LB7: questions about s475/stock

[danzick]

So I am considering building my own s475 kit over stock. I have my own tig welder I plan on tiging all of the plumbing. I guess my main question is how does having a s475 over stock work with factory components? I dont plan on opening the engine up at all. I was also planing on leaving the stock head bolts alone. How is the spool up with a factory stall converter? My plans are to mantain the 500+/- HP that I currently have but have it more reliable with lower EGT's. I rode in a buddies 2006 dodge with a 6.7 engine and twins. He does not have it all modded out. Just 50 hp injectors. The truck daily drives awesome and pulls his 40+ ft triple axle toy hauler like its not even there, pulling big hills at 70 with 1100-1200 EGT's.

 

[plowboy_lbz]

Works great with the stock motor. My truck has been over 600 hp for the past couple years on a completely stock motor. A duramax is nothing like a psd or a cummins so don't liste. To those guys. If you have a stock trans I wouldn't do it till you build your trans. If you just want to stay at 500 hp the. Built your trans, add a lift pump and some good tuning and call it a day. Much simpler than adding twins for the power your wanting.

 

[danzick]

I have been at 500+ for over a year now. My transmission is built, and I have a fass lift pump. I feel like every time I step into the throttle My insight is flashing at me. If I run WOT from 2 gear to 5th locked im looking at 1550 and up. I just dont like seeing that out of my engine. Im looking to cool those EGT's down. I have water/meth and Its a pain. Half the time the tank is empty and I just find it a hassle and i would like to get rid of it. I thought about a s366, but for pretty close to the same amount of money I can build my own kit and have good spool up and good top end.

 

[SickLL7Crenshaw]

I have been at 500+ for over a year now. My transmission is built, and I have a fass lift pump. I feel like every time I step into the throttle My insight is flashing at me. If I run WOT from 2 gear to 5th locked im looking at 1550 and up. I just dont like seeing that out of my engine. Im looking to cool those EGT's down. I have water/meth and Its a pain. Half the time the tank is empty and I just find it a hassle and i would like to get rid of it. I thought about a s366, but for pretty close to the same amount of money I can build my own kit and have good spool up and good top end.

Who does your tuning?? I'm running the s475 over stock on my lly and love it. Been on this setup for 2 years. Factory head bolts also at 126k :thumb:

 

[plowboy_lbz]

You won't regret twins. If you have the means to do it yourself then go for it and don't worry about your motor as long as you have good tuning.

 

[danzick]

Using kory's. Great tunes. My next question would be about the coolant tank. I like the looks of the smaller aluminum ones. I could tig one up pretty easy. Are they as simple as they look? An aluminum box?

 

[plowboy_lbz]

Using kory's. Great tunes. My next question would be about the coolant tank. I like the looks of the smaller aluminum ones. I could tig one up pretty easy. Are they as simple as they look? An aluminum box?

Yes.

 

[danzick]

sweet. I think those look a little better than shoving the factory plastic one up in the corner. Most kits I see use a 2 piece hot pipe between the 2 chargers. Is that necessary? or just makes install a lot easier? I just see an extra clamp and fitting that I could eliminate.

 

[Chevy1925]

the 2 piece makes install easier. I bought a moroso surge tank from trent long ago, works awesome and i like the looks as well.

you will love the twins. you can have your cake and eat it too as it was said long ago

 

[danzick]

Sweet! I enjoy fab work a lot so it will be a good project for me. Not in any hurry at all I just wanted to ask a few things before I started hunting parts down. I wasn't planning on making a new bridge but I see a lot of kits use one. Can I make it fit without?

 

[Chevy1925]

shouldnt be an issue. my kit uses the factory federal y-bridge.

 

[danzick]

good to know thanks. 4 or 5 inch down pipe? I assume 4 inch would be a lot easier to fit and probably cheaper to get bends for. Is there much of a gain to be had for a 5 inch down pipe? also, Looks like most kits drain back directly into the pan. would it be in my best interest to drop the pan to drill/tap it? or do people leave it in and flush it out some how?

 

[Chevy1925]

I'm running a 4" and the big tune is close to 800hp, i can't 5" will make that big of difference but I have not tried it. It's definitely easier to fit between the frame and motor.

Mine drains into the valve cover and have no issues. Most do the oil pan and yes, remove the lower pan when you drill it.

 

[danzick]

great. thanks for the good info. I will probably drop the pan and do it that way. Probably go with a 4 inch down pipe.

 

[plowboy_lbz]

great. thanks for the good info. I will probably drop the pan and do it that way. Probably go with a 4 inch down pipe.

That's what I did. Most stressful thing todo. Take plenty of time to do it. Measure measure measure!

 

[danzick]

Is it a lot of work to drop the pan on one of these trucks? my next question, what material do I use for plumbing? Id like to keep cost down, but I can tig weld just about any material. what thickness? 14 gauge? 16? going to try and get a pretty stout estimate on total cost.

 

[Chevy1925]

Get under the truck and look lol, it's not hard to drop the lower. You can't drop the upper without pulling the trans or motor though

 

[danzick]

upper? I guess I dont know enough about these motors. I just thought there was one oil pan. luckily I get to pull the valve cover off again here soon to replace a couple injectors that went bad after 4000 miles.

 

[danzick]

OK, so with some research I answered most of my questions. My next one that I didnt seem to find a good answer for was aluminum vs aluminized for the intake side. I have an aftermarket intake horn and I hate how its steel and has surface rust on the inside. I wanted to do aluminum tubing for the intake elbow at the big charger, and the piece connecting the 2 chargers. Is it really necessary? or is aluminized fine? its a fair amount more than just aluminized. Especially the 5 inch 90 for the intake. I plan on keeping this truck for quite a few years as it has 70k on it. So I would like to build my parts to last.