is this a good turbo choice?

[74valiant]

so i just picked up this turbo at a good price and decided to see if it will work good with my setup. the turbo from what i see is a garret gt37va .90 a/r. i beleive it cam off of a 6.6l deisel chevy truck. other than that, i am pretty unknowledgeable about turbos, so ill make up for that with pics

the car i want to put it in is a 74 valiant 4dr. 360 rebuilt with stock bottom end stock rebuilt heads. rebuilt 904. no cam yet and still have only the shortblock assembled. im only looking to push 6-8 lbs of boost using this single turbo setup. pretty much just wanting to do this for some extra power and for the awesome turbo sound.

 

[74valiant]

anyone ???

 

[Bill Dedman]

I don't know one turbo from another, but I have a Vortech V-1, S trim centrifugal supercharger on a 360 Magnum that is stock except for the cam (very mild Hughes) and I can tell you one thing.

You are gonna LIKE what 8 pounds of boost does for your sedan! I run 10 pounds of boost and I'd bet that 8 pounds from a turbo would pretty much equal 10 from a centrifugal blower like mine, as regards horsepower output, because of no parasitic drag.

It transformed my car; took it from 13.35 to mid 11s, and from 102 mph to about 118.
It's a different car. You won't believe the difference.... My car is a 3,400-pound '72 Valiant 4-door.

Good luck!

Bill

 

[Jimmy]

I don't have the answer but I don't think anyone will until you take it apart and figure the trim, although the info may be available if it is stock for the diesel it came from, try searching the diesel forums for the model or check garret, they may even have compressor maps for it there.
here is a good link to explain trim and A/R
turbo-size-r-trim.html

 

[Prine]

You asked your question in the right place, so I'll answer it the best I can...and try to educate you at the same time.

Theoretically YES....that particular turbo is close to the size your 360 would require.....maybe a tad on the "small" size though.

Diesel engines do not have the wide RPM band that a Gasoline Engine does....so where that Duramax would be tapped out at 4500rpm.....a 360 will rev into the stratospere in comparison.....6500-7000rpm +.....right?

6.6L is the size of the Duramax engines' bore x stroke....right?

V8 for V8 the 360 is .7 of a liter smaller.

Without a Turbocharger in place......which engine would require MORE AIR to run throughout its RPM band?......the 360 right?

With the addition of the turbocharger, sized by a GM Engineer for a 6.6L Duramax power levels......you might begin to see that this turbo would be one of the smallest that you could put on a Gasoline Blow Through V8 and not be restricted by the turbine side by 6000rpm.

Yes You could Use it.....But WHY?.....a BRAND NEW Properly sized turbocharger that can support 750hp can be had for a REASONABLE investment (around $750) at Precision Turbocharger.

You (just like the other guy asking a comparable question in here) need a PT6776R turbocharger.

Ohhhh yeah.....this gig is Super Expensive too.....(turbocharger + the rest of the system)

 

[65TerrorCuda]

According to the turbocharging book I read, diesel turbos have a different oil seal that isn't designed for the higher vacuum of gasoline engines, allowing oil to be drawn into the compressor side of things if swapped over. I have no idea if this is true, but I ran it past a John Deere mechanic buddy of mine and he thought it made sense. He said diesels basically don't make vacuum? News to me

 

[Bill Dedman]

According to the turbocharging book I read, diesel turbos have a different oil seal that isn't designed for the higher vacuum of gasoline engines, allowing oil to be drawn into the compressor side of things if swapped over. I have no idea if this is true, but I ran it past a John Deere mechanic buddy of mine and he thought it made sense. He said diesels basically don't make vacuum? News to me

Diesel engines have no throttle; when theywwant them to idle, the injectors just spray in less fuel. They can get away with that because Diesels are not restricted to the narrow mixture requireements that gasoline engines have to use in order to have combustion.

Gasoline engines need a fuel/air mixture that is in a rather narrow range, or combustion will not occur. I think it's somewhere in the area between 8:1 to 16: 1, but Diesels will run with a much wider mixture range than that.

So, they run without a throttle.... no butterflies.... wide open, all the time, and the power output is regulated simply by adding more fuel in the injector spray, or less if less power is needed, like at an idle.

So, without butterflies in the induction system, they don't make vacuum like a gasoline engine does.

Since they never have a vacuum in the intake manifold, they don't need the kind of seals that would be required on a gasoline engine.

Hope this helps.

 

[65TerrorCuda]

Yeah Bill, that pretty much clears it up I'd say. :-D Strangely I couldn't find any info on the net about diesel turbos on gas engines being a no-no. I know for sure you're not supposed to use a diesel turbo on a draw-through carb, but I think those installations are pretty uncommon anymore

 

[Bill Dedman]

Yeah Bill, that pretty much clears it up I'd say. :-D Strangely I couldn't find any info on the net about diesel turbos on gas engines being a no-no. I know for sure you're not supposed to use a diesel turbo on a draw-through carb, but I think those installations are pretty uncommon anymore

I think you're right on all counts. Buddy Ingersoll's AA/MC 2-liter Pinto was the last superstar with one of those.... mid 9's at 136 mph (!)

 

[pishta]

Diesel Turbo on a Gas motor has been done many times, successfully. As for the 2 different seals available, there is a carbon seal and a dynamic seal. Carbons are old school and cant be used with a draw through because of the vacuum involved, Possibly what was referred to. Another difference is Diesel turbos may not have an integral waste gate, but some do. Also diesel turbos usually have a larger exhaust side than a comparable gas model. They are also rated lower in diesel apps, ie, same 600 hp diesel turbo is about a 1000 hp gas turbo. So, as to your question, yes they can be used, its just sizing them that can be a challenge.