:. Projects/Mods .:. TCE/Wilwood brake upgrade .:
| Materials: |
|
| ·L1R (or similar) Turbocharger |
$1,200-$1,400 (options) |
| ·Outlet elbow, tubing, etc. |
~$100ish |
| ·New gaskets (misc - see below) |
~$50ish |
| Tools: |
|
| ·A few SAE wrenches &sockets, for the SAE Oil line and return bolts. |
~$varies |
Introduction
Not a whole lot to say to a DSM'er about the benefit of a turbocharger - they're the only things that make our cars go! There are just a few special notes to make about this particular type of turbo that I chose for my car.
Being an avid road racer and autocrosser, low-range response was extremely important for my car. Most DSM'ers can get away with having a turbo that starts to wake up around 3,500-4,000 RPM, but for my style of racing, I needed something that would be at full boost in the low 3's, and if possible, even before.
The newest readily available technology to improve boost response over traditional bearing turbos is with a ball-bearing center housing design. These have a very low-friction internal bearing that improves transient response tremendously, and improves boost threshold RPM somewhat as well. The downsides to this new style of turbo is cost, and some will claim, longevity.
The AGP L1R is one such Ball-bearing turbo, a near twin to the FP2544. As I write this, I believe both of these turbo models have been superceded by 'updated' models, so the naming conventions may not still apply, although there will still be many similarities.
To delve into the longevity issue once again, I am not an expert, but I have been told this by a few folks that are: While the ball-bearing cartridge can take higher thrust loads (think high boost), they are more sensitive to heat, to cold, and are extremely sensitive to bearing contamination. Hence, you see the filter in the oil line for these turbochargers as added protection. It's up to you to decide if it's a game you want to play.
The L1R is based off of Garrett's newest line of compressors, and flows 44lb/min, according to Garrett's chart. This makes it about roughly equal to a 20g in maximum capability, although it does seem more efficient at higher pressure ratios (boost) than the venerable ol' 20g.
Installation
Installing an L1R is much like any other turbo install, with the exception that it points downwards, like a 20g, and will necessitate some changes to lower lower intercooler piping, in all likelihood. As such, since it is similar to other DSM turbo swaps, I'm not going to go into excruciating detail, (as VFAQ.com does, and will hit the high notes I noticed, specific to the L1R.
But first, some eye candy: pictures of the L1R, and a comparison to my old Big16g. See figures 1-10 :-).
Now that you've finished with that, I'll mention the only difficult things I noticed during install of the L1R:
1.) Clocking the turbo: As a fully-adjustable Garrett turbo, you can 'clock' every piece on the L1R to suit your fitment needs. This is a blessing and a curse, as getting it all right can be a nightmare. After installing and removing the turbo many times, I finally arrived at a decent method. Before I continue, if you don't have slim fans, I would highly suggest removing them. You may even want to drain the coolant and remove the radiator to give yourself plenty of room to work. Besides, don't you need to do a coolant flush anyway?
There are two adjustments you can make on the turbo between the 3 pieces: the turbine relative to the center housing (CHRA), and the compressor housing relative to the CHRA.
To quickly get the turbo lined up, first, loosen both adjustments slightly, so you can move them. (6 gold bolts on the compressor housing, and 6(?) darker ones on the clamp between the turbine housing and teh CHRA). Bolt the turbo loosely to the exhaust manifold.
The first 'clocking' you can make is the turbine housing relative to the CHRA. Move the CHRA until it is more or less parallell with the ground. By this I mean that the flat surfaces of the oil feed/return flanges are parallell to the ground.
Check that you oil return fitting lines up flush, and that your water return fitting will line up as well. Mark the relative positions of the turbine and the CHRA with a sharpie.
Next, position the outlet of the compressor housing as you see fit. Where this goes will depend on your intercooler piping and fan setup. For my slim Flex-A-Lite fans and Supra Intercooler, see figs 11-15 for how I did it. Once again, don't forget to mark its position with a sharpie when you are happy, in case anything moves.
Note that you will need something to attach to the outlet of your turbo. I bought a 90* red silicone elbow from AGP for my outlet, in case I ever had a FMIC setup that required me pointing the outlet towards the driver's side of the car. AGP and FP will also weld a 90* elbow on the outlet for you, if you so choose.
Double-check that the turbine housing has not moved relative to the CHRA as well.
Pull the turbo off the car, and tighten down everything before reinstalling. (although note #2 below:)
2.) Sealing the turbo: This is a relatively minor point, but I found it worth mentioning. Some of the six gold bolts that hold down the brackets, which in turn hold your compressor housing tightly to your backing plate, are tapped through all the way to the inside of your housing. This means that since they are not NPT threads, you will have boost leaks at the 4 of the six bolts that go through. To seal them, you can either use some Teflon tape, or some industrial "pipe dope" pipe sealant material.
As well, some Garrett users (not specific to the L1R) have reported boost leaks originating between the junction of the compressor housing and the backing plate. The compressor housing seals on the large (1/2" wide) circular surface you see when you remove the compressor housing. A thin layer of RTV or other sealant around this surface will help to completely seal your turbo against introducing any (albeit very minor) boost leaks to your system.
3.) - The oil-return line: Fortunately, you can re-use your stock 1g oil return line with the L1R. However, you have to hog out the upper holes, where it mounts to the new turbocharger, since the new bolts are larger diameter.
You can either take the oil-return off of your car, or you can stuff a rag or two down the oil line while you drill the holes out, as I did. You want to ensure that no metal shavings get down into your oil pan! If you do elect to remove your return line, make sure to have a new gasket for that fitting, and RTV the bejeezus out of it when you do reinstall it, as getting that sucker not to leak is a giant PITA. (figs 16,17)
The larger bolts present another problem, in that getting a socket on the head of the bolt around your water line can be quite difficult. Leave the front banjo bolt for the water line out until you get the oil return bolted into place, and you may have to bend it out of the way a bit to get the turbo, gasket, and oil return flange all lined up. Swearing copiously helps immensely here.
4.) Water Return Line: When installing this turbo, you are able to use your factory water line. However, in the particular arrangement of bolts that I ended up with, the banjo fitting on the end of my line interfered with one of the bolts mating the CHRA to the turbine housing. To fix this, you may need to grind small amounts off of that fitting with a dremel and a grinding bit, until you have enough clearance to fit the banjo bolt and fitting flush with the turbo. (figs. 18,19)
5.) Front water pipe clearance: The main external water pipe for your car runs right behind the turbocharger, under the manifold. The cooled water runs out of the radiator, up through the lower radiator hose, through this pipe, and back into the water pump.
On turbos with larger compressor housings, it is sometimes necessary to put a few judicious dents in this pipe to ensure the compressor housing does not contact that pipe. I had to make some very tiny adjustments with the L1R. And, I had to munge the water feed line a bit too. (fig 20,21)
6.) Oil feed line issues: The new oil feed line that AGP sends with the L1R is a very nice piece. Costs you about $100 worth of Earl's and K&N stuff. There are two sticky points about this oil line. First is getting it tight on the turbocharger. There is a small fitting that screws into the turbo that can remain in the turbo. The oil line attaches to this flair fitting. However, getting a wrench in there can be quite difficult, so you may have to angle the line a bit as ultimately did, to allow access to the line. (fig. 22)
Secondly, since the line is not angled the way the factory hard line is, you cannot bend it too sharply, or it will put too much stress on the junctions in the fittings, and perhaps cause it to fail prematurely. In my case, this resulted in the filter element being placed directly over my BOV return tube (you DO have a return tube, RIGHT?).
As such, I had to cut off about an inch from the BOV return tube of my Dejon pipe, and adjust my return hose accordingly. No big deal, just make sure you've got the capabilities and materials should interference arise. (fig 23,24,25)
Impressions, Results
Moving up to a big turbo definitely makes some changes!
Lag/Spool:First: does the boost response of the ball-bearing turbo justify the cost? Absolutely. the boost threshold RPM of this turbo was nearly identical to my 16g. Transient response (as in shifting, or feathering the throttle) was near instantanous, better even than my 16g, which was pretty awesome. Only in some situations did the size of the compressor seem evident, and it was hard to pin down. Sometimes it would seem significantly laggier than the ol' 16g, up to 300-500 RPM slower.
Power: The pull of this turbo was amazing. The early spool coupled with the larger compressor resulted in a truly ridiculous powerband - 3,500 RPM to 8,500 RPM and still pulling.
My previous best at 24psi on the 16g had been 104mph in the 1/4 mile, my only 1/4 run with this turbo, at 24psi (only) on this turbo was 112mph, although that is with the addition of a few more parts (Intake manifold, 2.5" O2, Primarily). At the 30psi this turbo easily generated, no doubt that number could be much higher.
Note also these numbers are at 6,000' elevation, which takes a significant performance hit on your car. Regardless, the similar boost level should tell you what good, cool, efficient boost can do for your horsepower.
Conclusions, Other notes:
One thing that the larger turbo definitely exposes on your car are the next weak links. here are a few less-than-obvious things to definitely think about before buying a larger turbo, and especially before turning the boost up significantly. I'm going to assume you know about having proper fuel delivery capability!
1.) Head Bolts/Studs: While Kevin of AGP assured me that the stronger 6-bolt head bolts in my engine were strong enough to handle the abuse from this turbo, more cautious owners, and DEFINITELY 7-bolt owners will want to invest in ARP head studs before boosting beyond 22psi or so.
2.) Blow-Off-Valve: While the 1g DSM valve is a great BOV, even it has its limits. Mine would crack open at about 19psi, and while this was OK for the 16g, which could only generate about 22psi steadily. (24psi max) You will need a valve that can hold boost to at least 30psi, and this will require some research on your part. I never did find a valve I was happy with.
3.) Boost Controller: The amount of exhaust going through your engine with this big turbo can be substantial, and as a result, the exhaust backpressures can become quite high. The 14.7psi spring in my HKS wastegate was not up to the task of holding closed against more than about 24psi.
To snap the wastegate shut, I would have needed to buy an EBC such as the HKS EVC EZ (which I did) or a Profec B( has high boost issues) to take advantage of the dual-nipple setup on the HKS gate.
4.) Air Metering: Although extensively hacked, even at 17psi, my 1g MAS began to overflow and drop counts, causing a horrible misfire/surging problem in my car. Upgrading to a 2g MAS solved that problem, and improved part-throttle drivability, and gas mileage.
That's about it, I'd say. Double-check your car for leaks, refill it with coolant if you drained it, and go out to see what your new turbo feels like - I bet you'll like it!!
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fig 1 - my 16g
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fig 4 - look at that porting!.
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Final Pricelist
| Item |
Cost |
From |
| AGP L1R Turbo, Oil Line, 7cm gasket |
$1,300 |
AGP Turbo |
| Silicone outlet hose, 2" pipe |
$0 |
AGP Turbo (special package deal...) |
| TOTAL: |
$1,300 |
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