Reply With QuoteRight on Chrisjjanfd3s
I personally would go a 13B if it were NA though, the slight difference in capacity is very noticable.
If you can do all the fab work your self it will work out heaps cheaper than a 4AGE conversion because you wont have to worry about all the EFI gear. And trust me a 12A will have alot more torque than a 1.2 piston engine. If its a weekend car id recomend going for an engine with some pretty agressive ports (PP or BP).
Oh and the whole reliability thing is BS. If you take care of your engine it will take care of you. People always complain about reliability, but I've got a 300BHP 13BTT it will easily last 100,000 KMs id like to see how many people have done that with a 4AGTE
Right on Chrisjjanfd3s
I personally would go a 13B if it were NA though, the slight difference in capacity is very noticable.
Hachiroku since 1994
Originally Posted by LittleRedSpirit
Thanks for clearing that up Frak - i thought that was the case. impressive
ive been for a spin in a mazda101 (i think) had a 13b BP went well just didint seem to have much pull
No probs, alot has to do with the intake system, if it's an old school engine and still running the nikki 4 barrel, doesn't matter what port job you do, you'll be hard pressed to put out over 150bhp flywheel.
the nikki flows around 300cfm of air. We have found on the dyno that a rotor needs around 2cfm of air to make 1hp where as something like an sr20 will do 1hp from 1cfm of air. We measure air usage on the engine dyno.
another short story, many years ago, I build a 13B monster port for my brothers R100, he puts a weber IDA on, as you may or may not know, weber carbs come pre-jetted for the engine they were originally designed for, the 48IDA was originally used on a Porsche called a 904(twas a race car) and comes fitted with 37mm chokes(venturi's) anyway after building the engine etc I tell him he'll need atleast 42mm chokes to make grunt, he can't see how a few mm's can make a big difference.
Anyway he drives the car around, complains it has no grunt and basically insinuates I did a crap engine, eventually I talk him into getting some bigger chokes, he got a couple of 44mm's, I put some 220 mains(from memory) he went out and it was a completely different car, he come back shaking!
If you have an a rotor ya gotta let em breathe.
I have found on the dyno a twin system(for aslong as you can) is best for horsepower. I had a student who had a series 3 rx7 years ago, all stock, we dyno, crap hp, I tell him to get long primary twin system, he's only young, doesn't really understand what I mean, any way he got an exhaust/headers for it but short primary, on dyno, not much better, anyway after months of hassling him, he gets a long primary twin system, back on dyno, MASSIVE gains.
Hachiroku since 1994
a rotor owner once told me there is only 9 moving parts in one.
Frak I know you love 20v's how do they compare to rotories?
JJ
"my mind demands side pipes out of hear, now to command my hands to make them"
rotor=awesome
over the years ive been helping my mate with his 12a in a series 1? rx7
started off just a rebuild standard, i think it made like 100hp at wheels. (carby still)
next came efi, some sort of hybrid 13B injector setup, staged injectors. all run off a megasquirt. road tuned by us in the backstreets.
then about 1yr ago, we put a little 13B hairdryer one the side, still standard 12a specs. and this thing absolutly hauls ass. hes got a 13.2 i think at the drags, thats just king springs and semi slick tyres. we arent sure how long the apex seals are gonna last, but hopefully a bit longer. thats only on 7psi as well.
ive had a drive of it, and the response is absolutely insane, and forget about torque issues, plenty of that. the turbo at the moment is actually a tad small, starts losing boost at 7k or so. getting a bigger turbo soon, to keep the air coming at 9k+
they are fidly engines though, gota know what your doing, im not really that up on them, i just help out where i can. my mate has a really nice setup, has all the decent parts to make it reliable. its his daily driver too.
in short, if i had the money/time/room id have a 12a turbo (13b is illegal) in my ke70. even standard 12A efi was awesome, without turbo. the standard carby is a bit of junk from what ive been told.
oh and if your p plate, forget about any of this being legal. unfortunately your stuck with k motors for a few years.
In faith there is enough light for those who want to believe and enough shadows to blind those who don't.
- Blaise Pascal
Tim, 9 moving parts, depends if you count all the seals/apexes etc as seperate;
Your typical 2 rotor.
2 x rotors
12 x parts for apexseals for 2 piece
18 x parts for apex seals for 3 piece
6 or 12 x apex seal springs
12 x corner seals
12 x corner seal springs
8 x oil control rings
8 x oil control ring o-rings
12 x side seals(24 if twin dist engine, really old tho)
12 x side seal springs
1 x eccentric shaft
1 x front balance weight
there are a few more, but you get the idea, a few more parts than people think.
Tim, completely standard, say comparing a stock series 3 rx7 against my ae111, i'd take the ae111 as I know for a fact the engine puts out a heap more power.
modified, and I wouldn't bother with a 12a so would be 13b, but port job, weber/efi, headers/exhaust, i'd take the rotor any day as it will have alot more grunt.
Hachiroku since 1994
Tim, try and get out to an IPRA meet at Mallala, there is a local guy named James Sutton, who runs a Bridgeported, quad throttle,autronic 13B in his R100, it is VERY fast, I think he's doing 1.16.00, and mixes it with the turbo boys all the time, this engine makes over 200rwkw!!!!! and it's NA! He has to rev it, but hey that's part of the fun of having a rotor....10,000+ rpm
Hachiroku since 1994
ill try and check it out sounds pretty crazy!
i have only been in one rotor powered car, 13b turbo rx7 series 4 i think?? to be honest i was not very impressed not sure if it had any mods or not? i would like a drive of one just to see what they are really like. 10000rpm does sound like fun.
i used to be a real muscle car v8 head when i was younger and always payed out rotories now i drive a 1.6! and am intriged with the small rotory ha ha how things can change
JJ
"my mind demands side pipes out of hear, now to command my hands to make them"
Yeah rotaries are good
BTW Frak tour old daily sounds insane !!! i would love an RX3 coupe. My DD is a RX7 series 8 Bathurst R, its quite nice but has woeful fuel consumption (about 20l/100km when I granny it)
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