91_fc

Yeah. I finally got enough money form graduation and all to finally buy some new parts and continue fixing up the car. The parts should come in by the weekend.
Does anybody who put it in notice a big difference? I know i'll lose the low end torque but how much gain in the top end? RB claims 18 hp, but i just want to know from personal experience. I'm also planning to wrap the header in exhaust wrap and seal it with hi-temp spray (thermotec.com).

asherwood

I installed a MindTrain header and presilencer in combination with their 'Y-pipe' and found that there was a noticable increase in the available torque

flamin-roids

From what I understand its not really worth getting the header unless you are running a ported motor or carbs. But the RB header wieghs alot less than the stock header and if it doesn't make you lose power then go for it. I just kept my exhaust stock and I'm installing a race pipe to replace the cats. By the way I've heard straight pipes and gutted cats cause back pressure loss and 5th and 6th port issues. But I've only heard of it happening on S4 motors.

poor college student

that's b/c the s4 5th and 6th ports are activated by backpressure from the exhaust.

getting a header and presilencer is good b/c you are freeing up the exhaust, getting rid of pre-cats and the cats. there will be a noticeable gain in power from that.

asherwood

As mentioned above the S4 5th and 6th ports are activated by exhaust pressure, whereas the S5 uses an air pump to supply the pressure.

Also as mentioned even a non modified engine benefits from the exhaust improvements, basic "hot-rodding 101"

I have a definite increase in both torque and HP, no dyno runs to prove it, I just know that it feels stronger.

jon88se

91 FC, Do you already have a catback section?? If not the car will have a REALLY terrible exhaust note with the factory mufflers. A full motor-back exhaust consisting of an RB header, pre-silencer, cat replacement pipe and any decent catback will net you a big gain in power as for most NA owners, this is where power is generated. 20-25 hp at the wheels can happen here but don't look for big gains doing any other mods.

asherwood

I guess that is was good thing I replaced the factory 'y-pipe'

What I can tell you is that my system with the factory mufflers sounds very mellow, could even stand to be louder

jon88se

The mindtrain silencer is probably different...in my experience, RB headers and stock catback = LOUD and obnoxious tone.

oakback

I noticed a power increase, in the low and high range. Yes, the tone sucked. I eventually added 2.5" pipe from the presilencer to a single 2.5" in/out, 7" SS magnaflow muffler, and I still have enough pressure to open the aux. ports (S4, and the sleeves have been removed and cleaned).

91_fc

yes. i have the HKS cat-back system that i got from Mazdatrix.

Falcoms

Yeah, I have a GReddy power extreme cat-back and I am looking into the RB header, but with cat setup (I'm too cheap for the presilencer) so I am anxious to hear what you think about the header improvments!

RotaryBuddha

iTrader: (4)

rb header wont bolt up to the factory main convertor. its too short. you need to get the presilencer or the extend cat


presonally i like the presilencer