Adding an aftermarket turbo too stock?

[Gray 5.9]

Will adding an Aftermarket turbo thats one size larger than stock on the 3rd gens, make a little more power and be more fuel effecient, over just adding a power module? Lower boost + lower EGT's = denser air = more MPG's

 

[mattymac]

I went to a pretty good size single over stock. my fuel mileage went down across the board mainly because the larger turbos are less efficient at cruising/easy driving and mainly designed to flow air efficiently at higher boost levels. At 65 mph I would be 9-10 lbs of boost 600 deg. egt's and have gotten handcalculated 19 mpg. Now I am at 65 mph/2100rpm 5-6lbs 750-800 deg egts and get about 17. I needed a bigger turbo for egt's. I think piers makes a stock turbo mod that might do a bit more of what your asking.

 

[RMalone]

I agree with mattymac, a larger turbo will give less boost, slightly higher egt and slightly lower milage when cruising. But they provide the ability to support more fuel (at lower egt), and put a big 'ol smile on your face.

 

[Gray 5.9]

mattymac,

Your trucks pretty close to mine except you've got the 6spd. My boost is around 8psi, EGT is around 600, @ 65 MPH. I'm getting a little over 17 MPG.



Yeah seen the housing that piers sells for a stock turbo, just wondering If I would be better off switching too 3. 73's compared to what I'd spend on the turbo and a power module. The main thing I'm looking for is mostly milage, and alittle more power.



I know If I keep the RPM's below 2000 down too 1800, thats where the sweet spot is for economy, anything above 2000 rpm and milage goes from 17 too 15, even 100 rpms over.

 

[Devan Manis]

Do a search for "tone ring mod" and try that, its free if you don't mind getting a little bit dirty and will do more of what you want.

 

[jray]

I've been running the Piers modified 3g for the last 5 months. I can tell you that when not towing and while cruising under 70 mph I get great mileage. On a recent trip coming back from Laughlin, Nv. my overhead read 24. 3 mpg when I pulled in the driveway. After a fill up I hand calculated it at 22. 8 mpg. This turbo also reduces egt's about 150* on top end.



Piers is an excellent co. and I credit them for making a good product. However this turbo tends to bark alot on my truck when I tow in overdrive. My particular travel trailer is 29' and weighs about 10,000 when loaded. It is also high profile trailer and pushes a lot of wind. I complained to Piers about the barking in overdrive and they were honest and said that they had other trucks respond as my truck did. They also suggested that I move on to a B-1 turbo. Again I think Piers is a great co. and they offer great products, however this turbo didn't work well for my towing needs.

 

[hasselbach]

Odd, I have been calculating my 05 mileage from day one, and my mileage has gone up 1. 5 mpg with the addition of the sps66. I think its because there is less pumping loss and lower exhaust back pressure to deal with due to the larger exhaust housing. It takes more hp to make 10 psi than 6 psi at cruise rpm'

 

[Gray 5.9]

So do the 05's have a larger turbo on the exhaust and intake housing? If thats so, then I would want to leen towards changing my current turbo, though the newer ones don't come with the old fashion waste gate like mine.



Is it possible to install a 12cm turbo from an older 24 valver or 12 valver on my ISBe? or possilbly take a 12 valve head,turbo,p7100 pump and install it on my ISBe?



I got 21 MPG with my 94' 4x4 12v running 70. It had 230,000 miles on it Oo.

 

[TCluff]

if you dont want to add any fuel, leave it stock, 70-100 hp box, maybe the piers mod hy-35, call around and talk to some performance shops like piers or industrial injection, they would be most helpful, i have been averaging 19. 8 at 80mph interstate hand calculated... . that is about 10psi and 700 deg