Author Topic: Horsepower loss  (Read 7749 times)

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Stangman

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Re: Horsepower loss
« Reply #15 on: May 14, 2019, 07:27:36 AM »
Thanks guys, it was just a thought. I always wanted to put a stick in my car but  didn’t want to be breaking stuff. I just know that I wouldn’t granny shift and would break stuff. I have a TCI C-6 and converter, not Rollerized and was just wondering if a Jericho or Richmond tranny would be faster. Like was said I only go to the track 3or4 times a year and only put like 1000 miles a year on car. I’m home for a month after surgery and I don’t have much to do but think of stuff like benchracing.
« Last Edit: May 14, 2019, 07:30:38 AM by Stangman »

cjshaker

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Re: Horsepower loss
« Reply #16 on: May 14, 2019, 07:39:34 AM »
It would be an interesting comparison to see the exact same car/set-up being compared with a 5 spd auto vs. a 5 spd manual, but even that has several limiting factors, like trans used, how it's prepped etc etc.

And just to throw some nitro on the embers....I've always found this picture to be helpful  ;D ;D

Doug Smith


'69 R-code Mach 1, 427 MR, 2x4, Jerico, 4.30 Locker
'70 F-350 390
'55 Ford Customline 2dr
'37 Ford Coupe

Stangman

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Re: Horsepower loss
« Reply #17 on: May 14, 2019, 08:14:46 AM »
You just always think about what is the perfect combination. When I was a kid my car was a legitimate stock r code 427 lowriser with a edelbrock F 427 intake with a 735 Holley C-6 with a shift kit and stock converter , a 9 inch with 3.08 gears. With slicks and open headers if I remember correctly ( this was in like 1982 ) ran between 12.20 and 12.50.
Stroked it with a 428 crank original low riser 2x4 intake and twin 600s and install 4.11s and 3000 stall and went 11.69.
Now 485 3.70s and still same tranny and converter intake but with twin QF 750s drag radials and survival heads 11.11.
Now right before mt surgery I installed a BT 2x4 intake but obviously didn’t run it matter of fact didn’t even drive it yet.
Doug’s car is what brought up this thread I think with a stock 427 mediumriser motor running 11.50s and with 60 ft times that are off by 2 tenths he’s gonna have a great combination. It made me think of the whole horsepower loss through an automatic.
Great job Doug.
« Last Edit: May 14, 2019, 08:16:36 AM by Stangman »

cjshaker

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Re: Horsepower loss
« Reply #18 on: May 14, 2019, 08:37:33 AM »
It's interesting to bench race and make comparisons. Like you said, Joe, combo is everything. I've thought about why the steep 1st gear in my Jerico made such a huge difference. I think a lot of it has to do with the fact that I'm running a stock 3.78 stroke bigger bore engine. A 427 relies more on RPM than a 428 would, with its longer stroke. If I was winding my engine higher than what I do (6500 max), I could use more gear, but as it is, I'm crossing the line at about 6200, which is pretty much spot on for my build. A big stroker would probably get away with a numerically much lower first. But I'm no expert, so that's all guessing on my part.

No doubt Jay has a valid point on the extra gear and keeping the engine in its power band. That's why the new 'muscle cars', and their 10 speed autos are running some great numbers straight out of the factory.
Doug Smith


'69 R-code Mach 1, 427 MR, 2x4, Jerico, 4.30 Locker
'70 F-350 390
'55 Ford Customline 2dr
'37 Ford Coupe

chilly460

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Re: Horsepower loss
« Reply #19 on: May 14, 2019, 09:24:40 AM »
I seem to remember Rory chiming in on previous posts where he'd switched from C6 to Toploader (maybe Jericho?) with no other changes and noted a fairly significant improvement.  Hopefully he sees this.

plovett

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Re: Horsepower loss
« Reply #20 on: May 14, 2019, 10:06:19 AM »
What I was trying to say is "traction being the same" is not enough information.  Is the traction bad and the same, or fantastic and the same?  It means everything, IMO.

wowens

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Re: Horsepower loss
« Reply #21 on: May 14, 2019, 10:16:29 AM »
It would be an interesting comparison to see the exact same car/set-up being compared with a 5 spd auto vs. a 5 spd manual, but even that has several limiting factors, like trans used, how it's prepped etc etc.

And just to throw some nitro on the embers....I've always found this picture to be helpful  ;D ;D



My sentiments perfectly stated
Woody

plovett

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Re: Horsepower loss
« Reply #22 on: May 14, 2019, 10:21:03 AM »
I seem to remember Rory chiming in on previous posts where he'd switched from C6 to Toploader (maybe Jericho?) with no other changes and noted a fairly significant improvement.  Hopefully he sees this.

Rory races at the track with a good suspension, slicks, and a well prepared surface. Makes a big difference.  At extreme power/weight levels the autos come back to the top again.  Hence the two speed powerglides.  It is funny how it goes back and forth.

plovett

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Re: Horsepower loss
« Reply #23 on: May 14, 2019, 10:27:37 AM »
I do agree that the C6 is a power hog, but cheap and durable.

Falcon67

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Re: Horsepower loss
« Reply #24 on: May 14, 2019, 10:56:34 AM »
What I was trying to say is "traction being the same" is not enough information.  Is the traction bad and the same, or fantastic and the same?  It means everything, IMO.

You can only tune your manual with RPM.  When you let fly, you shock the hell out of the driveline.  I can tune my auto with lower rotating mass and with the converter which can do a ton of torque multiplication.  I can also pre-load my driveline to reduce chance of breakage.  Both require suspension work to optimize, that's for sure.  HP loss through the device is only part of what makes fast.  Plus I can pretty much be assured that my air shifter/RPM controller backed with 90 PSI of air can change gears way faster than you can with your arm+foot.

Other than that, manual takes more skill and can easily be seen as "more fun"   ;D

BattlestarGalactic

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Re: Horsepower loss
« Reply #25 on: May 14, 2019, 11:19:47 AM »
What I was trying to say is "traction being the same" is not enough information.  Is the traction bad and the same, or fantastic and the same?  It means everything, IMO.

You can only tune your manual with RPM.  When you let fly, you shock the hell out of the driveline.  I can tune my auto with lower rotating mass and with the converter which can do a ton of torque multiplication.  I can also pre-load my driveline to reduce chance of breakage.  Both require suspension work to optimize, that's for sure.  HP loss through the device is only part of what makes fast.  Plus I can pretty much be assured that my air shifter/RPM controller backed with 90 PSI of air can change gears way faster than you can with your arm+foot.

Other than that, manual takes more skill and can easily be seen as "more fun"   ;D

And there you have it in plain english.  The automatic isn't faster by any means(the HP losses are cut and dry), just easier for ones that don't/can't make a stick car work.  You can mush it around all you want, but that's the truth of it. Street or strip.   If I loosen my clutch up, I can get it to hook on water.  But then it's a real maintenance deal.  I like going rounds and not working on it, so I don't have it set on kill.  So Automatics are EASIER.  That's it.

The whole "shift faster"?   Not sure if you can compare apples to apples.  Yes, that shift noid will bang it hard.  Ever shift a Liberty equalizer?  It's instantaneously in the next gear.  No Lag.   Yes, you have to move your arm, blah, blah, blah.  But the time between gears is zero.  Beyond the clutch slippage as it changes.  Yes, it basically drives through the clutch as the next gear hits.  If not, parts would fall out of the bottom.  No different then converter slippage as it increases the load on the next gear.  I use the clutch on my GF5R.  Ya, slower engagement then clutchless.  But who cares?  I just want to run the same number, not worry about being .01 faster.   Last weekend, my two TT were 10.925 and 10.929.  Not too hateful for a 4000# stick car with 10.5" tire and TWO vacuum Holleys.  At Beaver, two rounds of elims I was dead on 2 and dead on zero flat out. 

The "glide"?  Everyone likes them for bracket racing because they leave soft(not much first gear) and only one shift so there is very, very little chance of missing it.  Plus it helps in consistency.  With only one change of gear, it removes all the added effects of multiple gear changes and the change of ET from them.  I know some dragster guys that basically shift their glide at about 60ft.  Just enough to get the car moving, then shift.   It's all about consistency.  ET isn't the purpose.  They just put bigger motors in.  It's too easy today.
Larry

cjshaker

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Re: Horsepower loss
« Reply #26 on: May 14, 2019, 12:02:06 PM »
And then there are air-shifted Libertys and Lencos. Or Lencos that use torque convertors. No shortage of ways to spend money on race cars, that's for sure!
Doug Smith


'69 R-code Mach 1, 427 MR, 2x4, Jerico, 4.30 Locker
'70 F-350 390
'55 Ford Customline 2dr
'37 Ford Coupe

Tommy-T

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Re: Horsepower loss
« Reply #27 on: May 14, 2019, 01:37:36 PM »
I bow down to the guys that like man-u-al transmissions. I'm not one, but the look of Hurst linkage sticking up through the floor is undeniably cool. I'll never forget Dale telling me that I'll put a 4 speed in my hot rod when I "grow up".
I've built 2 4 speed Fairlanes in my life. After driving them in LA traffic I couldn't wait to be rid of them. Plus...it's hard to hold your Starbucks in one hand and shift.
Yes, it's just easier to run a C6. As far as I'm concerned the only drawback is they're huge, especially the FE variation with the big round bell.
A few FE pals of mine switched to a C4. If you don't mind putting a new one in every 2 years, it's the way to go. It's tiny and not that hard to tear up.
As far as 4 speeds go, this is my observance. A stock top loader will not hold up to an 11 second or faster street car. Once you change to a dedicated drag 4 speed with a soft lok clutch your car becomes a REAL drag to run on the street.
A stock C6 with some easy upgrades and a commercial 10" converter (not a fancy custom job) will hold up in an 11 second street car for years. In my experience, when you freshen your motor, send your C6 to your trans guy for freshening. Rarely is anything broken. Still true is that your C6 is probably costing you a half-a-second over your C4 and stick buddies.

TomP calls us automatic guys "pink shirters". I've certainly got enough t-shirts with ATF stains for sure!

plovett

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Re: Horsepower loss
« Reply #28 on: May 14, 2019, 02:55:18 PM »
Are all of you just intentionally trying to ignore the difference between track and street?  It is a big difference.

JMO,

paulie

BattlestarGalactic

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Re: Horsepower loss
« Reply #29 on: May 14, 2019, 03:04:35 PM »
I could drive my wagon to work every day and never hurt the clutch.  It's light, real light.  I have two return springs on the z bar to make sure it pulls back.  Like I tell everyone, it's not an issue.  Only if you try to "show off" like you did with a 3200 rag disc.  You can't go around trying to chirp the tires.  The light clutch will not do it.  Just burn itself to pieces.

Paulie, I don't see any real difference between street and strip and auto and stick.   If you have a potent motor, any transmission can blaze the tires at will on the open road.  Oh, you can powerbrake and "leave softer" with an automatic.  Oh, I can leave at 2000 rpm with a stick too.  With a soft clutch there is MINIMAL difference.  Again, it's all in the set up.  MOST guys do not want to deal with it on the street.  Thus they use an automatic.  Plain and simple.  One isn't better, it's just EASIER for the masses.
Larry