A big theme of the last few years with this car has been fortifying it to survive motorsports better: Transmission kits, coolers, brake work, better seats, the new giant radiator – all of it an attempt to make it easier to drive and more reliable.
This post is about another item that won’t necessarily make the car go faster, but it will be much less liable to blow up. And that’s important. You don’t have a chance to win if you can’t even finish.
Over the past couple of years, I’ve coveted a setup Bray Lay showed me. He’d figured out how to use a machined aluminum spacer under the plenum with push-loc fittings to replace the vacuum lines. This setup imparts an enormous amount of confidence. One of the worse things that can happen to one of these cars is the fuel pressure regulator losing the reference signal from the intake manifold. Another big buzz-killer for my friends running speed-density ECUs is if the MAP sensor also loses signal. Both conditions will cause the engine to suddenly go lean.
In my case, the vacuum lines would often work their way loose from the vacuum block on the top of the engine.
I’ve also had the line come off the fuel pressure regulator.
Now, I’ve been lucky. Unlike a drag run, where you’re full-throttle and full boost for somewhere between 9 and 13 seconds, with autocross, you’re never at WOT for more than a second or two at a time. This aspect of my chosen hobby has prevented calamity. I’ve had these lines pop off – despite numerous zip ties and clamps – many times at events. However, I’m signed up for a couple of track days this year. Going WOT down a straight that’s nearly a mile long is in my future. A hose popping off under those conditions will be the end of the engine.
So, replacing these with push lock fittings is a no brainer. I had been looking at piecing a kit together myself, but recently Don Cruz at Cruze Perfomance has started offering a package with all the hard-to-get parts. And his kit is cheaper than putting it together yourself from Amazon and Fastenal. You may have to add a few things like some 1/8 NPT nipples, but you can get those at any hardware store.
The other item that needed addressing is what I believe to be my last oil leak: the turbocharger drain. The drain line on these car is notoriously difficult to reach when replacing it, so leaks are common once it has been disturbed. A click over to GN1 Performance out of California netted their turbo charger oil line kit, which uses a -4 supply line, a 60 micron filter, and a -8 drain. It’s expensive, but it is way cheaper than dealing with an engine fire.
So, first step in all of this? Tear down the top and front of the engine:
- Remove the ignition box and coils
- Remove the plenum and throttlebody assembly
- Remove the intake piping
- Move that upper radiator hose out of the way
- Move the lower radiator hose out of the way
- Remove the thermostat housing
- Remove the coolant tempurature sensor that’s to the passenger side of the thermostat housing
- Remove the turbocharger
With all of this out of the way, you can begin.
At the base of the block is a brass fitting that houses the oil pressure switch for the light in the dash and the feed line for the turbocharger. Clean it up, and remove the feed line from here:
The line kit comes with several shiny bits:
The oil line kit comes with two adapters:
The fitting on the bottom of the picture goes into the block fitting. The one on the top goes into the turbocharger. If you have one of those brass 90 degree fittings that adapts the turbo’s feed from NPT to a flared line, remove it. If, like me, you have a non-oem turbo, you may need a different adapter (I did, -4 AN to 1/8 NPT).
After getting those adapters in, flip the turbocharger over and clean all the gasket mess off the drain pad. Then attach the -8 AN male fitting with the included gasket and the old hardware.
On the engine side, remove the drain line fittings from the block. The black adapter in the kit screws directly into the block. Be sure to use some high-temp PTFE sealant for all of the pipe-thread connections, or they’ll leak. Don’t use the teflon tape, it won’t hold up under the heat.
Now comes what was the hard part for me. I installed the -8 line with the 90 degree swivel at the block side. The 45 degree is not a swivel end, so lining it up with the fitting on the turbo was a bear. GN1 recommends loosening the bolts on the turbo so you can clock the center section to line up with the drain lines. sadly for me, one of the bolts on the exhaust side was stuck, so I couldn’t pull that off.
I carefully screwed the fittings onto the turbocharger before I bolted it to the manifolds. That allowed me to wiggle it around and get the threads on the drain line started. Once they were on (but not tight!), I bolted the turbcharger back into place, then carefully tightened the fittings. Be aware, and make sure you don’t crimp the drain line.
Installing the feed line was much simpler. Depending on your exhaust routing, you may want to run it either behind or in front of the turbo. Your choice. Just make sure the filter and lines aren’t touching any exhaust parts or rubbing any sharp corners.
With this part done, it was time to move upwards to the vacuum lines. Here’s kit:
It comes with an intake spacer (I got the 1″ thick option, drilled for an IAT sensor), 25 feet of nylon line, a block off plate kit to go where the stock vacuum block goes, and all the fittings.
Now, since I’m running a regular MAF based ECU, I don’t need to buy a fancy MAP sensor that can take the fittings, I’ll use a clamp on that guy, but the fuel pressure regulator needs to be modified to accept a push-lock fitting.
This was tricky. The fitting on the regulator was tiny. I carefully disassembled the regulator, then used a drill press to enlarge the hole in the top half, then tapped it out to 1/8 NPT. Then carefully reassembled it.
If you aren’t secure in doing this without ruining the regulator, Don Cruz will do it for you if you mail your regulator to him.
From this point, things were pretty straightforward, except for one or two little nags. You basically assemble it:
Now, looking closely, you can see my new IAT sensor. You can also see how close it is to the idle air controller housing. Yup, the IAT cannot be connected. If you are doing this, and you are running a stock throttlebody, ask Cruz performance if they’ll drill your IAT hole on the side or the back, not the front. Big clearance problem. I won’t be able to use this new sensor until I change to a different throttlebody.
Hooking up the PCV is simple enough.
The system comes with this cool vacuum distribution block. I had to make a bracket to mount it next to the plenum.
With this mounted, it’s a matter of connecting stuff. The two clamped rubber lines you see are fitted to 1/8 NPT nipples, with one going to the MAP and the other going to the vacuum lines that power the HVAC vents, evap canister, and cruise control.
The two push-lock fittings go to the fuel pressure regulator and the blow off valve, respectively. The open hole will be closed up using a pipe plug.
On the topic of the ignition. If you have a stock ignition system, it should clear the plenum fine after installing the spacer. I, however, have the Bob Bailey TR6 ignition, and the box is larger. I had to enlarge the holes on the ignition box bracket so I could slide the ignition box back enough to clear the plenum. A drill press is your friend here.
Finally, carefully install the orange O-ring in the channel on the block off plate (I used a little bit of Vasoline to get it to stay in place), and install it. The screws appear to be stainless, so I put some anti-seize on them to hopefully prevent them from galling into the aluminum throttle body housing.
And really, that’s it. Hook up all the hoses, fill the radiator up, energize the fuel pump and set the pressure (since you screwed up the adjustment when you disassembled the FPR to drill it, remember?), and start it. Check it for leaks. To recap, you have disturbed the following:
- Upper radiator hose
- Lower radiator hose
- Thermosat neck
- Water temperature sensor
- Turbo feed line
- Turbo drain line
- All the vacuum lines
- All the intake piping
Double check it all, and start the car. Enjoy not having to worry about vacuum lines or oil leaks again!*, **
* Remember, -AN lines are not steel lines. They don’t last forever. You need to inspect them yearly, and replace the braided hose every five to ten years. Possibly more if you really put some miles on it.
** The Nylon line used in the push-lock fittings will get brittle due to heat. Inspect it and replace as necessary.