To get the numbers to line up with what I'm seeing on virtual dyno , I've had to change the BSFC parameter . In other words , there seems to be more power made for the amount of fuel/air going through the engine than what would normally be predicted for a rotary.


Edit : if Team were around he would have a fielday with that comment !

 

Team's not around?

 

no activity since October ....

 

I'm more stupid
Discussed it here a bit, might be helpful: https://www.rx8club.com/series-i-maj...-257683/page2/

Brettus: They mention 60lbs for 450FWHP for a RX7, but I suspect that the Renesis will have slightly more power pr lbs of air and fuel fed into it, this due to the side exhaust ports that recycle unburnt hydrocarbons, compared to peripheral ports who just spit them out unused. Does that make sense when looking at your numbers?

 

I think it's possible that by allowing the Renesis to breathe well on both sides of the turbo , that more power per lb of air can be made than on any previous rotary.
We all expected this to happen in the early days but never saw it due to the restrictive systems that have been fitted.

Based on existing data I'm expecting to see 400whp (460ish FWHP) on somewhere around 13.5psi and 54lbs/min.

Here are the numbers I've been manipulating to try and match the reality of what i'm actually seeing (with no muffler).

 

I'm still not convinced that Renesis has the same capabilities on the exhaust side when it comes to FI. As I've mentioned earlier, intake should be OK, since air density increases with the pressure, but when combustion is done, you have approx twice the volume(@15PSI) you need to evacuate out of ports, compared to original NA design. So I suspect a pressure buildup due to turbulent flow out of ports.

But nothing would be better than if I was wrong.

 

You are probably correct when cosidering ultimate power potential . However , at the 400ish power level it sems to be performing exceptionally well.
By giving the siamese a totally different exit path than the side ports I believe the exhaust gas evacuation has been improved over other designs that dump all the gas into one tube. That , plus the exhaust port mods we did and the large A/R turbine housing .......................

 

So when does your completely bolt-on, hassle free, 400whp turbo kit with Brettspeed tuning come available? Of course with priority of the first few off the production line going to long term forum members and existing customers

 

Haha .............. maybe in a parallel univerese .

Gotta admit I'm pretty excited to get her on the dyno .... had a vibration issue with the engine that was driving me nuts which I just fixed .

So won't be long !

 

Reminds me of the pirate that walked into a bar with a steering wheel in his pants. They bartender says "hey pirate, you know you got a steering wheel in your pants?!?" The pirate replies "aye, arghhh it be drivin' me nuts!!!!"

Sorry, I will now step away from the keyboard....

 

I literally just read that joke for the first time a few days ago

 

cool work! would it be possible to put the fabled BW EFR 8374 turbo in a similar setup in a LHD car?

 

Maybe ..........if someone was prepared to extensively modify the firewall .

 

Yup, if you're good with an angle grinder and sheet metal work With some panel work on the trans tunnel to expand it out into the RHS foot well it'd be possible to make room for the EFR frame and a bit of heat insulation.

 

well then I guess I will have to save up for some work then, brettus just has to flog the crap out of the turbo system to make sure its reliable long term!

 

Have booked the car in to get a new (custom) muffler fitted end of week. Going for nice long 3"ID across the back with a single exit . Hopefully it will give a deeper tone and sort my backpressure issue.

After that .... more boost and dyno !

 

Turbine backpressure results for new muffler @12.5psi :


.................Front scroll ..........rear scroll....RS no muff....RS new muff
3000..................5........................4.. ............3...................3
4000.................11.......................9... ............7..................8
5000.................14......................13... ...........9.................12
6000.................18......................17... ..........12.5.............15
7000.................24......................22... ..........17................19
8000.................30......................27... ..............................24



Half way between no muffler and the old muffler ....... not as good as I had hoped

 

 

How does it sound. What midpipe do you have?

 

+1 for deets

 

Well I have to say I'm underwhelmed with the sound as well as the backpressure reduction . Thinking about taking it back for another go at it ...................

It's actually quiet but still has a rasp that isn't pleasant to the ears when you get on the gas .
this is the design that was recommended to me , I wasn't sure about it but went with it because "that's how we do rx7s and they sound great" !
There are no resonators in the midpipe ATM so i'm thinking about going back to dual mufflers (with the 3" ones pctured ) and fitting a resonator. That might get rid of the rasp and make it a bit louder .

In other news ....... bumped her up to 14psi ...... things are getting crazy .....

 

My rear muffler is twice the size with two and its still noisy. Although turbo does help with keeping the noise down.

 

brettus, Step up your game man... I'm running 3.5inch straight pipe. My entire town HATES me. If it's late at night and I'm coming home fro shenanigans with friends, I often get text messages from people saying "slow down", "I just heard you get off the interstate", or my favorite "I can hear the song of your people"
My friends love to hear it. I hate it personally and will be adding at least a muffler when I put in the new engine.

Are you running the largest intake pipe diameter you can fit for your turbo location? What size is it?

 

Too much Rotary in the exhaust is a bad thing if you have neighbors.

BB cat back has a nice tone. Mabye look into how that was designed brett.

Travis

 

no mufflers ? you can't be serious !


We could only get a 63ID pipe through the engine mount.