Previous attempt got trolled to death - rotary racing advantages?
 

Ok, so we know how a v8 can be good in a street car.

But, yet, Ive heard rotaries really shine in RACING. So, I started a thread to try to get some real facts out of it (read: not press releases or empty/useless/stupid facts like hp/liter or that its small or doesnt recriprocate) like expenses on rebuilds, frequency of rebuilds, if its any better at going NA in the 2.x liter class (for a 13b) and 3-4liter class for the 20b, and na vs turbo type stuff.

No, Im not out to troll, but on the other hand, Im not here to listen to ricers spew the same old nonsense as before. Hard facts or credible experience, please.

See, Carl Byck is here enduro racing a heavily modified FC, so I know they can definitely work. And, the first thread I started had a TON of info in it! But, unfortunately, before I could read it it was deleted for whatever reason.

So for those who have facts and reason here, this is your chance to educate me and all the other 'piston heads' out there who are willing to listen. Again, this isn't a troll, Im not calling anyone or anything out, I just want to get the real facts here.

So far, all I as able to get before I had to leave my computer (and came back and found it gone) was that because you dont have to worry about a valvetrain with a rotary, theres no worry of springs wearing out or having to adjust lash or shim anything, and theyre naturally able to rev up to about 8K or a little over stock, and can be modded to go sky high with a diff stationary gear and two part e-shaft.

Anyone have anything productive to add? Im genuinely curious!

Since 1996, I have been vintage road racing an HSR IMSA GTU class RX-7 against mostly Porsche 911 2.9 and 3.0 liter, and the occasional Nissan L-28. I don't know about the Nissan engine costs, but a top notch racing air cooled Porsche flat six costs is very expensive, some approaching $30,000 each. Rebuild for the Porsche is $7000. My 12A PP cost $7000 to purchase in 1997 dollars, and was still running strong after 26 road racing hours on it when I pulled it out. In 2004 I built my 13B PP, wet sump, for less than $6000. If you can do your own work, a PP rotary can be re-sealed with carbon apex seals for less than a grand, counting all new seals and springs. If you want one to last and last many racing hours, my evperience is that they cannot be revved sky high. The 12A will rev a little higher and last longer than the 13B, but the extra torque of the 13B will jump out of the corners faster than the best 12A.

12A 9.4:1 NA PP can burn 87 octane pump fuel, and a 13B 9.7:1 NA PP can burn 92 octane pump fuel. This saves you a fortune over buying race gas. An NA rotary will loose power running 110 octane race gas, the stuff most piston race motors require.

See, this is good info - now this is a thread that can go somewhere. THANK YOU! :beerchug:

I personally think a lot of the problem with adoption of rotaries and perceived credibility of them is one of the reasons theyre so liked by those that are in the know - they are very obscure and a lot of the real nitty gritty is hard to find. It definitely makes it special, but it means a lot of what should be "on the table" during discussion isn't.

BTW, why exactly can you use the lower octane and lower compression (relative to the piston engines) with a rotary? Is it because of the bathtub chamber design and knock resistance?

Also, just out of curiousity - in-class, what ends up being the biggest competetor to the 13bs out there? Honda motors? Duratechs? Quad Fours? Limas?

Furthermore, anyone got input about the classes that allow turbo motors?

In which class? Are you talking about road racing, timetrials or auto-x? drag?

For "racing" the important part is the entire package, not just the engine. Vehicle weight, fwd vs. rwd, suspension design - they all play into the equation. Hopefully whatever sanctioning body has classed the cars appropriately so that they are competitive withing the class.

In SCCA Improved Touring (club road racing) the overdog in the ITS class (where the 13B FC's run) is currently the 3-series BMW. Other than that, FC's do pretty well there.

In ITA where the 12A FB's run, the current lead car is (IIRC) the Honda CRX. There were enough RX-7's running in ITA to where in certain regions (like the SE) they run in their own class, IT7.

E and F Production I am not sure about.

In the Grand Am Cup series, the RX-8's are doing quite well, but are suffering from reliability issues (not directly engine related) that all new platforms tend to go through during their first years at the track.

So, what exactly are you asking?

-b

What Im asking is what are these supposed advantages to rotaries in race cars vs piston engines. I have heard that rebuild costs are lower and they can go longer between rebuilds on average when done in high revving NA type builds, and those rebuild costs are lower if you have the knowledge to do it.

Then, I asked how a turbo rotary would compare to the typical turbo piston engine in racing.

Basically Im trying to dredge around for practical, credible experience and whatever FACTS I could find to back it up.

Regarding your comment about the whole car mattering... thats a given! I understnad that. I was asking specifically about the 'engine' variable from a cost perspective, basically. Speedturn's answer was basically what I was going for, but I redirected it fowards if anyone would have similar knowledge of turbo builds for race cars.

I guess you missed the part that his engine died?


-Ted

I think the point of low rebuild cost for an NA rotory is true. IMO in the real world of racecars there are NO advantages to a rotary, only disadvantages. An engine burns fuel to make power. Piston motors do a better job of that than a rotary. End of discussion. Racecars of course crave power so why disadvantage yourself right from the beginning? Sure you can make a lot of power in a rotary but at that point you're talking highly tuned race motors and a highly tuned piston motor still has the advantage IMO.

I'm a Mazda fan and enjoy my rotory but fact is the rotory doesn't represent some special technology; it's merely a gimmick. Let the hate mail begin! :p:

Why did it die?

DamonB, I would like to point out that rotaries share one significant advantage over piston engines for racing: RELIABILITY.

No valvesprings to constantly have to check and change, especially after an overrev
No valve lash, no valve seats, no guides
No split bearings and therefore no bearings held together merely by bolt tension
No piston skirts to crack
No wrist pin circlips to come loose
No head gaskets, just O-rings
And so on!

Yes it is true that, thermodynamically speaking, rotaries suck. But that is not as important as the fact that it is damned near impossible to kill a N/A rotary!

Bologna. Piston motors are just as reliable; in fact I'd say more reliable when judging on the whole.

In my world people build race motors to win the race, not merely finish it. People don't race to lose. You can have all the finishes you like but the guys on the podium also finished and they happened to kick your butt while doing it ;)

Damned near impossible, eh?

Perhaps you should contact rx7gslse. His 13b rebuild should be done by now. :D

The point is:

Advantages:
a) gasoline price (aka, no race gasfor the NA rotary)
b) relatively inexpensive rebuild process, since it is less likely to punch a rod through the block when it dies.

Disadvantages:
a) Less reliable
b) Less powerful
c) Less fuel efficient

I don't know if I would agree with that. I talked to a local racer who races EProd and a few other divisions; he talked about how much more life they get out of the rotaries per season verses the piston guys.

For a NA racing application, rotaries are very reliable.

"Life" as in what? What parts are failing, in what motors? Springs, valvetrain stuff, the rotating assembly, bearings, what?

My 2 cents:

If a rotary engine is kept in tune and operating under the proper conditions (ie, plenty of fuel and no overheating) it will generally last longer under racing conditions than a piston engine.

This is a very general statement of course. There are too many types of engines and racing to say anything specific.

the rotary has enjoyed a storied career in racing. It has won in every class it has been allowed to run. Recently since the 12a/13b has been out of production for the most part (I know the RX8 is a rotary) the support has died off. Parts have been harder to find and have become even more expensive. I also have had a hard time finding someone to do a good job of rebuilding the 13b. I should have acquired this talent years ago but it sadly is to late. With anything that gets old the good people who service these engine have also gotten quite expensive. For me this has caused a shift to another powerplant. It is not a performance issue but a service and support issue that has caused me to change powerplants.

I dunno Lucy... generally you can get more race hours with a rotary vs. a piston engine of similar tune, and get away with less maintenance. Keeping a high strung piston engine alive is an excercise in remarkably intensive regular maintenance. Rotaries, you change the oil and plugs, maybe do a compression test every now and then, that's all you have to do. (Mainly because it's all you *can* do...)

Winning once and DNFing two times usually gets less points than a 2nd, 3rd, and 4th. :)

I've done a driving school at mid-ohio with my n/a FD rx-7, and have watched over 20 races through the years at mid-ohio raceway as well. I always talk to alot of the rotary racers while I am there, back in the paddocks to see how things are going. I talked once to a guy named Glen Jung, driving a tube frame fiberglass FD in GT1 class. He was up against ONLY large cube v8's 400ci+ and by per the rules, he had to run a 13B p-port. A 13B running against 6.0 liter plus cars? Yeah, my thoughts exactly, he said it was frustrating to run, but he could take any of them in the corners, and get lost in the straights. He wasnt allowed to run a 20B!! Some guys even complained and wanted him to run side port and not p-port 13B!!! WTF!! Its like this for EVERY rotary racer I talk to is "restrictions of all types placed on the rotary, and p-port is a big no no for some reason. If the great piston engine is soooo damn good and reliable, why are the rules so hard on the rotary? Are you piston guys that scared to loose to a POS engine? If the pistons are so great, let the rotary run without 25mm chokes, let them run p-ports, just let them run fair for gods sake!! The rotary is cheaper, and MUCH more reliable than any piston engine I've seen on the track. Oh yeah, during that GT1 race Glen Jung was in, out of the 9 V8 monsters pushing 800hp, only 5 finished as the other four (I talked to them all) had engine failures during a 2 hour, 2 HOUR race!!! Glen beat two of them that were running, putting him in third place finish, with only 350hp. Which brings me to my next point, if a V8 is no heavier or worse than a 13B, why is it that a pure race car vs race car, the rotary race car handles better through the corners??? Food for thought. Moral of the story, people hate and fear the rotary, and dont want to be beat by it, so they slam it with restrictions so they can win. Political as hell.

Straight from the horses mouth...
https://www.rx7club.com/forum/showth...=515309&page=4


-Ted

I imagine when he was referring to life, he means how long the engine can make enough power to be competitive. I doubt there is anything stopping you from using an engine with lower compression if you don't mind being non-competitive.

I've never taken apart a race motor, so I can't directly comment on exactly what kind of wear happens when taking a beating like those cars do...

Show me a 1.3L NA piston engine making 300-310hp that has won 24hr races. Or a 2.6L NA making 650+ doing the same. Porsche's new LMP2 car which is absolutely state-of-art in sportscar racing is seeing around 480 out of 3.4L.

The rotary hasn't always been the most powerful engine in it's racing class but Mazda built the winningest record in IMSA with year upon year of reliable service. The overall win at LeMans was a study in this philosophy. The Silver Arrow Mercedes were quicker no doubt but they broke. The TWR Jags could put down competitive laps but at 6.5L they were very thirsty beasts and they couldn't use their advantage and not run out of their fuel allotment. Tom Walkinshaw openly admitted they were surprisingly outpaced by the Mazda. The rotary happened to be just right that day.

In more grassroots terms the rotary has a decided advantage over it's competition in terms of running costs and build/rebuild costs. I can build a front running SCCA ITS engine from the ground up with all new parts for less than $4000. The engine I won the Cen-Div title and 6 of 12 starts with last year cost much less. The same front running BMW engine will set you back 50-100% more. Hell, Huffaker has an ad in this months Sports Car for Spec Miata engines priced at $7000!!! An ITS rotary can be expected to give 5 years (12 weekends per year) good service. The BMW engine will be pushed to make 2 years and still be healthy.

As was mentioned the NA rotarys don't require high dollar race gas. Which really isn't so high dollar anymore since pump fuel is rapidly catching up in price. The question of why was asked. The rotary by nature doesn't make good use of anything over 10:1 compression ratio. Goes back to that nasty thermal inefficiency that was also mentioned. At that limit pump fuel works just fine. In a highly tuned piston engine running compression ratios of 14-16:1 there is obviously a need for greater knock resistance than 93 octane can provide.

The engine isn't exactly light by todays standards but it does provide for a lower center of gravity than a typical piston engine. That's pretty key in high end motorsports. For reference the 26B is listed at 180kg on Mulsanne's Corner website. The latest AER V8 endurance engine is listed 114kg. I'm assuming that's sans turbos. A Judd V10 goes about 130-140kg.

And FWIW 3-rotor PPs are allowed in GT1. Still not competitive with the 600+hp 310ci V8s but allowed none the less.

13bs are essentially 2.6 liters as 26bs are 5.2, but thats beside the point of the thread - HP/liter is specifically the kind of useless factoid I trying to avoid. No offence.

Rebuild costs and lifetime between rebuilds ARE something Im interested in looking at, however. ITS class is for FCs, right? Im really not too knowledgeable about SCCA clases, what would a RX7 run in that class usually? And what are the guys youre running up against, 3 series?

So anyway, to recap here - they lose compression slower than race-built piston engines and are cheaper to rebuild, and often cheaper to build in the first place, they dont run as high of a compression and thus dont need anything higher than 93 octane, and if something goes wrong you just pop seals, you dont put a rod through a block.

Well, that right there seems to be good reasons to use them in racing - you can spend more money on the chassis and tires that you WOULD have been spending on the motor and fuel!

See, we need more threads like this. FACTS are great :icon_tup:

for my 2 cents worth
One of the best features of most rotory powered cars is the low centre of gravity.
The FD has a very very good weight split and a very low center of gravity, this makes it a good prospect to turn into a race car compaired with most saloon cars.

While this is true, isn't this partly offset by the higher position of the output from the engine which raises the transmission?

It was quoted by the mazda enginners who took apart the 787b's engine after lemans, that it showed little wear, and could have run the race again no problem. Assuming all the other functions of the car were in operable condition. The problem with our tiny engines weighing so much is as you know the cast iron. Now run some Aluminum irons, and some lightweight rotors, you looking at a very light engine. Though I do not know how the aluminum will wear. You can always do some sort of coating, which the did on the r26b's engine

I agree putting a 13B against a 400cid+ v8 is stupid. At equal power levels the v8 would have such a broad powerband and so little strain on it relative to what the rotary is dealing with (you might as well compare a twostroke motorcycle engine to a truck motor) its majorly unfair. THAT right there is a result of overly stringent racing rules and lack of understanding.

Regarding the other statements you made, youre ignoring all the other variables when you make your assertions, thus making them... useless assertions. I'd imagine there would be weight penalties based on your displacement, and It also wouldn't surprise me if the v8 cars had a LA rear. Then again, I wasn't at the race, don't know the rules or the cars, so I dont know any better either. I do know the engine itself doesnt effect handling nearly as much as where its put and the rest of the cars suspension tuning and tires.

Just keep in mind people having draconian rules against what theyre not used to being run in the race class doesn't mean theyre afraid of it... I can't exactly show up to an autocross in a 2.3T RX-7 and whine that Im not going up against T-IIs with similar chassis mods because the rules place me in E-Mod (last I checked...) even though a 2.3T to a 13B is a fair comparison IMHO. I know for a fact most 2.3T guys would kill for a rotaries airflow, considering we need twice the boost to make the same power :P. And we both know there isn't anyone on earth whose terrified of a Lima, no matter how much esslinger shit I bolt on it.

Most likely the issue here is there is a major lack of comprehension and understanding because of how different they are, a lot of propaganda on both parties, and general dickwaving. If more people REALLY understood rotaries and we had more flexible or rational rules and guidelines, it would be a lot better, I agree. But part of reaching that is comparing facts without getting emotional or relying on empty facts.

Im trying to get away from that and move towards objective comparisons and facts. So, does anyone have experience of a turbo rotary in racing vs a turbo piston motor?

Exactly. DamonB made the comment earlier that:

And while I see his point, there is also the old adage that "In order to finish first, you must first finish" :) .

Clearly nobody races to lose. But on the other hand there are a lot of people who race because they enjoy the sport and the competition. If you are a pro, well that's one thing. But if you are club racing then you are out there it enjoy the sport. Winning a pro race means big bucks for all involved. Winning a club race means you get a piece of wood.

Budget is a huge concern for the amateur. Unlike F1 teams, I can't afford to replace my engine every other race. The less I have to spend on rebuilding engines means the more I have to spend on tires, brakes, fluids and fees (and tow vehicle, and safety equipment, ad. nauseum :) ).

Experience as well as second hand evidence from others all indicates that a properly cared for 13B will last (and stay competitive) longer than corresponding piston engines. A good example of this is from the old (very compeptive) Formula Mazda series. These guys were running open wheel cars with factory sealed 13B's rev limited to 6500 rpm. They suposedly could get 3 good seasons out of an engine without having to replace it, while their piston-powered brethern in other similar series had to replace engines much more often. I heard mentioned on multiple occasions that this reliability made the series very attractive for the budget minded.

Now in the land of club racing you will always have those people will the cubic-dollars to spend to make sure that they have a front running car. C.Ludwig pointed out the BMW examples from ITS. The Spec Miata guys are paying $5k plus the cost of a fresh crate engine for a Sunbelt motor.

But for those who are on a budget, the rotary represents a good reliable platform that is fairly easy to maintain.

See my earlier post. Chris Ludwig or one of the other ITS guys can speak better as to what people are actually running on the track. The class includes Acura Integras, Datsun 240-280Zs, the FC, Porsche 944 and the BMW 3 series to name a few. Go to the SCCA website and download the General Competition Rules (GCR) for the full lists for all the classes.

Good luck,

-b

wranklin - what about under boost? :p

I know street 13bs tend to go 50K generally before compression starts to take a decline and need a rebuild, but in race situations its totally different than street stuff - youre on boost almost all the time, making mucho torque, and thus loading the motor a lot more. How long do 13BTs last in racing? I know over boosting = seal goes pop, but assuming you dont knock I mean.

How do most race piston motors fair under turbo conditions? Id imagine the higher cyl pressures would beat up on the cyl rings and the pistons if not oil cooled would get rather toasted up, but you wouldnt need high revs or a wild cam (or wild ramp rates) to get plenty of power with a turbo so the valve train would be happier, as well as your rotating assembly as far as tensile loads anyway (rod bolts).

no disrespect, but your a mod and cant even spell rotary right? something isnt right here.

can we please not flame here...

With respect to piston engines and boost...for a given amount of power the boosted engine will generally be less stressed than the NA engine that needs lots of additional revs to achieve the same power. The inertial loading of the rods and bearings from higher revs is much greater than that of additional cylinder pressure at lower revs. There's a reason so many of the ultra-successful endurance cars have been turbo charged. The NA engines that last at those revs have over-square bores with very short strokes to limit piston speed and thus inertial loading. Those engines, while developing a nice peak HP number, aren't generally going to have the sweet torque spread of a turbo engine of the same peak Hp rating.

The first problem to deal with a rotary is the amount of heat that needs to be rejected. There's that thermal inefficiency again. Listened in on a great conversation Rick Engman was having about the 792 at the Mitty. What little info is out there says the car was plagued with cooling problems from the start. 14 years later Rick is still making modifications to the car to keep it cool for historic events. And that's all NA stuff. Cooling, cooling, cooling. Now throw boost on top of an already troubled situation and the problem is compounded. The total heat load of a 600hp NA 4-rotor will be somewhat similar to that of a 600hp forced-induction 2-rotor. However there is the additional need to cool the intake charge and the turbo is heating the engine oil as well. All those coolers have to fit somewhere. This site is littered with threads on cooling problems and most of the street cars that have issues only see short WOT bursts. Building a FI car to take a 20 minute sprint race, let alone long endurance tests, would be enough to keep the thermal engineers up at night.

Nice 1000th post ;)

Also, just thinking about things, I came to a conclusion, and Id like input on if its true or not:
<flamesuit>
The reliability of NA rotaries in race situations is due to their inherantly low compression (9.4:1 max, apparently) and lower BMEP due to thermodynamic inefficiency - they dont produce as high of a pressure and thus dont strain the seals as hard as if they were very well insulated and at higher compression.
</flamesuit>

The low compression is certainly part of it. If a rotary could make use of 14:1 compression we'd be doing it and we'd see more common seal failures and heat related problems as a result.

Another piece of the puzzle is that the rotors are only spinning at 1/3 crank speed. Combined with a short stroke even the heavy rotors, relative to a piston rod combo, don't produce noticeable bearing wear. I just got back from my machinists and had a long conversation with him about what I wanted done with an e-shaft that I'll be using in a j-bridge engine that will see constant use at near 10k rpm. A week ago I dropped it off and said I wanted it cut down x number of 1000ths. Today I showed up and he said he knew I'd made a mistake and only cut about 2/3 of what I'd asked for. I told him I was looking for total clearance of y and I already z so I needed x cut down. "But the bearing will wear to give you the total number you're looking for." No... The bearing doesn't wear. Still not sure if he believes me when I tell him I can tear down a 100k+ mile street engine and measure bearing clearance that is the same as the day it left the factory.

if rotaries are so great, don't you think more teams would be developing it?? Imo, the best road racing engine is a Honda :) in terms of reliability to power ratio

The development happens because the manufacturers have a vested interest in seeing their product perform and thus become a marketing icon. Audi went diesel with the R10 to showcase their capability in that area. Mazda is the only manufacturer in the world producing a rotary engine so the development falls completely on them. It's hard to make a business case for dumping large sums of money into a program when the net return is so small (read RX-8 sales). It's true that factory backed rotary development effectively stopped in the early 90s and the last 10 years have seen an explosion in terms of piston engine development in terms of power but more importantly reliability. One needs look no further than the marque endurance events that have turned into round the clock sprint races.

I don't think any of us are saying the rotary is the end all engine. It's not. But the original poster asked for it's advantages and in so many words asked those that are tempted to troll to not. Some of us have pointed out the advantages and you choose to troll.

We'll get to see next year how the Honda (Acura) engine stands up to the Porsche in the LMP2 class. Don't forget to check back here next year to confirm that I was right when I say that Porsche will firmly trounce the Acura through the ALMS season next year. Further Honda hasn't exactly set the world on fire with the F1 engines over the last several seasons. Troll, troll, troll....

One thing that recently has me more interested in further rotary development, is cermet coatings. The 787B had cermet coated rotor housings and side plates. A problem with any rotary is the amount of heat it wastes, and if building a rotary with cermet coated rotors, side plates, and rotor housings, the heat would be no longer transfer as much to the engine, putting less stress on cooling systems. A additional benefit is less drag on the side seals and apex seals, producing more power. And the last gain, is virtually zero wear to side seals and apex seals as well. JHB performs this service, and its not overly expensive, since its proven a race rotary is MUCH cheaper, it could be used to make a turbo rotary with better gas mileage, and less heat, less wear, and more power. Total cost increase would be about $1,500 to do a whole engine. Might be worth its weight in gold to me.
Side note- the aluminum side housings from racing beat are cermat coated, so the wear is next to zero.

Yes with most piston engines the out put is lower but in every car that I have measured the centre of gravity the Mazda RX7 FD was lower. When I compare it to a V8 the centre of gravity of the Mazda was a lot lower, and even when compaired to a Porsche the FD was lower. The other luxury most rotories have is with having less weight overhanging the front axle

You do realize a lot of that is due to the design of the car itself, right? I mean, how else do the other engines that people put into RX7s still have the same balance?

Thanks. I remember this coming up when people ask why there were so few rotary Miata swaps. Lower CofG than a Porsche flat six is pretty impressive. Visually, most 911 engines seem to be at or below knee level!

You are correct. BMW has managed to have 50/50 weight balance using looooong straight six engines which are very difficult to get behind the front axle centerline. I think the point is, however, that one can do it with a rotary in a more compact vehicle package than perhaps certain piston engine designs.

I would be interested to see the physical dimensions of a 13B versus some of the more modern 60° V6 engines. I just did an engine swap in a friend's Contour SVT (now a 3.0) and that engine, even with big DOHC heads is a really small, sqaure package. Comparison versus rotary cars is difficult, as most of the 60° V6 engines are installed transversely, a role for which they are particularly well suited.

There is a big difference between balance and polar moment of inertia and center of gravity. You can hang and 1000lb iron head V12 over the front axle and have a 50/50 front-rear balance by stacking the same amount of weight over the rear axle. The builder jumps up and down to say it's perfectly balanced but it still won't turn as well as a vehicle of the same weight where the mass is concentrated at the center of the vehicle. The first example has a high polar moment and it's more difficult for it to change direction.

I understand what PMOI is exactly. Ive also heard the bowling ball vs barbell (both of same mass...) arguement ;)

But that in and of itself is also to do with the chassis. All swapped motors Ive seen are behind the front axis centerline, either mostly or entirely, in the RX7s I've seen them swapped into. The RX7's design with the front wheels forward and the engine back against the firewall is to thank for that, and the fact that it remains the same with completely different motors in it is a testament to the flexible and effective design of them.

I was referring to club level racing, most of us can't afford to race at lemans.

the engine on a Porsche is a flat enging bit it is mounted reasonably high in the car chasis and behind the rear axle

Exactly. Move the axle centerlines around and you automatically change weight distribution. Look at old F/X cars, they went from 60/40 or somesuch to 46/54 mainly by sliding the front axles 5" or so forward, and the rears 15". Or how Porsche lengthened the 911 by a few inches (just in front of the rear axle) in '67 or '68 or thereabouts, partially for a longer, more stable wheelbase, and partially for the increased frontal weight.

Of course, the rear axle's position is more or less dictated by how much interior room you want to have, and the front suspension needs to mesh with the packaging of all the other stuff ahead of the firewall.

For a more contemporary perspective, Ford's FR500 "package" for the SN95 Mustang moved the front axle centerline a few inches forward, necessitating new fenders and etc. but it drastically affected weight bias.

Of course, in the Real World, a car is much more than one or two specifications figures, it is a sum total of a whole matrix of characteristics. Which is why Porsche 911s, with one of the *worst* layouts possible for handling, had dominated racing for so long. The initial layout sucks but hardcore engineering put to that basic problem resulted in good performance. (In not so many words, the 911 is a good car despite, not because of, being rear-engine) Likewise, Subarus, some of the sweetest-handling cars around, have the entirety of the engine in front of the front axle, but the suspension geometry and tuning overcome the basic flaws.

Road racing rotaries in Australia include:

2 X Australian Touring Car Championships
5 X James Hardie 12 Hour Bathurst wins (in fact every event held)

Then add in the multitude of amatuer racers, rotaries are arguably the most successful cars run in Australia. And this despite CAMS (Austs SCCA) ruling that the capacity be multiplied by 1.7 liters when being classed, add a turbo and multiply by another 1.8.

I raced my 13B BP for 5 years almost every weekend for 5 years without ever opening the engine, just minor tuning and oil. I won two state hillclimb titles and ran in many autocrosses, hillclimbs, HPDE and even a couple of rallycrosses.

Dammit dammit dammit, I read the entire thread and you beat me to this. :wallbash:

Just wanted to make sure it was here before I added my tidbit, i knew SOMEONE had to post that.

^Truth, a very important truth.

But basically, what you need to do is go buy an RX7 first and see if you think it would be good for your type of racing. Regardless of the trolling and flaming that has happened here, you have to realize that you came to a rotary based forum and asked if our engines were good for racing. The answer is most likely going to be yes from many of the members.

A good N/A build will last you and make you competitive in your class.

A turbo will last a while if it is well tuned, but will most likely not last near as long as the N/A.

Would I build one to race with? Absolutely. I'd also tear it down and do a soft seal rebuild every year when I was done, and also check my hard seals to see if they need to be replaced, but that is just me and I am anal about things like that.

My advice, try it, i think you'll be pleased.

You're not anal until you have every piece of your suspension Magnafluxed once or twice a year.

Hmm, that's actually not a bad idea either. :)

That really isn't a bad idea, but I am not completely certain of what magnaflux does. Isn't it just a way to clean the parts? Or does it make them stronger?

Magnafluxing checks for cracks in ferrous materials.

Which is why he uses the process to check his suspension members. If the picture next to his name is indeed his car, I can assure you that are no non-ferrous suspension parts on that car from the factory.