Max boost before heads lift?

[monkeyboi]

Nobody paid any attention to Towcat's post about turbo efficiency. ATS/Banks/Hypermax get out of their efficiency and start heating the air more which negates anything that would gained by higher boost levels. Heath I think had dyno numbers which proved it.

 

[dyoung14]

anyone who plans on high boost needs to use a psd turbo, dt466 turbo or some other turbo that will be efficinent, then you can make 20 psi non intercooled efficient boost

 

[bowedup2003]

Ok, got my first look at the new turbo I mentioned near the top of this thread today. Size wise it is not too much larger diameter wise than my Banks turbo but the hot and cool housings are thicker in size.

Can anyone give me a crash course in how to read and interpret those A/R numbers on the housings? Dimensionally it looks like it will be a good top turbo for my silly compound turbo idea, but I know that does not tell the whole story.

Bowedup

 

[bowedup2003]

One more thing, this turbo is designed to put out around 20 psi and it is wastegated, comes off of a 7.2L engine w/a max rpm of around 2400. It is also a watercooled cartridge.

Bowedup

 

[88 Ford]

So I'm in the Navy and I was in boot camp, I think I remember Barney's engine blowing up or something. Is it fixed yet. But anyway he was pushin around 20psi of boost from his compound turbo setup and had quite a bit done to it. The bigger turbo was a remote mount and was pretty well done. But anyway Barney would be a good guy to talk to on this topic.

 

[kas83]

An HX35 would be pretty good up around 20-25 psi, as that seems to be the low-end sweetspot for the efficiency map. Or an HE351. Open up the wastegate on either of these, and you'd have a quick spooling, good flowing, inexpensive turbo. Not a bolt-on deal, but with what is being talked about here, a bolt-on upgrade is the least of the worries.

 

[razorback]

ive been tossing around the idea of arp studs..then adding **** injection. only one of the good **** injection kits that injects fluid based on turbo pressure. i believe cheapet i have found is 500 and snow performance is close to 1k for a kit.. i will probably end up buying studs tomorrow because i need it.. ive even considered being a tester for the custom MLS gaskets...

here is a turbo calulator. www.turbofast.com.aus


also what type of bottoming tap do i need for head studs? whats the pitch/size?

 

[hesutton]

Nobody paid any attention to Towcat's post about turbo efficiency. ATS/Banks/Hypermax get out of their efficiency and start heating the air more which negates anything that would gained by higher boost levels. Heath I think had dyno numbers which proved it.

Yup, that is correct. With my pull with the Moose injectors, the truck pegged the 15 psi guage, don't know how much it made, but I know I lost 6 HP. The pull with the junk DPS injectors, my max boost was 12-13 psi.

Yes, the Banks, Hypermax, and ATS turbos can make higher boost, but at the cost of power. The intake charge is super-heated as the turbo is way out of it's effiecency range.

I never see my boost guage pegged on the street. The most I see is 11-12 and that's if I want to. The 15+ psi was just a dyno thing. An innercooler MAY help cool the intake charge, but it may not be enough.

If you plan on consistantly running boost higher than 12 psi (which is not a good thing for longevity of your IDI), get a PSD or DT466 turbo.

Heath

 

[Agnem]

Barney burned out working on his truck unfortunately. He never fixed it (I believe he developed a knock due to a damaged wrist pin) He was selling that motor for a great price, with head studs and the upgrades he had on it.

 

[Jake S.]

Jake S, thanks for you boost info! Is your ATS wastegated or nonwastegated? Do you tow much w/ your setup? What kind of egts do you see w/ 18psi of boost?

Bowedup

It is a non gated. I have towed up to 10,500k, but routinely pull a trailer and a small backhoe tractor, somewhere around 5,500k. I way i drive most of the time I shift at 2k rpms. When I do wind it out I can see high numbers in high gears as I have the non-gated turbo. On a fourth or fifth gear run when its -20 I can see high numbers, but on a average pull shifting at 3k it will pull 13-14 psi and 950 degrees. Only on a long hill around here (mile long) I can break 1000 degrees.

 

[bowedup2003]

Ok, I understand that Banks turbo will be out of it's efficiency range above 12psi. Next question: from looking at the compound turbo kits on the market the larger remote mounted turbo feeds air back into the smaller turbo mounted on the manifold/turbo pedestal, etc. If the little turbo spools the big turbo, then in turn the big turbo pushes the boost air back into the inlet of the small turbo, how does that not push the little turbo out of it's efficiency range? Is it because of the additional volume of air?

Also, was Barney running a compound turbo setup or a big single? Was his engine failure due to high boost?

Thanks,

Bowedup

Bowedup

 

[Agnem]

He had a remote mount PSD turbo under the truck. I forget the exact piping arrangment, but it is all well documented here in threads. Just look for posts by flatlander.

 

[redneckaggie]

I would think that the exhaust gasses are first plumbed through the small turbo and then both gasses are plumbed through the lage turbo

 

[kas83]

The small turbo COMPOUNDS the boost from the big turbo. In a nutshell, the big turbo is the small turbos intake. The small turbo isn't spinning any faster than it was at 8-9 psi, but the intake charge is 3-4 psi, versus atmospheric pressure.

Exhaust gasses first go through the smaller turbo, which starts it spooling. The gasses are then plumbed to the big turbo, then out the exhaust of the truck. With the small turbo spooling, it's introducing manifold pressure(boost), and in return, more exhaust gasses(drive pressure), to not only turn the small one, but to also spin the big one. At no point the large turbo going to spin as fast as the small one, nor spool as fast either, they are not designed for that.

The little one gets stuff moving, the big one makes the power for the big end. Compound turbocharging at it's absolute simplest form. Obviously other variables exist, internal and external gates, housing sizes, wheel trim, etc.

 

[Hyde]

To the OP that 6.2 you keep seeing with the twins is probably my bad its a friend of mines truck that I pimp the pics of a bit