nkeehn

Ok, so I'm going to be using a 18x12x3.5 on a 400hp engine. According to Corky Bell's books, that's too small. According to everything else I've read, it'll work. I figured it worth asking around and seeing what other people's experiences are... What's everyone using turbo and intercooler-wise? How much boost and how much power? How's it working out?

Zero R

iTrader: (1)

That size will be fine, for that Hp, especially if it is bar and plate. It wont leave you too much room to grow though. If I can ever get the time I will be updating the thread on turbo sizing with IC info as well. A lot of how well it will work is in the style/type of core, placement, and ducting properly.

-S-

nkeehn

You should post about sizing, it's kindof a black art in some ways so any info is good. Yes, I'm using a bar/plate and I don't plan on upgrading, 400hp is plenty for this application. It's a FMIC and I'm going to be planning on ducting it.
Here's a question for you, I'm thinking about improving the flow through the intercooler by making a sortof one dimensional bell mouth out of small piping on the front side of the channels. I was also think about putting them on the intake side of the intercooler inside the end tanks. Think it'll help?

nkeehn

Here are some pictures to help explain what I'm talking about...

Zero R

iTrader: (1)

Yes that will help in eff. I have done it here on mine you can use half round or small diameter tubing. I would do that as well as putting deflectors in the end tanks as well to help spread flow more evenly across the core. Doing both has shown to improve eff. as much as 10%. I wanna get most of this info up and most of it is common knowledge just like the turbo stuff, I just figure it helps out the guys on the board who don't know as much. It's good to see your putting in the effort to make a quality setup most just slap on a cheap tube and fin and call it a day.

-S-

nkeehn

Have you got any other tricks to increase intercooler efficiency without increasing size greatly or creating alot of pressure loss? I'm using 9.4 rotors with a blowzilla so anything to help reduce detonation is important. I'm even thinking about alky injection and a secondary water to air intercooler to help get the temperatures even lower, but weight and space are quickly are becoming an issue and it would be nice to simplify the operation of the engine a bit. Anyway, tell me what you think...

Zero R

iTrader: (1)

If your going to design and make the tanks, take the time to put in the baffles, and the half round on the bar ends. Limit the bends in pipework to a minimum and have tank entry and exit as smooth as possible as far as angle in and out. Doing these small things will add up as a whole. Minimizing any bends allows the airflow to be less restricted. Less work for the compressor wheel to work for the power meaning less effort required by the turbulators in pulling heat, and so on, and so on........ you get the idea. For 400whp I wouldn't worry about all the extra stuff needed for W/A IC.


-S-

nkeehn

what's your opinion on water injection or alcohol injection?

Zero R

iTrader: (1)

I think it has it's positives and negatives like with anything. I wouldn't design my system around it, or let me say have my system depend on it. I would build the car you want then look at that as a addition to...not a reliance on.

-S-

z-beater

I agree with zero. I think that it is a very handy thing to have. But many people see it as a bandaid. Tune with out and then use the injection and if you run out of fluid you will not be up the creek. Just my 2 cents.

pistonsuk

This depends on what you are trying to do. In your case it seems your main goal is to reduce detonation. If this is the case then water is your answer.

Water injections main function is the cooling of the combustion mixture by the heating and vaporization of the water. Water has both a higher specific and latent heat by a factor of roughly 2 when compared to alcohol. This means that water injection will remove twice the heat that the same mass flowrate of alcohol would remove. This value might be slightly offset if it is possible to inject more mass of alcohol than water. You must also consider that alcohol is a fuel which will also introduce heat to the combustion.

Justin

pistonsuk

How are you planning on attaching these bell-shaped covers? This looks like it will reduce the head loss over the IC, which should allow for more flow given the same pressure drop.

Another aspect that should be considered is the heat transfer resistance associated with the attachment of this piece, and the resistaince associated with the additional distance the heat must conduct though to reach the ambient air.

btw: In no way am I saying this is a stupid idea, just want to explore all aspects. I am a big fan of innovation.

Justin

nkeehn

I was thinking alcohol (toulene) over water because it is a fuel with a very high octane rating and a much lower combustion temperature. It won't take away from power as much and it will allow for more adjustment to the fuel mixture.
As for the intercooler modifications, the half pipe front will stream line the surface and allow air to flow more freely through the intercooler. The air flowing through the intercooler is doing most of the cooling so that little edge bit that doesn't get cooled will be compensated for.
Zero, I for one would love to see a post on proper intercooler selection and possible modifications. I think dispelling alot of the mystery involved with turbocharging would save more than a few wankels from death.

Zero R

iTrader: (1)

True but you have a few problems that go with it. 1)those who don't have the money to do it right and are too impatient 2)those who choose not to search and post the same question that is being asked three threads lower. As for the water injection I would use more water than "fuel" for reasons stated above by pistonsuk. It works wonders as a antidet. Tune/build your car to run at the desired power level without water. Use a little water as a buffer for suppression. Then if you want, set up the water system so it's mapable like fuel. You can then set up a second tune for when you think your gonna pick on someone. Switch maps turn up the boost and go. By doing it this way you are not always relying on water. Me personally I wouldn't tune to water and run like that all the time. I would rather tune to pump with possible water suppression and second tune for C-16.

pistonsuk

Tolulene, being a fuel, is not something I think that you would want to inject separately. That would be like having a wet nitrous system and turning off the bottle to only allow fuel in. Granted it has a higher octance rating, but this can only be useful if it is 1)replacing the low octane fuel and 2)there is an increase in manifold pressure or timing to take advantage of the fuels octane. By separately injecting it the above mentioned would be hard to control easily.

I toyed with the idea of having a separate fuel cell with a high tolulene content (maybe 50/50 with 94 pump, or C-16 if I removed the O2) and a secondary fuel circuit (regulator and pump). I was going to use a series of electronic soloniods to allow for the supply (and return) to the rails to be switched over quickly from the interior. That way in a matter of a few light boost runs (to drain the rails) you could up the boost (with electronic boost controller) and maybe get away with 20psi or so safely.

Justin