1969 Camaro Transforms From Big Block to Supercharged LT4 V8 at V8 Speed & Resto Shop

[V8TV]

At this point, the decision was made to install the later version of the LT4 supercharger hat, which will accommodate water / methanol injection jets from Nitrous Express.

Water / Methanol injection is a great tool to reduce the intake charge temperature, allow for more aggressive ignition timing, and therefore increase the power output of the engine.

The system uses basically the same solenoid system as a nitrous oxide kit, but this time, it’s spraying a water / methanol blend under much lower pressure. A reservoir tank and pump are needed, as well as some form of controller to make it work.

Here, the jets are plumbed into the new hat and the solenoids are mounted. Nitrous Express provides this service, which came out great.

[V8TV]

Alcohol pump:




The new hat didn’t match our desired color scheme, so it was cleaned, scuffed, and masked for some new color.



First color is a charcoal gray found in various accents on the car, like the window trim and door handles.



Then the fins were masked and the second color was applied, a bright and vivid red.







After unmasking, the fins were stripped and the ribs were returned to a natural aluminum finish.



The end result looks factory clean and custom tailored to the car. We also tuned up the LT4 badging and gray on the coolant hoses.

Looking good!

[V8TV]

The liquid side of the alcohol injection system required a pump and a reservoir, so we built a tank to fit in the driver side rear quarter panel out of stainless.



Here, the screw cap bung is TIG welded in place.





The tank and pump fit neatly in the trunk.



Here it is just before being painted.

[V8TV]

Next, the team wired up the T56 Magnum transmission using a Bowler All In One harness. This is a handy piece that incorporates all the connections required on a T56 for safe operation into one harness.



From Bowler:

“The All-in-One harness solution for the Tremec T-56 Magnum transmission comes equipped with all the connections pre-wired into one harness for a simple installation and ease of use. The small epoxy sealed controller is mounted to the VSS output using the existing bolt, and once the unit is powered up you will be able to connect via Bluetooth to your Apple or Android smartphone using our free app. The app will give you the ability to customize the input and output settings for each feature to ensure proper operation in your vehicle. The All-in-One harness eliminates the need for any additional equipment to operate the reverse lock out or generate the correct speedometer signals coming from your Tremec T-56 Magnum. This All-in-One harness solution is the perfect finishing touch for any Tremec T-56 Magnum conversion, and the only harness you will ever need.”

Unit mounted:



And the Dakota Digital OBDII interface to send the signals from the ECM to the dash.



These devices simplify the communication betweed various digital and analoge systems making it far simpler to perform these kinds of swaps.

Soon, the intake tube was made and the LT4 was ready to fire!

[waynieZ]

Very Nice!!

[V8TV]

The LT4 was finally ready to fire, and the crew double checked all the connections, hoses, fittings, and added some fuel. The calibration is from the GM Performance ECM with some adjustments made to accomodate the Drive Junky pulleys, exhaust, and custom air intake. We use HP Tuners software and worked with Mike Norris on the calibration to get the car in a driving state.







Initial drives we casual, as we datalogged the ECM and would beam it over to Norris for analysis. We’ve tuned many an LS, but this was LT4 #1, and we trust Mike to be a great resource on these kinds of projects.

[V8TV]

Soon we were ready to strap it down on the dyno and put some power to it and perform more datalogging and refinements.



Trevor at the wheel of the car and tune…



The results… 670 HP / 720 TQ corrected for weather at the wheels.



Driving the car is a blast… when the power comes on, you’d better be ready! It shreds tires at will. Two V8 Team members Trevor and Tyler took the car on a 600 mile shakedown run to the Holley LS Fest in Bowling Green, KY, with no major issues, save for a power steering leak at the rack. Overall, it was a great ride for them. Our freinds at Forgeline were kind enough to host the car for the weekend.





However, we’re not at the finish line yet. It turns out that the car has an issue with the throttle during upshifts where the RPM climbs a bit after the throttle has been closed. It seems this is a “thing” with LT4 swaps, and we’re working with GM and a few others to land on a solution… more on that shortly!

[V8TV]

We'll post episode 2 soon.

[V8TV]

The next chapter in the 1969 Camaro BBC to LT4 conversion video series.

[V8TV]

1969 Camaro LT4 install video Part 3 - driving and dynoing!