Bradan 456 resonator delete pipes

Philip- Only if accompanied by a lot more changes. That is a lot of hp. Hotrodding the Superamerica engine (shaved block for higher compression, bigger inlet passages, wider angle valve job, cams advanced, and optimized Motronic ECUs) only got 25 hp. Same for the 612 engine.

 

Dan- None of the 550s have precats in the headers.

 

550 headers fit the 575 or is there all kinds of electronic nonsense (O2 sensors...) that needs to be figured out?

 

After I replaced the center muffler with a Stebro X pipe my SOTP also gave me the sensation there was more oommmph available, besides the added sound.
But then a dyno test confirmed 400 HP at the wheels and 409 ft-lbs torque.
Difficult to quantify the gain, as I did not have a dyno test with the stock exhaust, but if we believe the MFR data, the gain should be of about 60 HP (the only other change from stock is the K&N air intake filters)

 

How much does 400HP at the wheel equate to? 15% more at crankshaft?

 

Sorry for the stupid question, what is SOTP?

 

Seat of the pants?

 

YES - SOTP

 

I'd like to get a set. Just for information, are they regular or stainless steel?

 

Do you think one should heat wrap the pipes, don't they get too hot and radiate the heat into the car? (especially in city traffic)

 

Opinions differ, but 15% is what is generally used by most people.

 

Do you have anything to eliminate the tail mufflers?

 

Actually, the straight pipes will heat less than the resonator because all that hot exhaust is not backed up behind the cork effect the resonator creates.

Here are a couple of Dan's runs showing rwhp for 575Ms. The bottom one shows before and after for the resonator cork.
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My car came out of your trailer and went into my garage, hasn't moved since. To much salt on the roads, Im look forward to spring. Thanks again for all your help. Ron

 

That's interesting data, Terry / Dan. One pf the fabricators was claiming a gain of 75 bhp from better headers on the 575s. If that's right, you'd certainly feel that!

 

Philip- Like I said, not sure I believe that without other changes.

 

Later 575Ms have Factory center straight pipes without any issues.

 

They sound great - excellent job, Dan!

Thanks,
Erik

 

Post a video if you can - thanks!