Most people seem to start with a catback...

What if I only got RB headers, plus a BHR midpipe (already underway) and never did a cat back?? Seems like the stock muffler is the least restrictive part...

or would i not be able to take full advantage of the headers and midpipe without also getting an aftermarket cat??

Any recommendations on headers?

And does anyone know how much the stock headers weigh?

And since I've already stuffed this thread full of questions already, why do women like scary movies so much

 

women like scary movies cuz they know they will never see the end as they will most likely be engaging in tongue wrestling with their boyfriend/girlfriend/husband/wife/twin sister

 

You should try less asking and more searching. Catback is mostly just for exhaust tone. You will get your minuscule HP gains with the BHR midpipe, and maybe a couple more with a header.

 

Reallyy wife/twinsister?? that's crazy! I'm glad this has been answered first

 

Fair enough..

But miniscule gains? I was expecting to see equal improvements from the header and midpipe.
It is getting rid of the cat after all. Forgot who's but in the dyno thread some guy got 5 whp from his midpipe.

I'm glad you agree with me on the catback though

 

do any of the above

exhaust just makes it sound cooler, headers make it louder. that's pretty much it, little gains will be had. If power is your quest N/A wise intake, mid-pipe, BHR ignition and N20 are the quick way to decent power adders, dont expect in anything enormous though.

 

Take those dyno's subjectively. A before and after comparison is only valid if it is on the same dyno, same day, same environmental conditions etc. In my opinion 5whp is miniscule. Think about it though, lets say you go with a Racing beat header + BHR midpipe, that’s 1k USD for realistically 8whp. For that cost you could have gotten a decent nitrous setup started and would make much HP for the $.

IMO if you want HP gains, get a midpipe then put your money toward an Accessport and some tuning.

 

I dislike nitrous, even though i believe it to be a reasonable upgrade. I just want the mods to be available 100% of the time instead of with the push of a button. Also don't like the idea of losing space and adding weight.

To me 8 whp is significant enough and I can feel and enjoy that difference on other cars. I am already almost satisfied with the power although I'm also really hoping that I will also improve my engine response by freeing up the exhaust.

As of now, I'm set on RB header, midpipe and RB flash. This should warrant between 10-14 whp. Good enough, then i can move on to other aspects of the car.

Any feedback you can give me on getting better engine respone other than flywheel and pulleys?? I remember a friend of mine had an NA FC. It just revved so freely, when i first drove my rx8 i was disappointed that the RENESIS has lost that great characteristic. Anyone know why?

 

cobb ap>rb flash.pullys are more for bling, but i do have them. also have header back exhaust(no cat) n02 and a bunch of other mods. you need to do some serious searching

 

Lighter smaller wheels and light brakes are the best way to improve acceleration, weight saved on the drive-train (unsprung) is at least 3x that of the rest of the car. Also a light weight battery will save 30lbs, ~1% of the cars mass for about $100

 

Other than forced induction, removing the cat will give you the most HP per dollar in the RX8. It's only 8-10hp but its there, and more you will see from headers, cat-back, intake, and pulleys combined. Only things that come close is AP and BHR coils.

 

Can I get lighter brakes, without sacrificing performance?

What battery do you recommend?

 

If I just replaced my coils with factory ones, would I feel any difference if I got BHR coils now?

 

So cobb ap is better because I can have it tuned at the dyno?? I don't have that option, there are no dynos in Guam! I'm just glad we have a few motorsport events every once in a while.

 

You wont feel any HP difference with the BHR coils, but it is still well worth it to get them. They are more reliable than the OEMs, you might feel improved throttle response in the higher RPMs. At least I did when I put mine on. Also, I have yet to be able to flood my engine since installing the BHR coils.

You dont need a dyno to tune a naturally aspirated Renesis. You can always subscribe to MazdaManiac's custom calibration service. He is also the only one you can get a new Accessport from - mazdamaniac.com

 

Brakes won't do anything for acceleration... at all

 

BHR noticed no difference in MAF with vs without cat. AP tuning will help. If the stock coils are in good shape, BHR coils won't matter much either.

 

Read what he wrote: "light brakes".

Any weight reduction in the car will result in better acceleration.

Any reduction in the rotational moments of inertia will result in better acceleration (but not higher horsepower though it may measure higher on the cheapo dynos most use.)

 

Back to the original question. There's nothing "wrong" with header + midpipe + stock exhaust, but nothing particularly right either. If you have money to burn, go ahead and modify; the results will be rather minor for the substantial cost.

All your other questions are answered in the sticky: https://www.rx8club.com/aftermarket-...8-link-235382/

 

brakes don't rotate. what are weight savings on light brakes?

http://www.racingbeat.com/press/mod-mag-rx8.pdf

Dyno-ed HP improvement with Mid-pipe. Some stock cats flow better than others but there is a measurable difference. Also mid-pipe weighs less than the stock cat, surely a better weight savings than your magic light brakes.

 

I'm pretty sure brake rotors rotate when you're driving.
Racing Brake makes two piece rotors which save something like 4.5lbs per front rotor and 2.5lbs per rear rotor.
That's a decent savings in unsprung weight. They are expensive though.

 

rotors perhaps, but not brakes/shoes/pads. 1000 for 4 rotors is alot of cash compared to a midpipe

 

and 4.5lbs per is a lot of rotating unsprung weight savings.

 

Rotors "perhaps" rotate? Wow.

The cost has nothing to do with the fact that lightened brakes will give better acceleration which you denied they would.

Almost no RX-8 hp mod is cost effective compared to many/most normal cars.

 

Did you actually read what they wrote or, for that matter, what I wrote, or even what you wrote?

You: removing the cat will give you the most hp/dollar.

Me: BHR showed no difference in MAF (=hp) between cat and no cat.

Magazine: The car made slightly more hp with the (HJS) cat than without.

Now you start talking about midpipes (which may or may not have a cat in them) and bring in a comparison to "my" majic light brakes which are neither mine, nor claimed by me or anyone else to be make a cost effective or even a major difference.

If there were significant gains to be had, would not have someone found them in the past 8 years of trying? Some may wish to spend $1k for 10 hp, and that's find if they do. Just don't expect that $1k to buy any more than that though, and more likely it's $2k to gain 10 hp.