Exhaust and Engine help/ Suggestions NEEDED!!!!

[montessaj]

Hey guys, I have some questions about my exhaust I plan on running. I really want your suggestions and input. I planned on running the 3" Pypes exhaust system with 40 series flowmasters, I also have some 3" QTP electric exhast cut-outs that I planned on running right after the collectors on full length hooker headers. My questions are, Should I run the electric exhaust cut-outs or is that excessive? Also is 3" too large for my application or should I run smaller exhaust.
My motor is a 383 Stroker with 10.1:1 compression, and I plan on running a head combo from Trickflow with aluminum heads and a 246/254 cam the whole combo is rated at 500hp. Here is the part number from Summit Racing TFS-K314-500-450. I will be using a victor Jr. manifold and a 750cfm carb.
The car will mainly be used on the street but may seem some track time if I can find the time to get down there. Any and all input on the motor/exhaust would be much appreciated. I want to get all my suggestions before I go ahead and put all this money into the car.

Thanks for all your help and suggestions.

p.s For those of you who requested I check on parts for you, no worries I have not forgotten. I will be back out and about after this week. We had a bad batch of storms roll through my area and I will be back out getting those things for you as soon as it clears up some.

 

[shotgun]

Flowmaster and cut outs seem redunant.

You are also on the borderline between 2 1/2 and 3" pipe.

This is what "I" would do and have done for customers.

3" exchange with the QTPs on the ends

Before the muffler put a Flowmaster 3 to 2 1/2 reducer ( the only flowmaster product I use), install the dynomax muffler of your choice and run 2 1/2 mandrel bend tails.

With this system you can have your cake and eat it too.

If you were local I could hook you up,so to speak.

Oh, just so you know, I hate Slowmasters, they are loud but atleast they restrict flow 8).

 

[montessaj]

So your saying run the x pipe with the cut outs in it, then down into 2 1/2 inch mufflers and tails? I just put flowmaster out there cause thats what I'm running now. Also what headers should I use if not Hooker? I want ceramic coated.

 

[shotgun]

Hope the link works,bolt the cut out where the caps would go on thier exchange system.

Nice thing is you still get the benefit of the x no matter what, open or closed.

I like Doug's coated, but am a Pontiac guy so can't say about fitment on a SBC.


http://www.pysales.com/iwwida.pvx?;item ... 1?comp=ppe

 

[montessaj]

If the cutouts were not involved here would you run the 3" into 2.5" mufflers or just a straight 2.5"?

 

[Vern]

Cutouts generally end up as a problematic novelty. A well designed system / muffler has no need for them. They then are stricktly to impress/scare the locals. Chambered mufflers such as the flowmasters somewhat cancel the benefits of the X in that they are suppossed to work with exhaust pulses. In general they are loud, don't flow well for a performance muffler, and tend to drone at cruise. But they do have that patened flowmaster sound that many love. For 500HP I'd use 3" pipe thru the X thru a straight thru type design muffler such as the Walker Ultra flow or Magnaflow and then 2.5" tail pipes. Great sizeing up front for torque and in the rear to keep velocity as the gasses cool. It will still be loud at WOT but mello at cruise with no drone and if your cam lopes you will still hear it at idle. Shotgun would hook you up I have always seen his posts as spot on plus he actually goes fast. Oh yea on the muffler biggest case you can fit under the body for best sound control without inhibiting flow.

 

[montessaj]

To be honest the only reason I bought the exhaust cut-outs in the first place was to scare the little hondas and hyundais shitless when they revved on me, but I can do without them if they will cause problems later.

 

[megaladon6]

i'd call pypes with your engine combo information and ask them about size and which muffler they recommend. if you'll see regular track time the cut-outs aren't a bad idea (and should be mounted at the collector). but on the street the pypes mufflers (even the street pro's, especially the violators) should sound plenty mean.
is that cam spec the advertised duration or at .050in lift?

 

[shotgun]

"If the cutouts were not involved here would you run the 3" into 2.5" mufflers or just a straight 2.5"?"

Either way,go 3" down to 2 1/2 with 20" case Dynomax muffler,turbo if you want less noise,Ultraflows for a more aggressive sound.

I kinda have a direct line to Pypes,they are right down the street and I work on Chris's (owner) cars.

They can order the Dynomax mufflers as a subsitute on thier kits if you know to ask . Ask for Stacy and tell her Bob sent you!

I reduce to the muffler, there is not enough room after the muffler to use a nice gentle reducer before the axle.
Don't use one of those stepped ones that kill flow.

Got to disagree with the cut outs at the collector.
If you are really tuning your exhaust,open header guys run extension from 12 to as much as 24 ".

My motor liked 18" on the dyno.

I am making a custom set of headers and using a 4-2-1 collector so we will see if it like these better.

With the cut out after the X,you have a similar effect.

The system I suggest is not perfect for race and strip,that system does not exist but this will get you close.

 

[montessaj]

megladon, Yes that is the advertised duration at .50.

SHOTGUN I appreciate your help and after looking at dynomax's site I am definetly thinking or going with them. I appreciate all the advice and I do think that I will go with 3" to to 2.5" set-up. I think this is really going to be a killer set-up.

I am still open to anymore suggestions you guys have, so if you got 'em let me have 'em.