Got some new headers put on the car today from Ric Shaw. Wondering how anybody else with headers find theirs? I know they don't do much but I just felt that with a high flow cat and good catback exhaust that the headers might just help it all out(as the factory headers are terrible if you have ever looked at them).
I can't say I had a chance to kane it on the way home but I did notice a bit more noise and also that I didn't have to change down to second gear as much when driving slowly, it seemed to have a little more torque at that low part of the rev range(around 3K).
How does this compare to you guys that have headers on your cars?

 

I installed the Racing Beat header and fabricated a resonated 3" mid-pipe and I feel a noticeable improvement in lowish-mid-range torque (between about 3500-5000). Top end didn't change very much though. Exhaust note is much more rotary-y

 

I've been wondering about a header too. There's not too much info here, it seems like most people think they're too expensive.

Thats interesting, I would have thought the upper end would have a decent improvement. I'm trying to find more info on headers, I'm interested in an all-motor Renesis.

 

These statements do not logically follow each other.

 

I know what you mean but when I say that they don't do much I mean they aren't known for increasing power by much but having said that, they must be an improvement over the factory arrangement which aren't even headers really. More like a chamber where all the exhaust just gets dumped in together.

 

technically you'll feel more torque (longer, equal length runners). i'm thnking about getting the racing beat headers myself...

 

I've been wondering about the headers also...

What do you guys think they would do when using forced induction like a Pettit SC with 12 psi and the cat-less Agency Power 3" exhaust?

I want to try and get about 335 rwhp and 225-230 tq with the Pettit. I've seen people with 227 rwhp and 217 tq without after market headers and was thinking maybe they would give it just a little bit more.

 

That's what everyone says. My coworker was amazed when he drove it with the header. It's definitely a noticeable midrange gain.

 

How much hp do the headers add?

 

Supposedly about 4 hp. I'd like to find more info though, because I'm sure a header would be much better than the log manifold we have for stock. Maybe with an Accessport it can be tuned to give more power/efficiency?

 

Getting fluid headers installed right now. I'll post up my review of them probably. Also, I'll get a HD video next time my girlfriend is around w/how they sound with agency power catback+fluid DR midpipe.

 

Why would any of you buy more than one header?

 

I'm not expecting any gains.

I'm getting mine in because my supercharger is on order. Headers+supercharger=5-10WHP. The only gains I'll be seeing would be a maximum of 1-3WHP N/A.. I think it will mostly unnoticeable, but we'll see. The above is all speculation..

 

I might just save the money for more significant mods then.

 

I have dynoed the car with and without the racing beat header. Max horsepower you will see with it is 2-4 whp and some minor torque gains.

FYI: i have the mazsport 3" dual res midpipe, 2.75 hks legamax, and at the time the racing beat intake.

 

I wonder of people who are installing super- or turbochargers (esp. the latter) are using the opportunity to do complete rebuilds, waterjacket mods, etc. I do not pretend to be an expert, but this does not seem to be an engine that likes a lot of extra strain or heat. (See the poster up above who is on his 3rd engine and says "no more turbos.") With the high cost of items like the Pettit and Hymee superchargers (and even some of the decidedly cheaper looking turbo rigs), I would think it a worthwhile investment to go a little further.

 

All in the tune.

Going FI on a non-FI car is a risk that you HAVE to be aware of. Your engine could detonate, **** could fly. Heavy engine modding also decreases reliability. There isn't a huge amount you can do with the water jacket on the renny, or porting. It costs THOUSANDS for very minor upgrades.

Spending money on a turbo then just "porting it while you're at it" is like buying a house then picking up a new SL65AMG. Just cause you're spending a ton of money, doesn't mean you have to throw ALL of it away. I'd rather have the money for a new motor than spend that money on porting and destroy the motor anyways.


/ENDCRAP

The headers actually really made my car feel different. It's much smoother to start from a stop and the powerband is stretched a little bit south. I love how it sounds as well. Good stuff. I'll post a soundclip some time soonish.

 

it seems like not many rx8 owners do the header mod. If there isnt much gain from switching out the headers from stock doesn't that mean that the engineers at mazda made a good job building the headers?

 

They did indeed!

 

That may be true but if you have a set in your hand and look at them it is hard to believe. They are barely headers..I am yet to see any dyno proof of aftermarket airboxes making any power either but they are very expensive too for what they are.

 

Yo Jimmy!

Only 2-4? Dude, I've seen a 10 hp VARIANCE on our header and exhaust designs. Hmmmmm........ And I would bet a new fresh Renesis engine that the dyno we use is very, very consistent.

Perhaps its the header?????????

 

Eric, I wonder if there is an available header, midpipe, rear section exhaust on the market that could come close to the gains you have seen.

 

Eric....

I have seen some rebuilt motors (rebuilt in Japan) with a simple intake and exhaust set up pull 196 rwhp. On the motor I had I believe the original dyno pull was 179-181 rwhp (with an exhaust on it and the racing beat intake). I added the mazsport coils, and int-x and bumped the hp to 201rwhp. With the racing beat header I was able to get to 204-205 rwhp. This number was accomplished after a number of pulls and tweaking of the tune.

Some reasoning I have come up with for the meager gains from the header I believe stem from one or combination of 3 things. 1. The motor has 50+ thousand miles on it and could probably use to be refreshed (The compression is fine though). 2. By the time we were able to achieve these numbers by messing with the tune we were definitely seeing some heat soak. Since the header is directly below the intake manifold there was a lot of heat being transferred into the lower intake manifold. At one point we let a fan blow directly onto the motor and header for several minutes. A heat shield is a must (Hint, Hint). 3. The design looks amazing but to fit within the stock constraints I believe limited the design which ended up with smaller gains. Since I have seen your header in person and in combination with your other thread and Teams thread I believe there is more power to be had with a different header and midpipe. In fact there was a point I tried to buy teams exhaust system but it had been sold.

Currently I have installed a 3” resonated midpipe to quiet down the exhaust tune (so I can maintain some professional stature at my place of employment). Let me know if you decide to make something.

I think this eventually boils down to a few things; what are you using the car for, do you really need the little power that you can get from the bolt on for the rotary, can you get better times by spending money on learning how to drive vs. those bolt ons.

 

Would it be a good idea to heat wrap the headers when using them with a pettit sc?

 

Where would you get a heat shield?