Current setup:

FLP longtube headers (1-3/4" primaries)
FLP 2.5" Y-pipe
3" midpipe
SLP dual-dual 3" stainless catback
Dual 2.5" cutouts welded into FLP Y-pipe

Proposed setup:

Dynatech 1-7/8" stepped longtubes
Weld-on Dynatech header collectors
MTI custom 3" Y-pipe
3" bullet muffler welded on each side of Y
Flowmaster dual 3" inlet to 3.5" outlet collector
3.5" midpipe
3.5" Flowtech cutout
3.5" QTEC electric cutout
3.5" to 3" reducer
SLP dual-dual 3" catback.

I like my car VERY quiet, that is why I want the dual bullets inline. With the electric cutout, I'll be able to pick up 25+ rwhp with the flip of a switch (my current setup loses about 25 rwhp through the muffler vs cutouts).

I'll try to dyno before/after. Might be interesting to see what a 434ci motor likes better!

Tony

 

Sounds like a deal.. If you go that route cut me a deal on your current FLP's and Y-pipe with the cutouts already in. I have 2 new flow tech cutouts sitting in my garage.. Remember I am poor at this point.. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

why dont you just put on the big tube headers and make a 3" y-pipe and mate it to the dual dual then just run dual 3" cutouts near the header collectors....

cheapest and most effective imo

that way you have open headers basically at the track or flip of a switch....or keep the cutous closed and it should be fairly quiet <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

tony...i sent you an email on what we discussed.

 

I'd like to see a true dual exhaust with cats and muffs leading all the way back over the axles myself....but then again the true duals aren't the quietest of exhausts. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

 

That sould acheive your goal. i like quiet too. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I had bullets in MAC ORP.
My 1 7/8" grots are quieter & less raspy so now I use a single 16" Dynomax race bullet in the I-Pipe followed by the QTEP then into a SLP D/D. Only draw back is clearance for a DSL or spohn type torque arm is trickier with the bullet.

Are the collectors Merge style?

 

Tony, drop me an email before you put those headers on. I have a little info you might be interested in....

Josh

 

I think the 1 7/8th headers with custom mandrel 3 inch Ypipe with dual 3 inch cutouts in the Y itself.
That would be the highest flowing for sure.
Then you could go into your SLP dual dual no problem. I would flange the intermediate pipe so you can drop your exhaust quickly at the track if you are on a diet <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Chris

 

Tony, since you are certainly a "no holes barred" kind of guy that likes to be on the leading/bleeding edge of everything here's my recommendations:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif"> I think I'd skip the stepped headers on a 434" motor and just use the straight 1-7/8" headers. Surely if it costs you a few ft/lbs of low end torque over the stepped design but I think you are in a position to spare it while trading this off for topend power</font></li>
• <font size="2" face="Verdana, Helvetica, sans-serif"> As for collectors, I would either use the standard merge collectors or you could be the first guy on the block to try this type of a 4:2:1 merge set-up below on the LS1 from Burns (the "big boys" seem to be leaning toward this style of header now)
  <img src="http://www.burnsstainless.com/Xdesign/4-2-1_wcutaway.jpg" alt=" - " /></font></li>
• <font size="2" face="Verdana, Helvetica, sans-serif"> For exhaust pipe I would look into using 3-1/2" collectors mated to the headers and then use the ovalized equivalent to 3-1/2" round which is 4"x2-1/2" for the extra ground clearance</font></li>
• <font size="2" face="Verdana, Helvetica, sans-serif"> Ovalized 4x2.5" "X" pipe</font></li>
• <font size="2" face="Verdana, Helvetica, sans-serif"> Ovalized 4x2.5" inlet "quiet" mufflers</font></li>
• <font size="2" face="Verdana, Helvetica, sans-serif"> Real dual exhaust tailpipes with turndown ends to help disguise the actual diameter
  </font></li>

<font size="2" face="Verdana, Helvetica, sans-serif">I'd bet money this set-up would gain minimum 0.25 ET and 3MPH over your current set-up and this would be through closed exhaust IMHO!

 

i would tend to agree with johnb.could be costly tho. but in a max effor ride like ours, i would do it.

steve frank

 

sounds good!

<img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

I have heard the Tri-Y arrangement is crap. Tony, I have a set of Dynatech stepped longtubes with merge collectors that I am selling, ill cut you a ME discount <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

<img border="0" alt="[barf]" title="" src="graemlins/gr_barf.gif" /> Twin Turbo's <img border="0" alt="[barf]" title="" src="graemlins/gr_barf.gif" />
<img border="0" alt="[barf]" title="" src="graemlins/gr_barf.gif" />

Talk about sick !!! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Doug
00 Pontiac

 

Tony,

If the average engine producing 400 hp requires 1 3/4" headers for optimum hp output then at 525 hp by ratioing tube ID areas, assuming .062 wall, 1.625 x 525/400 = 2.133 ID required. 2.133 + .125 = 2.258. You are going to need 2 1/4" headers. Your head ports are probably not that large. Might want to consider 2" though.

 

2.25" <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Tube volume increases exponentially, not linear. Also your formula is very sensitive to the assumption of 400 HP rather than say 425 HP.

 

Hey, I think some of you guys confused me for a rich dude! LOL. Sure, I've spent a ton of money on this car, but I've owned it for 4 years now <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

Anyone know of a custom header builder that needs a big-motor LS1 test car? haha

The Dynatechs are a *cheap* alternative for me. Nick, I can get them new for less than you want, sorry dude! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Tony

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> I think some of you guys confused me for a rich dude </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Let's see.....no wife or kids at home....YOU'RE A RICH DUDE! <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

You asked......so now just do it (just not the 2.25" <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> )

 

Ya know those big a$$ mufflers that run up behind the cab on a diesel, well...... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
No! How 'bout some Lakes pipes? Don't forget the heat shields! (roll some stainless and polish it, complete w/holes in the design of your choice) You can always use the SFCs for a hangar!

 

all that plumbing is just dead weight.

i think the trend is obvious, 434ci, 11.5:1 compression.. you should just go ahead and be the first to turn the primaries straight up and out of the hood.

<img src="http://www.secureperformanceorder.com/cat_images/500900800.jpg" alt=" - " />

well they are still dynatechs hehe

i was gonna slide them through your hood but my 'borrowed' copy of photoshop apparently expired <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

 

LOL! That is some funny stuff!

I still think I'll see some gains with the new exhaust and some dyno tuning. Is 540 rwhp NA possible with a hydraulic cam? <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />