Project Turbo
Turning Up The Horsepower
A new way to get the gases where I want them to go.
-To fit the turbo onto a non-turbo engine, the first thing to tackle is the exhaust manifold. In a stock Niva, the exhaust is managed with a 4-into-2 cast iron manifold, that then dumps into a long 2-into-1 head pipe. For my turbo engine, I wanted to keep the cast iron manifold, but the exhaust needs to go through the turbine part of the turbo before it exits. So the 2-into-1 headpipe has to go, to be replaced by a custom up-pipe and down-pipe.
-The up-pipe is the one that carries the gases from the exhaust manifold to the turbine housing inlet. The down-pipe is the pipe which carries the gases from the turbine outlet down and out into the air.
-The next set of pictures shows my stock cast-iron exhaust manifold, but all nicely painted with high-temperature aluminum paint. I also changed all the studs because one of them had broken, and one was bent, they cost 1.50$CDN each, but make life a lot easier, when you get new nuts too (it's fun when things can be screwed on and off by hand). For anyone who is interested, the studs were M8 X 1.25 X 36mm.
-The next thing was the up-pipe, now because this peice has to turn sharply upwards, I couldn't use any pre-bent exhaust pipe, so I had to make my own curve. I did this by cutting a few "pie-slices" out of 2 1/2" exhaust pipe, and welded them together with all of the small sides towards the inside of the curve. Because of the large diameter of the pipe, as well as the fact that the gases in this section are under slight pressure, I highly doubt that a tube with a nice smooth bend would be any more effective. Who want's to pay someone to make a curve like that anyways, when you can do it yourself.
-The second issue to deal with is the fact that the cast manifold has 2 holes, and the turbo housing only has 1, so all I did was cut the two header pipes off after about 2cm, and wrapped them with a big 3" exhaust pipe adapter, (3" outside on the fat part, 2 1/2" outside on the skinny part). Then I crushed the pipe to be able to get the studs past. It isn't all that pretty, but it will work.
-The next issue: the inlet to the turbo is about 1 3/4" diameter, and my pipes are 2 1/2" diameter. So I cut a bunch of slits into the end of the last section, and squeezed them inwards until I had a nice smooth neck that was 1 3/4", I also put a small chunk of 1 3/4" pipe on the end to make it come out flat and to have a nice peice to weld the flange to. The next pictures show the up-pipe in a few different stages of construct.
-The only thing that is less than perfect in my up-pipe is that when I welded two of the pie-slice together, I had two of the perpendicular sides together, meaning I had a flat section, then a more severe curve. If I had flipped one of the two peices over I would have had 2 lesser angles rather than 1 sharp one. Ah well, live and learn as they say, right?.
-A few notes: -The Niva's 2-pipe header is welded to it's flange by the inside for some reason, and the welds take up a lot of the pipe's cross-section, hampering flow. I welded the 2 pipes from the outside instead and removed all the weld from the inside with a die-grinder. You can clearly see where material has been removed on the following pictures, and see how big the holes are once it is painted, compared to stock (if you've ever seen the inside-welds I'm talking about). -I ran all of the flange surfaces on the top of a bench sander (belt sander?) to make all of the surfaces nice and flat and smooth.
-A few more notes: -The last set of pictures show what everything looks like when it is all bolted up. Notice I also took out the studs from the second flange in the up-pipe, I opted to have the turbo bolt down through the flange rather than have studs come up from the flange through the turbo's flange. The reason is clearance, I didn't want the studs in the way, and the bolts fit nicely out the bottom. Although the up-pipe flange has threads for studs, and the bolts thread through those (M10 X 1.5), I will put nuts on the bottom of the bolts for added clamping power. -I've found taps to be a very helpful tool in cleaning threads and rethreading holes that have broken studs in them. However, be sure to have good quality taps, cheap ones will break easily, always spray cutting oil on whatever you are threading, regardless of the type of metal, and always follow the intructions. The holes must be drilled to the right diameter before you try threading a tap, wrong diamaters will cause ineffective thread height (when the dia. is too large) or broken taps (when the dia. is too small). Good taps come with a chart of what drill bits to use for which taps. -Everything here is bolted up without any gaskets, I'm not forgetting, I just haven't cut some gaskets out of high temp material yet, but it will be done before final assembly.
-The orientation of the turbo is critical, I had to have mine low enough to be able to put a hose on the compressor outlet, it had to be far enough from the engine to leave room for the intake manifold and all other engine paraphenalia. It also had to be oriented so that the compressor inlet pipes will not interfere with the stock cooling lines. You can see in the first pictures where the coolant lines will be passing, relative to the compressor inlet.
-In the second picture, you can see how close the pipe, even with such a sharp curve, passes pretty close to the inner fender. I'm not too worried about this though.
