[J.t. Layman]

Was talking to a buddy this morning on the way to work about truck upgrades. I mentioned replacing the stock turbo with a 64.5. He instead suggested doing a sequential setup instead. Keeping the stock turbo and adding a bigger one while eliminating any lag at all. More horse and more torque. My question is how big should I go? I had wanted to add bigger injectors as well. Would I be able to add a 75mm turbo, then have 125's or 180's? I know I'll probably need a lift pump, so I was thinking the fass titanium series. What size would I need? Do I need a different cp3 or duals or is the stock good enough (which I doubt)? Would the regular 425 head studs be fine or would I need the 625's? Does it need a different manifold? Such as a modified second gen? Would any of the motor parts need replaced for the added power such as the push rods, connecting rods, or pistons? I'm giving this a lot of thought, hence the number of questions. Would a racing cam or heads be required? I would appreciate the advice. Thank you for your time?

 

[tryNto]

:welcome:

Here are some Threads on the subject. https://www.cumminsforum.com/forum/gtsearch.php?q=sequential turbo set up

 

[smelonas]

Stock turbo will choke if you try and go for big HP on compounds.

362 sxe is a great option for power lag and durability. Run a 75 on top for best use of the stock RPM range.

Sent from my SM-N950U using Tapatalk

 

[MoparProud]

Guys run a 75mm S400 in compounds all the time with the stock turbo, with absolutely EXCELLENT results. You're not getting rid of lag, and if you think your stock turbo has lag.....well it really doesn't. They light extremely well.

Sequentials...good luck. Instead of trying to reimagine the wheel, do a standard stock/475 compound setup and enjoy the hell out of your truck.

I've been in several stock/S475 setups and they are the best all-around setup for somewhere around 700hp on the planet, PERIOD. Save for my triples, there isn't a better driving/better spooling setup around. It simply doesn't exist.

Bonus is kits are available pretty cheap.

 

[waywardtravel]

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ That. I went 740 on a stock with 475. The 63/475 was a PIG comparatively. Engineered diesel 63/68 was a PIG comparatively. Read up on the mods list quoted.

 

[BigmanT773]

Welcome to the forum!

Lots of reading to do if you’re interested in getting into this hobby.

Your buddy is spot on with the twin turbo setup. I’d start with building the transmission first, and getting some EFI tuning. Once that’s done, upgrade the turbos. Stock/475 is a fantastic combo. Then once you’ve done all that start working on fuel.

 

[iamthecoop1991]

Stocker/475 is a super popular set up and there's plenty of places that sell the kits cheap. For 700hp ish it's unbeatable.