V6 Turboing

[SemperFi]

Originally Posted by 09CobaltSS/Turbo

Because it is like a Diesel .. Normal injectors squirt the fuel in the opposite stroke towards the bottom. DI has a VERY VERY small window of time to get the fuel into the cylinder. we are talking quarters of a milisecond to get the exzact amount of fuel for every stroke .. VERY complex

How do yall know all this stuff. Its impressive and entertaining.

But I do have a quick question. 6000+ seems like a lot for a single turbo, but i believe it. What I want to know is how much HP and torque gain do you think we will see? Because it better be more than enough to get faster than the SS, since the price difference between the two engines is smaller than that turbo cost...

[UsedTaHaveA68]

Originally Posted by 09CobaltSS/Turbo

Because it is like a Diesel .. Normal injectors squirt the fuel in the opposite stroke towards the bottom. DI has a VERY VERY small window of time to get the fuel into the cylinder. we are talking quarters of a milisecond to get the exzact amount of fuel for every stroke .. VERY complex

The "opposite stroke towards the bottom" is usually called the "intake" stroke.

And CobaltSS, the DI does NOT, repeat, does NOT inject fuel during the compression stroke. Do a little research before spreading false information on these boards. It injects it during the intake stroke, just like a normal engine. Taken from http://www.theautochannel.com/news/2...19/313350.html:

A diesel, however, DOES inject the fuel near the TDC of the compression stroke. The reason gasoline engines, including the 3.6DI, don't do this is because of the rate at which gasoline burns. Gasoline burns much quicker than heavier diesel fuel. If you were to inject it at TDC, where the air is extremely compressed and HOT, you would probably spontaneously ignite the gasoline. This results in an EXPLOSION, also called detonation. Everyone knows this is bad. In a gasoline engine, you want an extremely rapid, but CONTROLLED burn. Not an explosion. Thus, the only thing the new V6 has in common with a diesel is the fact that the fuel is injected directly into the cylinder. Absolutely. Nothing. Else.

Edit: Well crap, I tried to embed the animation so everyone wouldn't have to click on the link, but I couldn't get it to work. Sorry guys.

[fierodeletre]

Originally Posted by UsedTaHaveA68

The reason gasoline engines, including the 3.6DI, don't do this is because of the rate at which gasoline burns. Gasoline burns much quicker than heavier diesel fuel. If you were to inject it at TDC, where the air is extremely compressed and HOT, you would probably spontaneously ignite the gasoline. This results in an EXPLOSION, also called detonation.

If detonation occurs at TDC wouldn't the force of the "EXPLOSION" force the piston DOWN? Where it was going anyway? Detonation occurs because the fuel burns as the piston is still travelling upward. When fuel burns as the piston moves downward, the energy is allowed a mechanical "place to go" and burns much more smoothly. Diesels are nothing more than controlled detonators. They burn smoothly. So does the DI. It's controlled by spark ignition however.

Your explanation still doesn't explain why the DI motors use high PRESSURE fuel injectors on the same levels as DIESEL engines. Speed is not the issue. Quite a bit of engine power is used to attain that level of fuel pressure. Why do that when you don't need to?

[MerF]

Originally Posted by 09CobaltSS/Turbo

If anyone knows something about turbos, rear mounted turbos are junk. I made a thread about Forced induction already but seems the word "turbo" is more recognized.

I know about turbos, and you are wrong. Just plain wrong.

Originally Posted by 09CobaltSS/Turbo

......Imagine turning on a garden hose that is 100 ft vs 50 ft .. what hose will have water coming out first ? The answer is obvious .

Bad analogy for a bad point. The only reason you are waiting for that water is that the air in the hose has to be displaced first. If the hose is already full of water, no matter how long it is, the moment you apply pressure to one side water comes out the other. Instantly.

Now, keeping in mind that water doesn't compress this makes the analogy less pertinent. However the fact remains that the "lag" is negligible for the average rear-mount setup over a traditional manifold.

Originally Posted by 09CobaltSS/Turbo

LOL yeah you take Charge piping from a turbo and Decrease its diameter by half and see what happens LOL can you say Loss in PSI

Seriously? Do you understand physics at all? Smaller diameter with the same amount of air would actually increase PSI. That doesn't make it better, granted...I'm just pointing out to anybody who is looking for credible information to look elsewhere.

I will expand on the point he is trying to make though. Using smaller charge piping will decrease the efficiency of your turbo. So when you're at the strip and pulling 25 PSI on your next 9-second run you probably won't be able to (it's so hard to truly type sarcastically, but that was as close as I can make it).

The point is, you don't run a rear-mount in hopes of making huge numbers usually. Most people who are seriously making a racing build will build the manifold for the turbo. Rear-mounts are practically bolt-ons, there's no reason to worry about making the pipes >3" and you could get away with 2.5" charge piping just fine with a medium sized turbo making ~15 PSI.

Originally Posted by 09CobaltSS/Turbo

A turbo works by using the excess gas not being burned by the engine which is injected into the turbo pumping hot exhaust through the cold side or ( intercooler ) back to the engine .

Wow. I'm going to go out on a limb and say that you have a major typo and don't actually believe what you just wrote. I'll let you fix it, but in the meantime, anyone who is looking for valid information on turbocharging do NOT read this man's post.

[CamaroSpike23]

Originally Posted by vladkgb

theres no way a turbo or super charger "bolt-on" kit will be made and still run on pump gas. its impossible because the v6 has 11:1 compression due to the direct injection, this engine wont be able to take much boost at all before detonation will be a big problem. If the v6 gets any type of forced induction expect atleast a head change to lower the compression ratio, which = big monies.

the v6 is also a DI motor... similar to a diesel, which will typically run 15:1+ cr with donkey buttloads of boost as well.

Originally Posted by THE EVIL TW1N

I think the prices for a turbo upgrade will be closer to $6000+.

keep adding. remember, this will more than likely be a TT system when offered as both cars are true dual exhaust. I could see an STS system going for around 7-8k.

Originally Posted by SemperFi

How do yall know all this stuff. Its impressive and entertaining.

But I do have a quick question. 6000+ seems like a lot for a single turbo, but i believe it. What I want to know is how much HP and torque gain do you think we will see? Because it better be more than enough to get faster than the SS, since the price difference between the two engines is smaller than that turbo cost...

we know this stuff cus we read and work with these things. (some of us anyway.)

it wont be for a single turbo. more than likely it will be for a TT setup. similar to the vette setup. and priced accordingly.

Originally Posted by fierodeletre

If detonation occurs at TDC wouldn't the force of the "EXPLOSION" force the piston DOWN? Where it was going anyway? Detonation occurs because the fuel burns as the piston is still travelling upward. When fuel burns as the piston moves downward, the energy is allowed a mechanical "place to go" and burns much more smoothly. Diesels are nothing more than controlled detonators. They burn smoothly. So does the DI. It's controlled by spark ignition however.

Your explanation still doesn't explain why the DI motors use high PRESSURE fuel injectors on the same levels as DIESEL engines. Speed is not the issue. Quite a bit of engine power is used to attain that level of fuel pressure. Why do that when you don't need to?

detonation occurs any time the air/fuel mixture combusts when its not being ignited by the spark plug. technically it wouldnt be detonation at TDC because the spark plug should already be firing before TDC.

as for why DI motors use high press fuel injectors, its because they are in the combustion chamber, not in the intake manifold. what does this mean? basically that the injector has to be able to withstand the immense compression of the cylinder and still be able to spray the fuel and atomize it properly in a given amount of time.

[RT21]

Originally Posted by MerF

I know about turbos, and you are wrong. Just plain wrong.

Bad analogy for a bad point. The only reason you are waiting for that water is that the air in the hose has to be displaced first. If the hose is already full of water, no matter how long it is, the moment you apply pressure to one side water comes out the other. Instantly.

Now, keeping in mind that water doesn't compress this makes the analogy less pertinent. However the fact remains that the "lag" is negligible for the average rear-mount setup over a traditional manifold.

Seriously? Do you understand physics at all? Smaller diameter with the same amount of air would actually increase PSI. That doesn't make it better, granted...I'm just pointing out to anybody who is looking for credible information to look elsewhere.

I will expand on the point he is trying to make though. Using smaller charge piping will decrease the efficiency of your turbo. So when you're at the strip and pulling 25 PSI on your next 9-second run you probably won't be able to (it's so hard to truly type sarcastically, but that was as close as I can make it).

The point is, you don't run a rear-mount in hopes of making huge numbers usually. Most people who are seriously making a racing build will build the manifold for the turbo. Rear-mounts are practically bolt-ons, there's no reason to worry about making the pipes >3" and you could get away with 2.5" charge piping just fine with a medium sized turbo making ~15 PSI.


Wow. I'm going to go out on a limb and say that you have a major typo and don't actually believe what you just wrote. I'll let you fix it, but in the meantime, anyone who is looking for valid information on turbocharging do NOT read this man's post.

Wow. I think the dude you were "correcting" is all the above:

a. has no idea what he is talking about
b. has no idea that he doesn't know what he is talking about
c. is feeling really silly right now
d. wishing he never posted on this thread.

[Grape Ape]

Originally Posted by CamaroSpike23

as for why DI motors use high press fuel injectors, its because they are in the combustion chamber, not in the intake manifold. what does this mean? basically that the injector has to be able to withstand the immense compression of the cylinder and still be able to spray the fuel and atomize it properly in a given amount of time.

The DI engines need high pressure injectors (& fuel pumps) because they do inject during the compression stroke in certain modes Mostly light loads and cold starts not high loads where knocking is a threat. Here is a pretty good article on them: http://autospeed.com/cms/title_Direc...0/article.html

They mention about half way down that the computer opens the throttle wider in the first mode (Stratified Charge Mode) to reduce pumping losses.

The higher pressure should also produce smaller droplets which would in turn provide more cooling of the air (actually just faster, but time is limited).

[MrIcky]

Well one thing that is 100% clear from this post: Many people don't fully understand turbos, and maybe moreso on the STS's.

I still think the STS looks pretty good for a bolt on set-up. Despite the long routing, it does appear to be easier to set up for a street application. Watching an install video, it appears to be something doable in a garage over a weekend.

[Mr. Wyndham]

I really like the STS setup. Clearly, its not the ideal system for a racecar...but how many people build honest-to goodness racecars, anyways?

[MrIcky]

Originally Posted by Dragoneye

I really like the STS setup. Clearly, its not the ideal system for a racecar...but how many people build honest-to goodness racecars, anyways?

LOL, as many posts as you've read Dragoneye, you'd think the answer is obvious. Your answer is 'everyone here' .

[Mr. Wyndham]

Tuche...

[fierodeletre]

touché <--- sorry

So do the GM DI motors use the Bosch system? Or the Mitsubishi system? Or a proprietary one? Something else? Pretty neat tech write up though Grape Ape, thanks for that. So it can both fire during the compression, the intake or a mixture of the two, or both. Crazy.

[Rock]

Originally Posted by SemperFi

How do yall know all this stuff. Its impressive and entertaining.

But I do have a quick question. 6000+ seems like a lot for a single turbo, but i believe it. What I want to know is how much HP and torque gain do you think we will see? Because it better be more than enough to get faster than the SS, since the price difference between the two engines is smaller than that turbo cost...

Usually a 50% increase in power across the board, so somewhere around 400-450 at the crank. It could be potentially more or less depending on how agressive a setup is built. You got to pay to play. The more power you want the more it costs. You figure a Garret GT30 Turbo costs around 1500-2000 dollars, and it's one of the more popular turbo upgrades nowadays in addition to gt35r
http://siteground207.com/~protegeg/p...roducts_id=695
Sample of an upgrade for the Mazdaspeed3.
I'm not too familiar with 6 cylinder turbo setups personally, but previous posts are correct, in that most kits will more than likely be twins, and small snails too. Most of the 350Z kits are twinsetups, but I'm sure some people WILL make singles for those on a budget or want big power from a big turbo instead of two little pea shooters.

Sample of a Single Turbo Kit for a v6 from a good turbo company:
http://www.turboneticsinc.com/produc...category_id=65

Here's a Twin Kit, not sure of the pricing but on another site it was close to 8k:
http://www.airpowersystems.com/350z/350z_tt_tuner.htm

Notice they get almost double the stock output.

[CamaroSpike23]

Originally Posted by MrIcky

LOL, as many posts as you've read Dragoneye, you'd think the answer is obvious. Your answer is 'everyone here' .

not really.

everyone might talk about how they would like to build a race car or how they turned a wrench on one or two or that have taken their bolt-on car to the track once or twice, but there arent a lot of members out here who have built their cars into full/near-full race cars.