Budget Based Pushrod 5.0L Turbo Build & Dyno
They say it’s often hard to see the forest through the trees. No truer words have been spoken about performance projects, as we get so fixated and wrapped up in the little details, that we forget about the big picture. A perfect example of this is when it comes time to turbocharging your 1986-1995 5.0L Ford. Whenever the word boost comes into play, the performance wheels start to spin. What size turbo should I run? Should I use an air-to-air or air-to-water intercooler? What diameter tubing should I use for my Y-pipe or turbo manifolds? Is a divided housing better than an undivided on my V-8? Of course, the perennial favorite is always, how much boost can I run? These are all excellent questions, but the endless hours we fret over these minor details are hours that can be better spend on major projects. We call this performance pixilation; looking at the project through a microscope stops us from seeing the big picture. Here’s a little secret. Forget about the divided housings, tubing diameter and billet wheels, and just get the turbo, any turbo, installed on your motor. That’s when the fun starts.
This is especially true when looking to run boost on a 5.0L Ford (the original, not the Coyote). The reason for the concern on a factory 5.0L application is that boost (from almost any turbo or supercharger) can push the power limit well past the breaking point of the production block. These blocks tend to crack from the main webbing up to the cam bearing housings. Because this limitation exists, there is no need to get crazy with special billet wheels, custom housings or even dedicated, tubular turbo manifolds. Sure, it sucks to have these limitations, but if we look on the bright side, we see that it makes things easier on us to reach that power level. No need to resort to expensive turbos or even dedicated turbo kits. Toss almost any kind of boost on a 5.0L, and you can easily produce your very own a budget block splitter.
For this project, we had our local muffler shop build the necessary tubing required to connect our stock exhaust manifolds to our existing Y-pipe. That’s right, we said stock exhaust manifolds, as in stock, tubular, restrictive, factory 5.0L H.O. manifolds. You remember those, you probably threw yours away back in the day and replaced them first with shorty headers, then equal-length shorty headers then (hopefully) long-tube headers. Little did we know that these same crimped headers could serve effectively as turbo manifolds. For our system, we chose to combine the stock manifolds with a super cheap eBay turbo. Purchased for just $163, the GT-45 (style) turbo was capable of 800 hp, or more than we ever hoped to see with our 5.0L. The problem is actually not one of power, as the torque production seems to be what splits the stock blocks.
Having chosen both our manifolds and turbo, all we needed to do was connect them to the remainder of our system. For most 5.0L enthusiasts, the Y-pipe is something you will need to build. The Y-pipe merges the exhaust flow of both banks and directs that exhaust to the turbo. The Y-pipe typically features a T4 (or other) turbo flange to mount the turbo. The Y-Pipe must also feature a second outlet for the waste gate.
Waste gate manufacturers supply the necessary flange, so all that is needed is a short section of tubing to connect the waste-gate flange to the Y-pipe. As luck would have it, we already had a Y-pipe from a previous application that fit our dyno. Rather than build a second Y-pipe, we simply made tubing to connect the stock exhaust manifolds to the existing Y-pipe. Here is a little tech tip, you can often find Y-pipe sections of tubing on single-exhaust vehicles at the junk yard. They can sometimes be found cheap at local muffler shops as well.
To find out if the combination of stock manifolds, cheap turbo and muffler-shop madness really worked, we installed the DIY turbo system on our test motor. The motor came from Blue Print Engines, and was essentially as stock 302 short-block with cast internals. The original iron heads had been long-since replaced by BPE’s own CNC-ported aluminum heads. These heads were teamed with a Comp XE274HR cam and a TFS Street Burner intake.
We first ran the little 302 in naturally aspirated trim with 80-pound Accel injectors, a set of Hooker headers and Accufab throttle-body. So equipped, the 302 produced peak numbers of 386 hp and 374 lb-ft of torque. After the baseline, we installed the turbo, including an oil feed and drain line to the turbo. Boost from the eBay turbo was run through an air-to-water intercooler from ProCharger, though at this power and boost level, any (or even no) intercooler will work (especially if running E85).
Run at a peak boost of 7.8 psi, the turbo system pushed the peak power output to 549 hp and 555 lb-ft of torque; torque production hovered right near the 550 lb-ft mark for over 1,000 rpm (from 4,100 rpm to 5,200 rpm). There was certainly more left, but we already succeeded in building a budget block splitter.
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