I may have found my life-mate
 

After looking for roughly 3 months... and researching for many years. I finally found "the one", and she fell literally on my front door. Having looked at 8's with bumps and bruises all over high miles incompetent owners and overpriced ready to die engines she showed up less than a mile away from my house. Went and looked two days ago love at first sight. I'm getting a compression test done on Monday, and if all's well I'll be joining the family shortly there after :D. I'd love to hear you're opinions on price vs compression numbers. I've already decided if she's over 8.0's across the board I'm buying her. I'll try to talk him down a bit. If they are 8.5+ (pipe dream) I'll be completely happy with 11.5k. And if it's under 8...well I'm not quite sure. What do you all think?

2006 Mazda RX-8 SHINKA Edition

Looks like a beauty. I think anything above 7.5 would be OK. Its tough to say, as everytime I search for compression numbers on here I only find failing results, so I don't know what a 'good engine' for a 2006 would come in around. I'm very interested in finding out though.

Best of luck with the purchase.

kops,
Search "New and potential owners START HERE" sticky in the New Member forum, pretty much has the answers to most basic questions, including what the compression numbers mean.

I have read them many, many times. ~8.5 from the factory, anything in the 7's is usually good, above 7.5 is what I would consider good, and anything under 7 I wouldn't both with...even though a 6 is considered a fail by most dealers. These numbers are drilled into my head :o:.

What I don't know is, what kind of compression numbers to expect for 8's in whatever condition. For example, should one should be expecting mid 7s for a car in the condition mentioned by ElDragon0, or maybe one should still be expecting 8s? I know this will vary a lot depending on the owner of the car and many other variables, but I'd be interested to see what kind of numbers those of you with healthy 2006 8's are getting as a comparison, you know?

I haven't been able to find lots of passing compression results on the forum, most people only seem to post them when they're failing :(

^^ I think it's unrealistic to generalize typical compression results on any given car for the exact reasons you mentioned. Every car is a unique case and would seem almost impossible to predict results. I think most people would check their compression only if there was a reason to.
I don't think I have read any posts of someone getting a compression test just out of curiosity.
It's cost prohibitive unless it's someone with money to burn.
The only ones I can recall were some who got it as a condition pending a sale.

I've crossed just about every body part that is possible to cross in hopes for 8+ results. I am sure that the shinka would be more than lucky to have you as its driver. Now, just need to get those fins ready :D

:D Thanks Venko. I Called the dealership yesterday evening and apparently they don't do anything over the weekend. So I set up an appointment for Monday, the owner will be dropping her off in the morning and picking her up after work. The great thing was, when I called in I asked for a quote and the appointment lady called me back with a 260$ quote >_< for just the compression test, so I asked to be sent back to the service desk and got sent to the Service desk manager and he laughed at that quote. He said it wouldn't be any more than 100$.

On a note of the the compression results, No I can't really say I WON"T buy it if it's under 8. But I can say 7's are the worst numbers I could get. There IS roughly 1 year left on the warranty. So if it's in 6's I'd be able to get a new engine next year (most likely) if it's in the 8's I won't have to worry about it for some time if ever as long as I take care of her. ^^ And really I'd almost like to see 6.5 or lower :X I'd love a new engine in her. But 8+ is ideal.

Well, one bad thing about getting a new engine right away is that you will have to go through the break in procedures. If I remember correctly, you aren't supposed to go into high rpm for a while until its been broken in.

I would have a hard time resisting the temptation, especially if I just happened to buy an 8... Anyhow, I'm still pumped waiting for the results monday, hope you'll have good news for us :D

Anything below 6.9 @ 250RPM is a fail as per the Mazda specifications.

Not completely true. After getting hold of a large number of dealers I found that roughly 50% of them go by anything lower than 7 is failing, while the other 50% say anything below 5 is failing. I can find the spread sheet I made somewhere if you'd like. I did A LOT of calling around when I found an 8 with 14k miles on it that was pulling 6.3 6.3 6.4 / 6.4 6.4 6.5. (250 rpm) and the dealer said the engine was fine and wouldn't drop the price of 15k on an 04 ~_~. So I already know in advance that I'll be quite picky with the dealership's I bring her to.

Ahhhh!!! I'm so nervous. After checking this calculator :
Foxed.ca - Rotary Compression Calculator
Anything 7.7 or higher normalizes out to 8.0.... A bit upset that I'm paying for the test... but I'd rather have the car than deal with a pissy owner. The dealership will be calling me back within the next two hours with the results!
I'm just glad that it's only 100$ :) not the 260$ the original scheduling desk quoted me on.

P.S. EZDRide get your butt back in the irc

Test results: !!!!!!!!
Front : 8.1 8.3 8.3 @ 295 RPM
normalized @ 841 feet
7.8 7.99 7.99 @ 250 rpm


Rear : 8.8 8.7 8.8 @ 308 RPM
Normalized @ 841 feet
8.25 8.215 8.15 @ 250 rpm

Nice.

Very nice, looks like you've got a winner there.

Congrats on the results. I'm real happy for you Nick! You've searched hard and you deserve the prize at the end. The good results are lifting my spirits. I was in a pretty shitty mood from last nights accident, but now i have renewed my hope in miracles and happy endings.


Way to go nick :D

Yep.... only problem is now I'm rushed... I just found out he "needs" the sale done this week and I'm heading out of town Wednesday until the 7th... so I'm super duper fucking rushed right now.

Those numbers are good. Keep maintaining it and those numbers should stay the same for a long time. ;)

Tyler please make your own thread.....

Great engine with a great starter. A winner right there.

Done, moved all his posts and replies to his posts to here: https://www.rx8club.com/rx-8-discuss...denied-246844/

No need, it's been done before. Sorry for the threadjack, GL OP.

Congrats Eldragon!
All this compression talk is making me wonder if I should get one.

Ignorance is bliss?

I have concluded that Compression numbers work on a quantum level. Every rotary is simultaneously giving 5.0 - 9.9 at all times on each rotation. Once those numbers are checked, they will then effect your opinion of the cars performance.

That is indeed one perspective :)

:D Every thing is official, I get back from vacation on the 6th, sign the paperwork and hand the "good" man his 11.5k and the 8's allllll mine !!!!!!!