Twin Turbo 1995 Chevy 4-Door
 

I am starting my custom build on my 1995 Chevy 4-door short bed. I plan on swapping in a 1996 Cummins. Mods will include head studs, Cometic MLS head gasket or factory Cummins head gasket, Valve springs, and a 4k gsk. NV4500 for now, but plan on upgrading to a 6-speed down the road. I would like a compound setup for towing, 400ish HP. I am thinking stock HX35W with maybe a S471, but I would like to hear others input. I want it to spool fast. All the S471 turbos I have seen are twin scroll, is that what is generally used on compound setups?

I would go bigger than HX35 as your top turbo. But it also depends on your elevation. But both of those turbos should get you where you want to be.

Mostly 6000-8000 ft. I'm mostly looking for a quick spool vs max power

My buddy has spent fistloads of money on his 6BT (including compounds) to have both quick spooling for DD use, and also have the 500-600hp dyno number he wants. He doesn't tow... at all. The odd load of firewood is the only workout it gets. Runs 35-37" tall tires with 3.54 gears and breaks NV4500s repeatedly.

It really seems a waste, IMO, to go that route for bragging rights.

OTOH, you can have a very versatile truck with some fuel mods and a HE351CW. No, you probably can't pull 6% grades at 20,000 gross in OD.... but whats that worth to you? :humm:

I will be running 265/70R17 tires, which are about 31.5". Maybe 285/70R17 (33's) but no larger. I went with the S475 due to cost. I hope the compounds don't cause me too many issues, If they do I will sell them off and go with a single.

Didn't realize you had the compounds already. I'm sure you can make them work fine. My broke a$$ always looks at HP per $$$... hahaha

I ordered it last week. It's definitely not the cheap way to go. I've always liked the idea of compounds though so I have to try them.

The only thing that sucks about compounds is getting off the money to get Joe smoe to put them in the mail.

Attachment 30651

I didn't realize how big this turbo was, I'm starting to get pretty excited now!

Attachment 30655

Left to right: dirt bike turbo, Saab turbo, HX35, S475

you should not need compounds at 400hp. IMO thats total overkill. I did a 95 conversion alot like yours yours as few years ago that was 600 hp and lit immediately and had a single turbo. You can get 400HP pretty easy with a p pump. Is your truck lifted or 4wd? i had a ton of problems with oil pan clearance on the front diff. Twins are cool but for what your wanting i think you could make it more streetable with a single. Unless you want twins for the cool factor. If thats the case, stack em on in there!

I just read your build thread two days ago, good job. I want twins to make sure my EGTs stay in check while towing, have a fast spool up, and yes the cool factor. The twin setup should be more streetable than a single because the factory turbo should spool faster than a larger single and then the other turbo kicks in providing adequate airflow for higher HP. Plus it keeps the drive pressures lower. I am a little concerned about fitting them in there though. What did you use for your turbo pushing 600HP?

all said and done i ended up with a silver 62 from industrial. it lit quick and would slam you back in your seat. if i had to redo the build i wouldnt ever do it again. There was alot of problems fitting that engine in that truck and making everything work right. the ford trucks are 10 times easier to fit them into. my egts on that setup never got hotter than 1300. even towing heavy loads up grades in 100 degree CA heat.