DYNO 2003 & Calculating shift points.

[Loves302Chevy]

Grumpy, I looked through the links you posted in Rick's T-Bucket thread about gear ratios
and calculating shift points. So I learned that shifting at redline is not the best for lowest ET.
And the optimum shift RPM will probably be different for each gear.
This link, http://www.datsuns.com/Tech/whentoshift.htm, has an Excel file to calculate and
graph shift points, but I could not get it to work for me. I remembered that Dyno 2003 has
an iterator built in under TOOLS that calculates shift points for either best ET or best MPH.
Have you ever tried it?
I can't run it on this computer at work, but I tried it at home and it came up with something
like 1150 rpm for launch, 1600 rpm for the 1-2 shift, and 6000 for the 2-3 shift. Seems
wrong to me. From memory, Dyno 2003 comes up with 410 HP & TQ for the 334 SBC - 84
TransAm, 700R4, 4.10 gears, 6200 redline, 2400 stall, 28" tires.
I'll figure out a way to send you the related files if you can help with this. Mike.

 

[Loves302Chevy]

I got the Excel program to work. Numbers are input from DYNO 2000.


As you can see, with the huge rpm drop of the 1-2 shift (3.06 to 1.63),
the torque at the end of 1st gear will never equal the torque at the start
of 2nd gear. So what would you choose for shift points?
6500 rpm drops 46.73% to 3463 rpm from 1st to 2nd. And 2nd to 3rd
drops 38.65%. 6500 becomes 3988.
Camshaft range is advertised as 2000-5800 rpm.

 

[87vette81big]

The 700 R4 & 4L60E & 4L65 E
Made from 1982-2012 is actually a Terrible Trans to Drag Race with.
The 1-2 gear shift is Ultra Wide Ratio like a Dump Truck.
They actually work very well in A C4 Corvette.
None ever had 500 + Flywheel Torque stock other than the 1987-1991 Twin Turbo Callaway Corvette.

 

[87vette81big]

The Hot Ticket now with C5 Corvettes is to Dump the Stock 4L60E.
INSTALL A TURBO 400 TRANS.

 

[Loves302Chevy]

They actually work very well in A C4 Corvette.

Well, you have one. With similar HP & TQ I assume. Where do you shift?

 

[87vette81big]

Well, you have one. With similar HP & TQ I assume. Where do you shift?

99 % of the Time I just leave the 700 R4 Trans in Overdrive.
Once in a while I will drop down to 2nd gear at 70-90 mph and the drop the gas pedal Hammer....Super Passing power on the Highway.

 

[87vette81big]

Mine is only rated for 245 HP.
It feels strong & I do think its closer to 275 HP.
Torque is rated at 345-350 Ft/lbs.

 

[87vette81big]

Small engines perform well with a 700 R4 & tall highway gears.

 

[87vette81big]

Shift where you want to Mike, Have to experiment.

 

[Grumpy]

you will almost always want to do the math required to find where in the rpm band youll want to shift gears, and that point is almost always where shifting to the next gear allows the engine rpms to fall at or very near the torque peak in the power cure , that of course assumes you don,t need to exceed the max piston speed, and valve train control rpm limitations, and that also assumes you have the tires and suspension to allow the required traction for a hard launch from a standing start
(which most stock street tires are hopelessly inadequate for)
example
heres what DD2000 predicts my corvettes power curve looks like,

as a broad outlook, you want too shift to the next gear at an rpm level on the upper end of the rpm band near 6300 rpm where both piston speed and valve train control issues start to become limitations and fall back to between 3500 rpm and 4000 rpm obviously rear rearing, your torque converter stall speed , tire diameter and transmission shift kit, the transmission gear ratios, are all factors that may limit or prevent the ideal shift points.
now reality steps in
on my corvette the stall speed is about 3200-rpm, and the shifts will be controlled by the shift control and this happens at about 6200 rpm under full throttle loads.
the 700r4 gears are
700-R4/4L60..............3.06.....1.63....1.0.....70
you generally select a trans first gear x(times) the rear gear ratio that falls in the 10:1-10:5:1 range, for brisk street performance
a 3.45 -3.73 rear gear will be about ideal for drag racing with slicks


http://garage.grumpysperformance.co...electing-a-torque-converter-stall-speed.1715/

http://garage.grumpysperformance.co...late-gear-ratios-and-when-to-shift-calcs.555/

http://garage.grumpysperformance.co...hing-the-drive-train-to-the-engine-combo.741/

http://web.archive.org/web/20070128173316/http://members.aol.com/powerrslid/thm2004r.html

 

[Loves302Chevy]

Here is my DYNO 2003 TQ & HP for the 334.

 

[Grumpy]

the problem most guys face is the stock transmission shifts close to 5500-rpm
and the stock stall converter generally stalls at or below 2100 rpm,
where ideally you would want a 3200 rpm stall and a 3.45:1-3.73:1 rear gear,
to keep the engine operating in its most effective power range.
yes youll very surely feel the difference in performance with the correct combo vs stock

 

[87vette81big]

My Corvette has A Transgo 2-3 Shift Kit in the 700 R4 Mike.
It allows Full Manuall Control of the Valvebody if I drop the Shifter down to Low 1.
Holds any Gear as Long as I want it to.
I shift back to Overdrive and the 700 R4 functions 100 % as Stock.
The problem is the Stock C4 Corvette shifter is Bad for Street Race & Drag Race use.
Seems Ok till its time to Street race from a Stop light in town.
Easy to overshift.
Why it stays in Overdrive .
Nice Aftermarket shifters made but I never bought for my Corvette.
Putting my Time & $$$$ into my Pontiacs in 2016.

 

[Loves302Chevy]

as a broad outlook, you want too shift to the next gear at an rpm level on the upper end of the rpm band near 6300 rpm where both piston speed and valve train control issues start to become limitations and fall back to between 3500 rpm and 4000 rpm obviously rear rearing, your torque converter stall speed , tire diameter and transmission shift kit, the transmission gear ratios, are all factors that may limit or prevent the ideal shift points.

6500 rpm drops 46.73% to 3463 rpm from 1st to 2nd.
And 2nd to 3rd drops 38.65%. 6500 becomes 3988.
Camshaft range is advertised as 2000-5800 rpm.

The previous engine combination (with problems) could only rev to 5800-6000 rpm with the
Crane CompuCam 2050 with 1.6 rockers. It took forever to get off the line and could not spin the
wheels, either. When it reached about 3500 rpm, then it would take off like a rocket and run the
quarter with 108-114 MPH speeds. So many things were changed at once that troubleshooting
and tuning was nearly impossible. With the help of the members of Grumpys Performance,
ALL the problems are corrected this time around and I now will have a better combination.

My transmission is the later 30 spline 700R4 and has been modified with (I think - it was 17 years
ago) Kevlar bands, Kolene steels, Corvette servo, shift kit (full manual control), and a torque converter
that the Grand Nationals use (2200-2400 stall ???). Rear gears are 4.10, 28" tires. Also Hurst
Dual-Gate shifter. It also has that mod that you can cruise in OD at over 3/4 throttle. I chose the 4.10s
because I geared it for the quarter mile, but I drove it to work daily. Theoretical top speed is about 125
mph. Plus it only was a 145 HP 305 at the time and needed all the help it could get. Cruising down
the highway in OD is not bad at all (2400 at 70, I think).

Back then, I did not want to be cruising down the highway in OD and have the converter slipping and
heating the transmission fluid because I was below the converters stall speed. And nobody could tell
me if the converter lock-up overrode this scenario. That is why I went with that converter. The only
change I would like to make in the future is to the governor so that I can just put it in DRIVE and it
will automatically shift at whatever RPM I determine works best (between 6000 and 6500) at WOT.

Grumpy, installed on the engine right now, and before, is a gasket-matched Weiand 8000 EGR emissions
legal intake manifold (spreadbore q-jet mtg flange). I call it a baby STEALTH. That was a great intake.
But I can't use the Stealth without an adapter because I will be running an Edelbrock 1904 795 cfm M4ME
Q-Jet this time, after I remove the computer and its wiring from the car.

I am buying this hood this week:

which will give me some underhood airflow and clearance for a taller intake manifold and 1" taller
air filter element by changing the top of the air cleaner. I'm using the dual-snorkel 305 HO Assy.
(from Danger Mouse part 4 Super Chevy Dec 2002):
Test 10: Edelbrock Performer RPM "Air Gap" Manifold
We also "borrowed" this Edelbrock Performer RPM Air Gap (PN 7501) manifold from Westech to see
if it’s larger plenum volume would improve power, even though the engine still had the stock heads
and a small cam. It worked fantastically, giving us the largest single power increase of any part so far
with 24 more peak ponies and 20 more lb-ft of torque (over Weiand 8000).


I have a Performer RPM Q-Jet (not air-gap) that I planned on using if I ever got a taller hood.
If you were me, would you change the intake?
I don't plan to do it right away, but I will change the air cleaner lid to use the taller filter.

I also have this single-plane Weiand 7525 (2000-6000) that I added a removable plenum divider plate to. I call this one a
baby Victor Jr.

 

[87vette81big]

My Vote is for a Dual Plane intake for the Street Mike.
If your dedicated Drag Racing then a Single Plane intake be a better choice.
You have 334 cubic inches.
It should be easier to feed air in than larger cubic inch SBC Stroker engines.

Your Isky Cam is moderate duration.
Not as if you have a 240-270 degrees @ .050".
The Edelbrock 1904 795-800 cfm Q-jet I am Familiar with.
Will feed 454-455 cubic inch big Blocks bored out to 462-468 cubic inches to 7,000 RPMS with 300-350 cfm heads.
Its setup Super Rich with .076 " Primary Jets & "CC" Secondary Metering Rods.
Likely have to Jet down for the 334 ci SBC with The ISKY HYD Cam chosen.

 

[87vette81big]

A Q-jet only takes in what it needs for WOT Airflow on the Secondary Door.
If it never Fully opens on the 334 SBC That's OK.
Usually only opens Fully on 400-455 cubic inch Chevy & Pontiac.

 

[87vette81big]

108-114 Mph Trap Speeds are Really Good Mike....Impressive for 334 ci SBC.

 

[87vette81big]

There is Wet Flow also....
All Magazine tests are done Dry Flow.
Wet Flow is What the engine actually sees.
So its not so predictable ....

Look at the Results I had ....
I used an Offenhauser 360 degree Dual Port Intake on my 1965 Olds 425 V8 in my 1963 Grand Prix.
Intake is supposed to be Crap.
It has ungodly Torque on Tap....
Burns Rubber not even trying.
Just 3.23 gears. 4200 pounds Heavy car.

 

[87vette81big]

Your Weiland 8000 Intake must work OK.
108-114 Mph Trap Speeds.
Many LS stock can't match.

 

[Loves302Chevy]

Your Weiand 8000 Intake must work OK.
108-114 Mph Trap Speeds.
Many LS stock can't match.

That makes me feel so good. Hopefully, I can get it to respond off the line this time.

I was looking at the links Grumpy sent about torque converters and stall speeds.
Do you know of any reasonably priced with decent quality 3200 rpm stall converters
that will not be overkill for my application?