JS

iTrader: (4)

Thanks Jason,At least someone else saw what we saw too.
The Dyna stepped were NOT very good on a 346..

I lost power all the way up to 5900 and thats when the stepped took over.

Alot of guys will say my converter dictates the larger header since I'm shifting at 6600 and dropping back to 5600 but I dont agree.

My initial hit off the line (2600 FT brake) was down 17RWHP all the way up to 5700 and then it started to catch up but not until 5900.Sorry guys I'll take that kinda lauch power over 5RWHP from 6000 to 6600 every day.It killed the same amount of TQ too.

IMO I would run a Hooker or the "NEW TR L/T".
There both excellent headers for a 346....

JS

<small>[ November 15, 2002, 09:26 AM: Message edited by: JS ]</small>

RAGEman

iTrader: (4)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Fenris Ulf:
<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 1CAMWNDR:
<strong>So are you guys saying that my theory does not make sense? If so that is fine; just let me know what the deal is.
Thanks.
<img border="0" alt="[Firebird]" title="" src="graemlins/formula.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Your theory is wrong because you are assuming that both the stepped header and the straight 1 7/8 header have the same affect on exhaust gas velocity. The theory behind the stepped header, in simplistic terms, is to keep velocity up (as well as the massflow rate and help pull in a fresh intake charge, but thats a whole different deal) higher as it exits the combustion chamber, then a calculated distance down the primary tube it increases the diameter slightly (called stepping up, hence stepped headers) in order to keep up with the flowrate as the gasses lose kinetic energy rapidly. The dynatech stepped design is not the best; the 1 3/4 primary length varied anywhere from 2-3" of the others on the set I measured, so I really doubt any real tuning went in to the design.

Futral's car is using your standard 1 3/4 grots, and after a ride in that car last weekend I would have to say its running quite well <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That makes good sense too. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

RAGEman

iTrader: (4)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by quickWS6:
<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 RAGEman:
<strong>Thanks, Joel. I'm not really worked up, I'm just on a campaign to stamp out ignorance across the globe! That said, I decided on 1-3/4" SLP's with true dual. Results soon! After the 4.56's/28" ET Drags come in, I should be good to go! Oh, and a clutch. And a cage. And some susp...nevermind.

<img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Any reason you chose the SLPs over the others?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Of course. There's always a reason! Actually, I found a used set cheap. I researched and found that they made great power and torque, but complaints included difficulty of installation and ground clearance issues. Well, I figured I'd just set aside a little extra time for the install, and my car isn't lowered, so I don't figure to have too much of a problem with ground clearance.

Jason99T/A

iTrader: (21)

Here is the graph I mentioned earlier:

http://hometown.aol.com/jason99ta20/...pped_grots.jpg

Jason

John B

iTrader: (10)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Initially, we ran Dynatechs w/ 3.5" dia, 7" long extensions. This killed power down low compared to the Grots and still could not match what the Grots made up top. We then installed the 3.5"-3.0" reducer extensions and actually made more power than the Grots from 3000-3500rpms (around 8-10hp/tq), but the Grots recovered and surpassed the stepped headers from 3500-7000rpms (7-8rwhp difference)</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Jason, I looked at your graph comparing these two headers and unfortunately I find the results inconclusive. Dyno run 81 was made 11 days earlier than run 90 and it was almost 8PM at night versus the Dynatech run which was at ~3PM in the afternoon heat. I have personally seen 8-10 RWHP & RWTQ differences based on different run dyno times on the same dyno due to weather/humidity conditions.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Needless to say, I put the Grots back on that day. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This should be the correct dyno comparsion...same day with near same weather conditons...do you have a dyno comparison here when you slapped the Grotts back on?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">On a high-revving 346ci motor, I can see a properly designed stepped setup making more power though. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I agree wholeheartedly with your statement here because I honestly believe that my engineered stepped headers if put side by side a set of Grotts' mine would blow them away on both bottom end and topend power...too bad we couldn't make this comparsion!
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">A great test will be when Allan comes back to dyno the stepped headers he built for GTS SS's solid roller motor. Allan's 346ci car makes peak power around 7500, so it will be a great test over his 1 3/4" Grots </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Again, I agree, let's hope we get to see the results soon!
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Thanks Jason,At least someone else saw what we saw too </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">JS, not true! You saw power gained up top, Jason saw no power gain on top. You said power was less down low, Jason said power was more down low with the merge collectors! Just trying to keep the record straight <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

RAMBIRD2002

Let me take this time to add to the subject. I origionally got on the immediate defensive side when I read the post that stepped dynatech's made less power than the grott, or whatever it was. My mistake not informing you guys that it was not just the header. So now your all saying I told you so.......... However it was just exhaust, its all in the set up and configuration. I'll give you guy's an idea of what it consists of but I'm not giving sizes of collectors,merge's,ory,y-collector or pipe diameters. You all didn't believe me from the start, so why should I give you particulars now.
Any way after the STEPPED header there is a set of stainless steel merge collectors that actually cost almost twice as much as the header alone. Then we go to the off road y(not your average y-pipe). After that it flows into a trick y-collector. Out of the y-collector it turns into the stock ws6 exhaust.
The 394 torque # was uncorrected, I wanted to fire you up and it obviously worked.(rageman) But it did make that #. On the other hand SAE CORRECTED here are the #'s 363/378. Yes SAE corrected with the exhaust mentioned above and a lid. I am a fabricator by trade and also do some work with Miller Race Cars(4th gen specialist's) We have done some serious homework as far as R&D. So is it believeable that a stock 346 with a stepped header made 50 more?? WHO CARES because I have it and you don't, so believe what you want. As far as Rageman in your sig it say's fastest internally stock ls1. Well seeing how I have only a couple of mods and we have a real close sae dyno comparison, Mabey we will meet up at the north vs south shootout in the spring if it happens. You already got beat by 3 tenth's in the first 60ft (according to your 1.70 short time) One last thing Rageman, what happens when you drop the clutch at 6000 rpm on the street?????? Mine hooks like a SOB with little tire spin, with your 1.70 60ft I doubt yours does.

JS

iTrader: (4)

John my graph looks very similair to Jasons,The dyna didnt catch my MACS until 5900.Jason graph shows the exact same thing.

He did make alittle bit more power than I did down low but nothing great,then it fell on its face from 3500 on...

Believe what u want,Steps are worthless unless u shift at 7500...

JS

1CAMWNDR

iTrader: (21)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by RAMBIRD2002:
<strong>Let me take this time to add to the subject. I origionally got on the immediate defensive side when I read the post that stepped dynatech's made less power than the grott, or whatever it was. My mistake not informing you guys that it was not just the header. So now your all saying I told you so.......... However it was just exhaust, its all in the set up and configuration. I'll give you guy's an idea of what it consists of but I'm not giving sizes of collectors,merge's,ory,y-collector or pipe diameters. You all didn't believe me from the start, so why should I give you particulars now.
Any way after the STEPPED header there is a set of stainless steel merge collectors that actually cost almost twice as much as the header alone. Then we go to the off road y(not your average y-pipe). After that it flows into a trick y-collector. Out of the y-collector it turns into the stock ws6 exhaust.
The 394 torque # was uncorrected, I wanted to fire you up and it obviously worked.(rageman) But it did make that #. On the other hand SAE CORRECTED here are the #'s 363/378. Yes SAE corrected with the exhaust mentioned above and a lid. I am a fabricator by trade and also do some work with Miller Race Cars(4th gen specialist's) We have done some serious homework as far as R&D. So is it believeable that a stock 346 with a stepped header made 50 more?? WHO CARES because I have it and you don't, so believe what you want. As far as Rageman in your sig it say's fastest internally stock ls1. Well seeing how I have only a couple of mods and we have a real close sae dyno comparison, Mabey we will meet up at the north vs south shootout in the spring if it happens. You already got beat by 3 tenth's in the first 60ft (according to your 1.70 short time) One last thing Rageman, what happens when you drop the clutch at 6000 rpm on the street?????? Mine hooks like a SOB with little tire spin, with your 1.70 60ft I doubt yours does.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">So with those exhaust mods, but a stock WS6 cat-back you picked up 50RWTQ on a stock 346. Wow, what kind of tune do you have in the pcm??
Seems like the stock IM pipe and muffler could be a cork. Have you tried an aftermarket cat-back??

RAMBIRD2002

No tune, however just recieved my Predator so can't wait to get back on the dyno. Haven't tried any aftermarket cat backs yet, soon I will try the hooker cat back.

slvrbird2000

Well then great #s RamBird. Thanks for answering my question. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Scott

Colonel

"So with those exhaust mods, but a stock WS6 cat-back you picked up 50RWTQ on a stock 346. Wow, what kind of tune do you have in the pcm??"

Remember, we're comparing UNCORRECTED numbers. His was of trying to make it seem like he picked up ALOT more than he really did. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" /> I think most of us here knew that it was either <img border="0" alt="[bullshit]" title="" src="graemlins/gr_bs.gif" /> or trickery.

Hell, might as well compare uncorrected numbers from 100 degree weather and then again in 20 degree weather. Do a simple mod like porting the throttlebody or gutting the cats and then claim a 50 HP increase for IT! <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

slvrbird2000

I hope you all recognized the sarcasm in my last post. LOL

Scott

Colonel

LOL! I missed that! DOY! Ahh, it's been a LOOOoooooooong day!

RAMBIRD2002

Hey Colonel, your avoiding the point of the post. The thuth still stands the Dynatech stepped header works on a 346 END OF STORY. And we weren't just going off an uncorrected # the SAE #'s speak for themselves for what it is. So now tell me it is bull or trickery.

1CAMWNDR

iTrader: (21)

At what rpm were your gains made?

CrankinYankee

I'm assuming that you are asking for peak numbers? Torque peaked at 4500 and power peaked at 5400.

CrankinYankee

I'm assuming that you are asking for peak numbers? Torque peaked at 4500 and power peaked at 5400.

RAMBIRD2002

Good memory! your right on the money pal. thanks for answering for me.

hondakiller

iTrader: (3)

there's also been posts about the 1 7/8 grott's being too big for stock cube cars and theres been people who've swapped them on and not lost power anywhere even on a bolton only car. theres got to be more to this issue than just primary size if there are people seeing big gains and others see big losses below say 5000rpm and small gains above. grotts are widely regarded as the best ls1 header but dynatech's arent exactly el cheapo's either. maybe thats why flp keeps a 2.5 inch y-pipe? is there anyone around with a 3 inch y-pipe and flp's? i ask because dynatech's and flp's are the same header besides dynatech's lacking emissions equipment and the flp's arent stepped obviously.

1CAMWNDR

iTrader: (21)

Those peak numbers, were those where the 50 lb-ft gain was made, or was it somewhere else in the curve??