Spf Exhaust
 

Is it the headers or mufflers that are the H.P. killer? If one could only replace one of the two, which would be more worth while?

The side pipes. Talk with Eric at Performance Engineering for his perspectives and true dyno results between the two.

Ex SPF 760 and 1568.

Depending on your engine combination.... if you are running a 400'ish small block I would doubt it but I am basing this on what I have read and in talking with a couple SPF dealers not personal experience. The expense of hacking up your side pipes, welding in new collectors and mufflers then having the new sidepipe/mufflers recoated is quite expensive with little reward. Cost per horsepower appears to be very high. Having said this if you are looking for a certain sound well that is a different story.

There are one or two fabricators that specialize in SPF header/sidepipes that may be worth looking into. There is a spirited thread or two on these fabricators. My understanding is that a quality product can be purchased for a price.

Now if you are running a BB or a stroked BB there may be significate HP to be gained from a header/sidepipe swap.

Depending on your engine there may be other options to produce the elusive HP/TQ number we all search for. Details are needed

Others with real world experience will pipe in soon.

Regards,

Ed

who sells the free flowing exhaust???its a 427so slightly stroked and bored.

Sparks,

Did you get another SPF?

Where are you around Rockford?

I changed my mufflers and headers out on my stroked sb (427"). I have not redynoed since the change.

I know of a few other guys who have also done different combos.

I see you use to own 1459, I remember when you had that for sale. I was in the market at that time, just not quite ready to buy though.

Lets here some details...............

I live just east of rockford. should have my new(used) one by xmas(i hope)

Have you found a car yet?

Are you looking for a BB again?

You must be excited.

found one> its a 427so. VERY EXCITED! dONT CARE HOW COLD IT IS ,AS LONG AS THE STREETS ARE DRY!!

Here is what the inside of your SPF factory mufflers look like:

http://www.clubcobra.com/photopost/d...PF_Muffler.jpg

SB cars have very restrictive headers...they do not match up well to the exhaust ports on most cylinder heads. Some day I will find $1,000 lying around and spend it on a custom set. I recently saw a used set go through here for $500 (for the AFR heads). If I had AFR heads I would have jumped on them.

For BB cars, the factory 2" ID is a joke (urrgh...I mean, choke).

-Dean

Meaning From The Exhaust Or The Header?

Craig- Dean is talking exhaust / sidepipe. That is a pic of a cut sidepipe he is holding and it shows the 2" inner core.
You can remove the baffles in the SPF pipes.......but they get pretty LOUD.
You can also get some SS pipes in either 2 1/4 or 2 1/2 inner cores. The bigger the cores the larger the HP.
The SPF headers are 1 3/4". You can get larger headers, but keep in mind that too large a header tube can cost you TQ. I probably wouldn't go over 2" headers if I were buying new.

Agree. It's not so much the header pipe size as it's the header-to-cylinder head-flange that needs to be cleaned up. If I had the skills I would do just that and have them re-coated.

As in all things, there is no one answer for all

As Ed pointed out, the performance benefit of bigger mufflers is somewhat dependent on displacement. All SPF side pipes are the same, so increasing the muffler diameter has more benefit for 500ci’s than it does for 400ci’s. That said, it is not only the muffler size that hurts. The SPF side pies also have some built in restrictions, particularly in the collectors. While the big blocks see more advantage than the small blocks, even the small blocks will get an increase in power from improved side pipes.

As for the headers, this is more dependent on what heads you have on your small block. SPF supplies the same headers for all Windsor style engines, while all Windsor exhaust ports are not the same. The SPF headers fit the stock 351W head well, but if you have the FRPP “Z” high flow head or equivalent, there is a miss match between the head and header that will cost you some flow,

Ron Roberts, Firefly Performance Products, www.fireflyperformance.com has been working on this for the last six years and has developed both stainless steel side pipes and headers to address the issues. I worked with Ron on his first set of side pipes for my SPF with 514 and I got significant increase in both horsepower and torque. Here on the Firefly web site you can see my dyno sheet http://www.fireflyperformance.com/Pipes/index.htm

Of course performance is not everything…. These Firefly pipes are knock out gorgeous and sound fantastic too. Take a few minutes to peruse http://www.fireflyperformance.com/

Craig

it would be nice if they had a before and after sound /video clip on there site. have any of you guys recorded your before and after?

I have not recorded the sound Sparks and it's been my experience that you really can't get a good indication of the sound from a recording. You really need to hear it in person.

My pipes are the Firefly Competition model, the least restrictive and the loudest. They are louder than stock, but I really do not find them ojectional and after about 15000 miles I have never had a complaint from the law or otherwise that they are too loud. Of course, opinions will vary, but this has been my experience.

Craig

The FF website said only a few db's louder. Maybe its more in the tone?

Tone is definately different pipe to pipe. I've listened to a lot of diferent pipes and the stainless steel pipes always seem to have a "sharper" note than mild steel.

Craig

3-1/2" core, or 3"?

E :D

Hi Eric

Mine are 3"ID

Craig

they r pretty $$$$$$$$$$$maybe in a couple yrs...