I know this s a newbie question, but how can you tell if your engine has a detonation event?

 

Detonation is the word dude

 

Your correct and I have fixed it. Sorry I guess I should proof before I post.

 

A "single" event sounds like a firecracker and will usually produce at halting "snap" that you can feel through the chassis. It will sound like it is coming from the floor above your knees.
A "multiple" event will sound like someone is crushing an empty soda can in the same location.

 

See that's funny...don't really make since...cause everytime I blew a seal I never heard a noise at all. The last go around I just got on it and I heard the boost controller start doing it's buzz telling me I was over boosting and I pushed in the clutch and let off the gas and the car just died. I dumped the clutch to fire it back up and it was definably shot. First one was do to a lean out...knew I was low on fuel but didn't think it was that bad. I was about 3 blocks from the gas station. Gave it about half throttle started taking off...and it had a spot where it fell on it's face and I knew it was a fuel issue. But still yet never heard a noise. Stuck gas in it and it ran just had no power. idled and everything decently but just slow after that.

 

I cant believe anyone is really looking for anything substantial here... brand new product, very few using them, very short time they've been used...

its like looking for reviews on silicone coolant hoses a week after they came out... how the hell would anyone know. or perhaps, asking your buddy "hey, how was that vaccination you got 5 minutes ago? how's it working out for you being the first patient to recieve it?"

realistically, every one of these few guys could pop a motor and post their findings as far as seals, and it still wouldnt mean a hill of beans. you need to build a history before anyone can claim anything, either through years of of being in the market, or significantly less time being in race engines, or both.

 

For what it's worth...

RA (which was already mentioned) and ALS have been making "unbreakable" seals for earlier non-Renesis engines for years. Nobody has doubted that they don't break. I've never heard of anyone ever physically breaking these type of seals, although there may be someone somewhere on the internet claiming they have. The only people I have heard of who have warped these seals were running extremely high horsepower builds at 25+ psi. I'm talking 550+ rwhp. A lot of times something else will let go before the seals fail. One of the irons will crack or you will lose a different seal on the rotor.

The biggest debate is how much they increase wear on the rotor housings because they are harder. Some builders say it is significant/noticeable after tearing down rebuilt engines with 20k+ on them with those seals. Others say the additional wear is negligible.

As far as personal experience goes: I have been running RA "unbreakable" Super Seals on my '88 turbo engine since 2006 and have withstood multiple detonation events. They are the regular 2mm apex seals. They might have 10k miles on them at most, but they are hard miles. I have been using Castrol GTX 20w50 and the factory mechanical OMP that is found only on 86-88 Rx-7 engines (no premix ever). This OMP runs off a drive gear on the front cover and has a little rod attached to the throttle linkage to adjust how much oil is pumped. There are two injectors in the middle of the rotor housings and two in the lower intake manifold.

 

Here is the list of the detonation they have withstood over the past 4 years:

December 2006

21psi boost spike on a series 5 stock FC turbo in extremely cold weather. I had an MBC on the car at the time and I was playing around with a Terminator Slowbra on the highway. This occurred twice. I heard an audible thunk sound.

July 2008

After upgrading the turbo, I decided to [intentionally] turn the boost up to 21psi on racing fuel. This was on a 60-1 T04S turbo like the Greddy upgrade except much bigger housings, external wastegate, etc. A single vacuum hose was not secured properly and blew off the intake plenum. For whatever reason this was bleeding air from the MAP sensor signal (car had no airflow sensor) but the engine had no other major signs of a leak.

The result was that, during a 21psi 3rd gear pull on the street, AFR leaned out to about 15:1 and timing was excessively advanced by about 7 degrees. When the detonation occurred it felt like I hit a brick wall. The car would barely idle or make much vacuum. Three of my spark plugs cracked but the apex seals were intact. I overhauled the engine after that anyway. Apex seals were reusedand spec'd out perfectly. They had about 7000 miles on them max.

March 2010

After overhauling the engine I upgraded the turbo again to a Garrett T04R, similar to the Precision 6765. I'm running about 16.5-17psi on the street on 93 octane only. It's a bit of a trial-and-error process in terms of what the engine will tolerate for timing. Well for whatever reason the engine decided to detonate one night. It had the "marbles in a can" sound. I pulled 2-3 degrees of timing in the and richened up the mixture at lower boost levels. I haven't had any problems since then.

 

Thanks for the feedback arghx7 . For me personally having seals which will stand some degree of detonation is a major improvement for an FI,d renesis whether they wear the housings quicker or not . I have yet to hear about a FId Renesis that wore out rather than destroyed itself.
Wondering about your comments about higher wear rates and if using a higher % premix would help with that ????


And Paul : of course you are right but I still think the thread is useful .

To put it into context . There have been products sold on this forum (think Mazsport ignition) that everyone thought was the "solution" to a specific problem . Hundreds were sold and feedback was hyped up because everyone wanted to believe that they worked (me included) .
The same could be true of these seals so the sooner we find out if there are issues the better IMO .

 

understand and agreed Brettus

 

That's kind of my mentality. When an engine reaches a certain power level, it's most likely to go out with a bang rather than a whimper. There's never a "perfect" solution to anything though. Even with hard apex seals you can still damage something else should detonation occur.

I don't know about higher wear rates from the unbreakable seals. It's like anything else you read about on internet forums. It may be blown out of proportion, it may only apply to certain setups, or it may be spot-on. As far as adding a higher % premix... what I do know from late 80s Mazda literature is that in terms of wear under load, the big enemy is the temperature of the apex seal itself. And when the engine is under load there is in an inverse relationship between apex seal temperature and apex seal lubrication:

 

12500 miles and counting .......

 

9500 miles and counting...

 

900 miles and counting ...

 

OK - had my first major detonation event over the weekend while drag racing with Gregs .
I tweeked the actuator for more up top and the boost controller for more down low from what I've been running for the last yr.
First event was at low rpm 11-12psi maybe 4000rpm , so turned down the boost controller a few notches and that went away .
Then at the end of the run at 109mph in 4th I had a major soda can crushing event . I imeadiately backed off .
Have run at more boost than this before and can only put it down to some experimental plugs i was trialing .

So - engine is still running ok but idle may be a tad rougher so i think i may have lost some compression . Going for a long drive later today so will know more once i get back .

Don't think stock seals would have survived ......

 

And, by your own description, neither did the "stronger" seals.

I had experienced soul-smashing, sodacan-crushing detonation in the past with no affect to the engine at all. THAT is "surviving".
I've also had a single, relatively dull ping take out a motor completely.

It is all luck of the draw and has nothing to do with the size or composition of the seals.

I don't think anyone here in this discussion actually understands the kind of forces we are talking about with regards to a detonation event. The flame front during a ping is 10 times as powerful and 100 times as fast-moving than a normal kernel.

 

OK - I changed the plugs back to the BUR9EQPs and went for a long drive .
Idle came right straight away and low speed cruising which was starting to get jerky came right as well . So I'm blaming the experimental leading plugs for what happened - they probably failed to fire leaving the trailings to ignite the mixture .
However I don't want to test this out as it was enough of a scare to have it happen in the first place . Back to comfortable boost levels I go ...

 

Point taken - I'll stick to just reporting what happens without drawing hasty conclusions ...

 

Hmmmm....so seals out of aluminum are ok? Is this the reason there are so many 800+hp rotaries, pulling 6 and 7sec on the 1/4mi running on stock seals? Many of which detonate during tuning at upwards of 40psi? (end sarcasm here)

One small ping, one tiny mishap is all it takes to break stock seals, everyone knows that and many have experienced it. Ours take many pings and handle many mishaps before any plastic deformation occurs which has to happen before breakage occurs. We never claimed that they were indestructible...we said they can handle detonation. The metallurgy of the material we chose is better at handling vibration and impact, it's that simple. And yes it has everything to do with the composition of the seals...more than anything else for that matter. I don't know what you are talking about and how you came to the conclusion that size/dimension and composition have nothing to do with the performance of a critical internal engine component under stress...


Chris

 

We have a breakfast cerial here called 'wheet bix' . You really have to chew hard to eat it .Perhaps you should make your seals from that because they would be way cheaper and still work fine according to MMs theory .

 

My motor already eats apex selas for breakfast. . .

 

Possibly.

OK. Prove it.

 

not enough fuel for that boost setting?? how were your temps?

 

Right, that is why mazda goes through the trouble of making them out of hard metals when they could just extrude them out of cheap aluminum...

Ummm....did you not read Brettus post?
Here it is in order:
1. He suffered major detonation under load.
2. Engine is still running, seals are not broken.
3. From experience similar detonation would/has destroyed OEM ones (his own experience).
4. He does not work for ER (or is sponsored by us)

What more proof do you want?

That's exactly what he bought them for and they did their job.

No they are not rocket science and no they are not made of Unobtanium...they just handle detonation better through better metallurgy, plain and simple.

Jeez...

Chris

 

Chris, why dont you send MM some of those seals as a christmas gift.