UPDATE- dyno sheet on page 2

I've never seen this on rx8club.com, and I've certainly never seen one on another RX8, so here it goes.

After reading numerous threads regarding changing out the stock exhaust, yet gaining little or zero hp, I actually did not want to upgrade my exhaust.

Then, one day I stumbled upon this website -> www.badlanzhpe.com
They sell exhaust cut outs..... electronic ones.

After reading in Racingbeat's site that removing the muffler gained about 5hp, this was the way I chose.

http://racingbeat.com/FRmazda4.htm

Power Output
Performance gains are comparable with our REV 8 Street Exhaust:

Stock production engine - with muffler removed +5 HP
Stock production engine - with RB street or race exhaust + 3.5 HP


some pics.


I installed a switch right next to the DSC switch.
When I push up, the valve opens, push down, the valve closes.



So... I basically have a dump pipe I open up when I feel like listening to the thunderous roar of my rotary (with verified +5hp) and close it up when I see a cop near by.

I had this system in my 8 for the last 2 years or so and like it very much.
My girlfriend does not mind it at all, because... I close the valve when she rides with me~! LOL

What do you guys think?

 

I've seen these type of cutouts before but they were on Vettes and Camaros...and they were installed just after the header to gain as much power as possible. I think you just made real loud exhaust with no benefit what so ever.

 

"Thunderous roar" my ***!

An unmuffled rotary is a nasty crackly chainsaw rasp, that just pisses off neighbors.

But it's your neighbors.......

S

(and we'll be needing a dyno sheet before anyone believes it's a 'verified' 5hp)

 

dude thats crazy! how hard was the install? shoudlve done a DIY

 

Uhmmmm.......

Not the best idea to have your exhaust dump right under the middle of the car. With that setup, you will be shooting flames right onto the parking brake cables, suspension bushings, rear CV's, Brake lines, etc., etc., etc.

 

well, with the y-pipe, i just took it to a local muffler shop and had them weld it in.
The valve, i just ran the line along the bottom and plug here, plug there...
it's not that hard.
I guess i should've done a diy, but maybe someone else who likes this idea will do one and document it.

 

yes, just like your exhaust.

no flames. i installed it after the cat.
i had this on my car for more than 2 years...i think that says it all...

you can ask racingbeat for the dyno sheet.
i guess i should've written "verified +5 by racingbeat".
oh well...

 

It's only loud at WOT...and I actually squeezed out 3hp.

 

well, racingbeat says mine squeezes out 5, so i guess i win.

 

^In your mind, I guess that's a win. But please show us a dyno sheet with your very poorly designed exhaust and then we'll see how wins.

 

dyno sheet pics or never happened

 

+1 bad place to put that dump without having a turn down...

not just like their exhaust. their pipes are made end to end with performance in mind. you cut out the muffler which is the least restrictive part of the exhaust save the straight pipes...

i'd still say bad placement(unless you put a turn down on it) just because of flames. putting it after the cat means nothing as far as flames go... plenty of ppl have shown over and over that a fully stock exhaust can still throw flames, even with the cat. the fact that it is a bit more rare to see flames from a car with the cat intact wouldn't be a warm fuzzy about this either... that just means that if you were to 'look for it to be safe' that you'd likely see nothing and assume things are fine, when in reality you may be very slowly torching stuff...

2 years or not... gimme a bic lighter and a 4x4 block of wood, given enough time i could put a hole through it with quick short flames from the lighter.... put a turn down on it

 

This is a pretty silly mod, even if it did give you +5 HP. That's a whopping 3 ft/lbs of torque or so, and probably only gives any gains near redline at the cost of sounding like crap and being ridiculously loud. Taking the jack, tie downs, and compressor out of the trunk would have made your car faster than this did.

 

Interesting. This I didn't know.
I will put a turn down on it asap.
Thanks for the input.

 

I give you props. I have brough this mod up before. I have had cut outs before and they work like a champ on most cars (obviously better on Mustang). You should dyno it so everyone will STFU.

I find it funny that people are giving you **** when there are people here spending $300+ on intakes over 1k on cat-backs and getting no usable HP.

 

^exactly...but then again people also pay for the sound...some just dont give a FCK...

back pressure can be a good thing

 

OK, I understand you are just quoting RB's claim of 5hp - but seriously, how can you stand that awful racket??

S

 

Thank you.
I just wanted people to know that there can be other options out there. If the domestic guys are doing it, why can't the import guys?

Ok, Ok, I admit... I usually open it up doing a full throttle merge in to the freeway and shut it up right away. hahahahaha~

It's a cutout. I usually keep it closed. Also, when I opened up at horse thief at willowsprings I had on a helmet. I can't really tell if it's loud or not with a helmet.

Hope you get my intentions for this mod- I really, really like the quietness of the stock exhaust. And with the cost being 1/3 or 1/4 of a full exhaust, what's not to like?

 

stealth, it floats his boat...his little mod allows him to shut it off and go quiet, so i guess in HIS sense hes got the best of both worlds...a stock exhaust that works perfectly and one HELL of a straight pipe

 

That giant rusty can on the back of your car

Seriously though, I think that's why most people get an aftermarket cat-back... not too many people expect any noticeable performance gains.

 

my friend has something like this on his STI..it is well worth it

 

I've seen that on muscle and tings like that never on a rotary but if u like the sound that's all that matters.....

 

If people just bought exhaust systems for sound then they would be lining up to buy the OBX (which sound good). If they were buying them for looks they would just weld nice tips to the stock exhaust. I think it's more people just wanting to mod for the sake of modding and they feel somthing in the butt dyno so that satisfies them.

Don't get me wrong, there is nothing wrong with it, I love a sweet sounding exhaust. I just think its cool he took a risk and most likely it probably adds HP.

 

how?

 

My only advise would be to redo the switch and turn that valve down. How much did you pay for it?