X15 turbo replacement

[James187]

Hello, turbo on my x15 finally took a crap. VGT I think failed. Engine is the proformance cm2450. ESN 80350134. Looking for a more reliable than stock replacement option. Came across the {name removed}. They claim this larger mm will lower egt {and other nonsense claims} . I doubt most of that is true, but lower egt on a long hill would be nice and better fuel mileage is always a plus. I have insite, so calibration will be done regardless of the fact they claim it doesn't have to be.. Any opinions on this would greatly appreciated. Thank you!

[marek4792]

YTS out of Griffin, GA is really the only one recommended by Rawze himself. Although others have used HD Turbo out of Chicago with mixed results. I however been using a turbo from Excalibur out of AZ, now MO with good luck for 4 months now and didn't have to send my old one as they build them new with American made parts. Otherwise your local stealership is your best bet..

[3406E]

I would stick to factory. I used a zeki sold by once on a cm870 sold from momentum worx. Lasted about 80k miles pulling regular freight, truck wasn’t deleted either. However it boosted alot faster and smoother than stock but surely didn’t outlast it. The fins started to scrape the housing, luckily I heard it and and took it off the truck before it exploded. Changed it at a truck stop in the freezing cold myself.

[Rawze]

(10-11-2026 )James187 Wrote:  Hello, turbo on my x15 finally took a crap. VGT failed at 520k. Engine is the proformance cm2450. ESN 80350134. Looking for a more reliable than stock replacement option. Came across the {name removed}. They claim this larger mm will lower egt {and other nonsense claims} . I doubt most of that is true, but lower egt on a long hill would be nice and better fuel mileage is always a plus. I have insite, so calibration will be done regardless of the fact they claim it doesn't have to be.. Any opinions on this would greatly appreciated. Thank you!

Stop listening to the scads of morons over on social medai...

Over-boosting a modern cummins engine, especially in attempts to forcibly lower external EGT's is a VERY BAD THING. Over-boosting an ISX (really, any modern engine) to abnormally lower its EGT's causes the engine have HIGHER internal combustion temps, not lower.

It causes higher internal cylinder temps, trapping that heat being made into the engine, and lower than normal exhaust temps are seen because the heat is now being absorbed into the engine/cylinders instead of escaping into the exhaust system properly. This also creates more friction combined with higher oil temps, and almost always leads to dancing liners and premature head gasket failure.

The Ideal EGT"s on an X15 when in a 100% throttle sustained load is roughly in the (post turbo + de-mandated) 1050 - 1100F range. The high end of it is about 1150F or so. Holset (the turbo maker), when I asked a long time ago, told me that the max temp for a VGT is in the 1250F sustained, and a peak of 1350F EGT's for up to 3 minutes.

If the engine is de-mandated, a max boost of roughly 32-33 psi should be seen, and more then about 34~ish psi (absolute max) will severely shorten engine life.

If the engine is NOT de-mandated, all emissions + egr in tact, then the boost will often crest about 3-4 psi higher than this, because that extra 3-4 psi consists of inert EGR gas, artificially inflating the boost readings at the intake.

The factory turbo lasting 550k miles first go around, this is about right for it if no one took care of it and never took it apart and re-greased it / serviced it, and basically ignored it until it died.

- Buy a new(or reman) certified OEM or YTS replacement, and if the engine is used for heavy-haul applications, ensure it is the (36-mm) titanium-turbine version X15 turbo.

... and take proper care of it this time, and the engine will need an inframe long before the next turbo wears out.

=================

As far as those claims of those after-marketed turbo's go.. there has been some (non oem) reman, etc. out there that use a recently redesigned (about 2 years ago) modified intake billet wheel ... making the claims that you mentioned above. The reality is that it effectively Downsizes the turbo slightly ... making it slightly more responsive,,.. but its trade-off is that it is now less suitable for heavy-haul, high operating loads, as it will absorb a lot more heat.. and not live as long when run hard. This has been seen more than a few times around here.

Not a bad option for someone who is a hyper-miler and only uses lower HP ranges .. but for someone who tortures their engine all day with heavy throttle positions.. it has no benefit except to empty your wallet more often due to shortened life.

- Still, if I were to go with with that downsized (insert bulls$it fake marketing claims here) billet wheel for use with lower HP application, , I would not get a modded or after-market turbo from just anyone out there selling them. I would have YTS turbo build me one up from an actual OEM turbo, so that at least I know its not half-baked chineesium garbage that is only going to last a couple years and have issues all over again.