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Re: calculating peak rpm hp [Re: Cab_Burge] #2536863
08/15/18 07:27 PM
08/15/18 07:27 PM
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Mt Morris Michigan
mopar dave Offline OP
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I agree cab and if i would have never asked any of my silly questions i wouldnt have learned much. Been learning good stuff off this site for a long time now.

Re: calculating peak rpm hp [Re: B3422W5] #2536864
08/15/18 07:31 PM
08/15/18 07:31 PM
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pittsburghracer Offline
"Little"John
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Originally Posted By B3422W5
Originally Posted By mopar dave
For sure, but thought i might try short shifting at 6000 to start. Then 6500 and go from there.


Any such way like that will ultimately find out what i likes best.
Love ya man, but frankly you make things more involved and harder than anybody that has ever posted on here... lol




WOW 😮. That wasn’t a very cool thing to post. LOL.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: calculating peak rpm hp [Re: mopar dave] #2536868
08/15/18 07:36 PM
08/15/18 07:36 PM
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Posts: 2,457
Sydney,Australia
tex013 Offline
top fuel
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nothing wrong with checking others opinion/experience , if only to confirm you are heading in the right direction .

Tex


New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm
Power by Tex's Automotive
Re: calculating peak rpm hp [Re: B3422W5] #2536961
08/15/18 11:55 PM
08/15/18 11:55 PM
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
B
BradH Offline
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Val-haul-ass... eventually
Originally Posted By B3422W5
... frankly you make things more involved and harder than anybody that has ever posted on here... lol

I thought that was MY claim to fame? whistling

Re: calculating peak rpm hp [Re: BradH] #2536982
08/16/18 12:44 AM
08/16/18 12:44 AM
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Mt Morris Michigan
mopar dave Offline OP
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Could be, seems you two only answer my threads when you have something non contributing to say. Its real easy, you dont like my questions, then dont answer them. Plain and simple. Plenty of other guys here very helpful. I have have learned plenty from the others on here.

Re: calculating peak rpm hp [Re: BradH] #2536983
08/16/18 12:44 AM
08/16/18 12:44 AM
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Canton, Ohio
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Sport440 Offline
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Originally Posted By BradH
Originally Posted By B3422W5
... frankly you make things more involved and harder than anybody that has ever posted on here... lol

I thought that was MY claim to fame? whistling



I will second that. work up

Re: calculating peak rpm hp [Re: mopar dave] #2537050
08/16/18 08:55 AM
08/16/18 08:55 AM
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Charlotte, North Carolina
sgcuda Offline
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Ask any questions you like. That's how we all learn. There are never stupid questions, only stupid people. Lol! Some people on here make comments about the repetition of questions. Sometimes we forget that people come and go off of this site all of the time. What people need answers to aren't in the first couple of pages listed and we all know too well how wonderful the SEARCH function works on here.
My old combo with a 262/266 lift on my 440 liked a 6,800 rpm shift point. Car would slow down with a 6,500 or 7,000 shift. You'll find the sweet spot real quick.

Last edited by sgcuda; 08/16/18 08:55 AM.
Re: calculating peak rpm hp [Re: mopar dave] #2537060
08/16/18 09:57 AM
08/16/18 09:57 AM
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madscientist Offline
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FWIW once you establish your shift speed, you may want to try changing RPM for just one gear. For example, you may be able to run the 2-3 shift out a bit more than the 1-2 shift. Or it could be the opposite. It's not always that the engine wants to be shifted at the same RPM at every shift change.


Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
Re: calculating peak rpm hp [Re: sgcuda] #2537066
08/16/18 10:14 AM
08/16/18 10:14 AM
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Mt Morris Michigan
mopar dave Offline OP
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Well i could have just asked who on here has a engine combo simmular to mine that knows their max hp rpm, but i thought maybe their might be a calculator for this i didnt know about. I know the track will tell exactly what its gonna want, but just driving it sounds and feels like its about the 6600-6800 area. Will see. Thanks

Re: calculating peak rpm hp [Re: madscientist] #2537069
08/16/18 10:20 AM
08/16/18 10:20 AM
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Mt Morris Michigan
mopar dave Offline OP
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I may just give that a try. Watching the vid the tach is not moving much on the 1 2 shift, but the tires were spinning pretty good and spin even more now that i have the fuel mix better sorted out. Looks like 600rpm drop on the 2 3 shift which is same character of the vert when it was behind my 408sb.

Re: calculating peak rpm hp [Re: tex013] #2537093
08/16/18 11:36 AM
08/16/18 11:36 AM
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north of coder
moparx Offline
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Originally Posted By tex013
nothing wrong with checking others opinion/experience , if only to confirm you are heading in the right direction .

Tex



i do this often to be sure my old mind hasn't forgotten what i used to know. biggrin what's this thread about ?
beer

Re: calculating peak rpm hp [Re: mopar dave] #2537104
08/16/18 12:02 PM
08/16/18 12:02 PM
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New York
polyspheric Offline
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you may want to try changing RPM for just one gear. For example, you may be able to run the 2-3 shift out a bit more than the 1-2 shift. Or it could be the opposite. It's not always that the engine wants to be shifted at the same RPM at every shift change.

This^^^
All modern transmission have "ratio progression" in which the RPM % drop on shift is widest on the 1-2, and closes up as you reach final drive.


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Re: calculating peak rpm hp [Re: madscientist] #2537220
08/16/18 03:36 PM
08/16/18 03:36 PM
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Val-haul-ass... eventually
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Originally Posted By madscientist
FWIW once you establish your shift speed, you may want to try changing RPM for just one gear. For example, you may be able to run the 2-3 shift out a bit more than the 1-2 shift. Or it could be the opposite. It's not always that the engine wants to be shifted at the same RPM at every shift change.

A couple of Stock Eliminator people I know shift their 1-2 200-300 RPM lower than their 2-3. Never tried it on my junk, simply cuz I position the tach "straight up" at the RPM where I shift for easy reference.

Also, I don't use a shift light any more; I was always late on the shift when waiting for the light at the specified RPM. I'm more consistent w/ the approach above.

Regardless, I was never aware of any major shift lag time that caused my actual shifts' RPMs to be so much higher like some of you said. I'd like some type of data logger or playback tach to see what's happening across the whole pass, though.

Re: calculating peak rpm hp [Re: BradH] #2537228
08/16/18 03:41 PM
08/16/18 03:41 PM
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pittsburghracer Offline
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A powerglide kinda simplifies this option


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: calculating peak rpm hp [Re: BradH] #2537231
08/16/18 03:45 PM
08/16/18 03:45 PM
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Mt Morris Michigan
mopar dave Offline OP
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Yeah i agree. Ill have to get back in the habit of watching the tach. The shift light gave me the opportunity to watch another gauge or two(oil and fuel pressure) going down the track. I barely remember, but it seems like i tried this way back with my small block not seeing much if any difference.

Re: calculating peak rpm hp [Re: pittsburghracer] #2537234
08/16/18 03:48 PM
08/16/18 03:48 PM
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Mt Morris Michigan
mopar dave Offline OP
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Guess i could launch in 2nd gear.

Re: calculating peak rpm hp [Re: mopar dave] #2537290
08/16/18 05:43 PM
08/16/18 05:43 PM
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New York
polyspheric Offline
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You may also see different converter slippage on different shifts: the 1-2 has more torque, but the 3-4 is against higher load.
Once you find what works for you, the reason sort of matters less...


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Re: calculating peak rpm hp [Re: polyspheric] #2537294
08/16/18 05:58 PM
08/16/18 05:58 PM
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Mt Morris Michigan
mopar dave Offline OP
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Ok thanks. Didnt know that. Looking at the vid again on the big screen i see the 2 3 shift rpm drops 400rpm. Looks like it stays right in the power band all the way thru. I guess this would be a good thing?

Re: calculating peak rpm hp [Re: mopar dave] #2537334
08/16/18 07:17 PM
08/16/18 07:17 PM
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Minnesota
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At the pure stock drags, where you weren't allowd to add a tach, they use to say "when the fender starts to lay down, SHIFT"


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Re: calculating peak rpm hp [Re: Hemi_Joel] #2537339
08/16/18 07:26 PM
08/16/18 07:26 PM
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Mt Morris Michigan
mopar dave Offline OP
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There is a feel to it for sure. I grew up with 4 speed cars. I have a good feel when to shift. Nosing over might be a bit to late, but im definitely no professional .

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