LOL yeah! NO2 was an idea too.

I like the sound of Turbo spooling and the Blow Off Valve.
I am still dialing in my fuel injection. But when I do have mine running, the turbo lag is almost nothing. So I'm not worried.

 

First off, I apologize because I really have nothing to add about the original subject other than I think it will be cool when (and if) it's done.

Now, I'm not going to get into the turbo vs. supercharger debate, but I will say the Doc has been spot-on while a lot of others here sound like they listen to their fart-piped Honda driving buddies a little too much. What I want to address is the argument about Top Fuel dragsters. Y'all really need to think before you open your mouths. Why do they still run roots blowers? Because the rules don't allow anything else. Why? The NHRA and IHRA want to keep the cars somewhat "normal." Fuel cars have been blown since the fifties, and the fans expect to see a big blower on top and six-foot flames blasting from the headers. Call it too simple of a reason, but it's true. That also allows the sanctioning bodies to control them, without having to write more regulations for new components. Another thing is that the amount of heat and volume of gases generated by a fueler is beyond what any turbo can manage. Ever wonder why the flames are coming out of the headers? It's because the exhaust is on fire. There is so much fuel being pushed through them that the combustion process never really ends until the exhaust is in the atmosphere. That's right, when the spark plugs ignite the fuel, it burns in the cylinder, keeps burning as the exhaust valve opens and the piston pushes it out the exhaust port, and continues to burn while it's being shoved through the header. As far as the fuel they burn, yes they burn alcohol, but only a 15% mix. Why do they call them nitro cars? Because they run an 85% nitromethane (CH3NO2) mixture. The alcohol is only 15% of the total, and that's because there were way too many failures when they were running 95+% nitro, so the NHRA called for a maximum of 85% nitro. Fuel engines are actually very near hydro-lock when they are running wide open. They consume about 23 gallons per pass, including burnout, back-up, and staging. About 15 gallons is actually used on the pass itself. Do the math, that's 60 gallons per mile. All fuel engines are based on the Chrysler 426 Hemi, regardless of what decals or bodies they put over them. There are no Ford parts on John Force's Mustangs and no Chevy parts on Tony Pedregon's Monte Carlo. Yes, the engines in the dragsters and the funnies are the same basic construction. They don't have extremely high compression pistons at all. You don't build a boosted engine with a high static compression ratio. You design it to have a manageable dynamic compression ratio. If you knew anything about a Hemi, you'd know that to get high static compression ratios, you need a piston with a huge dome because the volume of the chamber is massive. This huge dome interferes with propagation of the flame front in the cylinder. Plus, they don't induce a lot of swirl or tumble when they compress the fuel/air mixture. Keep your eyes open when a fueler is being torn down, and you'll see flat-top pistons. Why? Because the blowers are making up for the low static compression. When you force as much air into the cylinder as they do, the compression skyrockets, so a low static compression is necessary. On average, a fueler has about 42-45 psi of boost. That's right, 42-45 psi. They need that much boost because nitro doesn't really like to "light off" unless it is under a ton of squeeze. It's actually a very stable fuel until you atomize and compress the hell out of it. You can see how they build power now. Massive boost and unimaginable amounts of fuel. All of this in a 500 ci version of an engine that was designed in 1963 by some gearhead engineers at Chrysler. Of course, when you build that much boost through mechanical means, you have to give up some power. In the case of a fueler, it's about 900 hp. Yes, 900 hp to drive the blower while wide open. Show me any turbo in the world that takes 900 hp to create 45 psi at 8500 rpm. I dare you. Any mechanically driven over-pressure device will require more power than an exhaust driven one given the same amount of boost and engine speed. The laws of physics force that, and they win every time. I guess I lied about not getting into the argument, so sue me.

 

LOL! I actually like a post with NUMBERS to explain things.

I also have to think you favor Chrysler [img]i/expressions/face-icon-small-tongue.gif[/img]

That's ok. I've had them all. Was all Ford for a while. Nothing but 302's.

Now I've got Three Mopars and that is all.

One is a 1974 Duster I am building slowly but suely. Guess what it is getting? A T U R B O [img]i/expressions/face-icon-small-smile.gif[/img]

On a late model Overhead Cam V8

Wait till I open the hood on that sucker at the race track!

 

Very, very good post 69HemiGTX. You know your stuff and it shows. About the only thing I can add is:

Many years ago a team was experimenting with two HUGE turbo's blowing into a 14-71. The idea was that when the huffer became a restriction the turbo's would help out and the efficiency would come up. I saw a picture of the engine. I was wild looking and the real deal.
Low and behold, NHRA outlawed turbo's on any fuel engine next year!!!! I was told because the turbo's acted like a muffler and NHRA did not want any noise restriction because that is what brought the crowd in. True or not; I don't know? I think another reason was that things were getting around 300MPH and NHRA did not want things to get too fast if this combo worked. I want to say Armnstrong had a hand in this engine but I don't remember. Maybe you do 69HemiGTX?
I know Armstrong had a 2 speed blower that he was going to put on a fueler. Low and behold that was outlawed also. I know that worked!!!!

Also let me say this. A little over 14 PSI blower boost is 1 atmosphere. That is the amount of pressure pressing down on the air to let it enter your engine. A 500CI engine with 45 PSI of boost on it now thinks it's a 1,600CI engine!!!! No wonder these things are fast................and expensive!!!!

 

I'd just be happy with 10 PSI [img]i/expressions/face-icon-small-smile.gif[/img]

Say Dr. I noticed on the bro in laws 318 Ram we turbo'd that when his restrictive cat and pipe would blow off at the clamp joint just 3 feet down from the downpipe he'd immediately get 2PSI increase.


I am still tuning my ATV. But also still running the STOCK muffler on it minus the plug in spark arrestor.

I wonder what the increase it may be to get some sort of free flowing muffler after my turbo?
I'm coming close to 10PSI right now, and that's with crappy tuning into the boost still.

 

I'm not sure I inderstand this, or maybe what you meant to say. Technically, 1 atmosphere, as you put it, is 14.7 (sea level) PSI, so 14 PSI of blower boost is "2 atmosphere's". I get into this alot with guys that think a 1 bar MAP sensor will measure up to 14 PSI of boost........NO, a 1 bar MAP sensor reads engine vacuum up to atmospheric pressure (no engine vacuum), which would be "0" on a boost gauge. For a computer system to be able to read/understand/display boost you would need a 2 bar MAP, which reads up to 14.7 PSI above atmospheric pressure.

Not saying you didn't know this, but if not I hope it helps along with anyone else that questioned this topic.

Later

 

Hey this is some good reading. Can anybody tell me how do you know if you are overspooling a turbo? I know the turbo needs to be sized to the engine but if the turbo was sized properly for a 650 and then going to a 730 with race head and 8:1, does the turbo need sized differently. I always read where they say a turbo is good up to a certain amount of HP....
you guys seem very knowledgeble.

 

"I'm not sure I inderstand this, or maybe what you meant to say. Technically, 1 atmosphere, as you put it, is 14.7 (sea level) PSI, so 14 PSI of blower boost is "2 atmosphere's". I get into this alot with guys that think a 1 bar MAP sensor will measure up to 14 PSI of boost........NO, a 1 bar MAP sensor reads engine vacuum up to atmospheric pressure (no engine vacuum), which would be "0" on a boost gauge. For a computer system to be able to read/understand/display boost you would need a 2 bar MAP, which reads up to 14.7 PSI above atmospheric pressure.

Not saying you didn't know this, but if not I hope it helps along with anyone else that questioned this topic."

I usually type guage PSI, but it becomes redundant. This time I didn't. Thanks for clearing that up.

"Can anybody tell me how do you know if you are overspooling a turbo? I know the turbo needs to be sized to the engine but if the turbo was sized properly for a 650 and then going to a 730 with race head and 8:1, does the turbo need sized differently. I always read where they say a turbo is good up to a certain amount of HP....
you guys seem very knowledgeble. "

Yes a turbo needs to be sized properly to work properly. There really arn't that many cartridges for what the ordinary person does with these things. The cartridge is the center section of the turbo. Then you have the exhaust snail size and turbin wheel size. You also have the compressor housing and the compressor wheel size.
Now, can get a little complex when you size these things but things overlap a lot.
For example; according to the books I have a certain turbo will fit everything from a 78CID to a 121CID. That is a lot of room for one turbo to fit. Now, within that room you can play with things like turbin housing sizes. If you make too little boost for your liking you can get a smaller turbin housing. If you make too much, you can get a bigger housing.

So I guess the answer to your question is; no you don't need to resize because there is many adjustments you can work with. One of the main ones is a wastegate. I have a turbo right now that can go 25+ pounds on one of my engines but I have it screwed down to around 8. This way I can run pump gas in it.
On a race engine you want to go a little small on the turbin housing, that way they will build boost fast but you can limit the amount with a wastegate. But on the other hand you don't want to go too small because it will be an exhaust restriction.

It's all a trade off game.

 

Yeah when I first was checking into Turbos people (on the internet) would always say how you needed to be EXACT on the turbo size and what trim wheels, etc. Many people throw around that turbo lookup chart thing with all the squiggly lines on it to figure turbo requirements. [img]i/expressions/face-icon-small-tongue.gif[/img]


But as I started asking people at the track about them (who actually USED turbos) about some used ones we had, wanting to use on a truck, etc they told me you can adjust a lot of things out with tuning. And like Dr Turbo said, you just don't want to be so small it causes too much of a restriction on the exhaust.

At AZtractor and Turbo where we bought the T04 for the bro in laws 318 dodge, and the little one for my ATV. He said people were running it on 660 Raptors and similar. But could possibly work on mine. Mine's 350cc, a far cry from 660. Yet it spools just fine!


Today I was working on it some more. I programmed more fuel based on the (2 BAR) MAP readings as it goes into BOOST and finally for the first time felt my ATV really pick up some power. I still had the fuel lookup map off in a few places where it stumbled for a bit as I accelerate, but then it gets to the sweet spot where I am now closer with my fuel and the damn thing screams to red line and floats my valves!!! It was kind of awesome actually.

Think I need to get the Valve Spring kit now for my Warrior.

I need to mount my LCD display and buttons somewhere to where I can access it when riding and then go make adjustments. A little more tuning and I'll make a video of it in action [img]i/expressions/face-icon-small-happy.gif[/img]

 

Man, some needs to explain what I would be getting into time and money wise on a turbo for a 660 raptor or how about a 250r ,I'm sure I will need fuel injection, if someone has any info please share