good exhuast setup for power?
 

ive been looking at the complete exhuast from RB and im wondering what some good alternatives are for power? i plan on eventually rebuilding and streetporting my rx7 12a, but im most concerned with power from the exhuast instead of being overly concerned with the noise level (unless its stupidly loud), by the looks of it racing beats is the only show in town? what are my alternatives for exhuast set ups?

https://www.ebay.com/itm/Turbo-Exhau...QAAOxyVLNS53J0


The ONLY exhaust that makes power.

id like to stay NA.

I just put a racing beat on mine. I'm going to be honest, I didn't like it at first but it seems to be better with some miles,maybe it has a break in period. The build quality is there the header is built like a tank. The muffler is very nice. I was pleased with the felt power increase.

power?.... racing beat heads are great but i wouldn't spend money on their new exhaust... doesn't sound good and looks cheap.. if i was putting together a NA exhaust i would get road race header and try to find the old style racing beat muffler two into one... and for the center i would just run straight pipe..... racingbeat sell duel flanges

the road race header from racing beat? i was looking at the dissasembled one. not sure where i would fine that muffler. now for s uper ingorant question, supposing i went that route, would i need a new carb, pump and tune?
or just tune?

ignorant question 2, how much do tunes generally cost?

^^^^That would qualify for "the stupidly loud" op is trying to avoid...
Op,if you're looking for bolt on best power/sound the RB streetport system is best bang for your buck. It'll last the lifetime of your car and then some. All the engine mods you can do will never max out the breathing capability of this long primary system. System is not inexpensive,by the time you cobble together something to make power and realize after the initial sound/noise the car has,after @100 miles you're over it. Even if you like driving with earplugs,you'll find the rotary power pulses and vibes will put an early end to your "system". If you look at repairing,redesigning to make it better,the cost of materials and if you're time is worth something to you...The RB system doesn't look so expensive for a tuned,one and done,never rust out,pleasant sounding system. Maybe you could buy a used system and save yourself some cash,look at classifieds on this site,post a want to buy there.

Look thru threads on this forum and elsewhere to see what the majority of people have tried to build for their cars and how it worked out. For certain members here will chime in on their experiences with and without RB stuff

If you have your original Nikki carb/pump,a tuned system wouldn't require any alterations to make more power out of the box. The Nikki is the best carb for your engine and lots of threads here on how to modify it for serious power upgrades.

so is the nikki good enough to get the most that i can out of the streetported 12a and exhuast? or should i look into something better?

thanks for the info on the RB system, i really dont want earplugs lol, some noise would be nice, but i dont want bleeding ears at cruising speed lol. that being said if i punch it noise can be nice XD

interesting, with a street port. and exhuast wouldnt i be looking at close to 50% gains? ill do more research but i think i saw the numbers hobering around there. something around 120 Whp

google road race header..... like i said if you could find a slant cut old style racingbeat muffler sounds the out of all of them.....you might not be able to make it fast but you can make it quick...free flowing exhaust there's no way around it.......... yes these are noisy engines but to get full potential u gonna hav to make some noise

1. Do the exhaust - RB SP setup is t he best for the bucks, even if the new muffler sounds less throaty
2. Upgrade your ignition to a DFIS on the leading. Lots of threads about that on here.
3. Upgrade your carburetor, either modify/strip the nikki or go weber. The modified nikki can keep up with a street port.
4. Electric fan

With these mods you will see approximately 50% more power. At one time my car posted 134 Whp on a stock 12A.

if you're really looking to max out the power of a stock engine, you need to do a lot of stuff.

1. you want the Rb dissassembled header. when RB assembles it, they cut right on the bends, and do some other funky stuff, you can fix it. pipe needs to come straight out of the engine for ~2"
2. the rest of the exhaust needs to be equal length. if one had nothing but time, you'd try a few different ones and see what works. 90" is kind of the standard, although RB recommends a little longer with a stock engine
3. the RB muffler flows fine, and is quiet, plus it fits the car.
4. ignition, you need new cap, rotor and wires.
5. spark plugs, use the Rx8 leadings, they are the racing plug in a street friendly heat range. they are just better. for trailing, either the GSL-SE plugs, or the FC/FD trailing is fine.
6. you need to look at other stuff, like ditching the fan. plus there are a bunch of under-drive pulleys, and there must be some street friendly combo
7. the nikki is very street friendly, many mods to make it flow more air, but if you're after max power, you need something else

Just to reiterate what others have said, Racing Beat sells a bunch of different options. Whether your car is street ported or not, you want the complete kit street port exhaust with the long primaries (doesn't collect until it enters the muffler). The only reason you would want anything else is if you are a) trying to pass emissions and need cats, b) installing a turbo c) want something loud and obnoxious, d) trying to maximize power for something other than a stock or typical street port, e) concerned more about weight than long life.

I wish I had gotten the RB Street Port setup. I got the stock-port single/short primary set and I'm very disappointed in the sound.

That's it, 15 minutes. Actually about 45 minutes, but it was more off than running. 15 minutes total run time, and the car has not run a single mile on the street on that Holley carb. Look for it in the classifieds this weekend for $50 shipped. If it doesnt sell (like my beautiful FB rims) it will LITERALLY become an anchor for my fishing canoe. Yes, 15 minutes total run time, on ramps, in my garage, and the Holley-caust ruined my brand new RB exhaust. Put an out of the box Eddy on and it leaps off the stoplight from 1100 rpm idle. Fuck Holley. Well, fuck this Holley anyway.

GSLSE,

When I was a kid my Grandfather (PopPop) had an ugly, loud, stinky car that he loved and my Grandmother hated. It was faded dark blue, had duct tape on one of the rear quarter windows, the trunk didn't close right, and it was a Plymouth Belvedere, which I thought was funny because of that stupid sitcom "Mr Belvedere" that was on at the time. My Mom-Mom said it drove terribly and the brakes didn't work, and wouldn't ever let him take us kids in it. But my Mom says he used to race people when they went grocery shopping, and he took it to car shows in the 70's (I'm a '72 model, myself).

When my Grandfather passed in '86 or '87 Mom-Mom put a "Best Offer" sign on the windshield and planned on letting it go for a couple hundred. First person that knocked on the door gave her $5K and drove it away. If I had known anything about cars back then (I think I was 14) I would have bought it. Pop Pop's 1963 Belvedere was a 413ci Max Wedge equipped, #'s matching "Super Stock" special that he ordered from Plymouth in '62. The car was rated at 410 hp / 480 lbft from the factory, had the batterty in the trunk, and ran mid 11's in the quarter mile (as delivered).

I've wanted one ever since I found out what Pop Pop's stinky old car really was, and Maxwedge has been my only forum name. These cars in good shape with common 383 and 440 big blocks sell every day for $40k, with the ultra rare 413 and 426 Max Wedge (and later 426 Hemi's) bringing over $100k at auction.

Vroom Vroom.

(pics are not my Grandfather's car, but the same year and motor)
https://cimg2.ibsrv.net/gimg/www.rx7...21a77d710f.jpg
https://cimg9.ibsrv.net/gimg/www.rx7...7e4bdad506.jpg

what holley do u hav ? played with jetting ? pics of throttle plate lookin down ... ones that RB sells are garbage..... 390 4150 hp with no choke .. that's all i ever used and will kick the shit out of all others.... make them idle perfect at 8

I'm going to guess that you're Puerto Rican.

no i am not.......

Not meant as any kind of racist remark. My BIL is a Puerto Rican rotary bracket racer. He says that my car won't run is because it h as s a choke, and that I need a 600cfm racing Holley. But, he doesnt have any carbed cars, and doesnt know how carbs Or chokes work. He pays someone to tune his FI turbo motors with a laptop.

BTW, if anyone really really wants a quiet exhaust, I have the original 12a setup from 85. Car had 25k miles on it when I pulled it off 3 years ago. Doubt I'll be going back to stock, but I kept it just in case. It's slow.

a lil..... u hav a 12a ? or 13b ?

askin him

He has a 12a alcohol turbo (80mm in / 135mm exh) in a starlet. Fastest 1/4 mile time is 8.9 @155 but he has to feather it 1/2 way down the track because he doesnt have his next license.

I have a carb'd non ported 12A street car, that I want to drive on the street anytime there isn't salt on the road.. I need a medium sized carb with a choke.

https://cimg6.ibsrv.net/gimg/www.rx7...b2b0ce8453.jpg

hi
 

It was a RB 465cfm (1848/4160), stock jetting. Throttle bores match intake runners (1.5"). Everything clean and rebuilt to RB specs Runs very lean. Nikki and Eddy run fine so I know it's the carb, not the ignition/engine.
I looked at that 390 but how do you start it on a freezing cold day in a parking lot? Pull the air cleaner and put a rag or carb hat on it? That's what the race guys here with the 600 HP Holleys are telling me but I don't want that trouble. I'm not standing in the rain outside a movie theater working on my engine trying to get it started. That's what chokes are for.

What jetting do you use with the 390?

Does mazdacomp still sell those lavarock mufflers?

i could be totally full of it or just 10 years out of date but the long primarily header, collected early with a good collector into 3" seems to be what most of the race shops will recommend for max power.

I'm pretty sure Dave lemon ran something like that and didn't go over the axle, it was routed across to the driver's side and out the driver's rear.

There was a guy on here, hyper something or the other that did some testing and posted about his results. I'd search for his posts, they seemed on point.

Also, what the hell, racing beats site says they still sell the good ole power pulse muffled system. I'd call them and quality weather it's been updated or not. There is another post on this recently and it appears completely different.

pm ed

well this got off topic.

anyway,after feeling like i lost a bunch of power all of a sudden, i noticed that my fuel filter next to my carb was almost dry for some reason, if i turned it off and let the pump run for a bit it would fill up, id let it get to about halfway and stat it, sure enough the level of gas would start to lower until it was dryish on the inside, i could still see fuel still trickling into it.

so i went down to orieles and got a different filter with less volume in it for the fuel to sit below the exit port., it seemed to help? of course that could be my imagination, so to do some more tests i took the car a bit out of town to a deserted area and did a couple of 0-60 runs. i got around 12-12.5 seconds. (my tires are old and crappy. probably didnt help) but, that was with it going slightly down hill since i dont know of anywhere else that isnt the freeway for that speed. seems slowish considering i had a slight downhill? dont they get around 11 (if you good i guess) seconds at stock? for what its worth i did a compression check before i "feel like i lost power" and i was gettoung around 90 normalized across both rotors and all faces. dead even.

augh. might just be slow cause old. and stock.

which is what brings me back to the question i asked initially but slightly different.

im thinking about getting rid of the rats nest and when i do that, the thermal reactor. (aka massive heat generator) has to go right? if i were to get these Disassembled Road Race Header Kit for 74-85 12A - Racing Beat
when i do this do i need to A get a tune (stupid question, im guessing i do) B need anyhting else to to mate it to the stock exhuast where the headers exit? exra piping? or is it going to come out at about the right spot? hell since im there.

Back in the day C & D clocked the RX7 at 9 seconds for the 0-60 times. So yeah 12 would be slow.

There is no power gains to unlock by deleting the rats nest itself. You'll make more power with the header, which means you'll be removing the air pump and valve, making a few of the rats nest solenoids obsolete, but you can still keep the purge valve, shutter valve solenoid, a/c solenoid if so equipped, and the two vacuum advance solenoids which help with smooth off throttle deceleration. That stuff isn't holding you back unless you have vacuum leaks. Best approach is to remove, clean up, and replace all the hoses and bench test the solenoids, then reinstall.

instead of just replacing stuff, you might want to do some testing. and as a for instance, if your fuel pump is weak/tired then adding an exhaust will just make it worse.

i would suggest testing the fuel pump. you need a stop watch and a container with markings on the side. if you pull the hose off, and put it in the container, a good stock pump will do more than 1400cc/minute. if you put a gauge on it and deadhead it, it will do about 2.75psi. if your pump does not meet the specs, you need to look at the filters, and then the pump itself.

next thing to look at is the ignition, i like to just replace the cap and rotor and plugs. i check the wires, new is around 8k ohms, the more resistance you have, the less ignition power you have. NGK wires are good, but some other brands have too much resistance right out of the box, and should not be used.

then you want to look at the exhaust.