C-Turbo or D-Turbo? - Steel Soldiers::Military Vehicles Supersite

brhino89 · 07-30-2009, 00:12

Hey all, I am new to this site and I am planning on getting an M35A2 in December after I am in the Guard. My question is, which is better, a C-Turbo or a D-Turbo on an M35? Please explain why and the Pros and Cons of each..Thanks a lot! Answers are very appreciated..Brian.

m16ty · 07-30-2009, 00:25

They say the "D" produces a little more boost but the power isn't noticable. Basicly it's just the sound thats the difference. Some people like the scream of the "C" and some don't. For me the type of turbo wouldn't make or break the sale. I've got a "C" on my truck but that's just because that's the way it happened to be when I got it.

I've got a freind that swears my "C" turbo truck has more power than a "D" turbo truck I have for sale. I've driven them both and that's not the case, he just thinks the "C" truck sounds more powerfull.

brhino89 · 07-30-2009, 04:20

Cool, thanks a lot guys! I am going with the C Turbo then. I had thought the D Turbo came with a Whistler as well, but I guess not..I love the Whistle on these bad boys, I have heard a few go by at around 3:30 in the morning and well, it shook my house a little and woke me up fast! Haha, your help is much appreciated!

gimpyrobb · 07-30-2009, 09:27

You are confusing your terms. Are you asking about c & d motor blocks, or about c & d turbos. There are both. I have been told by the guys that rebuild the turbos that the D is made better. I have yet to see shorter lifespan in the C turbos though.

ken · 07-30-2009, 09:38

The "D" turbo has a bigger bearing, a extra heat shield, and a larger compressor wheel and housing. The "D" also has a better oil flow system for the bearing. The "C" sounds better to most guys. The "C" is more than capable of outlasting the truck. But is more prone to baking oil in the turbine end seal ring. Your power level is far more dependent on the fuel rate setting than witch turbo you have.

gimpyrobb · 07-30-2009, 10:14

Oh yeah, go on a road trip with someone with a C turbo. After I helped Stretch bring his m108 home, I knew I would never want a C turbo. The whistle is fun for short trips. long trips suck with them.

swbradley1 · 07-30-2009, 11:44

I have two trucks, one with a C turbo and one with a D. The C turbo truck far and away outperforms the D. That being said I think the C truck has the IP turned up and the power has little to do with the turbo.

I'll agree with Gimp, it can wear on you driving a C unless you have lots of good hearing protection on the whole time. I never noticed the difference in the turbo until I had both of them sitting side by side running one day.

sw

jimk · 07-30-2009, 11:59

I could add- the D has an updated (modern) compressor wheel design. I put a D on a LD(non-turbo) smoker and it pegged the 15psi manifold press gauge, with very high EGT. I turned down the pump over 2 full turns and it still runs stronger than most. Currently 12psi at 2500rpm/13 at 2600 w/ safe EGT. The whistle may be the turbine blade tips, or vortices coming off them, exceeding the speed of sound.

rat4spd · 07-30-2009, 14:26

I love the sound of the "C", however it is just ungodly loud. I'm not talking about concerns going down the freeway. Sometimes I drive the truck to work.. I work second shift. When I come home I have to stop in a local gas station for a few minutes to cool things down. Otherwise that truck idling in my driveway would cause a revolt in my neighborhood. You can hear that turbo idling two blocks away.

mudguppy · 07-30-2009, 18:57

Quote:

Originally Posted by jimk

.... The whistle may be the turbine blade tips, or vortices coming off them, exceeding the speed of sound.

no. a turbo would not last long if this where the case, nor would it even perform well, if at all. it would likely fly apart way before that.

the whistle is produced as a by-product of the exducer design. typically, the fewer the vanes, the more prone to whistle a turbo has. example: ford 6.0L powerstroke - '03 motors "whistle", '04s much less, and '05 - '07s barely at all. '03 turbos had 10 vanes, then 13, then 14 and 15 respectively.

however, inducer design can also produce quite a bit of whistle. example: 2nd gen cummins - go remove the "silencer ring" and you'll get under-hood whistle, especially if you remove the stock filter box.