wrxracer55

iTrader: (3)

i know people have thrown out the idea of doing a renesis swap, and it would be a lot of work for all of the electronics, but what about swapping in a carburated version? it is essentially a 13b. would a 13b carb manifold bolt onto the engine? i know you would have to do a custom exhaust due to the new design, but is this an unrealistic idea? just a thought. any opinions?

hondah8er

Why in gods name would you want to carbuerate it? Thats so 80's. I would not even bother with that idea.

hornbm

I think it would be pretty sweet. Renesis with a phat weber 48IDA. Should be good for some pretty decent power

Gregs

not as much as the EFI though, i HIGHLY doubt it....

lovintha7

There was someone who posted a picture with a Renesis engine/tranny and everything, including the engine cover in a first gen. Do a search on Renesis SA22C, since I'm too lazy to do it.

hornbm

yeah it was done in japan, on a S1

DriveFast7

iTrader: (1)

carbing a renesis should be do-able with the right manifold. and you can take advantage of the higher redline and power of the renesis motor. i bet it would be easier to just put a rx7 motor in there.

how much for crate rx8 motors?

hornbm

yeah really if someone just made a carb manifold and a header that would bolt up to the racing beat exhaust system id be set!

wrxracer55

iTrader: (3)

yeah, i just thought it would be something different from the older 13b. not sure how it would mount up, b/c i think the renesis has a different engine mount system. i liked the ideas of the improved ports, and if you could street port that puppy with a holley or weber, i'm sure it would make great power.

rotarygod

iTrader: (1)

The motor mounts are on the rear rotor housing. The intake manifold bolt pattern and port configuration will not line up with any 13B parts. You'll have to build a manifold. The front cover bolt pattern is the same so theoretically you could adapt an early front cover with a distributer. The water pump bolt pattern is new though so you may have to figure that one out.

wrxracer55

iTrader: (3)

sounds like more work than its worth. guess if i do a swap i'll just stick with the older 13b. thanks for the replies.

gerbraldy

Carb'd is the way to go, fuel injection is so highly overrated. Stick a carb'd streetported 13bt motor in there.

red13brx7

fuel injection is not over rated. HAHA. But I think it would be great to do a carbed rx8 swap.

rotarygod

iTrader: (1)

LOL!!!!!!!!!!!!!! Whatever!

hondah8er

I can't even respond to that either really! It boggles my mind how some people are stuck in the 70's and 80's still.

hornbm

aint nothin wrong with a carb, its cheap easy power

hondah8er

Sure. But carbs are finicky....cold starting is shitty with a weber, and it lacks the refinement of efi. And its not modern day like EFI.

hornbm

yeah if I had tons of money id take EFI in a heart beat.

but after the computer system, getting it tuned, the actual fuel injection parts to begin with, it gets real expensive real quick

hondah8er

true enough...i'm just talking about the factory ecu not a standalone efi.

hornbm

if you knew how complex the rx8 factory efi system was, youd beg for a carb before putting it in your first gen.

That would be funny as hell to see an OBDII system in a first gen tho

Sterling

Much of the "underrating" of carburetors comes from ignorance on the basics of carburetion and a limited selection of carburetors ill suited for usual street needs for the rotary.

Manntis

Carbureting a Renesis seems a bit like retrofitting a propeller onto an F-22.

rotarygod

iTrader: (1)

That's a good comparison.

I never said carbs were bad but to say that fuel injection is overrated and that carbs are the ONLY way to go is just downright ignorant.

hornbm

no kidding, fuel injection is allways better in the end, but I would REALLY like to see how well the renesis performs with a weber 48IDA on it!

Slammed_GSL

iTrader: (14)

I asked this same question at the Pineapple Racing tech day (Subject was the Renesis, had one apart for comparison) Some one asked about a carb on the Renesis and Bob said it was possible but doubted it would make more power. I chimed in about the pulses that are part of the intake system and how the new motor is tuned with those in mind. Any new manifold and carb combo would need to do alot of dyno time to match let alone exceed the OEM EFI system. Mazda is the authority on these motors and no backyard yahoo is going to dream up a carb system that is more efficent. Think about it, they took a NA motor and almost matched the power of a stock FD 235 vs 255, that in itself says they squeezed this engine for all it worth....for now. SC or Turbo would be nice for the future.
Sorry for the long post.