Is it more for towing or race?
Is it more for towing or race?
Honestly it's going to be an all around kind of truck I'll be towing with it not as much I would say as I will be racing though. But I do need it as a daily driver as well. If that doesn't work then what do you suggest my move should be?
Head Studs first. Your compound turbos could do some damage. Of everything they are about the hardest to complete too.
2003- 3500 RWD Automatic. S & B intake, BD Intercooler, Pusher Air Horn, MM3 Double R Tuning, Turbo Timer, electric Flex-a-lite fans, FASS 95, 50 HP tips, upgrade to 351 turbo, 3.42 gears, Twin air compressors, air bags, Remote dual oil filters, Hellwig sway bar, Front Winch. Home made Fuel Heater, BD Exhaust brake with Torque Lock. Tons of TLC
I've been around since the early days of 6.7 performance as well steve. Even with a larger compressor blade you can't get rid of exhaust as fast as the 6.7 requires. As far as performance goes a VGT can not compete with a compounded or even single s400. Stew even went with a 66 non VGT on his 3rd gen and gained mileage correct me if I'm wrong stew.
Also with the s400 I'm running with custom tuning drive pressure is 1:1 and boost is 52 psi on stock bolts so far so good
from my research for a good all around single turbo on our 6.7s an S465 and S467.7 seem to be the most popular. A couple guys on here a running BIG singles on stock fuel, i had a thread asking for input that might interest you... i'll link it over. everything i've read a 400 frame is definitely a must. the 300's are too restrictive. as for sound, no matter what, changing turbo will change the sound. and to get rid of the restriction you'll want to swap out the stock manifold. i could be way off, but i dont think a 3rd gen manifold will change it any more than just the turbo will. def be a deeper throatier tone, but not as drastic as the 2nd gen.
now for the record in the different thoughts on turbos... my stock VGT on my 09 has been tuned and tweaked to hit 38psi with 52psi EBP, i know not the most ideal, but alot better than stock 2:1 at 32 PSI boost she hit 45 EBP again, not ideal, but for how the manifold and VGT were designed i think are pretty good and fairly safe. EGT's stay pretty tame as well.
again, focusing on singles, but might give you some ideas http://igotacummins.com/showthread.php?t=2774
So would a large single work better for an all around use than a compound of twin set of turbos? If so why?
Flip that, a large single will have a ton more lag then a proper compound setup
Compounds are very nice on the street when set up correctly. In the case of the "add a turbo" kit it requires heavy gating to let the exhaust bypass the stock restrictive manifold. These kits if not set up properly can cause extremely high drive pressures that can in turn increase combustion pressures that in turn blow head gaskets...even with studs.
The other problem with copmounds on a stock 6.7 is that when set up correctly they bring on the torque at low rpms...which is great for towing and spooling up, but very hard on the stock PM rods. This is why a somewhat "laggy" large single can be an advantage on a 6.7...torque comes on at a higher rpm which is not as hard on the rods and they stay together.
^^^^ exactly why you see less blown engines with a big single than compounds. And the s467.7 is quick spooling when setup and tuned properly. Though you lose the exhaust brake unless you go with an aftermarket version. The 6.7 loves big singles.
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