turboing a Corvette....without the turbo

[E_SolSi]

so its kinda like what i do?

1st - 2nd - 5th

 

[Celerity]

the 2/3 lockout is only on automatics i beleive....

basically it shifts you from 1st to 4th under normal aceleration

I have just crushed the 4+3 myth.


I just went and test drove a 1986 Vette with 4+3. It's a 4 speed manual,

R 1 3
..2 4

The top of the shifter is a levered button (Think old Subaru 4WDs) and this button engages the Overdrive. now here is where it gets neat,

gears 2,3 and 4 have overdrive. If you activate the OD you shift from 1st to 2nd.. Let the RPMs come up, and then you let off the gas, and it will drop the RPMs about 500 rpm. You can choose to sit there, or go on to the next gear which does the same thing. You can use all 4 gears and it will drive like your typical V8 4 speed. Low gears, nice torque range and it's good to go. But if you engage it, it's .. . like it's really loping along.

If you're in OD and and the OD is spinning (the rpms are down, and you give it gas, it immediately shuts off and takes you up 500 rpm. So it REALLY adds a punch.

the ultimate goal of the 4+3 is to improve gas mileage.

so i'm going to check the finances and see what I can pull together.

 

[phunky.buddha]

It made Autoblog!

 

[89_Si]

Skip shift is a 1st to 3rd shift under normal acceleration, was on all 4th gen fbodys and vettes. $30 dollar part to bypass.

 

[Celerity]

What the fuck are you talking about ?

 

[89_Si]

What the fuck are you talking about ?

Read up a few post...

 

[klyph]

Mine's better, my diabolical plan involves a vaccume air pump from a house hold hoover!

HA! you should have named it the:
Positive Engine Nitro Induction System

 

[Airjockie]

well...if the engineering was envolved enough...I can see this running as wished, but it would envolve the use of LOX, an extra injector, and a wastegate of some type.....

 

[Celerity]

Read up a few post...

no no no.. this 1 to 4 shifting thing you're talking about .

 

[Airjockie]

HA! you should have named it the:
Positive Engine Nitro Induction System

The extra tubes required for the nos would feel too ribbed for her pleasure...and the premature detonation caused by expanding fluids and gases would signal the shifter actuator to loose control at a certain temp and speed. Thus the actuator would pull out at the wrong timing required for the induction to happen. It would be a huge negative default, and the engine would have to be called Injection Malfunction Potentially Operational Temperature Exciter Negative Timing.

 

[klyph]

only a Valved Interference Actuated Gravity Reduction Armature could solve that problem.

 

[Capt. Orygun]

HA! you should have named it the:
Positive Engine Nitro Induction System

Hepa-vac Aligned Reciprocating Directed

Positive Engine Nosecone Induction System

 

[NissanNiNjA2nd]

T56 Manual Transmission Description and Operation

Manual transmissions are identified by the number of forward gears and the measured distance between the centerline of the output shaft and the counter gear. The 6-speed, 85 mm manual transmission, used in the Camaro/Firebird, incorporates the following features:
An aluminum case
Fully synchronized gears with an enhanced synchronizer cone arrangement:
Triple-cone: FIRST, SECOND
Double-cone: THIRD, FOURTH, FIFTH, SIXTH
Single-cone: REVERSE
An internal shift rail mechanism
Tapered roller bearing supporting the mainshaft and countershaft
Caged roller bearings under ail speed gears
Solenoid inhibit of SECOND and THIRD gears
Solenoid inhibit of REVERSE gear during predefined forward motion

Gear Select - Skip Shift (CAGS)
To ensure good fuel economy and compliance with federal economy standards, SECOND and THIRD gear are inhibited when shifting out of FIRST gear, under the following conditions:
Coolant temperature is above 50°C (122°F)
Vehicle speed is 20 - 29 km/h (12 - 19 mph)
Throttle is opened 35 percent or less

Reverse Lockout
A reverse lockout system, consisting of a reverse lockout solenoid, which operates a reverse lockout mechanism, is utilized to prevent shifting into REVERSE gear when the vehicle is moving forward at a speed of 5 km/h (3 mph) or more.

Vehicle Speed Sensor
The vehicle speed sensor (VSS) is a pulse type input that informs the PCM how fast the vehicle is traveling. The VSS system uses an inductive sensor, mounted in the tail housing of the transmission, and a toothed reluctor wheel on the tail shaft. The teeth of the reluctor wheel alternately interfere with the magnetic field of the sensor, creating an induced voltage pulse as the reluctor rotates.

Reverse Inhibit Description and Operation
The reverse inhibit solenoid is a safety feature which prevents an inadvertent shift into reverse at speeds above 5 km/h (3 mph) . The system consist of the following components:
The powertrain control module (PCM) .
The reverse inhibit solenoid. With the ignition ON battery voltage is supplied directly to the reverse inhibit solenoid. At forward speeds above 5 km/h (3 mph) the PCM grounds the control circuit of the reverse inhibit solenoid. This energizes the solenoid and mechanically blocks the shift lever from going into the REVERSE position.

Skip Shift Description and Operation
The skip shift solenoid is a performance feature which forces the driver to shift from first gear to fourth gear during light acceleration and low engine load conditions. This feature is used to ensure good fuel economy and compliance with federal economy standards. The skip shift system consist of the following components:
The powertrain control module (PCM) .
The skip shift solenoid.
The skip shift lamp. With the ignition ON, battery voltage is supplied directly to the skip shift solenoid. The powertrain control module (PCM) controls the solenoid by grounding the control circuit. When the skip shift system is active the PCM also grounds the control circuit of the skip shift lamp. The lamp illuminates to inform the driver that the 1-4 skip shift is engaged. The PCM determines when the skip shift system is active when the following parameters are met:
The vehicle speed is between 24 - 31 km/h (15 - 19 mph) .
The engine coolant temperature (ECT) is greater than 77°C (171°F) .
The BARO is greater than 76 kPa.
The accelerator pedal position (APP) is less than 26 percent. When the conditions are met the powertrain control module (PCM) grounds the skip shift solenoid control circuit. This energizes the skip shift solenoid and mechanically blocks the gear shift lever from going into the second or third gear positions. When the drivers pulls back on the shift lever with the system enabled the transmission will go into fourth gear.

When the conditions for skip shift engagement are no longer met the powertrain control module (PCM) disables the skip shift solenoid, allowing the driver to use second and third gears.
Once the skip shift solenoid is enabled the system will not be re-enabled until the vehicle speed returns to 0 km/h (0 mph) and the conditions for enabling skip shift solenoid are met.

So how do you disable it?

Its free, you just have know how to work on a T56.

 

[klyph]

Uh, take out the skip shift solenoids.