Twin Turbo Skylark 350 Progress by sean Buick 76

By diyauto
( 2 )

5 minute(s) of a 265 minute read

3-15-2013

3-15-2013


I know me too! It is a long road ahead with this project, I work WAY too much to get things done quickly. 


I am about to place an order with TA to get the last few things I need for the engine, then a few trips to the local parts store for some random things like battery, fuel pump, fittings, harnesses, parachute etc. 


The main things I am doing are:


-Completing the fuel system to handle 1000 HP

-Adding the driveshaft loop

-Dropping in the good Buick 350

-Putting the interior together


This will get the car up and running and will start with 8 PSI of boost, get the car insured and plated and put on a few miles and break in the engine. 


The next phase will be the next winter where I will pull the th350, move the X member and put the built up SP-400 trans in place, custom driveshaft, Water/methanol injection for intercooling, crank up the boost to 20 PSI, sort out the tune on a chassis dyno, and finally some track time in the summer of 2014



3-17-2013


Yeah I hear ya! I bought a nitrous kit for the car today! I am running a 50 shot of the good stuff and it is set to shut off when the boost hits 4 PSI... When I have the 8 PSI boost setting this will help the car get up to boost even quicker and then after the boost hits 4PSI the nitrous will shut off automatically. The kit is actually designed to run with turbos and to shut off at whatever boost setting I pick. 


Then when I crank the boost up to 10-20 PSI I will leave the nitrous on the whole time as the nitrous also intercools the air and fuel!


People have been running a small 50 shot on Turbocharged V8 engines and gaining 80-100 HP at the wheels due to the wonderful way nitrous works with turbocharging! 


So my plan on low boost is to leave off idle without any boost, have the nitrous spray till 4 PSI and then the turbo will take over from there... It takes about 1.5 seconds for the turbos to go from 0 to 20 PSI however with a little shot of nitrous it will be even quicker!



4-10-2013


Well after about a month of research into my fuel system I finally sorted it out LOL.... The stock fuel tank and pickup, lines etc are NOT going to work for my application.


I found a fuel tank built for EFI applications and it features extra baffles, and a large hole so I can mount a MASSIVE fuel pump in the tank, and it is galvanized so it should last well. I always say start with a good clean fuel system and a rebuilt carb so I am taking my own advice. Top of the line 10 AN fuel lines go to and from the fuel tank. A Boost referenced fuel pressure regulator will feed the Holley 650 Carb which is modified to handle boost. The fuel pressure will rise with the boost to keep things in check. 


I did not want the fuel pump out of the tank due to cooling issues and being that I wanted to ensure it was never "pulling fuel" up hill out of the tank or running dry. Ideally an elect. pump is either in the fuel tank or down under the fuel tank and gravity fed. Obviously the factory setup does not work in my application. 


The reasons I avoided a fuel cell are: I want the trunk space and I do not want possible fuel fumes in the car. I also like the sleeper look of the stock tank in place and I also want the capacity as I want to drive the car 200 miles between fill ups. I considered sumping the fuel tank but then I have to worry about it leaking and it would be obvious with the sump and my car is a sleeper... Tinting the widows to hide the cage LOL.... Flat hood etc. 


An air fuel sensor on each side of the exhaust along with exhaust temp moitors will help me keep the carb in check. A throttle position sensor will be attached to the carb and the megasquirt computer will data log everything from the air fuel ratios, exhaust temps, intake temps, throttle position, RPM etc. This way I can tune the car like a modern tuner WITHOUT any computer actually controling the fuel or ignition system. At some point I may swap in the EFI system I have but I think I can get it running 98% perfect with the carb, MSD triggered HEI and MSD ignition box. Using a MSD Boost Timing Master ignition box so I can set the timing to retard under boost. 


For timing I am starting with 18 degrees initial timing, 12 degrees of mechanical advance all in by 2300 RPM and 10 degrees of vacuum advance on a ported vacuum source so I will only get vac. advance at part throttle. One way check valve in the vac. advance line so it does not blow off under boost. Then I will play with the amount of boost that the box takes out. Starting with 0.5 degrees per PSI of boost (so 5 degrees with 10 PSI). This should be conservative and leave me with 25 degrees of timing at 10 PSI of boost.



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