Turbo BS Thread

What are you looking for? @BananaMan

 

I've got a holset he351w twinscroll that's going to be feeding my 2tr build. Nobody makes a decent regular turbo header for it, and there's definitely nothing out there for a twinscroll header for it. I've tried finding books or literature of some kind to make one myself, but I haven't had much luck. I know you want the exhaust pulses from two cylinders going to one side and the other two to the second, but figuring out the math and volume and everything to get the pulses hitting at the right time to really take full advantage of the twinscroll is what's getting me.

 

You need equal length and paired runners for true twinscroll. So 1and3 are paired and 4and2 are paired. Merging each one for proper scavenging without taking tons of space is kinda hard. My BMW manifold and turbo are twin scroll and takes up a good bit of room because of it.

 

I'm lucky in the fact that once the AC lines and factory air box are out of the way, there's a good bit of space to work with. So I hopefully don't think space will be my limiting factor. Although it is a big turbo, so I'll have to see.

 

Firing order is 1-3-4-2. It's easy to visualize the pairing if you take the head off and rotate the crank. 1 and 4 pistons both come up at the same time, obviously only one of those will fire per cycle (1). Rotate again and 2 and 3 will both come up, now (3) fires. Rotate, now (4) fires. Rotate, lastly (2) fires. So to space the pulses out evenly, pair 1/4 and 2/3.

Runner length and diameter are next. Obviously equal length helps. Sometimes it's difficult with packaging, do the best you can. Smaller runners have higher gas velocity and will choke sooner. Bigger runners flow more up top but typically don't spool as quick. I usually use small runners, 1.25" sch40 pipe. Can still make plenty of power, it fits in tight places better too. You really need to be honest with yourself, are you planning on a high revving 800-1000whp 4 cyl vehicle? Then probably use larger runners. No, then smaller.

I'm using 1.25" sch40 on my 3.4 v6. Matches the port dimensions and I'm not looking for more than 400hp currently. Definitely not equal length due to space. I tried making it equal but with the coil bucket brace I couldn't install it, so I wasted a day on that basically.

Just make sure everything fits and you can actually access all the bolts.

 

I'm aiming for 500whp, I was thinking 1.75 sch40 to flow for the big turbo without choking too soon. I'm aiming for 7500 rpm with a custom cam grind from WEB cams, along with LCE's pro HD 20+Lb valvetrain kit.

 

1.5" sch40 is your friend.

 

1.25" sch40

1.5" sch40

 

https://www.enginebasics.com/Advanced Engine Tuning/Short Vs Long Tube Headers.html

 

Does that come with a wastegate? As well as a selectable spring pressure?

What does the rear of the turbine outlet look like?

Is that a T3 inlet flange, and what is the turbine A/R?

Lastly....make sure to only test drive out of boost, until the proper fueling is implemented....A bit of a given, but heed that universal warning

 

Nearly finished on the race truck. Upper support bracket for the intercooler, and a gauge or two to install, and it will be ready for tuning. Added in a little extention and bend, from the scrap pile, then welded in a bung for the AEM wideband.



The owner came buy, and had him have some fun practicing TIG welding on his transmission cross-member. Then I added in some reinforcement. That thing was flexing like a bow. I need to get a better picture. This piece ties the very end to the main truss. 3/32, 309 filler was used for that.



Got a little muddy on a test drive....that was quite fun.



This is the start of the upper supports for the IC.

 

So in this picture, it looks easy to modify to fit the wider width of a 3rz header. On the bottom plane of the runners, as referenced by the photo, a cut and and add a straight piece in. Mount to 3rz flange.

 

Pulled straight off a 2006 Cummins. Internally wastegated and as adjustable as you can make it. I have a smaller version on my Jetta and have it somewhat reigned in at 28psi using the internal wastegate and manifold pressure. They're fairly simple to adjust and if the OEM spring rate is too high you just get another that isn't as strong. 98% sure it is a t3. Can't tell if it's a single or double scroll, would assume a single, but the exhaust mani is not a complete log.

Dude wants to sell complete as is.

 

Is this for you, or the one @BananaMan was referring to? He said his was twinscroll.

 

Almost. The port spacing was a little off as well. But all the manifolds would put the turbo at the back of the bay and tucked in tight to the motor. Which when mounted to their respective engines would be underneath and to the front/back, or side actually. Since some were for the rear engine MR2.

 

For me. I'm hoping to wait out a guy on facebook for a lower bid. It looks rough on the outside but should clean up. Didn't want to pay more than a rebuild would cost me combined when I could get a new one. If he won't bite on the $200 low ball then I'll be passing on it.

 

Being resourceful just takes time.

 

Yes. Meanwhile I can gather other stuff up. After looking at that exhaust mani on my computer Ima say it's a twin scroll. Just looked up the Cummins firing order and 1-5-3-6-2-4 would lend credence that it is a twin. Especially if 1&2 are on the short side.

 

Mine was a rebuilt pull, just like this, and it's T3 but it's not twin scroll. I use this wastegate actuator

$165 Turbosmart (TS-0626-1262) 26 PSI Internal Wastegate Actuator for Dodge Cummins Turbo Diesel Engines

https://www.amazon.com/gp/product/B00B2HE006
You can pretty much build a HE351 the way you want it
https://agpturbo.com/3rd-gen-cummins-t3-divided-inlet-4-4-he341-he351-outlet-14cm-for-s300/

 

Hey all I'm working on a turbo build for a 98 3rz and I'm trying to find a denso o2 sensor that threads into an m18 1.5 bung with this plug:

Anyone happen to know a part number?

Edit, in case anyone is wondering the denso part no is 234-5622.