Tudor

Hello All,
My name is Tudor, I'm from St. Petrsburg, Russia.
I'm designing a "track day" roadster. What I have now uses Hyabusa engine with 180hp and 180lb complete with 6 speed geargbox. This allows for a very light (~1000lbs) and seriously fast car. How ever it has it's drowbacks
1) Engine revving that high (10k+) is not overly reliable
2)One needs to learn to drive such a peacky engine - no torque at lower RPM
3) Some people love but some hate dog style gear box
4) Overall - not everyone is really ready to drive something that feels and drive like a pure race car - comfort is non existant.

So I thought that I need a version with automotive engine. After some looking around I felt in love with this little rotarys (13B REW).
Now correct me when I'm wrong
Light and compact (don't know exactly but "rumors" say that it's not much over 200lbs)
Not very hard to get - lots of engine bulders listed that offer rebuild engines with 24000miles warranty
Lot's of power even in stock form (255hp)

Now here's the list of questions I have - please take a look and may be add a word or two. Any help/advise will be highly appriciated.

1) Is RX7 (3d gen) gearbox available same easy as rebuild engines? If so what is price estimate? How much does it weight? Same questions apply to diff.
2) Most engine builders quote engines without neccesary ancillaryes - what is needed for 13B TT, how easily available?
3) ECU: Is original available? I have expireance with motec M800 in a touring car I used to race - great thing but seriously expencive. There are AEM, TECi and Haltech - all at lower price. What would you say about them?
4) Engine wiring harness (original) how easily available? where?

5) Does anybody have a CAD model of 13B TT so I can put it in my chassis CAD model?

6) Sorry for this one. "average" street porting - how much power/torque? At what RPM?

7) This one is not any better - sorry guys. Which engine builder would you suggest in terms of providing complete service. Deliver worldwide - engines complete with wiring harness, ECU, Exhoust (developed together to clear the chassis etc.) reasonably priced and reliable garanties? Who has enough knowledge to work on something less usual? Thought nothing special if one remembers that rotarys are used in many classes in SCCA. So there must be a lot of expireance using them out of RX7s...

8) First project is front engined so it's possible to use stock tranny. Next one will be my true love - mid engined project. So does anyone aware of some transaxle ( non dog style) that is possible to use with mazda rotary?

Thanks a lot for your help. Sorry for my English - I never was first in class

Thank you
Ted

turbojeff

iTrader: (30)

A complete 13B-REW weighs in at around 390lbs. That includes AC, PS, alternator, airpump, flywheel, emissions, belts, etc.

Guessing some you won't need AC, airpump, emissions and probably not PS. Ditching that stuff will probably save you 50-60lbs. Get a lightweight flywheel and save another 10lbs, go single turbo and probably save another 15-20lbs. Using those rough numbers the engine installed in your machine may come in around 300lbs.

The block alone is around 200lbs.

Mahjik

iTrader: (1)

Tranmission cores are usually fairly hard to come by but can be rebuilt. Part are readily available from Mazda or MazdaMotorsports.

Typically you just want to freshen up your normal "non-internal engine components" of your fuel, cooling and oil systems.

Yes, original is available. The aftermarket ones are also available. The programmable ones are only as good as the tuner.


Yes from Mazda or MazdaMotorsports.



Street porting typically adds an extra 5-15% depending on the size of the port. Every engine rebuilder has their own idea of what a "street port" is...


Pettit Racing if you are looking for an engine for racing.

http://www.pettitracing.com

They are a race shop so they know their stuff when it comes to prepping rotaries for that type of application.

Tudor

Many thanks guys! I could not expect to get help so soon...
You're as fast os your cars

Thank you
Ted

BigIslandSevens

iTrader: (4)

I might add a suggestion.. Contact Higgi on the forum. he is pretty knowledgeable with the rotaries. more of a FC guy but the T2 engine is a good platform as well for your aplication. yes there are some advantages to the FD engine. In the long run if you are porting and such, you can still build one hell of engine.

Tudor

Thanks All,
Any ideas on gearbox and diff weight? Is diff Mazda's original part?

Thank you
Ted

BigIslandSevens

iTrader: (4)

the diff assembly( housing gears etc..) probably weighs in around 80 pounds.

The tranny is around 80-130. I can lift and carry them easily, so that is a guess.

Malloy Mazda in Woodbridge, Virginia. USA sells reman trannies as well i believe. I seem to remember them quoting me around 2K for one. It also had some warranty period i believe.

Malloy Mazda's Telephone # is 1-888-533-3400 Ask for Ray Crowe

I believe he sent parts to someone in Cyprus before. But i do not know for sure their ability to ship to Russia. I would not see a problem as long as Putin doesn't

Tudor

Nah I guess he doesn't (Putin) unless that engine or trunny has mustash and barb and talks chechenian.

Thank you
Ted

pomanferrari

iTrader: (1)

Are you nuts? Japanese motorcycle engines are dead reliable. I met a Hayabusa owner running a GT28 turbo at 10 psi for 40K. My last two ZX6 had 60,000 miles before I sold it.

Do you even know how to drive a track car? 1000 lbs with a 180 h.p engine is pretty damn good. Add a small turbo GT28 and you're getting a reliable 300 h.p.

Again, you must not be too bright. First, the non-synchro tranny of the Hayabusha does not require declutching during upshift whereas the 5 speed synchros do. The throws are much longer on the RX7. The shifter on the Hayabusha is a sequential 6 gears.



Now I'm going to have to say DON'T BE STUPID. Stick with the Hayabusha in your 1000 lbs race car. Need more power? Get a turbo from Velocity Racing.com for $5000.00.

pomanferrari

iTrader: (1)

200 lb engine including a 6 speed sequential tranny, add 30-40 lbs for a turbo complete with water injection for 450 h.p.

You must be ******* nuts to even contemplate dicking around with the RX7 engine. I would run the RX7 engine only if your car is over 2000 lbs. Otherwise I'd run with the Hayabusha engine.

Upgrade to a GT35/40 turbos and you can see 500 h.p at max boost or 300 reliable h.p.

Tudor

Hi pomanferrari,
Thanks for your input. You can call me nuts - no problems here .
OK 1) Jap. bike engines are NOT reliable - period. At list if you put it in the car - much bigger strain than it see in the bike. I do have two engines in my shop - one in the works and another waiting. Complete rebuild after major disaster. I must say that GSXR1300 (Busa) is ecpecially unreliable compared to another engine that we use here (Yamaha R1)
It needs dry sumping (read expensive) because it can not cope with lateral and even longitudinal (under braking) accelerations that it see in the car.
Dog style gearbox is loud and harsh - as I sayd some love it some hate it.
If you look for more power and torque in Busa engine I'd prefer TTS supercharger (at list in car application).
I do know a little bit how to drive a track car. I was working as instructor in racing school for 4 years. After that I was racing profeccionally (means making leaving out of it) for 3 seasons in RTCC (Russian touring car championship) THis doesn't mean I'm fast or something but I do know a thing or two about driving.

So why I'm looking for rotary option is - I need less brutal, smoother engine option.
Remember this is NOT a race car. It's a track car - one that could be driven on public roads.
I do realise that a lot of my customers would not really care about driving it on track but would love to show up on public road.

Thank you
Ted

Tudor

Hi again,
Any one knows exact figures for gearbox and diff weight?
Any ideas on possible transaxle (sincronised) choice for mid engined application?

Thank you
Ted

rotoboy661

hey man mid engine is also "do able"

just need some adaptors

i saw a 13b on a vw bug which was mated it its transaxle

mike

Dan Stevenson

Tudor,
Try a google search for the "legend" racing series. The look like mini vintage cars and they use a Yahama motor (1200 cc) motor in them. I would really study that design before attempting messing with an RX7 motor.

pomanferrari

iTrader: (1)

If you insist on the FD engine, know that it's twice as heavy, requires a lot of cooling capacity both for engine and IC. There is also the issue of tuning.

Re the Hayabusha engine, it's in the Radical Race Car of England weighing about 1200 lbs.

The grass is not always greener on the rotary side.

Tudor

Guys I agree that bike engines ARE great. In fact I believe that this side of world (F1 being another) they are on the very top. Absolutely stock Yamaha YZF R1 2004 makes 180hp... out of 1 liter! And that sound... Oh Mama! Bike engines is what we use already and this was my first and obvious choice!
All I mean is I want to have an automotive alternative engine with sincronized gearbox - for those who want something less racye but still with lots of power and more mid range torque than bike engine can offer.
When I'm looking for automotive engine option I want.
As light vs power/torque as possible (for reasonable money)
I have a feeling that mazda rotary are among lightest in weight vs power/torque - am I wrong?
As compact as possible (vs power/torque)
Have a feeling that rotary is one of smallest out there.
Readily available from reliable source and reasonable price.
Looking at some business websites I have a feeling that I can have relatively reliable 300hp 13B engine for about 4000$ with 24000 miles warranty
Than I need a gearbox and diff - rough estimate makes me think that it's possible to get used and rebuild for about 2000$ (just a guess havn't got any quotes yet)
1500$ for ECU and I'm done
7500$ gives something compact , relatively light and at last but not list a lot of potential tunability.

If someone can point me where I'm wrong here - please do so.
If someone can point me to another automotive engine which is better in same price range - please do so.

Thank you
Ted

PS: There's also 20B - just saw a site where they offer 20B's for 3950$

diyman25

Hello for cheap HP not thing can compare to Rotary.(no need to change valve, head, crank, rod, etc etc) to a point (under 500HP).

For transmission and diff. you dont really need to use factory part right ? because for 2G you can get a brand new transmission from http://www.g-forcetransmissions.com/tran_gt-5.asp. that is race prove and can hold town of TQ they also sell the adep plate too and a lot of RX-7 race car using this set up too. plus the factory dont use normal mounting point for TRAN/DIFF. we have one thing CALL PPF. more time to custom, more money to spend and for diff just use FORD rear end( that what every one use in europe right?) when every one using it, the price is cheap

for factory harness, brand new one is about 650. I change mine on my FD.

also do you really need to put turbo on your project. because on NA with "right porting" meaning BP PP. the 13B REW can output 300HP and I seen some guys drive this type of car on street before. much cheaper than turbo and wont have issue on cooling but you will loost a lot of TQ.(rotary run very very hot) oh btw for rotary engine you also need a big *** oil cooler..


I am assume you are building a Lotus style kit car right? if so there is some one already buid a RE power lotus 7 style car here. here is his web site http://www.laminarauto.com/ but I dont think it work any more. but you might found more info on web
below are the some pic I found. they are all rotary power. the bug eye is even power by 20B

Tudor

Thank you Diyman25,
I'll have to contact you for some more questions

Thank you
Ted

Tudor

Thank you Diyman25,
So for 2000$ I can have that T-5 tranny - I will contact them monday. Also I do agree that I don't neccesary need RX7 diff. Everybody uses ford sierra diff (in UK) which is about 70lb. There's relatively new option - Rover Freelander (aluminium housing) diff 25lb only. There's a quaife version of torsen LSD available for this diff.
Now you write "the factory dont use normal mounting point for TRAN/DIFF. we have one thing CALL PPF. more time to custom, more money to spend " sorry but I didn't understand what you meant here - because of my bad English and luck of knowledge. Please explain.

for factory harness, brand new one is about 650. I change mine on my FD. -
Is it full car harness (icluding wipers, lights etc, etc) or just engine wiring loom? Does it includ sensors etc?

"also do you really need to put turbo on your project. because on NA with "right porting" meaning BP PP. the 13B REW can output 300HP and I seen some guys drive this type of car on street before. much cheaper than turbo and wont have issue on cooling but you will loost a lot of TQ.(rotary run very very hot) oh btw for rotary engine you also need a big *** oil cooler.."
300 hp without turbo... with "right" porting meaning BP PP.... what is that? Can you please get a bit more thorought here?
Your advise is highly appriciated.

No it's not Lotus 7 type car. In fact I hate english kit cars - I do build and sell them here - thats why I hate them . In fact I wanted to make midengined version but investor say that front engined would have to go first.
Main difference from Lotus style cars. (Hopefully ) MUCH stiffer (torsionally) chassis with apropriate fron,side and rear crushable structures. Push rod suspension and some reasonable attention to aero package - I'm studying aerodynamics and CFD engineering for two years now.

Thanks again for your poractical advise/help. Anything also you'd like to share would be highly appriciated

Ted

diyman25

yes I think if you plan to build a track day car. the T5 will be much bette idea. they are cheap , and race prove. the down side you have to use Ford clutch disc for your rx7.

PPF. it is hard to explain. basicaly 3 gen rx7 dont have typical transmission mount. instead it got a large bar connect from tranmission to DIFF. so more time to custom the mount the more money you will spend
http://www.justmiata.com/ProductItem...&CategoryID=35

and for more info on PP http://www.mazdatrix.com/r-20.htm check here for idea
and infact 99% of mazda factory race car use PP check here for more info http://www.mymazdarotary.com/mazda_r...paper_html.htm
basically PP is what rotary origional design from. they are very very loud. a lot of over lap. not too much TQ under 5 how ever the TQ curve is flat. but the power after 5K is great. it will keep pushing until 10K. And power range is 250-350 depend on your setup(usually mean the size of carb or the TB size now a day with much bigger carb size pushing behind 330Hp is not a dream). In my option, I like it better on race only car but if you can lower the sound it would be great on street too but usually it kill the power).

Cool I wound like to see your design soon. so not like a lotus. will it look like ATOM? or holden kit car from aus. or even a TVR look? I like all this small company from Europe they are full of life and creattion. too bad we dont have this type of company in USA

Tudor

MANY Thanx!!! What a cool links!

This is what I was looking for some practical advise from friendly, helpful and knowledgable people.

Those group C cars was my always and true love. Nissan P35, Toyota Gorney Eagle MK 3, and of course the most gorgeous prototype of all times Mazda RX792P - that car had HUGE potential but they just closed the series....and it just didn't have time to start shining. People behind it was great - some of most knowledgable people in racing at the time. Aero was done by Jozef Katz - author of "Race Car Aerodynamics" and many SAE papers...... list goes on.

Thank you
Ted