Ball Bearing Turbo experiences- want to hear from you

This is not my theory but I have used it and it has been used by many very high HP engines, gasoline and diesel. Compact manifold and those sleeves in Cat engines help keep the exhaust energy and velocity high in the manifold before turbo. That energy is then used to spin very large turbocharger that you need for very high horsepowers. If you have large manifold you need smaller turbo to be able to spin it fast enough but with smaller turbo you can't get high horsepower. There is also some other negatives with larger manifolds concerning gas exchange but I think my english skills are not enough to explain it.

C-18 manifold is for C-18 and B-manifold is just antique.. Cat engineers knew what they were doing and it was not for NOX emissions. Bigger manifold flows more in the flow bench but real race engine builders don't care much about flowbench numbers, pulses and velocity are much more important.

 

Your english looks fine to me, please carry on......

 

I think what Lenny is trying to get at is that each OEM manifold is TUNED to a particular engine setup. A mechnical engine like a B model is not going to develope the same pulse energy and harmonics in the manifold as an ACERT will or a C15, ect.

The C18 manifold may cause a loss of pulse engery as the gas velocity drops significantly entering the manifold maybe compared to a properly spec'd C15 manifold.

I think you have to address each engine build, the parts you want to use and it's intended application before you can say if a particular manifold is better than another. In a work truck you need far less manifold than most people think, you can actually go backwards by using too large a manifold or one that is not tuned for your engine.

 

Pipe diameter is mostly about rpm range you want the engine to work, not the power levels. If you have stock rpm, use stock manifold.(ported and coated is ok but not enlarged) C-18 manifold might work better at higher rpm, maybe over 2500 rpm, just a quess. In B-manifold times engineers didn't know so well what they were doing and engines were completely different, especially turbo and fuel injection.

 

I agree with Lenny as well, I didn't think the B manni is all that people make it out to be. The only reason I dumped the stocker was for egt. I know it will flow more than a stock C15 but I don't think it's neccesary anymore for big power. The head ports are the size of the stock manifold, the way the exhaust enters the big B square ports it seems very turbulent to me and I doubt it will flow any better than stocker in this case. Also to me jakes are really important and with the B you pretty much lose most jakeing power. Now I know you east coasters will say it does fine on the hills out east. But out west with the elevation and thin air I can't build more than 7 lbs! Where out east I can hit 15+. With that being said I'm going back to stock manifold to get my jakes back. I'm sure the turbo is killing it to some but the way the exhaust pulses and loses velocity through the B manifold I'm quite sure that's my jake killer.

Last month I made 980whp with a cam swap and some ECM work. I'm going to bolt the stocker up and see whats up, in time I'll put it back on dyno and see the difference and like Lenny says I'm sure I'll be surprised with the outcome. Yes egt might be slightly higher but with 56psi of boost I'm sure there's enough air there to keep it cool. That and I want my #### jake brakes back!

 

Isn't the C18 manifold about the same as the B manifold?

 

Still using the MT stage 5? and 59 injectors? and what cam did u use?

Not to bash u or nothing but depending on what turbo u are using. More boost isn't always cooler temps. It has to be in the turbo effiency range or its gonna be too hot and kill ur egts even more. Less boost with a bigger turbo say 30lbs is normally better for more power then a smaller one with say 40lbs.

 

Yeah no #### I know that ive seen a compressor chart for this turbo and its still in its efficiency range at that boost, barely.

Still stage 5 and 59s. 800 horse boat cam.

 

What are ur temps under high load? You got jakes or pacs?

 

I also lost jaking power going to the BB turbo (about 5psi) and I stayed with stock manifold and went to smaller A/R........Not sure why it did this.

Even though the exhaust wheel is the same size as the stock one the compressor wheel is bigger on the BB, IMO the engine wont have enough air flow to spin the compressor wheel fast enough on engine braking.........Yes?