RICE RACING

Hey, I just wanted to apologise for my "attitude" in the closed thread.

I too have used Ianetti seals and like them, I just do not like the price !

Any way, no excuse for my comments ...... I too could be acused of being a "dumb ****" for some of my ideas.

setzep

About time you admitted it!

rx7passion

lol were you being a steamy **** peter? sorry i had to

setzep

"But you gotta remember they deal with a fair few homosexuals who have trouble dealing with the stench from their mothers anus, let alone with knowing what the **** they are paying for."

Somehow you always find the right words to use.

RETed

Don't lie...admit it, you're just a post *****!


-Ted

Panic7

Guys, I am new to this forum but i believe from my experience with FD's that 2mm are the best.

At this moment i am having a new engine builted from a Japanese tuner of FD's. His opinion on apex seals is that 3mm are out of discussion. For lightly modified engines that are street used he recomented 2mm Mazda originals whereas on heavily modified race engines the recomented 2mm racing apex seal.

I have been talking to many Japanese Tuners lately and the most of them proposed to me the above as well.

I have no reason not to believe Japanese record setter tuners for their knowledge on Rotary engines.

Without aiming in offending American tuners, on my opinion the philosophy of the American tuners/racers is to built an engine that will race today and rebuilt it tomorrow at low costs whereas Japanese tuners/racers built engines with reliability and longliveness in mind. There is no doubt that Japanese tuners bulit the best rotary engines in the whole world. After all the RX7 was borned in Japan.

Resource

Okay that's super but which 2mm racing apex seals are you refering to?

lane_change

iTrader: (20)

I wonder what Wankel thought was better when he designed the Rotary?

jeff48

Y'know guys, I just got back from Road Atlanta Petite LeMans where I got up close and personal with the crew that services and drives the Mazda 4 rotor LMP675. Interestingly these guys run 3 mm ceramics.

When asked about what to do to make my car more bullet proof, the head tech suggested 3mm ceramics. He has NEVER had a single 3mm ceramic apex seal fail. Of course the bad news is that they cost him $2K a set. (Remember a set for him is 12 seals). 'Nuff said!!


Although not on the issue of seals, One other tip from the tech about protecting your "O" rings is to make sure your coolant temp never gets above 88 degrees C. The rubber starts to go above that temp. And also make sure you spec your housings to .004 inch.


The car ran fairly well 1 min 22-27 sec laps (102-107 mph) until it slid into the wall. After some quick repairs she was back on the track, but later suffered irreparable transfer case/gear box problems.


There was also a LMP 675 in a 3 rotor configuartion (not a 20B but a custom built turbo powered job using 6 port engines as a basis). He also retired with transfer case/gear box problems.

BTW here's a closeup of the 4 rotor engine.

fdracer

well, what you're saying is to basically keep the engine cool. but what's the best way of going about doing this. what to they do to ensure that their engine stays cool.

Panic7

RESOURCE i do suggest 2mm Mazda Apex Seals. If you need an engine to be durable you have to use mazda original. They can handle power but they don't like detonation. With a good tuning you can have great results with 2mm originals but you have to be extremly careful on your A/F ratio not to lean too much your mixture to make more HP sacrifising durability.

I'd like to make a commend on what Jeff48 said. Aftermarket 3mm ceramic seal are without doubt more durable than the stock ones. Have you ever wondered thought what damage do they cause on the rotor housings. Your friends at Road Atlanta Petite LeMans might be using them but please do ask them how frequently do they rebuilt their engines and after how many racing hours do they change rotor housings?

fdracer

i thought they do less damage due to the lubricating quality of ceramic. that's why they make the bb in turbos out of it. no doubt they rebuild after every race, but they would do the same no matter what type of seal they use.

DaleClark

iTrader: (55)

Mind, the 4-rotor is non-turbo - I have known a few people that have blown motors with ceramic 3mm apex seals. The biggest problem is they TRASH everything when they let go.

I'm also in agreement on 2mm seals. 3mm seals simply take an extra ping or two before they let loose.

Dale

Panic7

Abasolutly right.

If detonation happens no matter what seals do you have they will break down. Now do you sacrifice a whole engine for an extre ping or two. Ceramics totaly destroy the housings after break down.

fdracer

yeah i know, i was just talking about normal wear. i though ceramics have less rotor housing wear.

Panic7

According to japanese tuners there is nothing with less wear than the mazda originals

jeff48

As to reliability and longevity of the engines running 3mm ceramics....Eevn if they change them after every race (which they do not) is anyone out there willing to claim that their cars could exist for most of one race doing 390+ laps on a 2.54 mile track in under 1 minute 30 seconds per lap for 9-10 hours and all the while jamming the gears, running to redline and negotiating severe elevation changes---I didn't think so.

There is a fundamental difference between the wear and tear exacted on an LMP675 and a daily driver or even an occasionally raced (solo II or roadracing included) rotary. It is fundamentally unfair to compare the fact that they MAY rebuild their engines every three to five races (which some do not), to your hoping to get 100K out of your daily driver rebuild.

If the ceramics are good enough for these guys, that is enough recommendation.


As to the question of how they keep their temps down...the answer may well surprise you, I know it did me.

1. Do not consider the use of any "unpressurized system" that relies on any special coolant (look to the threads touting this stuff and then remember this advice from guys who spend their whole lives making their engines as bullet proof as possible).

2. Make sure you have plenty of unobstructed radiator surface area.

3. For most of the year run water only (perhaps a little "water wetter" as the only acceptable additive)

4. For colder weather, the judicious use of antifreeze is recommended to avoid the catastrophic freezing of the system (never over 30% antifreeze unless necessary to avoid freezups however). Of course during the cold weather, you should have less problems with overheating.

5. Make sure the housings are spec'd to the .0004 or just don't bother to put them together in the first place.

Overall, this is the advice of people whose word I respect because I have seen the results. I thought I would share my good luck of having been able to talk to these guys with you all since I have learned so much about rotaries from all of you.


If you disagree with anything said here, as is your right, please remember that this is my opinion and does not require an angry or challenging response.


I hope you all get the chance to go to one of these races next season, it is a great experience with some outstanding people.

Badog

Uh-huh. Once a lawyer, always a lawyer!

rx7tt95

The 88 degrees C is strange... Considering the stock thermostat on the FD opens at what, 84 degrees? It'd be pretty unrealistic to think that one could keep an FD under 88 degrees in any/all conditions. Normal operating range is usually what, 84 to 95C? I'm willing to bet that Mazda had a target range in mind and, with fingers crossed, I'm hoping they'd actually use a seal which could tolerate that temperature range.

If you spoke with Jim's engine builder, this is also the same guy who said that 14.7:1 was the ideal fuel ratio for a rotary at MADS last year. We all know that simply isn't true. I think he simply operates in a nether region you and I only dream of :-) and doesn't have much correlation to engine parameters for a street-driven turbocharged rotary. Naturally he'll know more than the entire forum combined, but it's sort of like giving Einstein an algebra quiz.

I normally see operating temps in the 85 to 93 degree range depending on how hot it is (South Florida!) even with the datalogit turning on the fans early, upgraded radiator and 16lb. cap. At my current driving rate, I'll be at 100K within 1.3 years and as yet, have had no problems with coolant/0-rings (nor anything else for that matter). I'd consider taking what he says with the knowledge that it may not adapt perfectly to a street driven car.

Most, if not all, sanctioned race events require the removal of all coolant and ask that water be the only element in the cooling system. I'm sure others could talk about water vs. coolant heat transfer with more authority than I, but most know water is actually better. Isn't coolant also necessary to lubricate the water pump bearings? Interesting info though...
Michel

RICE RACING

I am sure he knows his applications, and I know mine.

It is natural that people who race for a living "believe that they know more than people who frequent forums" but it is a bit like the Corky Bell syndrome, That guy I am sure knows some things, but he sure as hell has made some monumental **** up statements !

Mazda race Engineers can be acused of this also, their fuckups are long and well documented, starting from the early 80's through to today no doubt ! There was a classic case here in Australia when in the 1983 Bathurst 1000 and through that years touring car race and other endurance rounds the most powerfull 13B was one run by the Slick 50 race car, it's engine was prepared by barry jones and it used stock apex seals !! and not many of the Mazda Recomended race parts, Alan Moffat even purchased one of the Engines built by jonespeed for evaluation to compare it to the factory units he was getting from Japan !

I for one do not discount anybody based on their ocupation or circumstances, if they are smart and have been working on rotaries, and getting them to live, then I for one listen to those people, regardless of how good I think I am.

Facts are factory seals do live, with no issues up to higher HP figures than many people can ever dream of. Everything though has thermal limits and mechanical (speed limits) and the ceramic seals are more tolerant of these excesses, but they are totaly unecessary unless you are constricted by some rule or competition in you class forcing you to push these mechanical limits to the maximum ! Which for the street enthusiast is TOTALY Impractical and pointless.

How many street turbo cars do you see needing to minimized race fuel consumtion @ max power running a lean a/f ratio of 14:1 and 60degC charge temp at 8000rpm !!!! Not ******* one, and you never will cause we cannot afford inconnel exhaust turbines ! or to replace an engine after a race or qualifying. A majority of race guys live in dream world, not their fault, I wish I could dream more

Opinion from a "dumb" forum member who daily drives a 566bhp street trim 1st gen with std seals. i think I will go read corky bells book now LOL

HWO

the truth is, if everyone put their little 5cent secret into the hat, one helluva motor could be built, but i cant see it ever happening, can you?

setzep

I don't know if that would ever work because rice racing would be stuffing the ballots with 95 cents worth out of a $1 into that hat


not that I'm saying thats a bad thing

maxcooper

Has the team tried the non-water coolant and found it to not work, or is that a speculative opinion? We know that water has the best ability to carry heat under ideal conditions, but that isn't necessarily the driving factor under real conditions, where block-to-coolant transfer may be hampered by localized boiling. I haven't tried the other coolant yet, but I have a bunch of it and I plan to make the switch at some point to see how it works. It would be interesting to hear if they tried it and it didn't work or if their recommendation to avoid it was not based on experience. I am not flaming or trying to start anything (that's not my style anyway) -- I am genuinely curious.

3mm ceramic seals are probably lighter than 2mm stock seals. Just because 3mm ceramics are appropriate for one application, that does not mean that 3mm seals of a different material are appropriate for another application. I used Mazda 2mm seals for my rebuild, based on reports of the downsides of 3mm (non-ceramic) seals (chatter marks, sealing problems), the fact that there are a lot of people making big power on Mazda 2mm seals, and RR's report that 2mm make more power.

14.7 might be the ideal ratio in some context (after all, it is the stoichiometric ratio) but that doesn't mean it is possible or practical to reach the ideal. I suspect there was some misunderstanding or miscommunication in that presentation.

Even geniuses have some false beliefs. And we all know that true beliefs can be mis-stated, misinterpreted, or applied to a context that was not in the mind of the speaker. I like books, reported experience, and even wild speculation. I think they all move us closer to the truth™ on some issue, even if they just provide a straw-man explanation of something that is shown to be inaccurate by further experience. Take them all in and use them to make decisions when you need to. But don't be surprised if what seemed best at some time turns out to be more complicated than you originally thought.

-Max

sbaker25

I spoke with these guys as well. I think the important thing to remember is that their application is NA and very different from ours.

For example, when I asked him about dealing with dealing with apex seal fractures due to detonation, he looked at me like I had two heads. It just was not a concern or consideration.

And he told me that they like to run on the lowest octane available and that it's an annoyance to them when the series mandates the fuel which is invarialy higher octane that they would like.

Obviously, this information is vague and incomplete, but I'm sure we can all agree that FDs do NOT run better with lower octane and leaner ratios... at least not for very long . What works best for them is not necessarily what works best for us.

It's all about intelligent application of information. Some things that could be learned from these teams would be very helpful/applicable, other things should be left as interesting narratives.

amemiya

well here is my 2 cents, I have tried running only water and water wetter in my first RX7 and after blowing the water o rings after 15,000 miles, and pulling the motor out I found that the o rings are extreamly craked, and brakable. Now I run evans coolant and when I pull my motors apart they are in great condition. I haven't had a water o ring fail sinse. Another thing the lower octaine is right you do want the lowest octiane possable to make max HP but, your tunning must be impecable with no mistakes. With added boost you have to have added octiane. For the daily driver who isan't competeing high octaine is safer and better since we aren't constantly checking abient temp vs coolant temp vs A/F vs combustian chamber pressure vs boost.

one other thing I thought ceramics didn't do any damage when blown??? I have heard that from many people that have used them????

those guys might be good at a short life 4 rotor N/A, but that is night and day from a long life turbo motor.