Nine Ball

iTrader: (38)

Merge collectors are not worth anything on a closed exhaust system. They would only possibly help on an open header setup, basically incorporating the Venturi effect and increasing exhaust velocity before complete exhaust release from the header. This basically is accomplishing the same thing as using smaller tubes behind the header, effectively increasing backpressure.

Once you bolt it up to a Y-pipe or muffler system, that Venturi will only act as a restriction in an otherwise smooth pipe.

Tony

Terry Burger

iTrader: (4)

My concern with merge collectors is I've heard you have to "dial" them in. I want something I can just bolt up and know it's giving me more power. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> When I go to a larger motor I'll have to use these dynatech headers with 3.5" merge collectors. They seem to be making a difference on large motors. Jason didn't you lose like 5hp with the exact same headers on your 346ci though?

XtraCajunSS

iTrader: (2)

I will see if Geoff will let me bolt the straight 3.5" collectors on today and dyno them before the 9" goes in...

I'm really a scientist at heart <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

My hypothesis is that the straight collectors, X-pipe, dual bullet muffler setup will be the ticket for power...

Shane

<small>[ July 12, 2002, 12:14 PM: Message edited by: XtraCajunSS ]</small>

Nine Ball

iTrader: (38)

Exhaust is very important, and most systems have some power left in them. "Tuning" the exhaust is always a good idea.

Most people fall into the "bigger is better" category. They don't understand compressible gas flow, especially at higher velocity (exhaust is supersonic, intake is subsonic speed). The statement should read "Bigger is better IF you need it".

For example, when I was 346ci, I tried dual 2.5" cutouts instead of a single 3" cutout, and lost over 30 ft-lbs peak torque. YUCK! My peak HP only went up about 2 rwhp. YUCK!

Another example, when Judson was running the 375ci solid roller setup (~500 rwhp) his car made more power and torque with 2.5" extensions on his open headers. The 3.0" extensions actually performed worse on the track and the dynojet. I found the same thing with my 382ci and open headers. Bigger isn't always better!

Tony

XtraCajunSS

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Terry Burger:
<strong>My concern with merge collectors is I've heard you have to "dial" them in. I want something I can just bolt up and know it's giving me more power. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> When I go to a larger motor I'll have to use these dynatech headers with 3.5" merge collectors. They seem to be making a difference on large motors. Jason didn't you lose like 5hp with the exact same headers on your 346ci though?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes he did.

TrahnZam WS6

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XtraCajunSS:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Terry Burger:
<strong>My concern with merge collectors is I've heard you have to "dial" them in. I want something I can just bolt up and know it's giving me more power. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> When I go to a larger motor I'll have to use these dynatech headers with 3.5" merge collectors. They seem to be making a difference on large motors. Jason didn't you lose like 5hp with the exact same headers on your 346ci though?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes he did.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">He lost power going to 3.5" collectors on stock heads and bottom end? Who would have guessed? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Jason99T/A

iTrader: (21)

(edited post - went back and looked at dynograph)_

Yes, the headers didn't do anything from 2000-2500, gained 10hp/tq from 3000-4000 and lost 5-6hp/tq from 4000-7000 by going to the exact same setup Shane has on his car now.

Nick, you never know if something will work unless you try it. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" /> <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

<small>[ July 12, 2002, 12:52 PM: Message edited by: Jason99T/A ]</small>

JimmyKash

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
<strong>
Most people fall into the "bigger is better" category

Tony</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well....bigger is always better in a turbo car <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Exhaust is so much simpler <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

TanRchy

TTT any updates? track times yet? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

XtraCajunSS

iTrader: (2)

I have the new rear installed and am awaiting a driveshaft. I have driven it with the factory aluminum shaft and from the outcome of a couple of preliminary street races, decent track times seem to be in the future. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

By Friday, the new driveshaft and exhaust should be installed. It looks like the first track visit will be the following Friday...

The biggest holdup in getting to the track is my job. I've been on the road for the last 2 weeks so I haven't been able to finish all the details on the car. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

I'll post results good or bad... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Shane

<small>[ July 22, 2002, 10:10 PM: Message edited by: XtraCajunSS ]</small>

VINCE

iTrader: (1)

We have the same color car.. Do not be surprised if your car feels down on power one day.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

XtraCajunSS

iTrader: (2)

Ok, so when are you getting the flames done??? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

BTW Vince, I forgot to mention in my previous post... 4.57 gears are a good thing... <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />

Shane

<small>[ July 22, 2002, 10:26 PM: Message edited by: XtraCajunSS ]</small>

bparker

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
[QBI can't wait to swap my FLPs for Dynatech stepped headers now!Tony[/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Do you know if they are going to make a set of stepped headers for C5s?? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

XtraCajunSS

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by bparker:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
[QBI can't wait to swap my FLPs for Dynatech stepped headers now!Tony</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Do you know if they are going to make a set of stepped headers for C5s?? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> [/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You know, as far as I am concerned, I'm not sure if the stepped header idea is valid. I think the car just needed more header and that the 1 7/8" is the way to go. I hope to do a back to back comparison of the stepped versus straight design... I'm not sure if I can make it happen but I am curious.

I know Dynatech only offers BBC headers for late model Corvettes currently...

Shane

STEALTH 415 C5

Nice #s,let's see some track times.Bparker,Cartek is selling 1-7/8 headers for the C5's.I have a set on my car right now,should have dyno numbers tomorrow.These are not stepped.

TanRchy

Well???

XtraCajunSS

iTrader: (2)

The car is nearly complete. I travel every week so progress on finishing it is moving slower than I would like. It sucks having to work... I did get the driveshaft installed this weekend though. I promise, the first trip down the track (good or bad) I will post.

Shane

Coach 02 A3 Z/28

iTrader: (10)

Hurry up, would ya? <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />

Coach

VINCE

iTrader: (1)

I need flames too.. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Thats going to take awhile. I need to get pics of the car. Those are some steep gears as well.. Damn you are planning to spin that sucker.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> I cant wait for you to finalize that project...

Black Sunshine/ 00SS

iTrader: (1)

Any results yet?? Perhaps I missed it, but is there a thread that details the specs on this motor?

This is an awesome motor. Hats off to Thunder Racing!! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />