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Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Wed Nov 08, 2017 11:50 am
by stealth
$50 says this goes 30 pages...........

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Wed Nov 08, 2017 11:52 am
by In-Tech
Perfect example Randy. That shows why RPM is king and none of this 28 pages of drivel. Thank You. :)

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Wed Nov 08, 2017 12:12 pm
by Stan Weiss
randy331 wrote:
Wed Nov 08, 2017 11:46 am
While this won't answer the OP question specifically, it may be an interesting observation.

I did a 383 ( Pseudo ) and a 355 that both made 525 peak HP. Pseudo made peak HP at 6000 rpm while the 355 made peak HP at 7200 rpm.

Both went in powerglide, Coan converter cars. Pseudo had 4.56 rear end gear and the 355 5.43. Both 30" tall tires.
Weight was 2950 for pseudo and 3000 for the 355.

TQ at peak HP rpm would be 460 LBs for pseudo and 383 LBs for the 355 at peak HP rpm.

Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60'
5.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile

In my experience the set in the car favored Pseudo, yet the 355 produced better ET and MPH.

With less TQ at all locations on the track, why is the 355 faster ?

Randy
Randy,
What was the stall for each?

Stan

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Wed Nov 08, 2017 12:45 pm
by Stan Weiss
randy331 wrote:
Wed Nov 08, 2017 11:46 am
While this won't answer the OP question specifically, it may be an interesting observation.

I did a 383 ( Pseudo ) and a 355 that both made 525 peak HP. Pseudo made peak HP at 6000 rpm while the 355 made peak HP at 7200 rpm.

Both went in powerglide, Coan converter cars. Pseudo had 4.56 rear end gear and the 355 5.43. Both 30" tall tires.
Weight was 2950 for pseudo and 3000 for the 355.

TQ at peak HP rpm would be 460 LBs for pseudo and 383 LBs for the 355 at peak HP rpm.

Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60'
5.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile

In my experience the set in the car favored Pseudo, yet the 355 produced better ET and MPH.

With less TQ at all locations on the track, why is the 355 faster ?

Randy
Randy,
If both convertor locked up / zero slippage the 355 @ 130 MPH is turning about 7900 and the 383 @ 127 MPH is turning about 6500 RPM. I would really want to see what each of those HP / Torque curves looked like after peak HP.

Stan

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Wed Nov 08, 2017 1:44 pm
by Frankshaft
randy331 wrote:
Wed Nov 08, 2017 11:46 am
While this won't answer the OP question specifically, it may be an interesting observation.

I did a 383 ( Pseudo ) and a 355 that both made 525 peak HP. Pseudo made peak HP at 6000 rpm while the 355 made peak HP at 7200 rpm.

Both went in powerglide, Coan converter cars. Pseudo had 4.56 rear end gear and the 355 5.43. Both 30" tall tires.
Weight was 2950 for pseudo and 3000 for the 355.

TQ at peak HP rpm would be 460 LBs for pseudo and 383 LBs for the 355 at peak HP rpm.

Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60'
5.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile

In my experience the set in the car favored Pseudo, yet the 355 produced better ET and MPH.

With less TQ at all locations on the track, why is the 355 faster ?

Randy
The answer is obvious, and has been mentioned at least 90 times in this thread. But I like how you ask questions with a question. It makes people THINK. Thanks for posting this.

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Wed Nov 08, 2017 3:59 pm
by digger
It's funny last time I accelerated an engine through the gears it was at the peak hp rpm for a very very short period of time. Hence you will never understand what's going on unless you know what happens before and after the peak rpm as it's the cumulative effect that matters not what happens at an instantaneous moment

Also it gave up a full second at the 1/8?

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Thu Nov 09, 2017 9:21 pm
by randy331
randy331 wrote:
Wed Nov 08, 2017 11:46 am
Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60'
5.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile
Thought I'd make a correction on this.

The 355 didn't run a 5.37 @ 106 in the 1/8 mile.

It ran a 6.37 @ 106

But I'd guess most anyone that has drag raced would have figured that out.

Probably be kinda hard to run a 5.37 @ 106 then also run a 10.11 @ 130 on the same pass. :D

Randy

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Thu Nov 09, 2017 11:25 pm
by GARY C
randy331 wrote:
Thu Nov 09, 2017 9:21 pm
randy331 wrote:
Wed Nov 08, 2017 11:46 am
Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60'
5.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile
Thought I'd make a correction on this.

The 355 didn't run a 5.37 @ 106 in the 1/8 mile.

It ran a 6.37 @ 106

But I'd guess most anyone that has drag raced would have figured that out.

Probably be kinda hard to run a 5.37 @ 106 then also run a 10.11 @ 130 on the same pass. :D

Randy
I thought a second quicker seemed really good :)
Any idea what the average tq was in the used rpm range of these 2 combos?

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 10:01 am
by randy331
GARY C wrote:
Thu Nov 09, 2017 11:25 pm
I thought a second quicker seemed really good :)
That would be good. :D

GARY C wrote:
Thu Nov 09, 2017 11:25 pm
Any idea what the average tq was in the used rpm range of these 2 combos?
I don't know where the sheet to the 355 is right now. It wasn't down loaded and put on computer with the others.

Randy

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 10:08 am
by randy331
Stan Weiss wrote:
Wed Nov 08, 2017 12:12 pm
Randy,
What was the stall for each?

Stan
5800 rpm for 355 and 5700 rpm for 383.

Coan said the 355 needed 6400-6500 for best et, but we never tried it. He had me build bigger engine instead.
They said 5500-5600 for best et with 383.
That's part of why I said the set-up in the cars favors the 383.
In my experience, a little too much stall speed is better than not enough, especially in a powerglide car.

Randy

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 11:11 am
by Cougar5.0
randy331 wrote:
Wed Nov 08, 2017 11:46 am

Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60' -
6.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile
60' -0.019
1/8 -.01
1/4 -.13

Odd that the 1/8th time shows there should have been minimal difference @ 1/4 mile.

So many variables. If you're saying the wider powerband is easier to get the gearing/converter etc. right, that's probably true.

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 11:59 am
by randy331
Cougar5.0 wrote:
Fri Nov 10, 2017 11:11 am
randy331 wrote:
Wed Nov 08, 2017 11:46 am

Pseudo ran a best
1.368 60'
6.38 @ 105.2 1/8 mile
10.24 @ 127 MPH

The 355 ran a best
1.349 60' -
6.37 @ 106 1/8 mile
10.11 @ 130 1/4 mile
60' -0.019
1/8 -.01
1/4 -.13

Odd that the 1/8th time shows there should have been minimal difference @ 1/4 mile.

So many variables. If you're saying the wider powerband is easier to get the gearing/converter etc. right, that's probably true.
Had the 355 had 6500 rpm stall speed (like Coan said it needed after looking at the dyno sheet ) with a custom cnc billet stator the 1/8 mile ET would be better.

Better power curves are of course a plus, but I have little doubt the 355 had more ET left on the table than the 383 did.

Randy

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 12:27 pm
by statsystems
randy331 wrote:
Fri Nov 10, 2017 10:08 am
Stan Weiss wrote:
Wed Nov 08, 2017 12:12 pm
Randy,
What was the stall for each?

Stan
5800 rpm for 355 and 5700 rpm for 383.

Coan said the 355 needed 6400-6500 for best et, but we never tried it. He had me build bigger engine instead.
They said 5500-5600 for best et with 383.
That's part of why I said the set-up in the cars favors the 383.
In my experience, a little too much stall speed is better than not enough, especially in a powerglide car.

Randy
AMEN on stall speed.

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 5:31 pm
by plovett
randy331 wrote:
Wed Nov 08, 2017 11:46 am

I did a 383 ( Pseudo )
Why is the 383 called "Pseudo"? Just curious.

paulie

Re: Which Is Faster - 600hp@6200 or 600hp@7100

Posted: Fri Nov 10, 2017 7:14 pm
by MadBill
Fifteen posts on this page! A couple more and we'll hit the magic thirty that stealth forecast! \:D/