Choosing The Right Turbo For Your Cummins!

Today’s video is a highly requested one. I get asked on nearly a daily basis, “what turbo is best for my application?”. While I am by no means a turbo expert, I do have to understand turbos and how they respond to given combinations in order to do my job of pairing the proper torque converter stall. Let’s use this video as a Think Tank and a conversation starter to get more turbo information out there! Please like and comment on the video. This helps KZbin promote it more and helps us get more engagement from professional turbo experts and gets better information out to more people!

[@savagefabrication795]

Pretty neat to be mentioned 🤜🤛 lol Side note I can destroy that t4 housing without giving up anything or I buy my housing back. If y’all wanted to try it. Most everything sounds good, awesome video! but lol. Always a but. The view on wg’s is kinda a older tech view. Nothing wrong with it but what happens is that the turbine wheel has its own map aswell and that map is essentially a compressor map rotated on its side. The turbine wheel has a rotational speed vs gas speed that it “wants” to be at. Meaning it’s shaft torque output to flow rate is at its best in that range. If there was no compressor wheel, just a turbine wheel, and you had a dyno attatched to the turbine wheel along with pressure sensors pre and post you can watch the turbine wheel’s shaft torque increase peak then decrease all while it’s speed is continuously increasing. This is the goal of the gate is to play the happy compromise between pressure ratio needed to reach the airflow target and maintaining the rotor speed of the hot side in a region that keeps it in its best flow/torque output range. We watch this with adequate sensor data and it’s a very neat thing you can adjust once you see it. The way the average enthusiast can adjust the rotor speed is via the compressor wheel size. The other way that is more involved is adjusting the pressures in the turbine side generally in the turbine housing nozzle or across the turbine wheel itself. The way to take a fairly educated look at this for the every day owner is to learn how to plot a compressor map out using iat and map. Then using a drive pressure gauge and tach to look for the drive spike. If the drive spike is occurring while there is compressor map left after a plot it is generally a good indicator that turbine speed is too high. It certainly can be other things but you need more sensor data to figure those out. Being out of compressor will have a falling boost curve at engine rpm increases-compressor beginning to choke, compressor burst, that’s about it. Reaching Actual compressor choke in testing/practice has been a little more difficult then I originally thought it would be. You kinda have to spec the turbo on purpose to do it. Generally what we see is the turbine just gets going way to fast a lot sooner and then drops off on shaft torque production/mass flow earlier. Which you feel as the driver with the motor laying over sooner. Or on a graph it’s where hp will be most the time. Since everything is finally so out of wack that the torque loss per rpm starts reducing hp. Way too much to type but hopefully this helps someone. Been adjusting the rotor speeds in compounds lately aswell via pressure changes and it’s kinda crazy how much it is adjusting the overall system by just moving the rotor speeds back over to there more efficient locations. Shaft speed sensors are kinda the best way to go about this but that’s not realistic to ask every person to have. But most have the other sensors already onboard :)

[@LoganbuiltRaceShop]

This was the type of response I was hoping for! Pinning this to the top for all to see!

[@savagefabrication795]

@@LoganbuiltRaceShop you got it all down pretty good :) it’s just alot to type and it’s what I live/breath/always learning lol. I am sure you can school me any day on trans and chassis stuff. I did meet the guy who helped tcs with the billet input which is super neat talking with him on transmission stuff.

[@LoganbuiltRaceShop]

@@savagefabrication795 I am alway eager to learn and I know by starting a conversation with this video, I too will learn something!

[@savagefabrication795]

@@LoganbuiltRaceShop I think I really great example that kinda appeared in a recent photo is the setup Firepunk built with the e gate on the manifold and a e gate on the interstage hot, costly, but it gives you full control over both chargers rotor speeds/ pressure ratios so both torque control and Charger efficiency can be accomplished extremely well. It does start getting into the questions of is the potential torque creation dangerous which is generally yes lol. Our motors are awesome but making it run at the same rpm/torque as a c18 cat is probably not the best idea. The flip side is you should be able to keep the average afr quite high if the chargers and gates are mapped well so you could be clean, cool, and responsive at a lot higher torque output in a wide rpm range and you can just control fuel delivery to scale out as a multiple of the factory afr. Cody did a killer job on the fab work on that build

[@AmisCorolla]

Thank you guys. We are kind of last of the dying breed, so it is kind of cool to see peoples get to gether sharing they knowledge.

[@1GenWalker]

About the stock appearing holset units. The 67/67 holsets have done around 700-900 horsepower I believe, it may have been more. Do keep in mind that small frame shaft with the 67 comp wheel may not live long. But 67/67 holsets can put down some power. Also tons of people including myself are going to be running hx35s or he351s as the high pressure charger for there compound setups as they thrive in there. 60/67, 62/67, 63/67 are the main wheel setups for these turbos . The game changer in small frame holsets is the turbine side.. 76/67 exducer/inducer turbine wheel is your friend, and make sure you find a good turbo builder such as Duncan Fenley to port out that housing and the internal gate ported equally as much.. although there’s always an option for a 14cm t4 housing. Which may be the ticket. I’ll be doing some testing. An external gate may also have to be used.

[@slowaf12v]

Great Video Logan!!! Thanks for the information!!

[@racedieseldave]

Great video!!

[@dbfabworks5320]

Love the video!!!!! I like all your experience with the s300 stuff. Im a compound guy myself for 12 valves and love the he351 platform also. Would like to hear more from you on the big turbo stuff and compounds. Keep it up!!!!!!

[@Thesongstaysthesame]

Awesome video, Logan! We’ve been running Wimer chargers on our tractors and pull trucks with wild success

[@wolfemanoutdoors]

Good video brother!

[@bcbloc02]

Even a 62 is a little large for my taste on a stock 12v 5.9 if you are going to tow very heavy as its not going to be willing to full party till you are over 2200rpm which with a loose converter can get by a lot better than a stick truck that is going to have to pull from clutch engagement till its desired highway speed so in town doing a lot of accelerating its hard not to be a smoke machine if the trailer is heavy (10000+lbs) on a 500-550rwhp setup. For towing heavy the 57mm s300g is a much better choice it can do 450rwhp and over 1100tq but it would be pushing it hard to do 500rwhp. That being said it will have the same power as the 62 400rpms lower and will pull strong from 1500rpm on up versus probably being 1900 to get the 62 going good. Twins are the ultimate solution for a tow truck though because you can have it pull strong from 1250-3500rpm with the right turbos and keep egts in check for 600rwhp where as egts will be out of control on that 62 making over 400rwhp.

[@allenstyer205]

Best turbo for spooling your freinds truck would be using is a stock appearing he351 from a third gen. I installed a small handful of stock appearing turbos with steed speed manifolds and they spool very fast. Fleece cheetah is a 63/65 and on common rails can be pushed over 800

[@1GenWalker]

I don’t recommend a cheetah for anything over 450hp. The turbine wheel is actually a 64mm and the 12cm turbine housings on them are extremely lackluster in the flow department. And the 64 turbine wheel don’t do shit for flow as well. Your egts and drive pressure will be through the roof if you try to push a whole bunch of fuel through a cheetah, ask me how I know I’ve done it lol.

[@allenstyer205]

@@1GenWalker I did 710 to the wheels on a bone stock turbo. I've raced and towed with a fleece cheetah on my truck already. There's nothing "lackluster" about it

[@1GenWalker]

@@allenstyer205which fleece cheetah? The 9cm or 12cm housing? Because the 12cm housing don’t flow for shit. Also your 64mm turbine wheel is holding you back.

[@allenstyer205]

@@1GenWalker seem to flow pretty good for me since I won 3 out of 4 dirt drag events and the championship at the local motorsports park in the 2.5 inch turbo class

[@1GenWalker]

@@allenstyer205 I’m just letting you know you are losing power with that 64 turbine wheel. And I just saw that yours is a 351, which is a 9cm housing which is the much better flowing of the two in stock form. But I’m telling if you send it out and drop in a 76/67 turbine wheel you will see an absolute world of a difference. I have experience with this😂 any turbo builder who knows anything about holsets and making power with them will tell you 64 turbines ain’t worth a fuck when it comes to making power. Now don’t get me wrong you can make power but your engine and turbo are suffering because of it. Extremely high drive pressure and high egts. And over spinning the fuck outta the shaft most likely .

[@ronniephipps6555]

I am trying to make 800 what do you think of the s475 turbo with 200hp injectors yes I am using head studs plus a water/meth injection an a anteater