Turbo systems for X1/9's

[lookforjoe]

Nice mockup. I'd say redo the piping in SS. Mild steel will rot from the inside out. Even though your climate may be dry, you can't remove the H2O by-product of the combustion process That was my (costly) experience with mild steel headers.

On the exhaust though, I think you will find the turbo does not act as much of a muffler. Even with 2 3" magnaflow mufflers and a resonator, the drone on my old wagon setup was enough to make you feel like your ears were bleeding. I got used to it, because it sounded amazing when taken up to 9K rpm - however I'd never do it again. I built a 3" turbo-back SS exhaust with a 3" electric cutout before the single muffler on my current Volvo. I can take a sound clip if you like. There is no (meaningful) muffling from the presence of the turbo in the system.

EDIT: just re-read your last post on the exhaust, and see that you have now included a muffler in the list

 

[Dr.Jeff]

There is no (meaningful) muffling from the presence of the turbo in the system.

Darn, I was hoping there would be some decent noise reduction from the turbo. The muffler I have is fairly small and a straight through design. Basically a stainless "glasspack" or "bullet" type muffler. Those do not do a lot of muffling. And the entire system from the turbo out the tip is short and pretty much a direct line. So again, not a lot of muffling. Guess it will be louder than I wanted. In order to add a larger muffler I'd have to route the exhaust pipes like a big "S", similar to the stock X exhaust, which will add a lot more resistance to the turbo's exiting flow. Think I'll try it as planned first and if it's too loud I can change things later.

 

[Janis]

There actually was noise reduction from same turbo. In video below loudest is conrrod hitting block
Before it started to bang on block, it wasn’t louder than some e30 BMW 2.5 with stock exhaust. Muffler was straight type.

 

[Dr.Jeff]

Thanks for the input Janis, that offers some hope. Although the rod banging is so loud it's difficult to know what the exhaust sounds like

The UT's are very small turbos, so maybe that has a bigger effect on reducing the sound levels coming out? In the past I've read some say their turbo acted as a decent muffler, but others have not found that (like Huss). I'm thinking it might have a lot to do with the actual turbo, the system layout/design, vehicle configuration, pipe size/length, etc? As you know I have the same turbo as you have in the video, so my original design idea might work, we'll see.

But I was already thinking about the exhaust system more. I have a V-band clamp that will be part of it, making it two pieces for easier installation. So maybe I could build a optional second section from the V-band rearward, with the longer "S" routing. Instead of heading straight back, it would go over to one side, make a 180 degree bend from side to side with a larger muffler, then another 180 degree bend back to the center for the outlet. That's a lot of extra bends and pipe though. However the two systems would be easy to interchange with the V-band. Possibly there could even be both designs combined with a remote 'cut-out' like Huss has.

I really want to maintain a center outlet for the tip. I like the look similar to these:

Or I could follow the Japanese trend and go more like these:

Here is the tip and short muffler I have:

Not much muffling in that muffler. But the tip is also a bit of a resonator, which might help a little.

 

[Mechanogeek]

I think the exhaust on the gold leopard print Lambo is definitely the way to go. Keep the heat up and off of the tarmac. Enough exhaust flow, and you gain downforce. Need to install a spark system and some extra fuel to the exhaust pipes to generate flames on demand! AND the biggest benefit is that the people behind you in traffic will at least have a clue that your little exxe is somewhere in traffic! Hehe!

 

[Dr.Jeff]

install a spark system and some extra fuel to the exhaust pipes to generate flames

Don't need to add anything to get Lambo flames:

But if do add the right gear, you can get even bigger flames:

 

[lookforjoe]

This is mine with the cutout wide open, low speed: go to 9:18

This was my old Volvo's turbo setup - it was much larger than what's on my current. This was during the redo to get rid of the mild steel header (no WG dump yet):

 

[Dr.Jeff]

I love cut-outs.
Nice work on the pipes.
To put it into perspective, your wastegate is about the same size as our turbos.

 

[Dr.Jeff]

Although I started this thread to talk about air flow and intercoolers, I'm enjoying all of the turbo related content. So I changed the thread's title to be broader. Please feel free to discuss any/all turbo topics. I know there are some members with complete UT engine swaps in X's, others have experimented with a turbo on the 1500 SOHC, and more that have turbo experience with various vehicles. And all of it is beneficial, especially to someone like me with no real prior turbo experience.

 

[lookforjoe]

I love cut-outs.
Nice work on the pipes.
To put it into perspective, your wastegate is about the same size as our turbos.

Indeed! The UT turbos are even smaller than the Garrett T3 / Mitsubishi TD04H-13c/g series used on Volvo's back in the 80's

 

[TonyK]

Turbo silencing exhaust note.

Just a point here the Abarth engine does not use a muffler as the turbo cuts the exhaust note considerably. The down side for Bob Martin is that he likes his cars loud. My Abarth powered X only has about 4 feet of 2" 304 stainless steel pipe and the car is not loud, nor is there a drone sound in the cabin. The Abarth Turbo spins at 230,000 RPM no typo here, I suppose because the turbo is small and spins so fast this has something to do with it as well.

TonyK.

Grimsby Ontario Canada.

 

[Dr.Jeff]

Sounding more like I'll be o.k. with my planned 'straight-through-muffler' exhaust, and not too loud.
Huss, from what I recall you describing previously, your system was very highly tuned and pushing a lot of power. I'm sure that must have a lot to do with the different sound level outcomes.

It's funny because I've been doing modifications to make the system more efficient, with the goal of reducing back-pressure and therefore decreased charge temps. But I think there will be unintentional side effects of those mods, like increased noise level. But that is part of the learning curve.

 

[Dr.Jeff]

Thinking more about the noise reduction with a turbo. With sound being energy traveling by air waves, the greater the power output (energy) and the greater the engine size/turbo pressure (air flow) the more sound will be generated. So with the small displacement of these engines, low boost pressure, and limited power level, they will be much quieter than something like Huss's Volvo. At least that seems to make sense from a science perspective.

 

[Simon Oaten]

re coolers,

tis worth thinking abt reqd mass flow (engine capacity * boost/static * inc in volume due to temp) and then the delta T across the core......

one is pressure loss versus flowrate, the other is delta T versus flow rate.......

2 bosch "T-map" type sensors will give you an accurate idea as to what is reqd.....

rgds
simon

 

[Dr.Jeff]

In another thread, "Mxgrds" said:
"My setup takes cooler air from outside the car, but also limits the intake air capacity. I didn’t realise who much air the turbo needs. Lately I was looking for the reason my turbo pressure dropped. This was the reason. I removed the hose and take the extra heat from the engine. Back to the drawing board."

What is limiting the air capacity? The location of the intake, the size of the tube, the size of the filter, or ??

 

[Mxgrds]

In another thread, "Mxgrds" said:
"My setup takes cooler air from outside the car, but also limits the intake air capacity. I didn’t realise who much air the turbo needs. Lately I was looking for the reason my turbo pressure dropped. This was the reason. I removed the hose and take the extra heat from the engine. Back to the drawing board."

What is limiting the air capacity? The location of the intake, the size of the tube, the size of the filter, or ??

My guess what’s limiting the air flow? The size of the tube, although it has the same diameter as the afm. The extra corners slows down the air flow. The lenght of the air intake. Without the cool air filter it drives better. You can hear the air sucked in.

 

[Dr.Jeff]

Thanks for the extra thoughts. It's interesting that there is a noticable difference with/without it.

 

[Dr.Jeff]

Aftermarket ECU question, for use with a turbo install.

Recently it seems there are several new options on the market for programmable ECU's. And they seem to be offering a lot more features for a lot less money than ever before. One thing I've been wondering has to do with the sensors most of these ECU's utilize. In addition to a crank position sensor for timing (fuel and spark), they also prefer a cam position sensor. The cam sensor is merely to tell the ECU which cycle the crank is on (as I understand). So it needs a signal every four rotations (hence the use of the cam) and is not as critical as the crank sensor as far as absolute accuracy (again, as I understand). I guess one question might be if all of this "as I understand" info is correct?

But my primary question has to do with utilizing such a ECU (requiring a cam sensor) on the X's SOHC. As far as I know there isn't a cam sensor for the SOHC that can easily be added. I did learn about one used on the Fiat Punto(???) that is essentially a replacement for the distributor. It is basically the lower half of a standard distributor with a wheel and sensor for the top half, no cap and high-tension wires, etc. By giving one signal per distributor rotation it is the input for the stock ECU on that engine. For use on the X's engine, replacing the distributor is not an issue as the aftermarket programmable ECU now controls all ignition functions with external coils. So this would work, unfortunately they are very difficult to get (in good working order) and very expensive if found.

But it has given me an idea. As an alternative could the standard X distributor be used as a cam position sensor by removing three of the four posts on the reluctor wheel? The distributor would now give one signal every four crank rotations (one distributor rotation), as needed. At least some (if not all) of the aftermarket ECU's are compatible with reluctor signals so I don't think that aspect would be an issue. The standard rotor would be left off and a replacement for the cap fabricated (basically a dust cover).

Any reason why this would not work?

 

[lookforjoe]

My guess what’s limiting the air flow? The size of the tube, although it has the same diameter as the afm. The extra corners slows down the air flow. The lenght of the air intake. Without the cool air filter it drives better. You can hear the air sucked in.

To be certain the air filter is not a restriction, this is a great calculator. You can use it for ID of inlet piping also.

 

[kmead]

There was also the crank sensor and belt pulley on the twin cam version of the 138 block, which should be possible to add on. Alternatively adding a toothed wheel and sensor seems like a simple thing to do relative to all the other jobs you are going to be doing to add the turbo, ECU, plumbing etc etc.

You could also add one to the back of the cam so the whole system would be like a more modern vehicle, crank position sensor for ignition timing and cam position sensor for injection timing.

More signal will be more accurate.

So there you have Karl’s just do this it will be easy thought for the day...