speedo calculator??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Longhorn Man · 01-28-2005, 09:56 PM

Can some one direct me to a site....or calculate this for me.
31 inch tall tires (as sitting with the weight on them)
4.10/4.11 gears. (can never rememver which it is....C/30 HO72 rear)
Auto tranny w/o lock up nor overdrive.
What'll my 65 MPH RPM's be at?
Can anyone tell me where to get non chevy Th350 gears? I was rather shocked to see they were not the same as chevy.
That sucker is readin 60 - 70 when I am only goin 40 - 50, and it is racking up some miles just putting around the lot at work.

69 Short Fleet · 01-28-2005, 10:02 PM

You might call a local shop with a dyno, I know my race bike mechanic in Calgary has one and dyno results were used as evidence in court as the rider (GSXR bike) disputed the police's radar gun. Just a thought, Doug

Z28Owner · 01-28-2005, 10:12 PM

Right at 2900 rpms http://www.700r4.com/sitemap.shtml

Longhorn Man · 01-28-2005, 10:20 PM

Sweet...that's right about what I was expecting.
I guess that isn't too bad.
Thanks for the link too!

COBRO · 01-28-2005, 11:11 PM

Longhorn Man the 2900rpm figure is correct but thats figured with total lockup with a clutch or a locking converter,I just went through this same game when I switched a th400 for the stick in my 72. I was turning appox.300 more rpm at the same speed than before because of the slippage in the non lockup converter I used. You can check out the thread "more rpms" on page two. HTH:::::::::::COBRO

LUV2XCLR8 · 01-28-2005, 11:22 PM

Quote:

Originally Posted by Z28Owner

Right at 2900 rpms http://www.700r4.com/sitemap.shtml

IS A TH350 A 1:1 RATIO TRANNY

Longhorn Man · 01-28-2005, 11:25 PM

Yeah, TH350 is 1 to 1.
I was kinda figuring that might be with no slippage. You're getting 300 RPM slippage at highway speed? That seems exsesive. I've never seen more than 200 or so. I have a TH400 converter in my Th350, so it'll either slip a bit more, or a bit less...I am pretty sure it is the latter.

jhow66 · 01-28-2005, 11:27 PM

Quote:

Originally Posted by LUV2XCLR8

IS A TH350 A 1:1 RATIO TRANNY

In high gear--yes.

LUV2XCLR8 · 01-28-2005, 11:31 PM

"GQ"S MOTOR IS A BUILT 1970 LT1 CAMARO BLOCK W/ FORGED
EVERYTHING, 3 DEGREE VALVE JOB, HEADS HOGGED OUT, ETC...
ACCORDING TO THE PO, CHART, TIRES & MY GEARS I COULD GO
OVER 200 MPH EASY WITHOUT EVEN PUSHING MY MOTOR.

OF COURSE, DRAG ON A BLAZER BODY CHANGES ALL OF THAT

Longhorn Man · 01-28-2005, 11:39 PM

Whats your gears & tire size, what tranny, and what's the redline?

LUV2XCLR8 · 01-28-2005, 11:50 PM

Quote:

Originally Posted by Longhorn Man

Whats your gears & tire size, what tranny, and what's the redline?

GEARS - STOCK 3:08'S OR 3:07'S

TIRE SIZE - 35 X 12.5 X 15 BFG'S (8" RIM)

TRANSMISSION - TH350 W/ NP205

REDLINE - BETWEEN 6500 AND 7000

Longhorn Man · 01-29-2005, 07:07 AM

at about 6000 RPM, your blazer would be doing a theoretical 200 MPH.

This is my old beater with 3.07's and 28 inch tall tires and a non lock up TH350.

LUV2XCLR8 · 01-29-2005, 07:16 AM

Quote:

Originally Posted by Longhorn Man

at about 6000 RPM, your blazer would be doing a theoretical 200 MPH.

EXCEPT FOR THAT BIG @SS BODY CAUSING WIND DRAG

bgood · 01-29-2005, 11:05 AM

http://www.tciauto.com/tech_info/calculators.htm
just for a second opinion i guess

LUV2XCLR8 · 01-29-2005, 11:08 AM

Quote:

Originally Posted by bgood

http://www.tciauto.com/tech_info/calculators.htm

NEAT SITE

Longhorn Man · 01-29-2005, 06:01 PM

Quote:

Originally Posted by Longhorn Man

at about 6000 RPM, your blazer would be doing a theoretical 200 MPH.

Remember though, in theory...comunism works.

69 longhorn · 01-29-2005, 07:55 PM

Andy, does your BOP turbo have the 1 1/2" speedo gears , like found in the 400 turbos? here is a slick site, for figuring speedo gears... http://www.novaresource.org/speedo.htm 69 L

Longhorn Man · 01-29-2005, 08:18 PM

Al, 1 1/2 inch gears does sound about right...I didn't know the 400 was like that...good news I guess huh.
Thanks man.

69 longhorn · 01-29-2005, 08:25 PM

Im not real familiar with the small bop turbo, but have been into the 400, in both chevy & bop style. they both take the same speedo gear setup. if you do have the 1 1/2" gears, the Nova site will get you dialed in on the gears, as well as working for the 3/4 " dia speedo gears.....that covers it from any Gm stick (early), to the Richmond I am running.... 350 turbo (chevy), & I think powerglide

69 L

01-28-2005, 09:56 PM	#1
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	speedo calculator??? Can some one direct me to a site....or calculate this for me. 31 inch tall tires (as sitting with the weight on them) 4.10/4.11 gears. (can never rememver which it is....C/30 HO72 rear) Auto tranny w/o lock up nor overdrive. What'll my 65 MPH RPM's be at? Can anyone tell me where to get non chevy Th350 gears? I was rather shocked to see they were not the same as chevy. That sucker is readin 60 - 70 when I am only goin 40 - 50, and it is racking up some miles just putting around the lot at work.

01-28-2005, 10:12 PM	#3
Z28Owner ......................... Join Date: Nov 2001 Location: benton, ky Posts: 288	Right at 2900 rpms http://www.700r4.com/sitemap.shtml __________________ 1971 LWB Chevy C-10 350/350 3:42 eaton

01-28-2005, 11:31 PM	#9
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,475	"GQ"S MOTOR IS A BUILT 1970 LT1 CAMARO BLOCK W/ FORGED EVERYTHING, 3 DEGREE VALVE JOB, HEADS HOGGED OUT, ETC... ACCORDING TO THE PO, CHART, TIRES & MY GEARS I COULD GO OVER 200 MPH EASY WITHOUT EVEN PUSHING MY MOTOR. OF COURSE, DRAG ON A BLAZER BODY CHANGES ALL OF THAT __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Big Piggy: "Goliath" 07 Kodiak C4500 Lil Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

01-29-2005, 11:05 AM	#14
bgood Registered User Join Date: May 2004 Posts: 80	I like to use these calculators http://www.tciauto.com/tech_info/calculators.htm just for a second opinion i guess __________________ 1967 C10 Short,Step 283\1460 Holley HEI Ign. Borg Warner T56 6 Speed! A-1 Electric life pwr windows PS,PB,Tilt 275\60R'S on Alum Mags all around Vintage Air A\C Grey cloth Buckets

01-28-2005, 10:02 PM	#2
69 Short Fleet Registered User Join Date: Nov 2002 Location: Kelowna B.C. Canada Posts: 1,086	You might call a local shop with a dyno, I know my race bike mechanic in Calgary has one and dyno results were used as evidence in court as the rider (GSXR bike) disputed the police's radar gun. Just a thought, Doug

01-28-2005, 10:20 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Sweet...that's right about what I was expecting. I guess that isn't too bad. Thanks for the link too!

01-28-2005, 11:11 PM	#5
COBRO Active Member Join Date: Jan 2005 Location: RDM,Oregon Posts: 285	Longhorn Man the 2900rpm figure is correct but thats figured with total lockup with a clutch or a locking converter,I just went through this same game when I switched a th400 for the stick in my 72. I was turning appox.300 more rpm at the same speed than before because of the slippage in the non lockup converter I used. You can check out the thread "more rpms" on page two. HTH:::::::::::COBRO

01-28-2005, 11:25 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Yeah, TH350 is 1 to 1. I was kinda figuring that might be with no slippage. You're getting 300 RPM slippage at highway speed? That seems exsesive. I've never seen more than 200 or so. I have a TH400 converter in my Th350, so it'll either slip a bit more, or a bit less...I am pretty sure it is the latter.

01-28-2005, 11:39 PM	#10
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Whats your gears & tire size, what tranny, and what's the redline?

01-29-2005, 07:07 AM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	at about 6000 RPM, your blazer would be doing a theoretical 200 MPH. This is my old beater with 3.07's and 28 inch tall tires and a non lock up TH350.

01-29-2005, 07:55 PM	#17
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	Andy, does your BOP turbo have the 1 1/2" speedo gears , like found in the 400 turbos? here is a slick site, for figuring speedo gears... http://www.novaresource.org/speedo.htm 69 L

01-29-2005, 08:18 PM	#18
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Al, 1 1/2 inch gears does sound about right...I didn't know the 400 was like that...good news I guess huh. Thanks man.

01-29-2005, 08:25 PM	#19
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	Im not real familiar with the small bop turbo, but have been into the 400, in both chevy & bop style. they both take the same speedo gear setup. if you do have the 1 1/2" gears, the Nova site will get you dialed in on the gears, as well as working for the 3/4 " dia speedo gears.....that covers it from any Gm stick (early), to the Richmond I am running.... 350 turbo (chevy), & I think powerglide 69 L



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