Turbo Project Parts

Updated 10/9/09

Progress Pictures:
If you want to see lots of pictures, click here for a pile of categorized thumbnails of my project that you can click on for full-sized images.

My Turbo Conversion Major Parts List

Part Needed

Expected
Cost

Source

Obtained?

Paid

Turbo - Garret T03, .60 comp A/R, .63 turbine A/R

$175

Used - Private Party

Yes

$165

Turbo - Garret T03, .60 comp A/R, .63 turbine A/R

$175

Used - Private Party

Yes

$175

K&N Air Filter #RE-0910

$40 each

Jeg's

Yes

$80

Header Material

$60

Home Depot/McMaster

Yes

$200

Intercooler

$100-$300

Ford Dealer

Yes

$230

Intake and Exhaust Piping

$50

Used/New - Private Party/JCWhitney/local supplier

Yes

$150

Holley 650 Double-Pumper Carb

$350

New - Jeg's

Yes

$350

Bonnet

$50

Fabricated

Yes

$10

Oil Lines (to turbos)

$80

Auto Parts Store

Yes

$15

Fuel Lines

$50

NAPA

Yes

$15

Exhaust Temp Monitor

$120

Jeg's

Yes

$115

Boost Retard Device - MSD 6BTM

$330

Jeg's

Yes

$330

Blowoff Valve

$45

Private Party

Yes

$0

Connecting Hoses

$30

NAPA

Yes

$100

Miscellaneous (hardware, fittings, etc.)

$50

Various

Yes

$150

Turbos:
After doing lots of reading and talking to people and seeing examples (back in 2002), I realized that considering my budget, I'd be best off with a pair of Garret T3 turbos with a .63 turbine A/R and .60 compressor A/R because they should spool up quickly and start making boost by 2200 rpm, be at full boost by 3000 rpm, and they should be able to take me to around 5500-5800 rpm before they become a flow limitation.

What's the source for the turbos? They can be purchased new of course, but I'm too cheap and broke for that. These turbos came on manual-transmission T-Bird Turbos in the mid-'80s so there are lots of them around. The automatic T-Bird Turbos had the same turbo but usually came with a .48 turbine A/R. That basically means it'll spool up faster than the .63, but it'll run out of breath (and become an exhaust restriction) sooner.

Where to get one? eBay comes to mind of course, but I was nervous about buying an expensive and complex part from some totally unknown party. Junkyards are great, but there aren't too many around my home town anymore. Besides, I didn't really know what I was looking for in a good turbo. Then I found the jyturbo e-mail list from Yahoo! Groups. I joined up in early December, 2001 and learned a ton of stuff and "met" quite few people as well. I became friends with one guy in particular and he happened to have a nice T3 on hand. Sold! $185 later it was on my kitchen table (wife rolls eyes). A few weeks later I found another one from a different person on that e-mail list for $125. Not as nice, but should work for a couple years without a rebuild.

Air Filters:
I wanted a conical-style K&N filter for each turbo, so I bought two new K&N RE-0910 filters. They have a 3" clamp-on hose at the base and they're 5" in diameter at the base, 4.5" at the far end, and 9" long. Longer than I expected or needed, but they work.

Header Material:
I really didn't know what to do about headers. I had to mount them so the exits face forward, but how? Flipped shorty (mid-length) headers? I thought about it, but I think they're too long. Chevy S10 shorty headers flipped around? Close, but the #3 and #5 primary tubes would have hit my steering components.

I decided to fabricate them. Fun project, but what should I use? Ever hear of "weld els"? I hadn't, but they are basically your typical schedule 40 "black pipe" you can get at Home Depot for plumbing, but they're cast into a smooth, 90-degree bend with beveled ends for easy butt welding. Except for the weight, they're perfect. The 1.5" weld els have an inside diameter of 1.61" (no, it doesn't make sense to me, either) and an O.D. of 1.90". Right on for my needs. Each 1.5" el costs about $4-$5 so the headers aren't cheap, but I figured the durability and ease of welding would justify the cost. Besides, what option is cheaper? Fabbing your own out of a header kit or buy buying 16-gauge mandrel-bent steel is expensive as well.

I did think about using some 16-gauge, mandrel-bent exhaust tubing, but I was warned that the thin-wall tubing might not stand up to the added heat and weight of the turbo hanging from it, so I went with the schedule 40 stuff. The straight tubing is from Home Depot, about $2/foot (2002 prices). The weld els I had to buy from an industrial plumbing supply place. You can also get them online at www.mcmaster.com.

Here's what the weld els look like. There is one 2.5" el and two 1.5" els:

For good information on home-fabbed headers using schedule 40 pipe, go to the SDS EFI site.

Here's the passenger's side header in various stages of construction. I had to make the ends that mate to the flange into an oval shape because the header bolts are right next to the ports. Add in the thick-wall tubing and there's not much room left over!

Here it is with the collector fabbed up and welded on, then with the turbo mounted, and finally after adding the driver's side header:

And some shots before coating the pipes:

If I were to do it over, I'd strongly consider trying to find some 14-gauge mild steel tubing for the headers. The weld els are very strong and easy to weld due to their wall thickness, but they are just so freakin' heavy. I haven't weighed them in their final configuration, but I really should. I think that before I did the funky 180-degree bend at the ends they weighed 30 pounds each, so together they probably weigh 75 pounds now, right over the front end where you don't want any additional weight! Ahh, if only I didn't have $150 and countless hours into the headers already...

Intercooler:
Turbo compressors really heat up the air before it comes out, even up to 350 degrees I've been told. Well, we all know that cooler air is denser air, and denser air makes more power. That's the whole reason for turbos! Intercoolers try to reduce the temperature of the inlet air as much as possible to make more power. One other benefit of the cooler air is that cooler air can help reduce detonation, thereby allowing higher boost levels.

I bought an ATI ProCharger intercooler from a friend of a friend to run on my Nova, but it just wouldn't fit very well at all. The core itself was 27" x 6", and the overall size was about 31" x 11". Too wide, and too short to be a good fit. The only place it could go was where the radiator normally is and it would leave big gaps around it...it just wasn't a good match.

Next, I bought an intercooler intended for a 2001 Ford SuperDuty truck with a Powerstroke diesel engine. Here it is sitting where my radiator normally goes. Much, much better fit than the ATI! I did have to notch the frame and do some cutting on the core support, but I'm glad I went this route. It sure wasn't the first time I cut up my car.

Intake and Exhaust Piping:
I needed to run downpipes from the turbine outlets to my existing 3" exhaust pipes under the car, and I also needed to run pipes from the compressor outlets to the 3" intercooler inlet and more 3" pipe from the intercooler to the bonnet. I bought a good assortment of 3" pipe and 3" connectors from a friend of a friend for a good deal, and here it all is. Yes, it's steel pipe, it's just got a little surface rust making it look like copper.

I used 1.5" pipe from the compressor outlets to a point near the intercooler and merged them into a 3" pipe. I've since learned that may be restrictive and will upsize it, probably to 2". As for the downpipes, I bought some 2.5" stock replacement flange sections from the parts store to match up to the turbo outlet flange and Mickey-Mouse'd some pipe between those and the existing 3" pipes under the car. The passenger's side was easy and direct, the driver's side was another story. See the Turbo Progress page for more info. I'll have to rework that setup at some point.

Carburetor and Bonnet:
I bought a new Holley #4777 650 double-pumper and modified it for blowthrough use. That means I had to replace the brass floats with solid floats, remove the choke linakge, fill the choke rod hole, and cut off the choke housing. No big deal. As for the bonnet, I fabricated one. I used 5" diameter pipe for the sides and the top. I may put in some sort of flow diverter inside it eventually.

Oil Supply and Drain Lines:
Turbos need oil, so I put a tee in the port at the front of the block and ran 3/16"" rigid steel lines (with a loop) from there to each turbo for the oil supply. For oil drainback, I'm running 3/4" heater hose (until I find some 3/4" oil/gas/vapor hose) from the turbos' oil outlets down to welded-in bungs on the sides of the oil pan near the front of the engine. The oil draining out of the turbos has been all whipped up and takes up more volume than the oil going in, and it's not pressurized, which is why the drainback hoses are so much larger than the supply lines.
 

Fuel Lines, Fuel Pressure and Fuel Pressure Regulator:
According to Mike Sitar (www.toohighpsi.com) all I need is to boost-reference my fuel pump and I'm good to go, which means simply running a supply line from the pump to the dual-feed line and a vacuum/pressure line from the bonnet to the pump. He said you have to boost-reference the pump if it only puts out the 6psi that mine does, and if you're boost-referencing that, why bother with a regulator? I guess he ought to know. And if that saves me from needing a $75 FPR, so much the better.
 

Fuel Enrichment:
Turbos don't increase the volume of air going into an engine, but they make it significantly more dense. That means more molecules of air per unit volume, which means more fuel is required to maintain a proper air/fuel ratio. Carburetors work based on the volume of air passing through the venturis, not density, so additional fuel must be added to the system when under boost to avoid an excessively (and dangerously) lean mixture. Some people plumb a fuel injector into the intake tubing that's run by a Hobbs switch which opens at a predetermined boost level. Others simply richen up the secondary mixture of the carburetor to make up for the extra air molecules, figuring if the secondaries are open, they're probably under boost and will need the extra fuel. Rudimentary, but rather functional. Others run a nitrous fogger nozzle operated by a nitrous solenoid which is controlled by a Hobbs switch. Complex and a little expensive, but very versatile. After hearing about a couple failed secondary enrichment systems damaging engine internals thanks to the resultant lean mixture, I'm a little hesitant to go that route. I'm leaning towards richening up the carb via jetting and the PVCRs and possibly the air bleeds. Not high-tech by any means, but it should be a lot safer than a secondary system. And it's free.

Exhaust Temperature Monitoring:
Keeping an eye on exhaust temps is wise in order to know what's going on inside the cylinders. I need to learn more about this, but it sounds like about 1450-1500 degrees right off the engine is about right. If you're running much higher than that you're probably running rather lean (which can cause damage), if you're running lower temps you're not making the power you could be.

I went mainstream on this and just bought an Autometer UltraLite pyrometer with thermocouple and probe for $115. It's much cheaper (although much less informative) than a wideband oxygen sensor system.

Ignition Timing Control:
Turbos create added pressure inside the cylinders, which is why static compression ratios are best kept low to avoid detonation. Detonation can be catastrophic in short order, and boosted motors need less timing than their naturally-aspirated counterparts. Many people lock their distributors at a certain advance, but that's not good for all-around performance and throttle response. I wanted to have some decent initial timing for throttle response and a reasonable amount of centrifugal advance for cruising fuel efficiency, but I wanted to limit the advance under boost conditions.

Enter MSD with their 6BTM ignition box. It's basically a 6AL box with their Boost Timing Master built in. The BTM will allow me (via a cockpit-adjustable control) to retard the timing anywhere from one to three degrees per pound of boost up to 15 degrees total retard. Perfect! That way I can run about 15 initial plus 20 centrifugal, but under full boost I'll be back at 20 total, which is a common advance amount for turbo cars. I'll play with the timing to see what's best while staying out of detonation. I like the added margin of safety this controller should give. Besides, I'll have the multiple-spark discharge and a built-in rev limiter. I'm already impressed by how much the MSD box has smoothed out my idle! The engine starts and idles much better than it did before I added the box. I love it.

Blowoff Valve:
A blowoff valve in the intake piping is strongly recommended in order to release sudden pressure spikes as a result of slamming the throttle shut under boost (like at the end of a quarter-mile run) which can have a detrimental effect on the turbos. I got one for free from a generous guy in California.

Connecting Hoses:
These are the hoses that connect the intercooler inlet and outlet to the pipes, the air filter-to-turbo connections, etc. The connection for the blowoff valve was easy, I just got a 1" I.D. radiator hose from Checker and cut it to length. Propbably $5 there. I got a 1.6" radiator hose from Checker to connect the long pipe across the top of the engine that goes from the driver's-side compressor to the intercooler. Another $8. The real money came from buying a 3.5" and a 6" piece of "turbo hose" from NAPA. It's silicone and supposedly pretty tough, but 9" of hose for $36 is insane! Especially ORANGE hose. Ugh. Then there was the 2-5/8" hose I had to get for the connections between the compressor inlet and the inlet pipe. Another $35 or so. This stuff really adds up fast!

I guess that's it for now. Progress has been on hold for a long time, but I'll update this page as the project continues.

Feedback and questions are always welcome, please click the "Contact" links if you'd like to leave some.

Copyright 2009 Bruce Johnson and Craig Watson