Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

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11-14-2002, 12:09 AM

#41

RAMBIRD2002

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

Thank you I proved my point by your last post. You are a real hero sitting behind your computer. Get on with your pathetic post's. And 1 more thing because you didn't take my advise before--GROW UP LITTLE BOY!!

11-14-2002, 12:22 AM

#42

Pro Stock John

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

Let's all simmer down.

Step'd headers are probably worth a little over 5000 rpms on a 346ci application, but there will be loss in lower end torque per Dynatatch, again most likely below 5000 rpms.

What do the S/E guys run?

11-14-2002, 12:31 AM

#43

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

I can't complain about the dyna stepped headers. are they worth anything over 1 3/4...I dunno but my power is still there <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

444RWHP/404 TQ from a 346 cid car

122 mph with 26 degrees of timing at 3600 lbs too <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

11-14-2002, 12:34 AM

#44

RAGEman

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by RAMBIRD2002:
Thank you I proved my point by your last post.<hr /></blockquote>No, you didn't.

<blockquote>quote:<hr />You are a real hero sitting behind your computer.<hr /></blockquote>Aren't you sitting behind your computer too?

<blockquote>quote:<hr />Get on with your pathetic post's.<hr /></blockquote>Okay, and you get on with your ignorance and lies.

<blockquote>quote:<hr />And 1 more thing because you didn't take my advise before--GROW UP LITTLE BOY!!<hr /></blockquote>Ummm....no.

11-14-2002, 12:59 AM

#45

RAMBIRD2002

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

BLAH,BLAH,BLAH, Rage your a waste of time and energy, shame on me for lowering myself to your level. Hopefully as you grow up you will get wiser with age.(for your own benefit). See ya little man.

11-14-2002, 01:23 AM

#46

Linear Velocity

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by John B:
One thing that never ceases to amaze me about this site (and every other one out there for that fact) is that an intelligent topic like this one gets started and we are 40+ posts into it with next to nothing for facts and data and a whole bunch of opinions expressed that cause people to tweak.

I don't have a problem with people expressing "opinions" on this topic but the reality is that JS is the only one that provided us with a partial data point on this subject for comparison purposes. And even JS's data wasn't an apples to apples comparison since it wasn't done on the same day/same dyno and we don't know if any PCM tweaking was done to optimize the set-up so I really don't consider the data point very valid unless we have more info here. And finally, no one has a back to back track MPH comparison for us which would tell the real story.

If anyone out there has a B1 cam in their stage II heads/cam 346 with 1-3/4" LT's, please post a dyno sheet showing it running through full exhaust so that we can compare it to mine because I would be willing to bet that you're not making more torque down low over my stepped headers and this should prove that stepped headers don't cost you bottom end power when they are mated to merge collectors <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <hr /></blockquote>Um..why don't you check my post again there, cowboy. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> No opinions, only facts. Funny how you moderators only look at the more well known guys' posts <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

11-14-2002, 02:51 AM

#47

383ss

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

I'll settle this WITH a dyno vs dyno comparision soon!!!

of course it's with a 382 stroker.

11-14-2002, 09:39 AM

#48

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by John B:
One thing that never ceases to amaze me about this site (and every other one out there for that fact) is that an intelligent topic like this one gets started and we are 40+ posts into it with next to nothing for facts and data and a whole bunch of opinions expressed that cause people to tweak.

I don't have a problem with people expressing "opinions" on this topic but the reality is that JS is the only one that provided us with a partial data point on this subject for comparison purposes. And even JS's data wasn't an apples to apples comparison since it wasn't done on the same day/same dyno and we don't know if any PCM tweaking was done to optimize the set-up so I really don't consider the data point very valid unless we have more info here. And finally, no one has a back to back track MPH comparison for us which would tell the real story.

If anyone out there has a B1 cam in their stage II heads/cam 346 with 1-3/4" LT's, please post a dyno sheet showing it running through full exhaust so that we can compare it to mine because I would be willing to bet that you're not making more torque down low over my stepped headers and this should prove that stepped headers don't cost you bottom end power when they are mated to merge collectors <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <hr /></blockquote>Well, if we can get Jason99T/A in here, perhaps he can give us some particulars on his dyno, or maybe we can get Fenris Ulf to tell us a bit more about Nick's dyno. Or perhaps Nick himself can come give us some details. FWIW, I decided to save a little money, and I just went with SLP longtubes, but it would still be nice to know the real story on the Dynatechs.

11-14-2002, 10:28 AM

#49

1CAMWNDR

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

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" />

11-14-2002, 10:53 AM

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Fenris Ulf

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by 1CAMWNDR:
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" /> <hr /></blockquote>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" />

11-14-2002, 11:25 AM

#51

Futral

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

This a good topic!

For comparison info,I will be dynoing Gordon's headers in place of my standard Grott design on my car next week,since I will be building a set of 2" headers for new motor <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

For a stepped header design to work,the stepped lengths have to correct in the total length.

Thanks Fenris <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

11-14-2002, 11:40 AM

#52

RAGEman

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by 1CAMWNDR:
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" /> <hr /></blockquote>Personally, I wasn't saying that at all. Your theory made fairly good sense to me, actually.

11-14-2002, 11:54 AM

#53

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by RAGEman:
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" /> <hr /></blockquote>Any reason you chose the SLPs over the others?

11-14-2002, 01:43 PM

#54

John B

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr /> Um..why don't you check my post again there, cowboy. No opinions, only facts. Funny how you moderators only look at the more well known guys' posts<hr /></blockquote>My sincerest apologies Silver Surfer...your are correct, I saw your post and failed to acknowledge it but not because of "more well known guys'", I was just getting annoyed at this post and only focused on one data point!

Your comments below are a very good data point:
<blockquote>quote:<hr /> they tested them on a 2000 Corvette and they picked up 12 rwhp N/A over the 1 3/4; but they really only recommended them aggressive h/c packages with a 224/224 and over cam. I dynoed 420 rwhp and 400 rwtq with no custom tuning thru my heads and 227/227 cam. I'd say the torque was there; I never got to get the setup tuning before the motor went but I think I could have seen another 10 rwtq from tunin <hr /></blockquote> <blockquote>quote:<hr /> 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. <hr /></blockquote>This is also a very valid point. My stepped headers are precision engineered and constructed with each tube only having a maximum variation of + or - 1/8" and are true equal length long tubes with the overall tube length also being held to + or - 1/8". I also use merge collectors. But....I am still open for anyone else's 1-3/4" longtubes with a B1 cam/S2 heads (346 cubes!) to compare against mine for low end torque !

<blockquote>quote:<hr /> A good source told me he lost power across the board with that switch. Subject car had a TR 230/224 cam, too. Is this normal or just a freak thing or what? <hr /></blockquote>My .02 here says BULL, let's see the data.....the more radical the cam, then better exhaust is required and stepped is better than constant size when sized correctly, period. Find me a Pro Motor than runs better with constant size headers over stepped!

11-14-2002, 03:10 PM

#55

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

"394 TQ at 4400? What was the HP at that RPM? What was the peak HP?"

Still curious. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BTW, I'm 28 years old if that makes a difference to you. Probably still too young and immature for your tastes. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

[ November 14, 2002, 03:11 PM: Message edited by: Colonel ]

11-14-2002, 04:48 PM

#56

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by JS:

Terry 125
GTSS 125
Raugh 124
Coach 122

ALL of the these guys have 1 3/4in L/T's and I think there MPH speaks for itself and this is FACT!!!!

JS<hr /></blockquote>Uh, just to clairify things a bit...
My best mph with my 346 ci motor using the custom FMS 1 3/4 to 1 7/8 stepped headers was 128.42 mph, and that mph was done in a DA of +1174'.
But you have to understand that my motor was setup to the extreme for a 346 ci, and I was spinning it up to 7600 rpm. It dynoed 461 rwhp/ 388 rwtq, hp peaked at 7100 rpm, thru a Strange 12 Bolt w/4.88 gears and a heavy *** 22lb. chromoly DS.
So, yeah I belive the stepped headers worked very well for my motor, but for a regular H/C 346 motor that won't be seeing any rpm's over 7000 rpm stepped headers wouldn't be necessary.

In hindsight, I guess the only thing I would of done differently (or should of done) <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" /> on my 346 ci solid roller motor was to upgrade to better connecting rods and or higher grade rod bolts, because I definetly found out how much those Lunati Pro Mod Rods and rod bolts could take. <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" /> lol
I'm quite positive that if I had the chance to run the car in some really good air with some sub DA's, 130 mph would of been possible.

Oh well, it's on to the 418 ci solid roller motor now, and a nice new shiney set of Custom FMS 2" headers! <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />

Gordon

[ November 14, 2002, 04:52 PM: Message edited by: GTS SS ]

11-14-2002, 08:56 PM

#57

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />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" /> <hr /></blockquote>Hmmm. Point taken. But I still say that on a 346" motor below 7,000rpm a stepped or full 1 7/8" header is of little good. Maybe 10 hp on top. And that might matter to some folks. I just think the straight 1 3/4" headers are the best for street/lower engine speed motors. Of course, you could talk for months about the coresponding heads and cam and what the headers wil do........... <img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" />
And I am only 29 so why am I even trying to make sense <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> ?

[ November 14, 2002, 09:28 PM: Message edited by: 1CAMWNDR ]

11-14-2002, 10:02 PM

#58

RAGEman

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by Colonel:
"394 TQ at 4400? What was the HP at that RPM? What was the peak HP?"

Still curious. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BTW, I'm 28 years old if that makes a difference to you. Probably still too young and immature for your tastes. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" /> <hr /></blockquote>Yeah, if you don't have a receding hair-line, dentures, and at least a few symptoms of senility, he won't answer you because you aren't worth his precious time. Imagine that. Someone thinking that about the Colonel. It's almost sacreligious. The nerve of some people.

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

11-14-2002, 10:25 PM

#59

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

<blockquote>quote:<hr />Originally posted by SStolen:
I have never seen a place that sells QTP/Grotts headers. I've only seem a handful of guys with them as well, normally higher hp guys though. I was going to go with the Jet Hot Coated Hookers for $600. How much are the grotts and any advantages with them? If the colonel has them then they must be better <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> Thanks.<hr /></blockquote>QTP and Thunder Racing are both buying the original Grotyohann headers (1 3/4" & 1 7/8") from the same manufacturer that has been selling them to Roger Grotyohann for years. Mine were sent out yesterday from Thunder to Norris Motorsports for my motor.

11-14-2002, 11:13 PM

#60

Jason99T/A

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Re: Stepped Dynatech's make less power across the band than Grot. 1-3/4"?

I made the swap from the Grotyohann 1 3/4" longtubes to the Dynatech 1 3/4" - 1 7/8". The Grots had 3" collectors with 3" diameter, 7" long extension past the headers. The Dynatechs had the 3.5" merge collectors with 3.5"-3.0" diameter reducer extensions 7" long past the headers.

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). Needless to say, I put the Grots back on that day. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

I will have the graph scanned and posted tomorrow night.

On even your most aggressive 346ci heads/cam setup, I feel the 1 3/4" Grots are the best header on the market for making best power below 7k rpms. On a high-revving 346ci motor, I can see a properly designed stepped setup making more power though. 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.

On a side note: We installed the exact same Dynatech headers that came off my car on XtraCajunSS's (Shane) 409ci solid roller setup. He dynoed 507rwhp through the TTS longtubes and 523rwhp through the Dynatechs. Here is the graph: http://hometown.aol.com/jason99ta20/images/shane409.jpg

We will be swapping a set of 1 7/8" headers once Shane gets a working tranny back in the car to see if that is worth anything. <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

Jason

[ November 15, 2002, 09:43 PM: Message edited by: Jason99T/A ]

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