turbo - max allowable gas temp for continuous operation

[mtomac]

Just got off the phone with an engineer from IHI the manufacture of the Duramax turbo. I told him I was truck pulling and needed to know what the turbo could handle. He said the maximum allowable gas temp for continuous operation is 1472 degrees F. He also said it can handle higher temp spikes for short periods. He said the temperature related limiting factor of the turbo is the nodular iron exhaust housing. He said the material will start to flake off the inside of the housing and particles will start to accumulate on the turbine wheel if high temps are sustained for extended periods. I told him my EGT gauge only reads up to 1500 degrees F and I am pegging it there and running 1500+ for 5 to 7 seconds. He said that wouldn't be a problem for such a short period.

He's also faxing me a turbo compressor map.

[ 05-22-2003: Message edited by: Micheal Tomac ]</p>

[hoot]

Michael,

Excellent info. Looks like you got ahold of a good info source for real egt numbers.

Thanks. I rarely ever go over 1300.

[Forced Induction]

Micheal, would it be possible to get a copy of that compressor map. If there is anyway you could scan it and post it that would be great. Good to know the limits of the turbine also. Once I get my truck back I'll get my gauges installed and see where I'm running.

J

[NCalDMax]

PMFJI but what's a "turbo compressor map"??

Just wondering.

[Amianthus]

WOW! That's unusual. Most of the time it's all but impossible to get a turbo map. It's a pretty hush-hush thing for most manufacturer's. Pretty cool.

A turbo compressor map is a graphical display of turbo performance for a given set of parameters. You plot RPM of the turbo to a given efficiency. Basicly it helps people determine what turbo would work most efficiently for a given engine and application.

I've never thought that the turbo was the limiting component as far EGT's go. It's normally been the pistons. Although, the alloy is pretty tough. Not to mention that EGT's are not metal temperatures. If you sustain high temps for a while, you will soak the metal and then it will melt. But running for short (30 secs. max.) periods of time shouldn't hurt anything. Maximum sustained? It's generally been thought to be 1300. I don't know what GM recommends (if they even know), so your results may vary. If you stay below 1300, I wouldn't think it'd be a problem. Hope this helps.

[Seattle Steve]

Great info! Just so I understand, is that inlet temp or turbo outlet temp?

[stutzismydog]

What would the EGTs be in a STOCK Duramax pulling 15,000# on a long 6% grade, with the air temp @ 100 Degrees with the pedal to the metal pulling as hard as it will go....Runing against a F**D. Can you reach the 1500 degree max temp in this scenario???

[ 05-22-2003: Message edited by: stutzismydog ]</p>

[Amianthus]

I shoulda clarified pre or post turbo. I don't use post turbo temps for anything really. There is just too much variance for it to really give me an accurate indication of the performance of the engine. Not to mention, the engine will fail before the turbo will (in most cases) from over heating. The only thing a post-turbo temp is good for is cooldown of the engine. But that's it, IMHO.

As for what the temp would be? I dunno. I don't own a Dmax. If I were to guess, I would say that the Allison would downshift and that would get you some where in the 1100 degree range. If not you might push 1200, if you were in OD. But I wouldn't expect much more. Not given the parameters you describe anyway. Dmax's I've seen run on the cool side in stock trim. But, like I said, I wouldn't know.

[sdaver]

hey mike post the map if you can........thanks......dave

[Burner]

Good work Mike! I'll tip my hat to ya on that one. ;) Do you think 105 MPH in the 1/4 is possible? Have you seen a Dmax with slicks?


Burner-----&gt; :D

[huntindog]

I hit 1236 a couple of weeks ago.
Southbound on 89 pulling 10,000# into Flagstaff Arizona. I don't know what the grade is, but it's steep. The 2 lane road opens up to provide 2 passing lanes.
I had OD locked out, tow haul engaged and started up at 70 mph.
I had to back off when the egts rapidly went over 1200, and actually registered 1236 on the recall. I believe it would've easily hit at least 1300,,,,, stock.
I don't remember the outside air temp, but it was comfortable in shirt sleeves at the gas station a few miles earlier. So probably 75-80 degrees.
I was quite shocked by the high temps, and before I had the gauges have driven that same stretch before. I am sure that I have had it hotter the last time when I had no idea how hot it was.

[BowTieDmax]

Micheal,
I quess I fell better now that someone else is seeing the egt's I was seeing with my truck last year at the pulls. As I said in earlier posts that the temps were my only concern for this years pulls. Because I would peg my gauge past 1500 degs. just with the regular juice, so I could only quess it will be worse with the hot juice. I gotta admit that I dought very much I would back off on the throttle because of temps while I was still moving towards the finish line. But I quess I would know what temp. the motor will melt at. But I have alot of faith in Isusu and GM. So I am going to stick to my believe. "Put it to the floor, and hope for the best"
Paul

[1822]

In stock form my truck would get hotter than with the Smart Box E. Towing a 12,000 lb.fifth stock, it would go over 1200 easily but with the box installed over a 5000 mile trip it was very difficult to get over 1100. Mostly it will kick down to fourth and the EGT will come down to 850 and still maintain speed or accelerate going up the grade.

[a64pilot]

I've also seen barely over 1200 in stock trim, but it was hard to get there. Bottom line, if it's pure stock, it won't hurt itself, engine or Allision if so equipped. It's only when we modify them that we have to ensure the testosterone dosen't overide the cerebellum :D . That's one reason I like TST's EGT limiter.

[mtomac]

sorry it took so long but here it is

Turbo Compressor Map - IHI RHG6 (http://antiquetractorpulling.com/images/DuramaxIHIturboRHG6.jpg)

[GSXRTURBO1]

Thank you!