he351vgt as secondary in compound?

cumminspwr11

cumminspwr11

New member
just as the title says. i picked up a ht3b over the weekend and im going to get started with my compound build, im currently running the he351vgt and was planning on hanging the ht3b under it but i havent been able to really find any good write ups on people doing this and how it performs.
i have a wastegate actuator controling the vgt right now as it is and was just going to run the boost reference off the charge pipe from the primary charger so when its pushing X amount of boost the vgt will go full open

im also planning on running an external 38mm wastegate on the hot pipe between the two chargers so i can control the primary, i read somewhere the ht3b runs best around 35psi, can anyone 2nd this?
 
no takers huh? guess im going to have to play with it and see what happens lol, i found out today the ht3b has a 26cm housing and im wondering if i should find a smaller one? im planning on changing my injectors to 5x14 or 5x16 when i start digging into this
 
I'm pretty curious about how you're controlling your VGT honestly...

But I'm not much help with the compound setup. I ran an HT3B under a hybrid mutt of a turbo and it pushed between 32-35psi at WOT if I remember correctly (neither turbo was wastegated). I can't tell you how it liked it or not as the secondary wasn't wastegated and made for some really high EGT's.
 
Can youou elaborate? He seems to be runnng fine without a controller now...the primary wouldn't affect it as far as i know....which isn't much.
 
ya i have been running the 351 for almost 3 years now about. i used a wastegate actuator off a 7.3 to control the veins and it runs off a boost reference. i would be happy to send a pic of it to someone if they want to post it up, i made it so i can fine tune where the veins rest under zero boost so it doesnt go fully closed. it runs pretty good, no problem laying some scratch from a dead stop and maxes out about 40psi of boost. has a pretty good top end-no problem punching 120mph. cruise really good down the freeway, tows great. i like it way better than the 60/60/14 i ran for a few years. i know there are better options but i got the turbo for free from a friend at dodge and im pleased with it.

im going to run two external wastegates one before each turbo to i can get the vgt out of the mix once the primary is spooled and another on the 3b since its a non gated housing and im not interset i running unregulated.
 
the only complaint i have about mechincally controling the vgt is i can set the smallest it will go which in turn sets the max it can open so its all in the amount of travel the wastegate acutuator has- so if i set it small then it spools awesome but hurts in the top end and when you are crusing the drive pressure is high. if i open it up a little it hurts the spool just a bit but then the top end ripps and the cruising drive pressures stay down so there is a good comprimise with my set up
 
i may, i know the veins are suppose to be about a 25cm housing when full open so it should be able to be free flowing enough
 
How high are you seeing drive pressure?

I don't see why it wouldn't work. Quite a few guys running a 351 as a secondary. And you have the ability to make the 351 exhaust side flow more. Of course you'll have lots of trial and error but once it's right should be well worth the effort.
 
i dont have a drive pressure gauge, i would just go off what my boost gauge was doing. like when i have the veins small i can cruise with almost no pedal @ 80mph and 8-10psi of boost so i just adjust it out until i can get the boost to sit at zero when im cruising. i know a gauge would help me out a ton but havent gotten around to plumbing it in. there is a lot of trial and error tuning but can fine tune it pretty good
 
cumminspwr11 said:
the only complaint i have about mechincally controling the vgt is i can set the smallest it will go which in turn sets the max it can open so its all in the amount of travel the wastegate acutuator has- so if i set it small then it spools awesome but hurts in the top end and when you are crusing the drive pressure is high. if i open it up a little it hurts the spool just a bit but then the top end ripps and the cruising drive pressures stay down so there is a good comprimise with my set up
Click to expand...


This is exactly what I mean
 
Ok i see, I'd prefer a visual though. I have not messed with VGTs, so i am a bit unsure.
 
hjoey- i would run an electrical controller if it was practical but the only one i can find for a 12valve is 800$ and im not interested in spending that mcuh money just to have a stock 6.7 turbo on my 12v, i would rather get a s300 or something along those lines for that much coin. and as i said above it can be tuned and run very well off a boost reference.

how do you post up pics on here? and i will put up one of it on the truck
 
I'd suggest rigging up a drive pressure gauge and tune from there. You can make a hillbilly setup for 20~$ just to know where you are.

Boost numbers are only a measure of restriction of our super piss poor flowing engines.
 
im definately going to be adding two temporary gauges one for boost pressure off the primary and one for the drive pressure
 
Can you change the point the wastegate actuator hooks to the arm so it will cycle the veins completely? I wouldn't think it would take a very big gate to control the boost. The he351 gate drilled out to 1 inch or 25 mm will completely control them.
 
yes I can do that, I just need to extend my arm a bit and move the wastegate a bit farther away and I could tune it in better, I also have a 8psi wastegate I could put on instead of the 7.3 gate which is about 17psi believe
 
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