Lock & Load

cortc

Great info and instructions , hmm m another worthwhile expense .

cheers
michael

RX8on19s

cortc,

Where in Miami did you do it? I'm thinking of this mod and would want to it with someone with expericnce.

Thanks.

cortc

Here is a close-up of the part number... The car is very smooth, more so than when stock...

cortc

RX8on19s: I will PM you, are you going to the meet this weekend?

Here is the info...

https://www.rx8club.com/showthread.p...threadid=27481

MrWigggles

I'm sorry it wasn't the automatic counterweight. It was the automatic counterweight.

I mean you could have said, "You listed the partnumbers for the front counterweight, but you are right it is the automatic counterweight regardless."

That would have taken some class.

I couldn't read the last four digits only the first 4.

-Mr. Wigggles

ACTman

Cool, thanks for the information. I will pass this on the Mazda speed. When I was speaking with them this morning, they didn't have any flywheel kits to check because they are currently backordered (at least at the warehouse). Just to clarify, you got this with the Mazdaspeed flywheel correct? I've kind of lost track, because of jumping around different threads, forums, and actually doing real work.

As far as smoothness goes, it doesn't suprise me. It's not the actual "feel" that I am worried about. It's really difficult to detect an incorrect balance in the engine. Thanks again.

ACTman

I didn't know I had to have class to answer. Darn, I should have worn my suit.

Please don't take my coments that seriously. I am pretty light-hearted. I quess it's hard to hear my tone of voice in print. I didn't mean to offend you in any way. Please don't egg my car.

Japan8

Hold on. If the front counterweight is the AT one, but the stock MT with this front counterweight and built-in counterweight is perfectly fine...then why is it an issue if you lighten the flywheel and just match up a counterweight that goes with the AT counterweight? Confused?

If there a problem with the stock setup? Does Mazda need to recall the cars and make a change at the factory in the front counterweight? If not, then why is this an issue with aftermarket counterweights? Shouldn't matching up to the AT counterweight suffice as it did for stock?

NewRXr

Hello, I'm new here so I thought I'd introduce myself a little bit first. I'm a professional mechanic that specializes in high performance. I don't own an 8, yet, but am considering it as a future option. I do own two 1st gen 7's both of which I've owned less than two years. I'm big time into Thunderbird SC's, I have three, which were the '89-'95 models with the Eaton supercharged 3.8 V6. I built one into the 12's at 3800 lbs so I've done a thing or two with late model performance cars. I've built many hot cars in my time and will probably always do so. I'm not here to play know-it-all on this board but I am very knowledgeable on the subject and as I've poked around here I've seen several posts where I can offer some advice. If the majority appreciates it great, but if I start getting flamed because I don't own an 8 or some such junk I'll just take off without any ado. I'll be the first to admit that I'm a Rotary novice, I actually got into them just to learn more about the engines but fell in love with the thing. Me loving a Japanese car, go figure. LOL


Lightweight flywheels work just as well in other cars also, it's just that most people don't realize it and never try it. That and many will always tell you that it'll kill the drivability or you'll lose torque and scare others out of trying them. I've had a 15 lb McLeod flywheel in one of my Thunderbird SC's for years now and it remains one of my faivorite mods to date though it has enough mods to run into the high twelves at best.

Reducing crankshaft weight works extremely well on any performance engine. This is the most effective place to reduce wieght on the whole car as not only is it rotating weight, it is also weight that must be accelerated more than once in a timed acceleration distance. Think about it, driveshaft, wheels, brakes, bodywork, etc. only acheive maximum speed once, at the final point of measure. Whereas the crankshaft and engine driven accessorys have to be accelerated from point a to point b in EACH gear required to reach the finish line.

In my SC I pulled 20 lbs off the crank by pitching the stock truck style factory flywheel and installing the aluminum part. That's 20 lbs less weight for the engine to accelerate up to 6000 RPM 4 times in the quarter, compaired to say 4 lbs I saved using an aluminum driveshaft that only goes from zero to 6100 RPM once in the same distance. With the 9000 RPM Rotary engine the difference is even greater due to the larger rev range it uses.

Vernon

ACTman

Who's on first, what's on second? Yes it get's confusing, especially when the conversation gets bounced around so much between people.

It's really not that complicated. Let's review: There is counterbalance on both the front and the back of the engine and they are 180 degrees apart (opposite eachother) from shaft center. The rotating parts between the counterbalancers are basically the same. Any change in the front counterweight has to be matched with a change at the back (whether it's a counterweight or stock flywheel). We found that the balance of the front counterweights from AT and MT RX8s are different and this difference is also present at the rear between the AT rear counterweight and the MT flywheel. When you remove the stock flywheel (with it's built -in counterweight, and replace it with an AT rear counterweight the balance is no longer correct.

cortc

First: Yes this counter weight came together with the flywheel; in the same box...

Second: These are the exact same parts as are installed on the 300 production Mazdaspeed RX8s in Japan...

Third: The engine is perfectly balanced with these parts installed; this is a well engineered and correct setup for the RX8 MT car...

ACTman

1. Thanks for the info about the Mazda setup. I am letting them know about the part numbers since they don't have parts to verify at this time.
2. They may have 300 cars that aren't balanced right but working fine, or they may have used the AT front counterweight as well as the rear one to make the balance perfect. Frankly I don't care about what's done in Japan.
3. "The engine is perfectly balanced"?? How can make this claim without taking your assembly apart and sending it off to get balanced? It may FEEL "perfectly smooth", but that's different.

I'll have more information next week when our tooling is done for our dynamic balancer. It will tell us how much descrepancy there is between the AT and MT balance. I am too lazy to do the math with our current bobweight system and it wouldn't be as accurate.

rxeightr

My MS Flywheel installation is on hold until this is resolved in my mind.

ACTman- I will be keeping my warranty intact, hence my rationale for the MS flywheel. Did MS give you any indication what their response would be, what action would be taken, and in what time period?

cortc

ACTMan: You have no idea what you are talking about, once again I know for a fact that this is a proper and balanced setup... I myself verified with Mazdaspeed in Japan... Please stop spreading/posting false rumors/statements in an effort to push your own products...

A MT Renesis powered RX8 is perfectly balanced with this setup!

This is my last response...

Japan8

rxeightr, wait if you feel that is best. I, myself, would just do the MS Flywheel and not worry about it. I believe that ACTman may have a real issue. It's not 100% settled and concluded yet, AND even if he does have an issue, that doesn't mean it carries over to the MS flywheel as well (as Mazda put it together, I'd hope that they'd get it right!).

Worst case scenario... ACTman is right and there is also the problem in the MS flywheel... well it's an official Mazda part, installed at a Mazda dealership. You're covered under warranty. There may be some inconvenience of your car in the shop, but otherwise... it's Mazda's problem to fix in this situation.

ACTman

No, it's too soon for that. I am working with the US side of Mazdaspeed. I am sure they will have to go back to the Japan operation to make any authorized changes which will take some time. It doesn't sound like anybody has had significant problems with the incorrect balance. The only probable consequence will be increased main bearing wear which will happen over time, and maybe increased vibration (but doubtful from what others report).

Omicron

Dirk, I think you are offering valuable information to this thread. However, you cannot use the forum to promote your own products unless you first become a paying site vendor. Please contact BOOSTD 7 (Ryan Scott) at advertising@rxtuner.com to arrange this. I have gone back into your previous post and edited out the information promoting your products. Please refrain from posting such info until arrangements are made. Thanks.

ACTman

Oops, the cops are coming to get me now!
Sorry, I totally understand. I didn't realize this would get so out of hand. I was also meaning to say sorry to the author for polluting the original thread.

IZoomZoomI

off topic regardin the warranty does everything have to be installed through mazda to retain the warranty? b/c that would seriously suck since they are charging 500 for the installation when I found someone that was going to do it for less. darn

cortc

Yes, it has to be installed by an authorized Mazda dealership...

Jailbreak'74

The cheapest i can find this flywheel for is $579.00 USD. How much did everyone else pay? How much in labor if you didn't perform the job yourself you think?

cortc

Thats not a bad price, it should run about 250.00 for installation...

ACTman

I emailed Ryan last Friday but no reply yet.

Instead of further polluting this thread and having our info considered suspect, for those sincerely interested in our balancing results drop me an email and I will share what we have learned. Most importantly, I learned Friday from a top rotary race engine builder (name withheld) that even a severe balance error should not harm the engine. So don't over-react (as I could probably be accused of). Have a nice day!

IZoomZoomI

hey cortc... 275 ??? thats actually not a lot maybe the labor rate is different. but the nearest dealarship around here is chargin 500 for install. whats your opinion on that ?

cortc

They are gouging, it is disturbing what some dealerships are doing to there customers... It's a 3 hour job tops, so if the rate is 75 your looking at 225-250; anything more than that is padding...