The shotgun effect does not always work with these trucks...

Picking up a bunch of parts and throwing them at the truck hoping that they work together. If your truck makes less than 525ish hp with just the TST and one of the proven pressure modules (on the correct settings of course)...you have "other" problems.

Where were you posting "when" you were having these problems? Somebody here might have been able to help.

 

It looks like your wallet isn't the limiting factor like it is for most folks so the "shot gun" approach and experimentation may be the best thing for you. What to expect from turbos in the way of performance seems is as varied as the personalities of those discussing them. What one person likes and expects in the way of performance can be way different than the next person. So the personality and experience of the person you get advice form has to be taken into account when the question is asked. Different people drive and work their trucks differently, and that has to be considered. Different turbo and fueling combinations work differently than others. Some trucks have been cammed or had head work done, which effects turbo performance. Then, you have to also realize what works in Texas, southern Calif, or the east coast doesn't really necessarily work in Salt Lake because of altitude, temp, and humidity differences, and interpeting the answers gets even more difficult.

You state you'd like the most power you can get. What exactly does that mean? You don't tow and don't want smoke, so that limits the answer a little. Are you going to drag race or sled pull? Do you want a dyno queen? How important are drivability and street manners to you? Nitrous gives large power gains - have you considered it? Answers to these questions help in the selection process.

The new singles have seen a big improvement over what was avialable just a few years ago. The Silver Bullet, for example, will handle in excess of 800 hp and 65+ lbs boost with a loss in low end performance that is supprisingly small. But it doesn't have low end of a HTB2-12, a turbo good to 500 hp, and the ability to start boost coming in at 1000 to 1200 rpm. A HTB2 is going to be a whole lot more fun and drivable on the street, with better throttle response, than the Silver Bullet ever could have, but with a corresponding loss of top end power. But to some folks, especially those not used to the low end torque of a diesel or thinking spollup form 10 lbs on is all important, the Silver Bullet may be the cat"s meow and everything they're looking in stop and go driving.

My knowledge of twins and the different systems avialable is limited, but in my mind, a system which uses waste gates instead of pop-off valves to vent excess pressures is going to be more effecient and makes more sense.

Lastly, I've personally known truck owners who switched for singles to twins, lost power on the dyno as a result, but have still been very satisfied with the driving performance increase and improvement.

 

Good post as always, Bart.

I look at it this way: every improvement in turbo technology that make as single turbo better benefits twins even more.

To make a charger even capable of handling the higher pressure ratios seen with boost over 50psi, you have to compromise other areas of the compressor map. There's no free lunch here.

I'd personally rather have two-stage compression where each of the compressors is 80%+ efficient, instead of one larger compressor trying to do the same, but with 60% efficiency.

In the end it's all about density, no matter how many turbos are involved. If you can get a lot more O2 into a given volume of pressurized air, then you will be better off.

Twins to me don't give the "hit" of power that a big single, because you're spinning two turbos up, and because they don't have as much lag to contrast against. Twins are more of a big "throb" of power.


I always tell people to go a little smaller on turbos that you think you want to, because spoolup matter a LOT more on a daily basis than 100-150° of peak EGT control. How often are you at peak EGT compared to going from zero boost to nonzero boost?

I'd stick with a single until your fueling needs are more than a 62mm compressor can support. Twins really shine when compared to a 64 or 66mm compressor.

Stated another way, I'd favor a single up to 530hp or so, and twins after that. If you tow, twins look better earlier in the HP chase.

jmo

 

I own both, Some simple observations going from twins to a single large modern charger are: Untill 8-10 lbs of boost the twins cool better, after that it is a toss up. Spool in my trucks are close in everyday driving. Either will do the job you want, I have towed 10k lbs with both and no problems. I think 3rd gens do better with a large single than 2nd gens though. Remember you are gonna spool slower than stock with either twins or a large single. To get twins to cool 600+ hp you are going to need a large primary which is gonna come up slower than some of the small twin sets available everywhere now days. It is all in what you want from your truck. I love my hx40/ b2 setup but there is something to be said about the simplicity in my silver bullet. Both are going to need studs, and care with your right foot till 190 degree water temps. Like Hohn said earlier 525hp and below stay with a htb2 /12 or sps62 and there is almost no downside, above that you have to make some decisions on what is most important to you. Tim

 

I appreciate all the time and info you guys have put into this thread----simply amazing the quality of information gathered here----you guys are great!!

Thanks again.