MAZDA GT cars - What engine?

[vincentrx7]

Are all the Mazda GT cars that you see running against the Porsche's and GTO's all NA 20b's? I've been trying to find out anout the engines but haven't found much info. If so, where are they getting their parts and engines?

[KaiFD3S]

As far as I know they are all P-Port N/A 20B's...

[Smokey]

they don't release much info on them, but they were nice enough to let me take a good peek under the hood when they were up at Mid-Ohio.

They're definitely PP motors, using 13b housings.

[Phoenix7]

now, are they renesis 20Bs? Are they older 13Bs? Try looking at the rules for the GT classes....I'm sure they say what you can and can't use....

[Drama]

older 20B`s

[Phoenix7]

they are using Cosmo 20Bs then....I know Phil did an interview with Speedsource but you have to talk to him about it.

[Herblenny]

I talked to the Speed Source guys last year about these engines.. They are not Renesis 20Bs and I don't remember if it was peripheral or not..

What I do remember is that the engine sits REALLY Low.. Let me see if I have a picture..

http://www.rotarycarclub.com/rotary_forum/attachment.php?attachmentid=5822&stc=1&d=1247079550

I asked them who built the engine and they told me that they did.. And I'm almost certain its base platform is the Cosmo 20B.

[vincentrx7]

I just wonder where they get parts like center plates and e shafts. Wouldn't they be underpowered compared to the Porsche's and V8 domestics like the GTO? I thought they were in the same class.

[Smokey]

they're definitely not down on power compared to the others in their classes.

They're tube frame cars, so as Phil mentioned they were able to place the motor wherever they wanted. (low and back). In the instance of the Speed Source car that Phil posted, you can see it's so low that they moved the adjustable sway bar to go over the engine instead of below.

I could get close enough to see that the motors are definitely PP, and are using rotor housings stamped with 13b, and they're using the 20b thick iron. The intake setups on the other Rx8 teams were almost exactly the same, so either the rules are pretty to the letter on that, or Speed Source is building and providing motors for the other Mazda teams....not sure on that one.

[dregg100]

yeah, they are all pp. and no, deffinately not down on power. a p-port 20b makes around 500bhp.

[gmonsen]

The motors are Cosmo 20b's with thick irons, P-Ports, and are NA motors making 475-500 whp. The motors up to at least mid last year were made by Roger Mandeville.

Gordon

[dregg100]

dont you love it when "the man" is right down the street from you?

[Chibana]

I believe that I heard on Speed coverage or read somewhere that the SpeedSource 20b engines make 415 hp.

Indeed. Here is the URL:

http://www.speedsourceinc.com/index.cfm?template=mazdacars&section=mazda

(I *love* watching these things go around the track, spitting flame when they downshift just before the apexes.)

[dregg100]

of course they are going to say less than actual^^

[ZachFD]

I just heard these beasts run on barbers last weekend. Absolutely nutty. They sound like F1 cars

[bop_rocco]

I just heard these beasts run on barbers last weekend. Absolutely nutty. They sound like F1 cars

They do sound awsome. Wish my car sounded like that.

[j9fd3s]

of course they are going to say less than actual^^

in this class they are restricted to a lower rpm, like 7500 or something, so 415 is about right.

the black one at sevenstock last year looked like a cosmo 20b with RB style PP housings.

[Rotary Inspired]

this should clear it up.

http://videos.streetfire.net/video/20B-TriRotor-Wankel_640747.htm

[Renesisking]

sorry this might be a noob question, but in that pic it seemed as if it wasnt F/I it looked carbeurated, unless i was mistaken by the intercooler thing on top of the motor.

[EJayCe996]

sorry this might be a noob question, but in that pic it seemed as if it wasnt F/I it looked carbeurated, unless i was mistaken by the intercooler thing on top of the motor.

That's nothing more than a box with an air filter on the top that houses the ITBs

[Renesisking]

gotchya, i've seen some people run them without the box on top, i've always wondered this however, since there is no intake to properly distribute air evenly to each chamber, couldnt one be working more than the other??? also, how much more performance can you gain since your only sucking air from the engine when you'd want cooler air for better performance.

[Whizbang]

i have been curious about constructing something similiar for my 82 but there is not much room for...well anything. maybe i should just be content with unifilters.

[Turbo II Rotor]

gotchya, i've seen some people run them without the box on top, i've always wondered this however, since there is no intake to properly distribute air evenly to each chamber, couldnt one be working more than the other??? also, how much more performance can you gain since your only sucking air from the engine when you'd want cooler air for better performance.

The air box is sealed to the hood and open at the rear to take advantage of the high air pressure zone at the cowl. That intake is drawing fresh air and it's being forced in at speed. Without the air box you would be drawing in hot engine bay air and you would have higher intake temps which would be less than optimal. The box is a much better design.

[vincentrx7]

I appreciate all the input. At the time, I was looking to source an e-shaft and thought I might would see where they are sourcing them. Interestingly enough, I just started looking up the websites for the race teams and most had phone numbers for their engine builders or engineers. So, I called them and talked to them. One guy said,"I maintain 8 engines and only have 12 e-shafts so I couldn't let any go". All the race teams were pretty nice. One team even hooked me up with their engine builder in California. I called him and talked to him for a long time about 3 rotors and what he recommended on engine builds. The race guys seem to get their eshafts from Mazda (Mazdaspeed) and I think they were $3500-$4500 each. They don't buy engines, just all the parts individually. This might be old news to most, but I found it interesting.