1qckdodge

Im looking at doing a set of twins to closely resemble the BD set, what do you guys think of these sizes for a daily driver running Mach 6s, studs, O-rings, and all the needed supporting mods? HE351CW with a ported wastegate 60mm compressor housing, and a Garrett with a 67mm 60 A/R compressor and 1.15 A/R ex. housing. Im thinking it should spool pretty good and still have enough cooling for the 6s as the bottom turbo is a little bigger than the one in the BD kit as well as the top turbo being a little bigger, Im not looking for ultimate hp I just want a nasty spooling 650hp daily driver, I already did 602 with my old SB66 so hopefully these will get me where I want to go minus the lag of the 66, so do you think this is a good setup, opinions please. Also forgot to mention I will be installing my PDR cam.

Troym61

1qck-

Check this out if you have time http://cgi.ebay.com/ebaymotors/Parts...1%7C240%3A1318
It might be what you are looking for.....

olddodgetruck

wow carl that garrett looks like one,or seven turbos i use to have

Mike Holmen

Which garrett you using for the primary? To me it looks a little small for 650 rwhp. I usually put my primary at around the mid 70's for the inducer size. The A/R ratio on the turbine should be increase if your running that small of a turbine. Your drive pressure will be higher to drive the primary. I'm building a set twins of garret 3588R over a S366. I'm only planning on running mach 2 to 3's. Unless you have that garrett just sitting around I would use a S400 series turbo or BTH-3B as they are cheaper and move lots of air to support 600+ HP. Happy building. I would also work the turbine housing of the 3rd gen turbo. You have to get the exhaust flow improved thru the wastegate so you can load-up the primary. I have a garrett 3788R in for surgery as we speak. I'm putting that over a S480 and plan on looking for more fuel. Its good to have a few twins turbo choices, just in case...

The camshaft is a good choice. You get the cam with 12v lift pump lube? Press on or bolt on?

gwhammy

Troym61, how do you like the he 351 on your second gen? I think the he351 would be the perfect top turbo on a set of twins. I've got a set ready to go on with a 3b and 26 cm housing. The wastegate is ported so hopefully it will flow enough to support up in the 500's easy.
Is that 3588r a ball bearing turbo? That's about the same size as the he351 isn't it?
Wouldn't a 67 mm turbo be to close in size to gain much volume out of it? I've been thinking a s-471 with a 1.01 housing would make a sweet turbo on top for towing twins and still get into the upper 500 on air.

Mike Holmen

The GT3588R is a small turbo and being a smaller turbo, there are pros and cons. The GT3588R is rated for below 450HP and to be used on small CID engines. It doesn't have a internal wastegate, like the GT3788R and has a single turbine volute. I'm putting in a 38mm external gate on my set-up. The 3588R has a low pressure ratio compressor wheel, only 3:1, so it will spool-up fast, but this perfect responsive secondary for twins. The compressor inducer is nearly the same size as the 3788R, just with a smaller A/R on the compressor housing and has a smaller turbine wheel and A/R ratio. The S471 would work as a secondary, only if you have enough fuel, it would be a dog in a 500rwhp (sled puller use the S400 as a secondary). As a primary turbo, its a sweet set-up over your stock turbo or the 3rd gen turbo. Just do some massaging of the wastegate, to improve exhaust flow to load-up the primary. The smaller 67 sized turbine (must be a GT4088 ) would work great as a daily driver, just would be tuff to get 650rwhp out of. You could bomb with some NOS, to get more air into engine. You also need a larger A/R turbine ratio on the primary, to reduce backpressure or drive pressure. It kinda of a balancing act. Most S471 or S474 has turbine A/R of 1.32, which is perfect. I run mach 6's, if it was my truck I would go with a slightly larger than stock secondary (GT3788R is perfect size) and use the S474. You get almost stock spool-up and you can pull 50psi in about 5 seconds. When my GT37 comes out of surgry, I'll post some pics on what I have done to the wastegate.

1qckdodge

Thanks Troy, Thanks Mike, this is the set I was going to bid on, Carl makes these kits and is local to me, I just didnt want to many people to see the link till after the auction, hahahahahahahaa, he does nice work and has ran this set already, but just like was stated above he said I might not have enough air on the top end, im currently running a 62/12 that I wanted to use as a top but im liking the HE351, also I could then sell my 62 and put the money towards twins, so a 3b or a HX60 will be good on the bottom? I just want a clean 650 with good street manners.

gwhammy

I miss stated, the s-471 with a 1.01 housing would make a decent bottom turbo. I'm starting on the 01 this afternoon to put the he351 over the 3b on. The truck has a drag comp and 125 stage 4 injectors. I'm thinking that's enough fuel for now as this is my wife and daughters truck. I'm looking for something to put under the other 351 on my truck just can't decide what.

I've had a bht3e with a 22cm under a stock hx35 and it spooled real decent. With 10 lbs. of boost the bottom turbo was already making 3 lbs.

I've also had a b1-b2 setup and didn't like it at all. Just spooled to slow for me but I like fast spooling turbos. I'm hoping the 351 spools faster than the hx 35 but I'm sure it won't be as fast as the hy35.

There is a set of 7X.012 injectors in the garage if the 125 horse ones aren't enough!

Mike Holmen

You could always put on a different primary for dyno day or drag racing. It just a matter of buying a different primary that has the same turbine inlet flange or building a different hot down pipe. Of course at some point the 3rd gen turbo would be a bottle neck, but thats the price for quick spool-ups twins. If you can work the wastegate this helps to improve or push up the HP limits of the secondary. A large external wastegate of around 42mm, is very helpfully in this matter. I'll post some pics of my 3788R with the mods that I had done. It should improve exhaust flow to the primary. Once you build one set, you have to build a slightly better set-up I find it relaxing to putting together new twins and allows me to survive the week at work.

gwhammy

I'm not after big horsepower, just want a decent running truck that really doesn't need to an eye on the exhaust temp all the time. This set has went together really good but having a spare junk block and head on an engine stand really helps. I'm thinking of bolting a heat exchanger on it next time to put a set together to fit with that.

That little gt you're using sounds pretty interesting and different than most people go. Where are you expecting it to light at?

The first set I put together had an external gate on it, that adds alot to the build and install. The second set I bought had one also but it was on a spacer and went together easy. I've got an external wastegate on the bench but right now don't plan on putting together anything that will require it. Maybe 1quickdodge will get his running first so we know how fast the he351 will spool on a set of twins on a second gen.

Mike Holmen

My little GT will light instantly. Might even have 1 to 2 psi at idle. The little bearing turbo, you can just rev it up to 140k rpm. The compressor map start down low around 50k rpm and its more a low pressure map, but move lots of air flow (around the HX-35 size). I plan on setting the wastegate down low at 10 to 14 psi (depending on drive pressure and egt's), so I can lite the S366 up hard. I'm also thinking about using a wastegate on the S366. I'll just unload the primary at under 5 psi and close the wastegate at boost pressures above that. This is too improve the primary turbine backpressure and have the secondary act like there is no primary turbo to slow down intial spool-up. You'll feel primary turbo bottle necking more so at hiway cruising speeds more than off the line when you lug the engine.

I'm not looking for big ponies but for a better fuel mileage set-up and very low smoke. I should be good till 500rwhp area and my limit will be the external wastegate, as I might need a bigger size than the 38mm. Max boost will be around the 50 psi area. A kinda nice towing set-up. I've been dreaming about building this set-up for some time.

The GT3788R/S480 twin set-up is more for drag racing and dyno events. It will take me around 2-3hrs to change out the twins and around 1-2hrs to change out my injectors. That set-up should be good for 800 to 900 rwhp.

gwhammy

So the gt35 must light the same or a little quicker than the hy35? I just took a hy off to start putting the twins on the 01. I really like that little turbo but it screams for mercy with the drag comp and 125 horse injectors. I may use it on a set of twins depending how the he351 works. I've got a 50 mm external gate that would pass more than enough air to get around the hy.
Let us know how this small set turns out!

Mike Holmen

Its abit bigger than the HY-35 and will lite faster than a HY-35. The GT35/S366 is an experiment, I bought the GT35 a few years ago for my 300 SRT 6.1L. I'm trying the twins out first without a external and no wastegates, then with a external and then with a gate on the S366. I'm also using small air tubes than normal. 3in between the GT35/S366 and the 2 1/2in to the intercooler. This is for instant throttle response that I want.

My current twins set-up is a GT3782R over a BTH-3B, I can pull some big boost number pretty quickly (max is around 80psi). It feels like one fast spooling large frame turbo. You can feel when the wastegate opens and 3B starts coming to lite up. Its feels kinda like a mini cooper just rearend you. If I wasnt a crazy dude that wants more and better, I would say that its nearly perfect set-up. I've run them with a small/big injectors 90, 125, 220 and 250. The bigger injectors get the turbos to spool faster. You can feel some choking on the top end pulls, but for my truck its a good around size. I've towed a 15k trailer with them as well using the 125 sticks. They work very good, lots of cool air. egt's around 1200 deg's

gwhammy

I got the twins running today! I think they are going to be just what I'm looking for. There's not alot of info right now as I was pretty easy on the trial runs. I don't have the pump tapped so the max horsepower was 125 horse edge injectors and what would be a 65 horse ez.

From a standing start with no brake these light at around 1450 to 1500. A little power brake launch and the tires light instantly. I also don't have a boost gauge or pyrometer on this truck( I know!) but there is absolutely no turbo whistle at this power level.

I'm running a very tight 5 disk convertor, I believe ats so it does get a little smoke before it spools. I'm going to set up a boost gauge in between the turbos and probably put the adrenaline on to use the moniters on the pulse.

I can lock the convertor in drive or od and the moment it gets to 1500 or before they light. At this level I really can't feel any transition but the he is probably big enough to support this fuel.

I believe you'll like the he 1quickdodge but they may not be big enough for the hp level you're looking for.

Mike Holmen

Cool buddy, sounds awesome, now just try to keep some rubber on the rears?

My truck set on kill, if I nail it from a start I can get a good 10 to 15ft of rubber, no brakes. I grab abit of traction then second gear hits, bam the tires as smoking again for 5ft. The rear kinda skates back and forth in the first and second gears. I can't wait to see how it works down at sea level. I can pull 50 psi in about 3-4 seconds off a standing start. I did decent a brake stand with a spare 01 engine/tranny/t case in box. Might have took some life out of the tranny, but who cares. I broke in the tires hides good, they where new and begged for it. Have you adjusted the wastegate yet? If you open it sooner, you'll get more top end (the primary will lite harder). Faster spool-up, don't drop the secondary pressure. Which wastegate actuvator did you get on the secondary? Take a pic for us to drool on. Snap a pic of the truck as well.