GT30 Turbine Question....

[Frank]

Which ones work with your 3" swingvalve? There is the common GT3076R (or normally called GT30R) and the GT3071R, with the later one slight prefered because of the smaller turbine, or so I would imagine. How would each of these turbine compare to a T3 StageIII turbine?

Thanks!

[Chris W]

Which ones work with your 3" swingvalve? There is the common GT3076R (or normally called GT30R) and the GT3071R, with the later one slight prefered because of the smaller turbine, or so I would imagine.

They all work with our 3" SV

How would each of these turbine compare to a T3 StageIII turbine?

Thanks!

See attached photo.

Chris-TU

[Frank]

QUOTE=Chris W]
They all work with our 3" SV
[/QUOTE]

Cool. I had thought that the turbines on the GT3071R didnt have the right bolt pattern to do this... just like my SC6152S turbo for a different car.

See attached photo.

Chris-TU

I take it that the GT30 wheel is on the right? Looks meatier, but of similar size. Sounds like a purchase in the very very near future!

Garrett pisses me off sometimes. I was restudying the GT30 line up. The big difference between the 71R and the 76R is the compressor. However the 71R has two turbines. One is the 76R's turbine, but it shows a different turbine flow even though the part numbers are the same. ERG! Of course the other 71R turbine is much different, flowing less for the same respective A/R on the 76R... I guess for the small liter big HP honda motors that rev - keeps the turbine from falling on its face at the upper range while still small enough to spool the system.


Frank

[Chris W]

They all work with our 3" SV

Cool. I had thought that the turbines on the GT3071R didnt have the right bolt pattern to do this... just like my SC6152S turbo for a different car.

To clarify, the TU version of the DBB GT3071R will work with our 3" SV.

I take it that the GT30 wheel is on the right? Looks meatier, but of similar size. Sounds like a purchase in the very very near future!

Garrett pisses me off sometimes. I was restudying the GT30 line up. The big difference between the 71R and the 76R is the compressor. However the 71R has two turbines. One is the 76R's turbine, but it shows a different turbine flow even though the part numbers are the same. ERG! Of course the other 71R turbine is much different, flowing less for the same respective A/R on the 76R... I guess for the small liter big HP honda motors that rev - keeps the turbine from falling on its face at the upper range while still small enough to spool the system.


Frank

Correct! Old technology on the left and new technology on the right. Don't get caught up too much in the specs. Sometimes trial and error is usually the best way to determine the correct turbo for your vehicle.

Chris-TU

[Frank]

To clarify, the TU version of the DBB GT3071R will work with our 3" SV.

So which GT3071R is that? The one with the 84trim .64a/r or the 90trim .86a/r? I would assume the later. Which guy just dyno'ed with a GT30R that had Paul's cal? What was his turbo?


Frank

[8valves]

So which GT3071R is that? The one with the 84trim .64a/r or the 90trim .86a/r? I would assume the later. Which guy just dyno'ed with a GT30R that had Paul's cal? What was his turbo?


Frank

Possibly me? I run a GT30R (yes, the 3076 w/ 4" anti-surge cover) and my cal is done by Paul. Full boost on the big 'ole TAFT S3 cam by 4100. .63A/R exhaust housing, with the standard 30R exhaust wheel. I think this is the epitome of the "straight 30R".

Aaron Miller

[Frank]

Yeh, it was you... Couldnt remember till now. Do you have your dyno sheet?


Frank

[8valves]

I do have the dyno sheets, only one was posted online though, the one when the IC pipe blew at 5200 or so I think. It's back on td.com under vendor section, mini TU dyno day/possible record??... or something like that.

It's really not a great representation of the turbo's capabilities honestly. I think the intercooler (dual core TD's, 2" piping) was choking it WAY bad. I knew it wasn't quite up to snuff, but now I'm starting to see it even more after getting more into compressor maps. With the pressure drop that I have (probably somewhere around 4-7 psi) I'm now off the compressor map of the 76 wheel.

Power would peak around 5000-5800 rpms then start to dive off. Torque peak was from 4300 to 5300 or so. Now I know this is the "typical" TD graph, but it's not what I built the setup to do. I was expecting a constant power gain till around 6500 and for it to level off and hold till 7000.

DSM's have run this turbo to 505 AWHP, so the turbine flow should be there for our cars, I would assume. The compressor on the other hand, since we're up in higher boost levels might run out like you warned me of earlier on. However, I'm not too sure. Nate at SlowBoy Racing (we do a lot of work with them on my brother's car) says that even with the map that the 3076 has, that they found it still likes to sing up till about 34,35 psi. If you look at the maps with our motors we're WAY off the right side at that point, correct?

I truly expect that with a real intercooler on the car for it to exceed the 400 barrier on this turbo with no higher boost than it is now on pump 93.

Aaron Miller

[Frank]

Thanks for the information Aaron! I think I am probably going to get a GT3076R provided I can use the 3" S/V that I have.

As for the compressor map details, attached is an example. I used James Reeves' motor because he probably has one of the best flowing 8v setups that is moderately obtainable, so in this example he will have better spoolup and less boost required per hp. Now you can achieve better spoolup, but that would be difficult. So since slower spoolup puts you more towards the center of the map and more boost shifts it up, then you can see you have plenty of room. A 2.2 would behave differently, but again, there is way more room. With the restrictions you mention, you could probably see results about .5pr higher then the example. I can see the DSM's making more power with this turbo then us even though we have more displacement. That is because displacement shifts you to the right, and as you add more boost which shifts you up, you run into where it slopes off up top. Basically with more displacement, you run out of compressor map sooner.



Frank

[glhs875]

I've got a couple of questions. How do our turbine housings compare to, and do our (Chrysler) .63AR turbine housings flow as well as the .63AR Ford type that is used on the SC6152 turbo. And if it does, can a Chrysler turbine housing be used with this type of turbo? I really like the way this turbo performs. Also, If a Chrysler turbine housing with an internal waste gate is used vs. the Ford type and an external wastegate, would there be any difference in HP potential between the two. Spoolup with either setup should be fine with my combo, I have a 4000rpm stall converter, so I can run a pretty large turbo just fine. I guess this would also be similar to putting one of the Chrysler turbine housings on a GT series turbo as well, is there a HP potential difference?

[Frank]

Chris can probably answer this better then I can, but it is my understanding that the GT turbines of similar T350 turbine sizes spool faster and similarily to the GT31 turbines that the chrysler used. The GT turbine housings come in multiple flavors allowing you to bolt them up to many different application including ours.

So basically the GT turbine will flow like a turbine on a SC6152 but spool similarly to a StageIII T3/T4 50trim Hybrid. Now also remember that because of the big compressor of the SC6152, it spools slower anyway.


Frank

[glhs875]

Chris can probably answer this better then I can, but it is my understanding that the GT turbines of similar T350 turbine sizes spool faster and similarily to the GT31 turbines that the chrysler used. The GT turbine housings come in multiple flavors allowing you to bolt them up to many different application including ours.

So basically the GT turbine will flow like a turbine on a SC6152 but spool similarly to a StageIII T3/T4 50trim Hybrid. Now also remember that because of the big compressor of the SC6152, it spools slower anyway.


Frank

My main question is, would there be a difference in performance if you took the SC 6152 turbo and kept everything else the same except a switch to the Chrysler .63 housing instead of the .63 Ford or standard Garrett type that was originally used?

[glhs875]

Power would peak around 5000-5800 rpms then start to dive off. Torque peak was from 4300 to 5300 or so. Now I know this is the "typical" TD graph, but it's not what I built the setup to do. I was expecting a constant power gain till around 6500 and for it to level off and hold till 7000.

Aaron Miller

That's the power range Iam striving for as well. I want to have a shift point around 7200 to 7500rpm's for the best ET. I feel some of the problem with the 8V acheiving those kind of R's lies in the valvetrain becoming unstable starting around 6000rpm. The Taft S3 cam is definitely a step in the right direction, as I was able to move my shift point up to 6200rpm on a stock setup, but I want more. I feel that a head that can flow 200+ cfm should be able to make power well past 6000rpm. That a fair amont of flow for a 34 cu. in. cylinder.

[Frank]

A 200cfm head at 35cui/cylinder is roughly 6350rpm for peak power. You could get a 240cfm head for alot of money, and peak power is going to be around 7600rpms. There is more too it then that with bore stroke ratios, but its a good rule.


As for the SC6152 turbine, the big difference would be fast spool (right on into the surge area), and a chocked top end because you would be unable to achieve the proper shaft speeds for a viable compressor efficency.


Frank

[glhs875]

A 200cfm head at 35cui/cylinder is roughly 6350rpm for peak power. You could get a 240cfm head for alot of money, and peak power is going to be around 7600rpms. There is more too it then that with bore stroke ratios, but its a good rule.


As for the SC6152 turbine, the big difference would be fast spool (right on into the surge area), and a chocked top end because you would be unable to achieve the proper shaft speeds for a viable compressor efficency.


Frank

Thanks, that answered my question. That means that the standard Garrett turbine housing will flow better than a Chrysler turbine housing, wheels being the same. What did you use to figure out cfm vs. rpm potential?

[Frank]

A sweet table at the bottom of this page... dang, giving away all my secrets! LOL.
http://users.erols.com/srweiss/tablehdc.htm


Frank

[glhs875]

A sweet table at the bottom of this page... dang, giving away all my secrets! LOL.
http://users.erols.com/srweiss/tablehdc.htm


Frank

I've always believed that if you give away secrets you'll get more and better ones down the road.

[glhs875]

That chart is neat! Those numbers seem very close to being right. But they are based on NA. I would think forced induction or N2O could extend the rpm range somewhat with the proper efficiency.

[8valves]

Thanks for the information Aaron! I think I am probably going to get a GT3076R provided I can use the 3" S/V that I have.

As for the compressor map details, attached is an example. I used James Reeves' motor because he probably has one of the best flowing 8v setups that is moderately obtainable, so in this example he will have better spoolup and less boost required per hp. Now you can achieve better spoolup, but that would be difficult. So since slower spoolup puts you more towards the center of the map and more boost shifts it up, then you can see you have plenty of room. A 2.2 would behave differently, but again, there is way more room. With the restrictions you mention, you could probably see results about .5pr higher then the example. I can see the DSM's making more power with this turbo then us even though we have more displacement. That is because displacement shifts you to the right, and as you add more boost which shifts you up, you run into where it slopes off up top. Basically with more displacement, you run out of compressor map sooner.

Frank

What's interesting is that mapped by the formula's I've been going by I am off the map at 32 psi. This is why I'm planning on not trying to raise the boost much more than where I'm at.

Reeve's motor seems to flow damn well, but I was struggling to see the relation you were going for there. I believe James car was at 29 psi when it did 406 or 409 and 464 tq. I was at 26 psi and gaining right on 10 whp per lb of boost on the dyno. Unfortunately we never got to see what it would do had the graph kept climbing like it should have. Coulda woulda shoulda though.

Excuse me if my thoughts seem cluttered, I'm actually in the middle of class right now responding real quick, so I'll try to get back on later and really read through what you were trying to get at.

Either way I love this turbo... just look at the compressor wheel size from the super 50 to the 30R and realize they spool the same, then tell me which one you'd want to run!

Aaron Miller

[Frank]

Oh trust me. I want to run the GT30R and will be soon. I didnt realize that your car was making so little power. Sounds like you need to uncork the sob. So yes you have some massive restrictions... about 10psi worth!

As for the equations, they are from my turbo sizing spreadsheet I developed which can be had here: http://www.squirrelpf.com/site/files...bo_v2_beta.xls It uses Excel and is developed off of equations from Garrett and a book of mine. You will find every map available including the 7.3L Powerstroke upgraded turbo.


Frank