, when an SII owner actually has a problem and a reason to go get a compression test then they will post up. Otherwise don't hold your breath on someone with a healthy SII going in and paying for a compression test.
As I said before, I'm talking about cars for sale, NOT cars with issues. People like Mario who are looking to buy what appears to be a HEALTHY car, get it tested and every single example I can find online is low 7s or high 6s.
Still waiting for proof to back up what you're saying instead of using ad hominem arguments.
1. Wow some of you are hostile. When someone's wrong, they're just wrong. Prove them wrong and move on. No reason to act like they are a threat to everything you hold dear.
2. I'm the guy gwilliams6 was talking about with the seat comments. Yes, the OE Recaros suck for daily use. If you need ANY lower back support, they are going to hurt. I use them anyway, because... screw it, I guess?
3. I had my 2011 R3 compression tested at a Mazda dealership before purchase. 21,107 miles at the time. Tested in Tampa, FL, which is pretty much sea level. Here were my numbers:
We are still waiting for someone to post up a S2 compression test result with low miles... otherwise you're all talking sh*t.
Probably the most sensible post in this thread. No argument on either side is worth much without real data.
I'd actually take it further: we'd need a hell of a lot more than one set of low-mileage S2 compression results to draw any conclusions.
This is the universal automotive dilemma: the only party with enough data to make the call is the OE, which has a vested interest in not giving us the whole picture. :-P
T-Von you are wrong. All Series 2 RX8s, including R3s have the same gearing. The R3s do not have different gearing ! R3s have suspension (Bilstein shock) mods, foam-filled members, and larger wheels and recaro seats and different trim. but they DO NOT have any different gearing from other Series 2s. The gear ratios changed between the Series 1 and Series 2 RX8s, but there is no change between any series 2 RX8s, including R3s. If someone or some dealer told you that, they were lying !
And the Series 2 engines won't wear down any sooner than a Series 1 engine if properly maintained, and properly driven.
You need to re-read my post again. I clearly stated REAR END and said nothing of transmission gearing. The R3 was a very high ratio 4.7 rear end gear to allow the engine to rev quicker and be more responsive. Due to this, the R3 will rev higher in every gear when compared to the regular models with have a 4.44 rear end.
The 2004-2008 all came with 4.44 (all manuals, different gearing for the automatics, 4.3)
The 2009-2011 all came with 4.77 (all manuals, different gearing for the automatics, 4.3)
And again... the R3 is a 2009-2011 TRIM LEVEL. The only R3 differences were seats, suspension, and body work. Everything else is the same to other series 2s (2009-2011).
Please stop with the "R3 specific" drivetrain stuff. The drivetrain was identical for all manual transmission 2009-2011 RX-8s, regardless of whether or not they were R3s, Grand Touring, Sport, GS, CS, etc... there are all TIM LEVELS, of which R3 is one trim level. Nothing else is different.
I just might be moronic enough to waste that money...
So as it turns out, I AM a moron... going in for compression test this Saturday... just because... it has never stalled and never failed to start hot or cold... it has just over 22k miles on it. (23425 to be exact...)
07-08-2015, 08:26 AM
. Like I said, it's not magic and it doesn't have to be in the 8's to pass with a solid number either. These are tight tolerances we are talking about here, there is a fine line between running fine and not running very well at all.
It has approx. 2500 miles on it.
