Intercooler Piping Routing Under the Car- Pic

[ktm]

I routed my intercooler piping under the car for a couple reasons. I was originally going to go with an I/C with the inlet and out on the same side, but I did not like how crowded the driver side would be.

 

I searched for hours and hours, went through a couple six packs just staring at the front of my car before I decided to run my piping under the car.

 

As you can see in the following photos, it is a very clean setup. What you see is the entire setup.

 

I hope these help someone in the future thinking about the same route.

 

 

 

 

[sweetleaf]

Looks good but I wouldn't really recommend it. Look at how long the pipes are and how many bends you have in them.

[ktm]

The air is moving at over 300 ft/sec.....an extra couple feet is nothing. The slight increase in volume is the other issue, but that would only impact the turbo lag. Again, given the velocity, the flowrate would be such that the incremental increase in volume would have a minimal impact.

 

As for the bends, there are no more bends in this setup than there are in a convential behind the fan setup - 4 bends for the inlet, 3 bends for the outlet. As a matter of fact, my outlet bends are very smooth. One 90 degree and two 45 degree. The bend coming up from under the engine is a 70 degree bend.

[Pyro]

Good choice! That is the way I did it. Also did it that way on 2 other Z's. Doesn't effect the response of the turbo in anyway.

 

However, I did run my pipe between the engine mount and alternator. And my engine is not quite as clean as yours. hahaha

[mario_82_ZXT]

Nice pics! I might consider doing it that way on my car.

 

What size intercooler are you running?

 

Also, Pyro, I don't understand what your BOV is doing, it looks like it's still venting into a charge pipe...

Mario

[cygnusx1]

Very nice. I didn't think of that when I was doing mine...what beer were you drinking. Maybe I need to switch.

[Pop N Wood]

The air is moving at over 300 ft/sec.....an extra couple feet is nothing.

 

Not sure I agree with that statement.

 

Turbo lag is the main issue. But headloss through all that pipe is not good either.

 

A pressure guage at the turbo outlet and manifold inlet will answer the question though.

[ktm]

My intercooler core measurements are 20x12x3. It's a little on the smaller side, but should flow enough for my horsepower goals. The overall measurements are 27x12x3. I looked for hours for an intercooler that would fit exactly between the upper holes and also include as many flow channels as possible, while not impacting the lower valence.

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=190139189047&ssPageName=STRK:MEWN:IT&ih=009

 

That is the intercooler I bought. According to Corky's book, I should be looking for a charge area of 66 sq. in. for 400 hp/600 cfm.

[Pyro]

The BOV vents into the suction side of the turbo. I'm still running the stock efi so didn't what to vent to atmosphere and lose metered air. Doesn't make the "cool" turbo BOV sounds but that is OK with me.

 

I ran a J-pipe for awhile and then later added the ic. I didn't notice any difference in lag and only measured a 1 psi pressure drop which I think is typical of any ic install. Just moved the boost reference to the manifold to solve the pressure drop issue.

[ktm]

Pop, you are correct about head loss and lag. However, I shall refer to Corky's book as a guide, which states that at 400 hp/600 cfm the velocity would be around 293 ft/sec (see page 62 of his book). The book also states that a 2.5-in. diameter tube will be adequate to flow 600 cfm without unreasonable drag.

 

Using 293 ft/sec, an extra 2 feet of pipe takes the charge air .007 secs longer to travel. Even moving 200 ft/sec, the extra 2 feet of pipe would only increase the time to .01 seconds.

 

Cygnus, Sam Adams Black Lager.

[FJ 280z]

Looks good but I wouldn't really recommend it. Look at how long the pipes are and how many bends you have in them.

 

 

 

dude, i think it looks great. you might be on to something here, the only downside i see is something coming up from underneath and hitting either the charge pipe or the coupler, or stuff hitting the piping, but if you think about it its not that much longer than honda charge piping or turbo kits for other cars that have miles of charge piping. who knows, pipe underneath the oil pan might act as a pre-cooler for the boosted air by air rushing over it cooling the pipe, might not drop it 50 degrees, but even 2 or 3 helps.

[tickwon]

Looks good!!

[Pop N Wood]

Pop, you are correct about head loss and lag. However, I shall refer to Corky's book as a guide, which states that at 400 hp/600 cfm the velocity would be around 293 ft/sec (see page 62 of his book). The book also states that a 2.5-in. diameter tube will be adequate to flow 600 cfm without unreasonable drag.

 

Using 293 ft/sec, an extra 2 feet of pipe takes the charge air .007 secs longer to travel. Even moving 200 ft/sec, the extra 2 feet of pipe would only increase the time to .01 seconds.

 

Cygnus, Sam Adams Black Lager.

 

It is not transit time that matters. It is pressure drop. Pressure drop and intake volume.

 

Tubing diameter is only part of the story. Take a fixed diameter pipe and make in longer and you will have more pressure drop through it. Just like needing a heavier guage wire as the circuit length increases.

 

And for lag, you need to be concerned with volume of the intake track. With a larger volume you will have a greater mass of air, and under pressure, more stored energy. It is overcoming the inertia of the air mass and charging up and bleeding down of the stored energy that can contribute directly to the lack of a throttle response.

 

I am not saying there is anything wrong with your set up. Looks sanitary to me. But I do maintain that the smaller the intake track the better, both in terms of throttle response and ultimate HP. That is why some people use air to water intercoolers.

 

Measure the pressure drop from the turbo to the intake at full load. That will tell you what you may have lost or gained but the longer piping.

[ktm]

Pop, exactly. I mentioned the very same concerns in my reponse to the first poster (intake volume increase). However, velocity does play a role with the volume increase in the form of Q = V x A. For the incremental increase in intake tract volume, the flowrate of 400 to 600 cfm will quickly fill that additional volume. Thus, I do not expect an appreciable increase in response.

 

Your comment regarding pressure drop is dead on as well, and is a concern of mine too. I am more worried about the pressure drop across my I/C than I am about the slight increase in length of the pipe.

 

If you play around with compressed air flow calculators, you will see that for the tract lengths we are talking about, the incremental increase in length, while doubling the pressure drop, is still below 0.3 psi. (3 foot pipe - 0.17 psi; 5 foot pipe - 0.28 psi). As a matter of fact, my piping is less than 5 feet. It is actually 4 feet long from the turbo outlet to the I/C inlet.

 

http://www.engineeringtoolbox.com/pressure-drop-compressed-air-pipes-d_852.html

 

Edit: Please don't take this the wrong way. I thoroughly enjoy learning and I view everything as a learning exercise. If I am wrong in my understanding, please explain. We got off on the wrong foot in the fuel pump thread.

[big-phil]

I almost did something like that also. I like it.

[Bernardd]

Bo, consider that I'm running 2" piping about 4.5 ft long and a smallish GN IC and make about 400rwhp. You will have no problems at all. Looks great.

[Vindicare]

Do you think there might be room for 3" piping? Doesn't look like it from the pictures.

[ktm]

Three inch piping would be quite tight. If your turbo outlet is 2 to 2.5 inches, just run a 2 or 2.5 inch coupler and short 90 degree pipe to clear the steering shaft. You can then run a reducer up to 3 inches. However, three inches will not clear the stock holes in the front radiator support.

[240hoke]

Looks really good man, you have a clean engine bay.

 

If you think about it it really isnt much different from running it around the front i would think and you are saving it from running along the radiator. In addition the pipe is above or at least even with the crossmember so hitting things really isnt a concern if you hit that pipe you have more to worry about (oil pan). I still believe single sided is BY FAR the best way to go for L's but youve come up with another good option.

 

Anyway looking sweet keep up the good work.

[wigenOut-S30]

Yeah that is a very clean setup.. And as austin said.. keeping it from going infront of the radiator saves you some heat soak. Is that aluminum pipe? If so that even saves you more from heat soak. Looking great KTM.. Very nice looking Engine bay..The only thing I would change is have some of the IC connections welded and get rid of most of the couplers. What size turbo are you running? and what psi of boost are you running? Also.. I am trying to collect data on different IC setups and air intake temps. If you could get some air intake temp readings of normal driving as well as boost? Thanks!! and again.. looks great!!