S70 with .48?

[John B]

My hybrid is too laggy. At what RPM do you guys think a S70 would come to full boost with a .48 stg 1 housing?

[Pat]

A friend ran one in his 2.5 CSX. It would zing up fast....very much like a stock garrett. Car was fun.

[contraption22]

I've also used this combo and it spooled very fast.

[tryingbe]

My T04E 50 trim turbo with a a/r .48 TIII turbine housing start spooling at 1600rpm with a 2.5L.

[John B]

My T04E 50 trim turbo with a a/r .48 TIII turbine housing start spooling at 1600rpm with a 2.5L.

Is a T2 turbine housing different from a T3?

[tryingbe]

Is a T2 turbine housing different from a T3?

Very different. TIII turbine housing have the swingvalve built into the turbine housing were as TII have a "swingvalve" housing.

But more importantly, what is the stall RPM for your torque converter?

[John B]

It is a beefed up tow convertor. It has a lower than stock turbo stall.

[John B]

I went with a S60 and .48 housing. The S70 I was going to use has a clipped turbine. Response is immediate!

[contraption22]

That should give you the response you were looking for!

[John B]

That should give you the response you were looking for!

Yes, it's much better for the driving I do.

[iTurbo]

How is the S70/.48 combo treating you? I ask because I have a couple of those turbos.

Specifically, one is a Buick GN compressor wheel in a "Nissan" compressor housing (A/R unknown) with a stage I turbine wheel in a Chrysler TIII .48 A/R turbine housing. The other is a GN compressor wheel in it's 'native' GN compressor housing with a stage I turbine wheel in a Chrysler TIII .48 A/R turbine housing.

I'm hoping that these will be 'fun' streetable turbos on a TIII good for ~300 WHP without jacking the boost WAY up. At least one of these turbos will be installed on a 2.5L TIII for street/fun duty.

[moparzrule]

I've also run the S70 with .48 housing/stock wheel. Spool was slightly slower than a stock T2 turbo simply because the wheel is much larger so it's takes a little more to get spinning. I'd say I reached full boost about 200-300 RPM slower than a stock T2 garret, wasn't much different.

On the dodge garage it says that he didn't recommend because of compressor surge. I didn't have any of those issues but just be advised it can happen. It's always better to get a .63 housing, I know they're hard to find but they are out there.

[ajakeski]

I just pulled a new but damaged 70 trim turbo off of a car in the local yard.
The compressor side is good, but the turbine shaft is damaged and the turbine housing is cracked. The turbine housing is .48 , the turbine is much larger than stock.


Attachment 51829Attachment 51830Attachment 51831Attachment 51832

[moparzrule]

Attachments don't work.

[Vigo]

"s70" is not actually a 70 trim. It does have a 70mm exducer diameter, though. Turbo nomenclature is pretty stupid. About the only system that makes sense is the 4 digit system that refers to the compressor inducer and turbine exducer diameters in mm, which are the main ones that you infer horsepower capabilities from. Like a Comp turbo 5347. That name actually gives you useful information. The whole 'trim' thing is stupid because it only functions across one 'family' of compressor wheels that share exducer diameters. So, an S70 would have a smaller trim number than an s60 even though they have very similar inducer diameters and ultimate power capabilities. Trim numbers just get people confused and dont tell you much.

[moparzrule]

I don't find it that confusing in the turbo dodge world. If you talk about a 50 trim, it can pretty much be assumed you're talking the T04E 50 trim because when referring to the stock T3 50 trim wheel everyone just says stock T2 compressor. And when people talk about 60 trim, you pretty much know they're talking the T3 60 trim because no one really runs the T04E 60 trim. But I see your point.

Most S70's I believe use a T04B S trim wheel anyway. I don't even know what the Grand National wheel was officially.

[iTurbo]

If I recall correctly, I did the supposed math on the compressor wheel of a so-called "Super-70", and it was also a 50-trim. It was in fact a much larger compressor wheel for the stock Buick GN.

[ajakeski]

I posted the photos to the gallery.

http://www.turbo-mopar.com/forums/ph...00&ppuser=2326

[moparzrule]

Can you take a pic with the compressor cover off?

[Vigo]

Well, it's definitely not a stock GN wheel because those had 7-bladed compressor wheels.

I don't find it that confusing in the turbo dodge world. If you talk about a 50 trim, it can pretty much be assumed you're talking the T04E 50 trim because when referring to the stock T3 50 trim wheel everyone just says stock T2 compressor. And when people talk about 60 trim, you pretty much know they're talking the T3 60 trim because no one really runs the T04E 60 trim. But I see your point.

Most S70's I believe use a T04B S trim wheel anyway. I don't even know what the Grand National wheel was officially.

Yeah, in our little community it's manageable because for whatever reason we tend to only talk about a tiny number of turbos. Once you start cross-shopping any and all turbos that fit your basic requirements it becomes really important to be able to correlate names to wheel sizes or at least just find the actual wheel measurements.

s60 and s70 are kinda funny because they have inducer diameter within 1mm of each other so their basic power potential is nearly the same, but i think the s70 is more adiabatically efficient at higher pressure ratios which tends to correlate with larger exducer diameters. Since most turbo dodges DO need to run a high PR to max out either one at ~350chp, i think the s70 is marginally better when you're trying to max it out than an s60 is, but most people dont actually max out their turbos anyway, so it's probably a wash for most people.