1/4 mile time for a stock 1972 GS350?

Not necessarily.This is what I was getting at before.
It's a fairly stock engine. It should be running 2.90 to 3.08 gears.
It's already got plenty of snap off the line to pull taller gears, but your power range only extends to about 4000 rpm. Taller gears will get you more speed @ a given RPM.
Learn the best way to launch it and you'll pull sub 16 second 1/4's.

Bob

 

Hes going 455 so the 350 numbers don't matter much

 

Any updates with this?
Did the 455/400 swap ever happen?
I realize COVID put a pretty bad damper on everyone's fun, but was Canadian GS 350 ever able to make it back to the track?
....and did he ever meet up with 71 Staged?
Inquiring minds want to know!

Bob

 

Bob, yes the 455 turbo 400 swap is completed. Mission drag strip has been closed for street legal s due to the pandemic. Same issue trying to meet up with Nando. Vaccine roll out is extremely slow, vaccine deliveries have been delayed to Canada........so it will be a while yet. I have a TSP 9.5 inch converter, drag radials.......hoping for mid 14’s with this stockish low compression 455 .......be assured I will post once I do run at Mission.

 

Thank you for the update!
I heard on CBC news the other day that Canada went back into complete lock-down.
Very sorry you guys have to go through this. Vaccines are available now, so its just a matter of time.
Since you have a 455 now, I suppose the continuation of this story will appear in another thread in a different section of this site.
Please post a link to that new thread here, once you have more to post about on this, so that we can continue to follow your exploits.
Stay safe. =)

 

The 88 MPH looks about right but, the E.T. is way high. In 1985 I bought my Son is first car, an original 42,000 mile '72 GS350 with A/C and lots of other extras. It also had the 3.42 option with posi. Shortly after buying it I put new plugs in, gapped the points, and increased the initial timing several degrees. I didn't touch the carb or the centrifugal advance at all. I did install a 14 inch chrome air cleaner with a 4" K&N element. Otherwise it was bone stock. With 245/60 x 15 Uniroyal tires it went consistent 15.40s to 15.50s at 87 to 88 MPH.

 

Bob, the rest of the story and pics is under the street strip 400/430/455 forum, last post July 25th....”blew up the 350....here comes the econo 455 build”. Lots of pics, was a fun transplant.

 

RKammer,
The 350 was a 92,000 mile original as fas as I know. Just didn’t have the jam to push that heavy car any faster. I eventually spun a rod bearing pushing the old gal ....so in went the turbo 400/455....

 

Bob, in Canada, we have varying restrictions province by province......in B.C., we are susposed to socialize with people living in your home only..our numbers are dropping. Can’t wait for vaccinations and get back to normal. We’ve lost almost 1100 folks in B.C. to covid 19, mostly older folks, terrible lonely way to pass. Will be nice to get back to car shows, family dinners....open the drag strip.

 

Thanks Larry

 

went to try and get the shot for my wife today . 10 to 4 . we got there at 10 . mile long line ,so they will run out long before the line .im in norcal .pretty rural . maybe 10 traffic lights in the county . look up the latest china8 day quarentene town . normal may never be again !!

 

Ok, so maybe I misunderstood the announcement.
It was the noon news, maybe a week ago now.
I swear they led off with an announcement that the whole country was going back into lock-down.
Glad to hear its not quite that drastic.
...and thanks to you and Larry for the heads up to the new thread.
Will follow that one from now on.

 

"Pure stock" and all of the modifications permitted therein is completely different thing than production line stock. As they left the showroom floor, 1970 G350s (the best performing of the breed) were high 15 second cars at best, assuming optimal gearing.

 

But how many modifications that you didn't mention were performed to get it to run a 13.56 @ 99 MPH? Answer: A lot.

 

But engine torque alone is no more significant than engine RPM in determining accelerative performance. At any given vehicle speed, drive axle torque is directly proportional to delivered engine horsepower, as determined by throttle position and selected gear. Dividing THAT torque by loaded tire radius gives us the tractive force that accelerated the car.

Here's how it all works, per me (a now retired mechanical design engineer):

HORSEPOWER and TORQUE

1 HP = 33,000 FT-LB/MIN; 1 circular rotation = 360 degrees = 2 pi radians; 33,000/2 pi radians = 5,252 (derived constant)

HP = TORQUE * RPM/5252 (Horsepower is Torque in motion, with each variable being mathematically linked to the other.)

Per basic algebra, TORQUE = HP*5252/RPM

Hypothetical Tire Diameter for Vehicles 1 and 2 below = 26.4” (Tire Radius = 13.2” = 1.1 feet; Tire circumference =2*Pi* 1.1 feet = 6.91 feet

6.91 Feet = 0.001308712 Mile


Vehicle 1:

Engine: “Torque Monster” 6.0 liter V8 (generic): 300 HP @ 4,000 RPM (Torque @ Peak HP = 394 FT-LB per the above” Torque” equation)

Calculating corresponding overall gear ratio for peak engine HP in 1st gear @ 35 MPH :

35 MPH = 184,800 Feet/Hour = 3,080 Feet/Minute

Velocity = Engine RPM * Tire Circumference/Total Gear Ratio

Total Gear Ratio = (3,080 Feet/Minute * 6.91 Feet)/4,000 RPM = 5.32:1

Drive Axle Torque in 1st gear @ 35 MPH = 394 FT-LB * 5.32 = 2,096 FT-LB

Tractive Force @ the Drive-wheels @ 35 MPH = 2,096 FT-LB/1.1 feet = 1,905 Lbs


Vehicle 2:

Engine: Low torque/high revving 3.0 liter V8 (generic): 300 HP @ 8,000 RPM (Torque @ Peak HP = 197 FT-LB per the above “Torque” equation)

Twice the RPM (8,000 vs. 4,000) permits twice the gear reduction (10.64:1 vs. 5.32:1) while yielding the same top speed of 35 MPH @ peak Horsepower in 1st gear.

Drive Axle Torque in 1st gear @ 35 MPH = 197 FT-LB * 10.64 = 2,096 FT-LB

Tractive Force @ the Drive wheels @ 35 MPH = 2,096 FT-LB/1.1 Feet = 1,905 Lbs


Conclusion: Both engines provide the same tractive force @ the drive-wheels @ 35 MPH in 1st gear. Assuming appropriately specified drivelines and prudent gear selection, a series of tractive force vs. vehicle speed plots would demonstrate that both engines provide comparable tractive force values at all vehicle speeds, thereby equating to comparable accelerative performance. This is attributable to the non-negotiable mathematical relationship between tractive force, engine horsepower across the utilized RPM range, vehicle speed, and the torque multiplier (total gear reduction and tire radius). It is AXLE torque that is the crucial factor in determining vehicle acceleration at any and all vehicles speeds.


Engine torque is no more significant than Engine RPM in determining this, since each is a 1st order determinant of Horsepower and, ultimately, drive axle torque and tractive force at any given vehicle speed.

 

Nope. Patrick Hale's formula (as also used by the Moroso Speed-Power Calculator) is clear on that. Mr. Hales is famed for the quarter junior software, holds a degree in computer science and used actual drag strip results of car's fitted with known "as installed" peak engine HP when compiling the related database. I'm a multi patent holding mechanical design engineer who's run hundreds of calcs using that formula for more than 20 years.

The formula: Approximate peak ENGINE HP = (Trap Speed/234)^3 * Race Weight

Unlike ET and 0 - 60 times, trap speed is largely uninfluenced by off the line traction and gearing variables. Such is the physics of drag racing.

Also, in flat out acceleration runs, the engine remains at relatively high RPM, especially after 1st gear (short duration). It's the UTILIZED portion of the torque curve that matters (along with the RPM at which it's delivered).

8 and 10 speed automatics are largely irrelevant in the quarter mile because they only use the first few ratios. In essence, they're 4 speeds in that regard, just like the old cars.

 

Also, the pre-197 model years advertised HP (and torque) were jokes. Read this:

 

MORE: 1971 Cadillac Brochure. 535 Gross Ft-Lbs of torque for the 500 CID Eldorado V8, but just 410 Net (same standard in use today). 410 is nothing by today's standards, yet that's the "mighty" 500 cubic inch Caddy. 1970 version was rated at 550 Ft- Lbs. Gross, which is 15 more than the '70 version and 40 more than the '70 Stage 1.