ElQueFør

I need help picking the right turbo. I've been doing a lot of reading but still feel noobish about it. Hoping I can get some good direction and recommendations here.

Vehicle:

1. 1990 RCSB Silverado
2. LQ4 with 317 heads
3. T56 & LS7 clutch
4. 14 bolt SF rear 4.88 gears and TruTrac
5. Walbro 255 hotwired

I'd like to make a solid 600RWHP maybe eventually kick it up to 700 at a later date. I'll be fabbing up most of the turbo system myself once I can get some direction as to selecting the proper turbo.... Planning on using stock iron manifolds. I have 3 manifolds to choose from also, truck, LS1 and LS2 manifolds.. I'm looking at a single 80mm turbo..... Probably a Borg Warner. What I really need help on beyond that though is what A/R? What flange? T4? T6?

My only changes planned for the engine itself are LS2 head gaskets, ARP head bolts, and a cam that works well with the turbo. Planning on leaving the stock shortblock untouched. Truck is a street truck, will be put back into service as a DD once it's on the road. Not really interested in hitting the track more than occasionally if even that, just a real strong street machine.

ElQueFør

Wow, already 132 views and no replies?

MY_2K_Z

iTrader: (1)

http://m.ebay.com/itm/Brand-New-S400SX4-75-S475-Turbo-T6-Twin-Scroll-1-32A-R-171702-Turbocharger-/172107250047?nav=SEARCHThis turbo should get you to your goals with tons of room for growth.
Those 4.88 gears have to go, get something in the 3.42-3.73 range.

Robby05

How much lag is acceptable to you? Gotta ditch those gear in the rear end for sure.

gametech

iTrader: (1)

I would go a little smaller on the turbo because of the t56. a 76mm will get you to your stated goals with less lag. Your fuel pump is a different story. It will need to be upsized. As for the rear gear, I see people telling you to change it without having any idea what tire size you are running. The ls7 clutch will be marginal at best, and the t56 may need help at the 700rwhp level.

MY_2K_Z

iTrader: (1)

He would have to be running like 38" tires for 4.88s to make sense with a t56

ElQueFør

Thanks for the turbo recommendation 2K_Z
.
I guess for a vague response I would like to minimize turbo lag but I don’t have the requisite experience to really figure that out like I would like to.

Loud and clear on the gears. I have a set of 3.42 gears and also another 14 bsf housing to rob gears from (also 3.42 would be my guess.) I had to slip the clutch a lot with the old 3.08 10 bolt I had with the 300FWHP SBC it used to have when the T56 first went in. The 4.88s were great comparatively.

Tires are 29” overall diameter. With the old N/A mild SBC it would move out really well in 1st – 4th. It is a big heavy truck with tall tires and the MN6 gear spread.

What fuel pump would be recommended if the Walbro 255 won’t do it? I’m aware of the LS7 clutch being rated significantly less than my goal and the T56 being a good candidate for some high HP help.

Having said that, I just converted this T56 from LTx to LSx and everything looks great, I’m just gonna run it till it explodes and then rebuild it or swap in my other T56.

With the 29” tires I will be reusing, the old ~300FWHP SBC trim and T56 4.88 it would turn about 1979 RPM in 6th at 70 mph.

Appreciate the input guys. Definitely helpful for me.

MY_2K_Z

iTrader: (1)

Walbro 450 will be plenty of pump for your goals.

ElQueFør

Where is that turbo made? Can't find any information as to where it is made so is it.................. China? Looks to be good quality in the pics.

How would you compare that turbo to say, a Borg unit like this one?

https://www.summitracing.com/parts/b...qwzBoCGM7w_wcB

ElQueFør

bump?

MY_2K_Z

iTrader: (1)

That's the same as what I linked in my first post

ElQueFør

Right, I just wondered about a quality difference if any between manufacturers.

MY_2K_Z

iTrader: (1)

It's the same exact turbo, same manufacturer (borqwarner) just cheaper.

BMR Sales2

iTrader: (40)

I'm doing a very very similar combination right now. 90 RCSB, SBE 6.0, Walbro 450. But I am running a TH400 with the stock 3.08 8.5" 10 bolt on a 28" tire. I plan on running the On3 7875. It will be a little laggy, but I plan on it being a daily driver and with the lack of overdrive and the amount of interstate driving I do, I don't need it coming in real low. For you, the 7665 may be a better option. My friend has had one on his SBE 4.8 Firebird for 3 years now beating the crap out of it without issue. Very responsive and delivered over 550 whp on 15psi through a badly slipping converter

MY_2K_Z

iTrader: (1)

That 7875 should be a light switch on a 6.0

BMR Sales2

iTrader: (40)

That's what I figured. It will take it a second to come alive, but once it does...

ElQueFør

LOL. I'm going to pull the trigger on the first turbo 2K_Z suggested, probably order it tonight. That's confusing to me that it's also a Borg Warner but it doesn't say anywhere on the ad nor on the casting itself?

You got any pics of that truck project?? I'd like to see it. And forgive my ignorance but what does SBE mean?

Also, could you guys weigh in on intercoolers, BOVs and wastegates, like which ones would be good buys? I've been looking around, mainly on fleabay but again, I'm overwhelmed with possibilities and choices.

laytoncamaroz28

iTrader: (10)

I got the on3 78/75 on my sbe lq9 and love it. I have a pretty loose converter but there's very little lag. Car runs strong too for being a tank at 3800 lbs race weight. I also had same turbo in sbe lq4 fox body and also ran good for a junkyard setup. Cars are in sig. Sbe means stock bottom end. Here's my build thread if your curious of some of the parts I used. https://ls1tech.com/forums/forced-in...-21-131-a.html

ElQueFør

Okay that makes sense. Another TLA (three letter acronym) lol.

What intercooler setup should I go with, does anything here stick out to anybody?
http://www.ebay.com/sch/i.html?_from...ER&_sacat=6000

BMR Sales2

iTrader: (40)

SBE= Stock Bottom End

It's nothing crazy, but she still cleans up nice after 265k miles . Tired old 305 isn't cutting it anymore haha. Got a good deal on the 6.0 so I decided why not. Always dreamed of doing this with this truck so I decided to stop dreaming and start doing







It starts really getting fun next week when more parts get here so I will be taking more pics then