My 4.0ohv turbo build thread

[Sevensecondsuv]

Hey, you want to sell me one of the hundreds of turbos you have laying around? I'm planning a turbo 3.0/4.0 project. I want about 5 psi and boost to come on at about 1500 RPM. I was thinking something like the .48 AR hotside / .60 AR coldside T3 I have on my turboranger would be just the ticket to do that on a larger displacement engine. If you have one that works good (doesn't need to be fancy or even clean) let me know how much.

 

[turbo cat]

The reason number one isnt creating any boost is because you have no pressure differential at the turbine. You have to have pressure differential for a turbo work, and the way you have it setup right now is with equal pressure going to both the inlet and outlet of the turbine housing. There is still flow, that is why you think its spooling, but it isnt actually compressing any air. For that to work properly, you have to have a small turbo going into a bigger turbo, and even at that, your not increasing the flow capabilty of the exhaust side. Just run a turbo off of each side, there is no reason to have all of your boost in by 1500RPM, and if there is, just run a bigger turbo with a smaller exhaust housing like a .60/.48 or .60/.63 T3.

There will be a pressure differential. The issue as stated is cmpressor one has half of the energy passing thru it as compressor two. Compressor two will accelerate quicker than 1 creating a higher vaccum at the inlet of 2. Compressor 1 will never have enough spool to over come the vaccum of 2. However If i switch them up. Compressor 2 will have no restriction at the inlet and will spool quicker than 1. It will push compressed air thru 1 and IF 1 is up to speed enough it will further compress the charge. I will play with this possibility tomorrow. If it dosent work. i will make one last change that will work on the hotside. Full compound turbines. two turbochargers of the same size can and have been used in compound setups. Generally you will have a low pressure trubo and a high pressure turbo. The low pressure turbo will be second in line on the hotside yet will feed the compressor of the first turbocharger on the hotside. This is how many compound setups were ran. Theres also no problem wit hfull boost by 1500 its a street DD not a race car. boost at 3500+ on a 4.0 is almost useless on a stock motor anyways. these 4.0ohvs make great torque down low and full boost at peak torque makes a fun to drive DD. i dont need max HP just maximum torque. i do have a super FMu now to feed the thirst of the motor. boost will be low until I get an intercooler. Im not 100% worried about this setup as 5 lbs of boost at 2-3K isnt spinning the turbo too hard. Either way Im going to get the truck running Asap as i have two other turbo rides to get on quick like.

 

[turbo cat]

heres some good info about staged setups and having a larger turbo feed a smaller turbo is mopst popular but two identical turbochargers can be used in a staged setup and i have seen this done before...

"Staged turbocharging, often called compound turbocharging, is a technique used to achieve extremely high pressure ratios by having one turbocharger pressurize the air coming into the inlet of another. It is common in racing with diesel engines (For example tractor pulling) due to their combustion properties that take well to high boost pressures and are not limited by fuel stability like spark ignition engines. Boost pressures of around 100 psi are common and as high as 250psi in some cases.

A normal turbocharger has a maximum pressure ratio of around three but there are turbochargers in existence specially designed for high boost which have maximum pressure ratios of typically 4-5.

In this configuration one turbocharger is used to pressurize the air coming into the inlet of the other, resulting in a multiplication of the pressure ratios. Same goes for exhaust plumbing. For example if both turbochargers are running at pressure ratios of 3.0 and the atmospheric pressure is one bar the resulting pressures will be three bar absolute pressure at the inlet of the second turbocharger and nine bar absolute pressure (eight bar gauge) at the inlet manifold of the engine. The pressure ratio in this example becomes nine

 

[RacinNdrummin]

The thing is though, turbo one will not have enough pressure differential to actually "do work". It wont create boost, and if its not creating boost, it wont compound anything.

Running full compound will be a huge restriction on that engine with those turbos.

 

[turbo cat]

The thing is though, turbo one will not have enough pressure differential to actually "do work". It wont create boost, and if its not creating boost, it wont compound anything.

Running full compound will be a huge restriction on that engine with those turbos.

It would be a restriction at higher rpm but would make great torque. And I may just wait until I find a pair of larger turbos. Or try the small T3s then upgrade to bigger when I can who knows.

 

[turbo cat]

time to play connect the pipes

runs likes shat with bigger injectors and no maf plugged in. I still like the lope lol.

 

[red85]

It sure sounds mean! Whatever that covered line is, it looks awful close to your exhaust.

 

[Iron Ranger]

Good thing that it sounds like that because of some unplugged components, otherwise it sounds like an old diesel thats about to die.

But when everything is plugged in, it should be ready to whip some ricer butts!

 

[turbo cat]

Well the turbine housinghs will be restrictive but it should make some good torque and thats what Im most after anyways. The setup will be a full compound setup. SHould be running tomorrow all I have to do is connect a few pipes together and it will be compounded. ALso this design does away with the need for a front dumped exhaust and so an intercooler can eventually take its place.

 

[turbo cat]

its is now truly compounded I still have to hookup the fmu before i can test

 

[turbo cat]

I had a battle with ther MAF to get the setup to run right with the stock ecu but i figured otu a way that works. The vortec still needs to be installed and it needs a muffler.

 

[RacinNdrummin]

Hurry up and get that FMU on there and turn up the boost.

 

[sittenHIGHon35s]

Hey man just say this post can the poster that did the swap pm me i am doing the some idea need some help

 

[rangerty]

....... what happened to all the pics?? i like the idea of what you have done but over half the pics are missing...

 

[multiranger]

Why is it all the really cool project post never get finished or posted... Nothing worse than reading an entire post only to find it goes no where!