RotaryBred

I couldn't find any threads regarding this engine... anyone know about it?

500hp and 400 lb-ft of torque

i want it!

rotarygod

iTrader: (1)

Um...yeah. That's a 4 cylinder.

That's the current ALMS race engine that replaced the 3 rotor peripheral port. The rotary was the R20B. The 4 cyl engine is built by AER. It is direct injected and turbocharged. The 3 rotor was naturally aspirated, much heavier, had less power and wasn't exactly a technological marvel by any means.

calculon

iTrader: (29)

wow.

hard f*cking core indeed

RotaryBred

yeah i looked at the pic again just after i posted and realized i just made my self look like an idiot.

Juiceh

iTrader: (4)

^yup.

diabolical1

iTrader: (3)

just blame it on someone else ... everyone else does.

GooRoo

iTrader: (4)

Was at the ALMS race at Road America and during the pit tour they told us they are limited by the rules to 35 lbs of boost. 35 LBS !!!

The wastegate setup was unlike any I've seen too... of course everything looked like a million bucks because that's probably what they spent.

Even without a rotary it is a very cool car, just like all the ALMS prototypes.

Black91n/a

They couldn't be competetive with the 20B, so they had to go piston. They were ~275kg (IIRC) overweight with the 20B, had to add lots of openings for cooling (drag) so they didn't have a chance against the Porsches. Due to the higher crank position relative to a piston engine they had to use the P1 gearbox, rear suspension and brakes which contributed to the weight. There was a good article in (IIRC) RCE about it.

Basically it was a big headache and with that basic engine being used in the Mazdaspeed 3 and 6 and the CX7 it also made sense from a marketing standpoint to make the switch.

t-von

iTrader: (8)

I don't get it! They were over weight with the 20b, but instead of investing money in Racing beat style aluminum side plates, they opted to fund a completely different non rotary engine? Hell if anything, since they choose to go with a smaller displacment engine they could have at the very least gone with a 13b with aluminum side plates (which could very well be far lighter than this thing) and some NRS ceramic apex seals for durability.

I may be unrealistic but, I can't see jumping of the rotary ship without exhausting all available resources.

Black91n/a

That would drop a couple pounds, but they were HUNDREDS of pounds over, due to the rotary necessitating that they use the heavier P1 gearbox, suspension, brakes and so on, then there's the aero penalties from the increased heat rejection demands of a rotary. The point is they were never going to win unless they started from scratch, so they made the logical, limited budget choice.

t-von

iTrader: (8)

I can see what your saying since the larger displacment 20b is a far more demanding engine. That's why I brought up the 13b as a more apples to apples engine weight comparison to the 4 banger. All things being equal, I don't see this turbo 4 banger being lighter than an all aluminum turbo 13b. Also what's the cost of that thing?

Black91n/a

They're probably not allowed to run a turbo 13B, and you can't make enough power with an NA 13B to keep up. It's the higher crank height (halfway up, vs near the bottom on a piston engine) of the rotary that necessitates the P1 rear end, not the power, torque or anything else like that, and that's where a lot of that weight is.

TehMonkay

iTrader: (-1)

No budget for a P1 car?

rotarygod

iTrader: (1)

In an article in Race Car Engineering, Mazda admits that they could have properly designed and built the Courage around the rotary from the beginning but chose not to as it would have taken an extra 6 months of work. They wanted to get into the season. They built each car literally a couple of weeks before the start of the seasons. If they'd have done it properly, they'd have started 6 months earlier. Why they don't understand this is beyond me. With the very limited time they had available, they chose the quickest solution they could find in order to get the rotary installed. It was basically the back half of a P1 car and front half of a P2 car. Not optimal.

There were many things that weren't done right on that car. It took them 2 years to figure out that their overheating issues were largely based on the fact that their water pump was cavitating. Come on man! Figure that crap out! It doesn't take 2 years to fix that. They could have gotten the weight down to minimums but they'd still have been underpowered. Then again the new car is faster but has only finished 2 or 3 races this year whereas the Courage while not fast would at least finish most of the time. You can't win if you can't finish.

They had released an original RFQ (request for quote) to several outside engine companies to build them a new rotary engine. They never got a response from anyone! They wanted a direct injected all aluminum turbo 3 rotor. That was the goal. How much of that was possible is another matter but that's what they were hoping for. When they sent out a 2nd RFQ, it was just for an engine that met their goals. AER met that challenge.

t-von

iTrader: (8)

^ Well that makes more since. Thx RG! It amazes me how some people go race, but yet don't have their own understanding of the science behind building their own engines. When I make it big, I'll take that challange any day of the week cause I believe in rotary's that much.

Black91n/a

I just re-read the article and it was 275lbs overweight, over 100lbs of that due to the P1 rear end.

A few corrections to what rotarygod said:
-They never said they had a cavitating water pump, but when they switched to a whole new champ car based cooling system, including pump, they paid attention to preventing it.
-They never said they didn't get a response to the aluminum turbo 20B RFQ, they just said that they had a change of heart between summer and autumn. Maybe they got responses but just didn't like them.

Sure if you read into it you might come to those conclusions, but it's not a statement of fact.

Now sure they could have started earlier and built a new back half, but hindsight is always 20/20. Maybe they didn't have funding at that point, maybe they hadn't even thought of it yet. Sure they could have skipped the first season, but it was also their most succesful with the lack of Porsche competition.

rotarygod

iTrader: (1)

On top of their issues, they had 6 different engine builders. They never stuck with any one person for more than a couple of races. Everytime they had a problem, instead of letting their curent engine builder fix it, they'd move on to another builder who had to learn what was going on with the car all over again. I think they'd have had more engine luck if they'd have kept 1 builder the whole time. That way they could have learned over time rather than having multiple people constantly relearn.

I don't understand why they absolutely had to enter the car that season rather than wait. If they are going to start building the car 2 weeks before the first race that kind of tells me that they aren't ready. Either jump in later in the season or start building earlier! I wouldn't plan to move into a house a mere 2 weeks after it's construction plans are drawn up. There'd be some huge compromises just to get a roof over my head by then. Same thing here. The old addage do it right the first time or do it again is perfectly displayed in their efforts and the irony is that although they wanted to do it cheap, building it properly the first time would have cost less than replacing the car 2 years later. I'm not in charge of the team and don't make these decisions though.

The rules aren't very well defined when it comes to forced induction on rotaries. The rules are only defined for nonturbos. Had they have gone turbo rotary, they would have had to get approval from the ACO. Those guys change the rules constantly so I wouldn't put much faith in their decisions. Their whole intention of restrictor plate racing is to limit power. The problem is it doesn't limit it evenly.

What they need to do is make the rules very simple. Have a total horsepower cap per class. Let's say 500 hp for P2. Once you do that it makes engine displacement irrelevant. It makes boost pressure limits irrelevant. It even makes engine type irrelevant. The team with the best car combination/setup/driver will win. Do you go small engine with a high turbo? Do you go larger engine without one? Do you do a larger displacement low boost turbo? How about a diesel? Piston, rotary, etc... As long as it's under the power limit, it shouldn't matter. That's what would make the most sense. The combo with the most average power will do the best. You can see advantages and disadvantages to each posible setup. I think this would yield some very interesting engine combinations.

rotarygod

iTrader: (1)

Just because they didn't say it in an article doesn't mean they didn't say it. It's all in who you know. Their biigest cooling issues were in fact due to water pump cavitation. That's why they went to the champ car setup.

They didn't get a response on the first RFQ. Not a single response. Again, not in the article. They had 2 articles in consecutive months btw. The 2nd one was on the new car. Marketing came into play and they rethought out their whole PR stance on the engine used. Their original goal was to use a rotary. Their second RFQ was for an engine that would work to fit their PR needs. AER came up with a nice solution. They already had an engine that was designed for deirect injection. It was their V8 race engine. The new Mazda engine is basically nothing more than half of the V8 engine. It's not their old 4 cylinder. Now the engine is proven and ready for direct injection. That was a pretty quick and easy solution and met their power and PR needs since several cars have the MZR engine.

I'm not drawing any conclusions. They are statements of fact. You just need to know who to talk to.

Black91n/a

I see, I just have the first article, and it sounded like you were just mis-remembering or something, as it sounded like you were paraphrasing it from that article.