twin turbo he351ve control same can bus no problems

  • 38 Replies
  • 1154 Views
*

Offline 65fpvmustang

  • Sr. Member
  • ****
  • 211
    • 65 mustang 83 ranger
twin turbo he351ve control same can bus no problems
« on: April 11, 2016, 08:50:18 PM »
paralleled 2 he351ve for testing purposes no issues.

*

Offline hakcenter

  • developer
  • Hero Member
  • *****
  • 623
    • 1998 12v Ram
Re: twin turbo he351ve control same can bus no problems
« Reply #1 on: April 11, 2016, 08:58:45 PM »
I figured you can parallel them. I was thinking of making a Y in the manifold and mounting one upside down reclock it, then half the turbo sizes I use!

*

Offline 65fpvmustang

  • Sr. Member
  • ****
  • 211
    • 65 mustang 83 ranger
Re: twin turbo he351ve control same can bus no problems
« Reply #2 on: April 12, 2016, 06:55:51 AM »
I think you need a he561ve and do a compound ;D

*

Offline hakcenter

  • developer
  • Hero Member
  • *****
  • 623
    • 1998 12v Ram
Re: twin turbo he351ve control same can bus no problems
« Reply #3 on: April 12, 2016, 08:03:46 AM »
Wanted to do something no one else thinks of, if a he351ve can do at least 400hp on a 5.9 then that's probably at least 600-700 on twins

*

Offline Rx7man

  • Crazy guy
  • Hero Member
  • *****
  • 908
  • Jack of all trades
    • '94 Dodge dually
Re: twin turbo he351ve control same can bus no problems
« Reply #4 on: April 12, 2016, 01:40:32 PM »
It's pretty complicated to get the flow rates correct...

If you run the two turbos NON SEQUENTIAL (not compounded), you're essentially halving the airflow through each compressor, pushing you over closer to the surge line at a given pressure ratio...
If you're running them sequentially, you probably will also run the hot sides sequentially, which would probably require different openings.. Also, it'll require different compressor characteristics.  With the hot sides sequential, you want minimal backpressure from the second turbo so that you maximize the pressure drop across the first, causing it to spool fast, and only once you get a certain shaft speed/ pressure ratio going you'd close the second one to get it going.  With sequential cold sides, the bigger (first) turbo doesn't need to be able to make huge pressure (a 3:1 ratio is lots), as the second one (smaller) will easily compound that to a 10:1 total PR, but needs to be able to get a decent pressure ratio with no help from the first in order to allow the heavy fueling to spin the first one up...

It's easy to get something that half-works and looks cool, but really hard to design something that excels.

I think to get a working twin VGT setup you'd be forced into being able to control each one individually
'94 dodge, Colt Cam, head worked, NV5600, 3.55's, SB clutch, Ford manual hubs w. hawk brakes, custom flatdeck, custom aluminum bumper, cab off restoration, totally new engine, Mahle pistons @19:1..HE351VE with 67mm turbine and 67x95mm compressor
440hp/1000 ft lb @ 2400 RPM

*

Offline 65fpvmustang

  • Sr. Member
  • ****
  • 211
    • 65 mustang 83 ranger
Re: twin turbo he351ve control same can bus no problems
« Reply #5 on: April 12, 2016, 05:52:02 PM »
what rx7man said perfect. I don't have diesel so one of you guy's should test this lol.
Did you guy's know a guy in the 30's was running over 100 psi boost.
If i can get my hands on a m2 holset for under 1k i'll put it on my 65 mustang. ;D

*

Offline hakcenter

  • developer
  • Hero Member
  • *****
  • 623
    • 1998 12v Ram
Re: twin turbo he351ve control same can bus no problems
« Reply #6 on: April 12, 2016, 07:46:14 PM »
I don't see how the compressors inlet will be halved as twins, only the exhaust side will.

Literally need to cut the mouth off a manifold and just make a Y for testing. I'm sure the manifold will love a gillion pounds on it lolol.

I'm sure they can be paralleled, would it be better than a large single.. MAYBE. Pressure isn't the only thing happening to drive turbos, going to loose half the heat, etc etc. I would be more than willing to try it if someone would fab up a manifold for me :D

*

Offline Rx7man

  • Crazy guy
  • Hero Member
  • *****
  • 908
  • Jack of all trades
    • '94 Dodge dually
Re: twin turbo he351ve control same can bus no problems
« Reply #7 on: April 12, 2016, 09:49:03 PM »
I wonder if there's any way to re-address the turbo... the other option would be to scrap the entire circuitry on it and have the lilbb control a BLDC motor driver, or have a second CAN controller.. neither of which are very pretty solutions.

The engine takes in so much air.. if you have two parallel turbos feeding it, each has half the air flow, but must still operate at full pressure, thus you're moving closer to the surge line... If you were to do this with either smaller turbos or bigger engines, it would work, but that's usually not as good a solution as a bigger (usually more efficient) turbo.

If they're sequential you have the problem of controlling pressure ratios and shaft speeds, and the primary (bigger) turbo needs to flow a greater volume of air than the secondary.

Note: I'm rewording my definition of primary and secondary to match what seems to be industry standards... Primary is the bigger, and usually first in the flow of the cold air, secondary (smaller, first to spool) is the one first in the line of the exhaust flow... it's pretty confusing.

If you had VGT turbos for both, I think you could effectively run both off the exhaust manifold and not run the hot sides in series.. at low boost ratios you keep the big one closed, open it up enough to get 80-100RPM, then start opening the bigger turbo's hot side, which will make it come on, though more slowly than in a series connection, the plumbing would be easier.   It could be done, but I don't think it would be better.

sometimes theres a reason things are done the way they are, and compounded turbos are a good example.. I would LOVE to try it with a pair of VGT's though.. I think you could have some wicked results... I would look into a different compressor wheel for the 351 though.. one designed with less inertia to spool quicker, though with less pressure capability.. you wouldn't need to get 4:1 ratios anymore, 3:1 would probably be about right so you could throw the fuel at it quickly, but once the big one fires up that PR would drop to 2:1 or less...

Someone get me a bigger VGT that's CAN bus controlled and I'll do it!... Anyone got some 12V injectors that can throw the fuel at it?
'94 dodge, Colt Cam, head worked, NV5600, 3.55's, SB clutch, Ford manual hubs w. hawk brakes, custom flatdeck, custom aluminum bumper, cab off restoration, totally new engine, Mahle pistons @19:1..HE351VE with 67mm turbine and 67x95mm compressor
440hp/1000 ft lb @ 2400 RPM

*

Offline hakcenter

  • developer
  • Hero Member
  • *****
  • 623
    • 1998 12v Ram
Re: twin turbo he351ve control same can bus no problems
« Reply #8 on: April 12, 2016, 10:38:26 PM »
Again twin turbo you combine the cfm of the turbo outlet, it doesn't get halfed otherwise there's no point in putting 2 on ;)

Which is why in a lot of twin turbo setups, you'll see 2 turbos smaller than a single, that flow more than a single combined, better bottom end, less top end.

ie:

2 200cfm turbos vs 1 350cfm turbo, even thou the 350 will make more peak

*

Offline Rx7man

  • Crazy guy
  • Hero Member
  • *****
  • 908
  • Jack of all trades
    • '94 Dodge dually
Re: twin turbo he351ve control same can bus no problems
« Reply #9 on: April 13, 2016, 08:59:54 AM »
Yes, you combine the CFM of the two turbos.. each one is flowing half..
Now if you're doing this with a 351, that puts it closer to the surge line.. if you were to take a pair of hx30's you could probably do it just fine
This is only for parallel turbos of course
'94 dodge, Colt Cam, head worked, NV5600, 3.55's, SB clutch, Ford manual hubs w. hawk brakes, custom flatdeck, custom aluminum bumper, cab off restoration, totally new engine, Mahle pistons @19:1..HE351VE with 67mm turbine and 67x95mm compressor
440hp/1000 ft lb @ 2400 RPM

*

Offline hakcenter

  • developer
  • Hero Member
  • *****
  • 623
    • 1998 12v Ram
Re: twin turbo he351ve control same can bus no problems
« Reply #10 on: April 13, 2016, 09:55:04 AM »
The 351 flow doesn't change, it isn't closer or further away from surging. They combine output in the IC piping.

If each turbo is running 60k @ 300cfm, you get 600cfm at the motor. But it isn't each compressor is considered to be running 600cfm on the sheet. They are still right in the middle.

*

Offline Rx7man

  • Crazy guy
  • Hero Member
  • *****
  • 908
  • Jack of all trades
    • '94 Dodge dually
Re: twin turbo he351ve control same can bus no problems
« Reply #11 on: April 13, 2016, 01:55:24 PM »
My point is that at a given engine RPM, the motor can only ingest so much CFM.. it's a direct function of VE, temp, RPM, and displacement... Using 2x 351's trying to push 4:1 pressure ratios isn't going to work, you're bordering on surge at 2000 RPM using only one of them.

So 5.9L/2 x 2000RPM x .8VE = 4.4 M^3/min.. if you're running at 4:1 PR (44PSI boost) that's 17 M^3/min, or considering 1 m^3 is 35 cu ft, it's right at 600 cu ft/min.. that's the max amount of air the engine can ingest, regardless of what the turbo(s) are capable of producing.

If you have 2 HE351's in parallel *TRYING* to push 4:1 PR into a 5.9L at 2000 RPM, each one will be moving half of the 600 cfm, or 300 CFM, but each has to still do the 4:1 ratio.. thus if you plot that on the graph, you'll see you're WAY off into surge land, while if you only have one of them, it gets to move all the airflow, and it's sitting about as close to the surge line as you'd ever want to design it for.. 120,000 RPM, 600 CFM, and 4:1 PR.

Now if you were revving to 4000 RPM and kept a reasonable VE, both turbos would be happy at 4:1, while a single would be way out on the right side choking itself

'94 dodge, Colt Cam, head worked, NV5600, 3.55's, SB clutch, Ford manual hubs w. hawk brakes, custom flatdeck, custom aluminum bumper, cab off restoration, totally new engine, Mahle pistons @19:1..HE351VE with 67mm turbine and 67x95mm compressor
440hp/1000 ft lb @ 2400 RPM

*

Offline 65fpvmustang

  • Sr. Member
  • ****
  • 211
    • 65 mustang 83 ranger
Re: twin turbo he351ve control same can bus no problems
« Reply #12 on: April 13, 2016, 06:37:12 PM »
this is about as good as we can get. holset m2


*

Offline Rx7man

  • Crazy guy
  • Hero Member
  • *****
  • 908
  • Jack of all trades
    • '94 Dodge dually
Re: twin turbo he351ve control same can bus no problems
« Reply #13 on: April 13, 2016, 08:43:05 PM »
I could only watch the first few seconds of that vid, looks interesting, but it looks VERY similiar to what the 3rd gen FD Rx7's had from the factory.. they were twin parallel turbo, and had TONS of problems because the controls to get them to work together were so finnicky and intricate..
There was the primary turbo, which always had no controls on it, but the secondary was a nightmare.. It had a valve in the cold side outlet to prevent backflow, as well as a bypass valve.. On the hot side, it also had 2 valves, one was a "prespool" valve that opened when the primary turbo built up about 9 PSI, it would open, allowing some exhaust to spool up the secondary, when it got going the bypass valve would close and the check valve would open, with very specific timing events.. and of course since everything was vacuum controlled with solenoids, one cracked hose anywhere would throw the whole thing for a loop.. it had so many sensors and solenoids it would make your head spin.. I got the car cheaper than asking because it wouldn't start.. it wouldn't start because the coolant temp sensor was broken and the ECU defaults to thinking it's at 210F, so it wouldn't go into cold start mode (simple fix!)

I ended up tearing the twins out and putting a T66-1 in with a Microtech ECU... 10% of the wiring, 200% of the power.. Yeah, you had to wait a little for the turbo, but it was worth the wait, 3500 RPM came along and YEEEEHAW... It's making over 500 RWHP now on that same turbo.
I'm going to try to convince him to put a lil'bb and VGT on it with a 68mm wheel.. I think even if peak power doesn't increase much, it'll be quicker
'94 dodge, Colt Cam, head worked, NV5600, 3.55's, SB clutch, Ford manual hubs w. hawk brakes, custom flatdeck, custom aluminum bumper, cab off restoration, totally new engine, Mahle pistons @19:1..HE351VE with 67mm turbine and 67x95mm compressor
440hp/1000 ft lb @ 2400 RPM

*

Offline hakcenter

  • developer
  • Hero Member
  • *****
  • 623
    • 1998 12v Ram
Re: twin turbo he351ve control same can bus no problems
« Reply #14 on: April 13, 2016, 08:49:56 PM »
Wait doesn't VE go over 100% when you super charge *rolls eyes* kind of the idea behind 'forced induction'.

Volumetric Efficiency (and the REAL factor: MASS AIRFLOW), by EPI Inc.

Quote
tHere is an example of how useful that relationship can be. Suppose you decide that a certain 2.2 liter engine would make a great aircraft powerplant. You decide that 300 HP is a nice number, and 5200 RPM produces an acceptable mean piston speed (explained HERE). How reasonable is your goal?
The required VE for that engine will be:
Required VE = (9411 x 300 x .45 ) / (134 x 5200 ) = 1.82 (182 %)
Clearly that's not going to happen with a normally aspirated engine. Supercharging will be required, and you can use the 1.82 figure to calculate the approximate minimum Manifold Absolute Pressure (MAP) needed (1.82 x 29.92" = 54.5" MAP, or 24.6 inches of "boost") for that power level.

There's no theoretical maximum VE a motor can use boosting, until metal fatigues from pressure. That's how we make small motors pretend to be big motors. Going over the 85% VE


With VGT, I don't see why no one has actually twin'd a pair of 351's