wolfy

iTrader: (1)

I have an SBE gen 4 6.0 going together, going into a RCSB 95 GMC. It's my Dad's truck, just something to throw together fairly cheaply to play with with while we're building his 29 Ford coupe.

so far parts list roughly looks like this:

SBE gen 4 6.0
stock 317's, with PAC1218's
LS9 head gaskets
Stock truck intake
JFR 218 cam

twin EMUSA 69/77 GT45's with 46mm waste gates and 50mm blowoff valves
FrozenBoost type 26A2W intercooler
Possibly a meth kit as well

It will probably live most of its life on the waste gate springs around 6 lbs, but it would be nice to turn the boost up to 18ish lbs every now and then and make decent power. We're not looking to set the world on fire, just have little fun in a 38-3900 lb truck.

I'm curious to know what ya'll think about the combo as I'm looking at it right now.

93camaro_zzz

iTrader: (13)

Sounds like a fun project. Keep us updated.

wolfy

iTrader: (1)

Once we get a little farther along, I'll put a build thread together.

I just keep going back and forth. He wants a little bit of rowdy to his idle, I don't want to kill the drivability and fun factor of the truck by overcamming it.

We've talked about an ProFlo or Holley intake, but thats a lot of money just for looks basically, I'm not sure either one would be a good fit for this power wise or money wise. I'm not really sure where the stock truck intake leaves us though, or whether or not it's worth getting a TBSS or NNBS truck intake.

And then injectors. Will 80's be enough? I'm intrigued by the thought of decapping some flex fuel injectors, just not sure how reliable they will be, or how far they will get us.

I was pretty convinced that a pair of on3 70's would work, but I'm intrigued by the EMUSA kit that has the 69/77 GT45 with blanket, 46mm wastegate, and 50mm blowoff valve for $299. Seems like a 9.5:1 6 liter should light them alright, and i can upgrade the waste gates and blowoff later if we wanted/needed. Just seems like no-one has actually ran these in twins on an SBE yet. I can do all the fab work myself, and i have enough room in the truck that I could always upgrade the turbos later to something else with a T4 flange. I'm just thinking that the T3 flanged GT35's seem a little small fro 364 CI's, with the possibility of going bigger on the motor down the road.

I'm just kind of trying to think it out before getting a couple of grand into it. We're trying to do this without spending a ton of money, but I'd like to think we could make 800rwhp give or take. This is kind of a sloppy mechanic/ebay-ish build, I just would rather not blow it up on the dyne or on the first hit, lol.

I already know...cheap, fast, reliable; pick two...

Forcefed86

iTrader: (4)

Still waiting on an LS to do this… I say go for it!

The gt45’s will be a bit lazy initially, then come on like a light switch in the upper RPM. (probably start making positive pressure around 4k) Not really matched well for a quick spooling cruise around town on low boost hot rod IMO. 73runabout built a pretty healthy 351 ford with a set that I’d guess would easily make similar power to a mild 6.0.

Think you’re leaving a lot on the table with that 218/218 JFR cam on that setup. Great cam that works well for single turbo setups with typical exhaust back pressure. With twin gt45’s you shouldn’t have any back pressure. So you don’t need a low overlap “turbo cam”. You can cam it just like you would an rowdy NA 6.0. That means you can go aggressive on the cam and it will have a mean sounding idle that will perform well under boost too.

You can see an intake manifold shoot out here that basically puts all the intakes you were questioning up against each other on the same engine with graphs. Should give you a good idea what to expect power percentage wise between the lot. Any OEM intake is more than good enough for an 800whp goal on a 6.0.

http://www.hotrod.com/articles/20-ls...ifolds-tested/

80lb injectors will be fine on pump/race gas to 800whp with the appropriate fuel pump(s) and regulator. If E85 is an option you’ll want 120-160’s.

Good luck!

wolfy

iTrader: (1)

Lazy boost down low is mostly fine with me, it will keep him out of trouble driving it around on the street, until he really wants to get into boost. I'd like to see positive pressure starting little earlier than 4k, if i could maybe crutch it with a 2" hot side and start seeing positive pressure around 3500 id be willing to do that, not sure if that small of a hot side will start getting me into back pressure issues with these turbos.

How far will 80lb injectors actually take us on gas, a2w intercooler and possibly meth injected? Anyone have experience the ebay 80lb injectors for $189?

According to that article, the TBSS intake looks like our best option, but the factory truck intake doesn't look too far behind it, it may work for us.

If not the JFR cam, what would be a good cam with stock 317 heads and stock truck or TBSS intake, that might help the turbos spool a little quicker, keep some tq down low and have a good chop at idle? I was looking at some of the Vinci cams, but haven't heard much about them.

Forcefed86

iTrader: (4)

The 351 with twin GT45's actually used a 2" hotside as well. Still didn't hit positive pressure till 4k. Starts on post #344 in the link below.

http://www.theturboforums.com/thread...-73-140/page23


Local made 855 hp to the tire on E85 with 80's on a mustang dyno. That was with 68psi base base pressure and 3 255hp walbros. How far they will go depends on the base pressure and fuel pump capability. That would have been around 1100whp on gas.

As far as the cam goes, alot depends on the budget. With the factory intake, valvetrain, bottom end... you can't get too RPM crazy. So going too rowdy on the cam can actually hurt you. I'd look for something similar to this depending on your budget. BTR .650 dual springs and some push rods... you'd be good to go.

https://www.summitracing.com/parts/hrs-190385-12

Can always call up JFR, LJMS, Tick, etc and tell them what you are doing. They will custom spec you a cam cheaper than the vinci cams I'd bet.
parts

wolfy

iTrader: (1)

Well, I talked to Lil John and he was pretty adamant that the GT45's would be WAY too big for what we're doing. The more I'm thinking about it, I'm also thinking we won't really be happy with them.

I think we might be circling back around to where we started when we were just kicking ideas around about turbo'ing this truck and started talking about twin on3's. The hot side of the on3's seems to lend itself better to what we're trying to accomplish. It looks like we're going to be sitting right at 9.5:1 compression, and we'll be on pump gas as well. Trying to decide if the 70's would be right for us or if we might as well just step up to the 76's. I kinda think that we might be better off with the 76's. Am I wrong for thinking that the 76's would respond just a bit later than the 70's for cruising, but still be responsive enough to see boost start and build much quicker than the GT45's would have? Although, I'm not sure which A/R would be best for us. Seems like the .68 is really small. Would we have trouble with the .96, or do we REALLY need the .81 housings?

Lil John recommended his TT Stg 2 cam for us (226/235 .605/.610 114+5) when we were talking about the GT45's, what do you think about this cam with the on3 76/65's?

slowlsx

iTrader: (28)

Like forcefed mentioned you will need some overlap in the motor but seems like you already figured that out. I love JFR cams I have one in our 5.3 and single billet 72/83 but I don't think it's the right application.

I think it would be cool to run the GT45's but I really wish they made smaller AR housings.

With the on3 turbos I don't see why you would even consider the 76's if the 70's will support your goal easily and if you only want to run 8-9 psi I would look no further then the 70's

Forcefed86

iTrader: (4)

Really depends what you are looking for. You literally can't beat twin gt45's for cost VS performance. At $190 each shipped, nothing else comes close. For $380 you basically get a laggy S480 with less back pressure that you can cam more aggressively.

I don't think that twin LJMS cam will take full advantage of the 1:1 BP ratio with twin gt45's. It will work great of course with smaller turbos more suited to the engine. With the GT45's you want to tighten up the LCA a ton and keep the lift/duration moderate to give tons of low end. Something like a 109LCA with 220 or less duration at .575 or less lift IMO. That will help get the turbos online fast. Right cam mixed with the correct converter and I think a 6.0 will light the gt45's just fine. (which is of course a guess, I haven't done it)

If you plan on spending actual money, of course there are better suited turbos out there. Rule of thumb is to keep the exh wheel and compressor wheels close in size. The 76/65 on3 turbo is horrible split and a crap design IMO.

2 of these would be much better. (and cheaper)

http://www.ebay.com/itm/Rev9-TX-72-6...-/141729459209

Floader

iTrader: (32)

What about the GT35's? They are dirt cheap and would come to life much quicker.

T/ALT1

iTrader: (3)

Yesh I think the GT35's would be good too.