L16 turboed??

[MicroMachinery]

Here's a fun read.

 

http://community.ratsun.net/topic/11154-daves-new-510-project-l-boosten/

[Driftease]

Well I understand the principle of both. But I always thought on a carbed engine it would mess with fuel delivery. You jet your carbs in accordance to your environment. Wouldn't the changing boost make the jets only efficient for a certain range then youre running lean or rich?

Any engine modification will REQUIRE fuel system changes especially with carb, even a change such as a header will need jet change to do it right. Having said that yes it does mess with jetting requirements hence the term tunning. It is also required with fuel injection

[smoke]

what? B)

[Driftease]

Normal intercooler pipe couplers will fit right over the r1 carbs, i cut them in half, and then actually used intercooler pipe off each carb to the plenum when i did it.

If normal I/C couplers are used they should be bi layer with a tannish color on the inside which is flouronated silicone that will better handle fuel comming into contact with it. short term plain one layer will work but the gas will over time eat away at the silicone

[spudly13]

guess it depends on your idea of short vs long term, there going on a year and a half now and still holding up fine, not saying they won't break down, just throwing it outr there

[Driftease]

Depends on the makeup of the couplers. I shoot for lasting a lifetime as i am very lazy and do not intend on doing things twice. Having said that if i had all the stuff in front of me to do it with the exception of flouronated silicone I would probably say fuck it and put it togetherand just line the inside with electric tape to stop the fuel from touching the silicone. Sorry wasn't trying to call you out on it or anything.

[spudly13]

Haha yeah that makes sense, wasnt trying to be defensive ort anything, I'm just the type that will use whatever's sitting in front of me!

[ggzilla]

Isn't that the very definition of turbo lag? At first, no difference from non-turbo then a second later an awesome kick.

 

By contrast if you fit an engine twice as big, the kick is immediate. It never feels like the smaller motor.

 

Ya when i had the setup on my honda i had no lag. It felt the same before and after i had the turbo. Then boost kicked in it was awsome.

[smoke]

This is true, but it is literally a split second that it feels like a smaller engine (I should add here, if done the right way). Many look at it cost wise, good power will never be super cheap, but you are going to have to build a 3.2 with a good flowing head, big carb, healthy cam and some compression to stay with a 1.6 liter with around 15psi of boost. Of course, if you leave the 1.6 bone stock with that kind of boost, sooner or later you are going to break something. Now, that is not a solid fact, because I have seen many exceptions to that rule, even I have have done it a time or two and gotten away with it. That's the thing though, if it's living a long time like that, you are "getting away with something". 

 

The way I look at bigger engines is....I love them but I am always bothered by leaving so much power on the table. In example, if I built that 3.2 liter, why not have it pump the same air as a 6.4, after all, I used all good parts to build it, that would handle boost. It will bug me, but that's more of a personal defect. That old 'no replacement for displacement' still holds true, no matter what size engine you have, you are increasing it's displacement with forced induction. These days, with fuel management, boost control, anti lag and so on, lag is nearly non existent. As a matter of fact, I had a car that I made lag more on purpose to get a faster 60 foot time, well, I did it for one race day, then tuned the suspension better than it was so I could actually use all the fancy stuff I had.

[RTB]

That isn't quite true though is it Smoke? you're not increasing the displacement with a turbo, you're just shoving more air and fuel into the combustion chamber. You have to lower the compression ratio or else you would be blowing head gaskets left and right. On a NA motor you can run 10:1 compression and run street gas. You would not be able to do the same with a 10:1 motor that has a turbo. Obviously a properly built turbo will probably be more powerful than a NA motor but by how much and is that option even streetable? In the end I feel more confident in a NA build because there is less that can go wrong.

[smoke]

I am going to strongly suggest you read Corky Bell's book if you have an interest in learning about how a turbo engine works. But, here is the short version, you ARE increasing it's size, at it's base, an engine is nothing more than an air pump.  A 250 inch engine running at 80% volumetric efficiency put out X amount of air at seal level which is 14.7 psi, a 500 inch engine operating at 80% in the same atmospheric pressure will pump twice as much air. So now, assume that you were able to pump twice as much air with the 250 inch engine. You will be therefore be pumping the same amount of air as a 500 inch engine. How? By running 14.7 pounds of boost through said 250 inch engine you have forced and atmosphere into it. Think of your shop air compressor and the air stored inside it as energy. At 50 pounds you have x and 100 pounds you have that much more, but it's still in the same sized tank, just compressed, this is very similar to how a turbo works, it's compresses the air.

 

Now, onto compression. Lowering your compression on a turbo engine has really nothing to do with gaskets. It has to do with the fact that the compressed air makes your car have gobs more compression. You lower the compression to avoid detonation. I will give you an example, you are talking about building a 10 to 1 engine right? Well, an 8 to 1 engine at 15 pounds of boost is 16 to 1, well, like 16.6, but lets not get hung up on that. That's what is great about a turbo, you can run streetable compression until you want to crank the boost to it, You went from having a mild mannered run about car, to a high compression large engine just by letting it boost.

 

I hope what I said here was clear and easy to understand, If you're interested in learning or have any questions, I would be more than happy to help you out.

[MicroMachinery]

Obviously a properly built turbo will probably be more powerful than a NA motor but by how much and is that option even streetable?

 

A wise man once said...

 

Its suprising what some people can street.

[smoke]

And, I forgot about that part. A turbo engine is SO much more streetable that a hot NA engine. Lower compression, stockish cam, small carb as apposed to a high rpm, peaky NA engine. The torque curve alone will floor you on a boosted engine.

[Driftease]

I can respect either build style but I do have to say that my 3.1 stroker was not easy to drive respectfully it was kinda fast but compared to a stock l28et turned up to 15 with an I/C it was not as fast. There often is fewer things to break with an N/A that is logical but by that logic you should also be riding a bicycle to avoid having any more than three parts that are able to break. for track use (real track not drag) an N/A setup can be desirable due to simplicity for the budget minded weekend warrior but if I want a fast street car I am going turbo. 

[Driftease]

I should add that i am in the midst of getting stuff together for a VH swap that will have to remain NA for a while due to me being a broke ass most of the time. I will build 180deg headers and a 3 stage intake to see what I can squeeze out of it.

[RTB]

Thanks for explaining smoke. I have very little experience with carbed turbo engines so its harder for me to wrap my head around the concepts. I think my 2.2 stroker will give enough power and torque for days. Maybe in the future I will build a 2.2 turbo, like kirden.

[MicroMachinery]

We're all learning. Thanks for being humble.

[smoke]

Yeah, it's not super easy really, I have been doing it for a long time and learn new stuff very often. One of the very best example I can use for turbo charging is in a video I posted earlier in this thread of a guy's car from 'drag week'. This event has been going on for quite a while, the times and mph these guys are running in the 1/4 mile was just unheard of from a street driven car years back. They have to drive these cars from drag strip to drag strip all over the country, no trailering. A handful of the cars are pulling 200 mph plus in the 1/4. That's rubbing right up against professional pro stock drag race only cars (which are not allowed to run forced induction). The difference is of course, the one in the video is a metal car, no carbon fiber body, it rolls over the scales at 3200 pounds and makes the drive from track to track without breaking down, heating up and so on. The way he does this is that it is a huge cubic inch engine, but it's low compression, not a crazy camshaft and such. So, when he is just cruising down the road, he is creating no boost (boost comes from engine load). So, at that point, he is just running a big, low compression engine that is just plugging along with no effort. But, when he gets to the track and gives it boost, he has a 2000 horsepower monster. A turbo set up like this is kind of like being able to select which engine you wish to run. Do you just want to float around town, go to work, go to the store, fine. If out of the blue you decide you want a super high compression race engine, it's right there under the hood waiting for you to give it the go ahead.

[Trophy24]

Even though I understood the concepts you describe, You are making me want to turbo my KA and I can't even drive my car yet!

 

I'm going to pick up that book and learn more.

[smoke]

Another really good book that really dives into turbo carburation AND is explained in real straight forward talk is VW based, but that really has no bearing since the principals are the same, The book is called 'turbomania'. Seriously, it's a great read, a little dated, but will still really help a guy get a handle on it. Here it is. 

http://www.amazon.com/Turbomania-Turbocharging-Engine-Bob-Tomlinson/dp/999938272X

[Driftease]

Even though I understood the concepts you describe, You are making me want to turbo my KA and I can't even drive my car yet!

 

I'm going to pick up that book and learn more.

I have a set of wisecos for sale for a ka-t they are standard size 8-1 in a E 9-1in a DE

[Trophy24]

I will be running a DE. I think I am at least a year away from "phase two" on the car. Still not painted yet...

[Driftease]

lol paint is last after its fast