New build, need some advice (long post)

[Cschafer]

So after several thousands spent on my last first gen with no end in sight I got out of the diesel game for a while. The cost of after market parts left me quite dissapointed, mainly turbo's and clutches. So i got into jeeps and am quite happy spending $100 everytime it breaks instead of $1000 like the dodge but I can't quite seem to shake the cummins bug and have been collecting lots of parts for the last couple years. With the latest purchase I'm just about ready to start putting it together. It's gonna take a while but this time around i'm doing everything cheap, not buying any high doller b.s. and building everything myself! Sorry in advance to you mopar faithfulls but I will never build another dodge! If I do it will be completely my own wiring harness.

The new truck is a 71 chevy 4x4 long box, drive train as of now will be ve pumped cummins (of coarse), 47rh auto 2wd, divorced 205, kingpin 60 front, HO72 rear, 4 link coil front, striped as light as possible shooting for 4500 lb. won't settle for anything over 5000 lb, full cage, 33's and as much hp as I can get out of a ve. All around street toy, drag strip, puller, dyno and sand dunes machine is the idea.

Engine is a 95 12valve, rebuilt, enterprise cam, ported head, o-ringed block, switching to ve cover and pump

Trans i'm building myself, billet servos, red clutches, hd bands, billet apply lever, tight single disk converter, tuned valve body, maybe full manual, plan is to find exactly when you need 3 disks and billet shafts

I acuired my old 6x0.018's back and the last original KTA 14mm head and roter still in a box. Hopefully will be sending out a non ic pump to have it installed soon.

Here is the questions. As said above I won't be buying any $2,000 turbo's this time around. These core he351ve's cought my eye and I think have a good advantage for the ve pump. As I learned before for max output you have to have a small fast spooling set of turbo's to make good numbers with the rotary pump but yet they still have to flow the air for extreme power. seems like the p-pump guys can put on huge turbo's and compinsate for horrible spool with huge 3000 rpm plus fueling. So the plan is for 3 vgt holsets at 65lb/min flow and fast spool with low drive pressure it seems to be a good canidate for the secondary and two of the same in parellel for the primary chargers. The flow rate's seem good and the advantage of tuneable spoolup and the ability to open them up and get them out of the way for my blue bottle of air seem like a great combination. Guys that are already running them say they can see 5 lbs of boost at idel with the housings closed up. This leads me to believe that you could run 2 of them in parallel (3 cylinders to each one) and still have good spoolup. 2 three into 1 headers with them mounted high I think would be my initial setup. If they didn't spool fast enough I would put a third one under them and compund them. In this system would the two primary's steal too much heat before it gets down to the secondary?

So, do you think it can spool 2 in parralel? Will it hurt too much to run the exhaust through the primaries first then the secondary (oppisite of normal compounds)?
sorry for the book. Been thinking for a while, it's time for some feed back.

[ahale2772]

well just rember that each trubo is getting half the cfm that it would normaly, logically it could definitly work and would be cool, i think the best means of doing it would be to get 2 smaller turbos (the 351's would work if u could dial the turbines in) and keep them in a good efficent range so that u focus on good cold air and not spinning the death out of the turbos, there has got to be a way to make good power without a semi truck turbo, like KTA always says hot air dosent make power, im rootin for ya i want to see it work

[Cschafer]

I think with 2 of them there would be no way I could overspeed them. Technical it would be like hanging a hx60 on the manifold but I think with both housings shut down into exhaust brake mode (I believe is 3.5 cm) I would think they would light ok???? The air will definently be cold! I had a co2 spraybar on my 90 that did a pretty good job of icing over the intercooler but I think on this one I might play with some water to airs. If it does get compounded it will be cooled between the stages also.

[JQmile]

Looks like a cool build, but I would build the triples like a normal setup--one off the manifold and then two as the atmospheric chargers. Nothing spools a turbo as well as another turbo

[dvst8r]

Problem with running them in parallel is you really need the PR from compounds to push the extra air through these terrible heads. Two HE351ve's in parallel would be like running some where in the S475-S480 as a single. You could make it work, just won't be a lot of fun on the street. Also those bigger chargers have a lot more PR on the top end of their respective maps. You started out on the right track by realizing that you needed to get air into this quick to get power out of the VE, and unfortunately ended up on the opposite end of the spectrum.

If you want cheap chargers, use that HE351ve or the cw version as your secondary, and then get an HT3b, or an S475 or GT4294 / GT4202 or HT60 or any number of chargers to be found @ truck wreckers.

Oh and forcedinductions has brand new S472's and S475's for $599.

[Cschafer]

I already bought 3 351 ve's to the tune of $285. I realise spooling a 130 lb/min turbo as a single isn't a fast deal with a 5.9 at 1600 rpm but I figured with a 7cm ex housing it might be possible to get it done quickly. I guess I'll run all 3 and compound them. Should be fun to tune! Are any of you guys intercooling between the turbo's? Is there any real benifit to this or is it better to worry about getting it cold before the intake?

[dvst8r]

The problem that you are missing, is that even if you can physically get them to spool quick enough, you will still run into surge issues.

You are far better off to run them as a set of triples. A number of people have done inter stage intercooling, normally with an a/w setup for packaging issues. I am sure for a race vehicle it would be worth it, for a street driven vehicle probably not so much. IIRC WOP does and a/a intercooler but no aftercooler, not sure if it is better or not.

[JQmile]

So let me get this right. You're thinking of running two in parallel, and then if that isn't enough you'll compound while still running the bulk of the exhaust energy into the two charger setup first, and have your smaller charger after the twins on the exhaust side, but the intake piping will be a normal triples setup? Is that right?

[Cschafer]

So let me get this right. You're thinking of running two in parallel, and then if that isn't enough you'll compound while still running the bulk of the exhaust energy into the two charger setup first, and have your smaller charger after the twins on the exhaust side, but the intake piping will be a normal triples setup? Is that right?

Yes that is correct. though I think I'm being talked out of even trying them in parallel. If I go through all the work to make 3 into 1 headers I didn't really want to get rid of them if it needed compounded. Most people around here think it will lose too much heat through two exhaust housings before it gets to the secondary. Lookin like i'm gonna build triples with correct exhaust routing.

[JQmile]

At first I was like
But now I'm kinda coming around to the idea of the reverse exhaust setup..

It seems like it would be a great way of not overspeeding the single turbo, but then again, it would probably just be more simple and proven to install an external wastegate if needed.