As the title says i would like to compare them. I'm a noob at this stuff so i wanted to know yall opinion on them. In the distant future i'm looking to do a swap in my FB. i know the Tii is the most common one but is that because of price or is it that much better than the renesis? I'm going to dig up some stuff too but i also want to know yall opinions since i have no expireince with them. please discuss and thank you.

 

TII is turbo. Renesis is NA. TIIs are cheaper and easier to find, make far more power, and the swap is better documented and in many ways easier. Properly set up the Renesis will be more reliable and get marginally better gas mileage.

 

+1

 

Lets say i turbo'd the Rensis, could it ever have the potentail for power that the TII does?

 

sure you would but the renesis is SO rediculously controlled by computers you would basically have to take everything out of the rx8 for it to function properly.

 

13BT (T2 engine) has more potential than the renesis as far as peak power.

As far as reliability, the renesis wins hands down in NA form.

The turbo rx8 I had for a while w/ standalone and full exhaust made about 280whp at 8.5psi and that honestly, was at the top of what the greddy turbo I was using would do. It was reliable, never detonated, pulled hard - even when I tore the engine apart, the housings were fine, apex seals fine. I just wanted to refresh the engine as we were rebuilding everything.

IMHO though, for a new guy - go T2. Its way more documented than a renesis swap and ultimately much cheaper to deal with for now. In a few years the renesis parts may come down, but its pricey right now.

I can make twice the power in a 13BT w/ the same amount of cash...

 

true. dj essence^

I just got off rx8club.com. so far the highest hp numbers is around 235. thats not bad. especially my stock engine is 130ish and thats pretty fun. oh well. i'll keep researching

 

Ok thanks for that input.

 

The highest on rx8club should be more than 235 - check the turbo guys. I think one guy is making over 350whp w/ his renesis... like I said mine was 270-280 depending on the day/dyno used at 8.5psi. The greddy kit only makes about 200 to 240whp in "bolt-on" form, but the emanage sucks and the boost is too low

 

Renesis engines are harder to turbo because they're high compression.

For a high compression engine there is a hell of a lot more thought and work involved than there is when working with an engine that's meant to be turbo.

The way I see it is this:

Turbo II

Pros:
- Easier and cheaper to find an entire "long" block and ECU compared to Renesis
- Well documented, not very difficult swap
- Many people over many years have done many things to these engines and know how to make power out of them. So there's a huge amount of support for you when you want to find out what route to take, or how to do this-and-that
- More headroom for power (port, bigger turbo, aftermarket ecu)

Cons:
- Older technology (slightly, still newer than what's in your FB now)
- Hard to find low-mileage cores compared to the Renesis
- Turbocharged cars a bit more difficult to tune and maintain
- Requires higher octane fuel because of compression


Renesis:

Pros:
- Newer engine technology for reliability and power
- Non-turbo engines tend to have higher reliability
- Easy to find low-mileage cores
- Runs on Regular, booyah
- Better for the environment?
- Potentially better on gas

Cons:
- Harder, less documented swap to perform
- More expensive for less power
- Lots of the enhancements *surrounding* the engine in the Rx8 are hard to bring over (I hear they have a tricky returnless variable pressure fuel system?!), so you have to improvise and sacrifice, losing power in the process.
- Harder to squeeze more out of the block in N/A form, high comp and thin apex seals make it harder to reliably boost


Of course, this information may or may not be accurate. This is what I've gathered by overhearing other rotorheads talk about them, or reading on here. None of this is firsthand, so I could be way off on some of this

Jon

 

Thx John. Useful info.

 

I plan on doing a Renesis swap eventually... I have seen some of the Greddy RX8's and HKS 8's running close to 400RWHP...

as for power, I think it has the potential but the aftermarket is still very slim pickings compared to the 12A and 13B mods you can get.

Also to swap over the engine, there is a lot of computer and electrical work that needs to be done not to mention fuel and such.

I'd say TII would be way easier in the short and long run.

Renesis if you have the money, patience, and the strive to try something very challenging.

 

From what ive seen on this forum thus far, Jon is not completely wrong often. So id take his post with a fair amount of credibility even if its all 2md/3rd hand.

As he said some of the stuff is alot harder to swap over..fuel systems ecu etc. The TII will be eaiser and cheaper to get alot of power out of them.

 

I would like to see Mazda produce a natural aspiration 4 rotor engine RX7 for next gen. With FI. Turbo optional. So it would be affordable instead of getting a 2nd mortgage.