Turbine Housings

[LemansWagon]

Does anybody know if the turbine wheel is different from the 84-85 T3 on the early carbed regal turbos with .82 A/R turbine housings? Just wondering if you can swap a .82 housing onto an 84-85 T3 in place of the .63 housing without a wheel change. If not can you do it if you change the wheel?

 

[charlief1]

Click on the second link in my sig for the info you want. I think it will help you quite a bit and I have pics of several different turbos from the early carbed to the 86-87 design. Hope this helps.

 

[LemansWagon]

Sweet, thanks, very useful. I'm going somewhat in the opposite direction though rather than switching from the .82 to the .63. But obviously it goes both ways and it looks like I can use the bigger turbine wheel and housing on any T3.

Let me explain my thoughts: I have several 84-85 GN T3's, a couple 79-80 carbed turbos, and a couple of T4's from a deisel (BIG 1.32 A/R turbines). I want to take two of the T3 centers and put the T4 wheels and compressor housings on one side with the .82 a/r wheels and turbine housings on the other. The goal is to twin turbo the 396 in my Chevelle (see sig). I thought about just swapping the compressors onto the 84-85 turbos but I am concerned the .63 a/r housing will spool up real fast and die early on a big block that's already putting out 425 hp n/a. Probably choking it by 4500 rpm. I was think that if I could swap on the .82 a/r turbine it might be just right.

 

[charlief1]

I hope you read through the whole thread. A .63 AR exducer will work great for a 231 CID engine and if you're using a 396 BBC then divide it X2 and what do you get? 198 CID. I think the smaller AR will help you spool it since you plan on using 2 of them. I doubt it will run out of steam unless you plan on turning 9K or so.

 

[LemansWagon]

OK, finally had time to peruse the whole thread. I see what you are saying. I was concerned because I know that the mustang guys using t-bird t3's (same as 84-85 GN) on 351's are limited to less than 5500 rpm. But I wasn't thinking....that's most likely the compressor not the turbine. With the T4 compressor that would be moot.

I do plan on spinning it to 6k but no higher. It'll go to 6300 right now but it's not any faster that way so I shift at 6.

 

[LemansWagon]

Your carbed thread has also given me some inspiration for my turboed Lemans wagon project. I have so far collected an 84-85 GN turbo, 86-87 GN headers, and a holley 4bbl intake. I was going to run a blow through set up on it but when I got a bunch of turbo stuff from a friend free (that's what prompted the whole turboing my chevelle idea) it came with some carbed turbo stuff including a couple draw through 4bbl adapters. Now I am thinking a possible draw through set up instead. I'm thinking with the turbo mounted in the 86-87 location I can make an adapter for the carb intake and run a pipe to it. Then make an adapter to run a pipe from the carb adapter to the turbo inlet. In essence a draw through set up without the hood clearance issue of mounting the turbo on top of the intake. Plus then the choice of turbos goes exponential. What do you think about that plan Charlie if you aren't concerned about stock apearance like you are?

 

[charlief1]

Draw through system are tempermental to say the least. The blow through is much easier and just as effective. You need to look up Warwagon (Adam) and see what he's done with his so far. If you want to see what an extreme version of a draw through is do a search for Rick Dobertin. He did a wild set up on a 65 Nova and again on a Pontiac J2000. Way ahead of his time and I have no idea what happened to him.

 

[LemansWagon]

Then back to blow through it is for my wagon project. I thought maybe the draw through would be easier to tune because you just treat it like it's on a larger engine. No mods to handle pressure.

But let me verify this 100 percent because I can't find anything definitive...the stock 86-87 turbo has a .63 A/R turbine, correct? And the mild upgraded turbos that people often install are essentially T3/T4 hybrids that retain the .63 turbine housing? But aren't those using much larger housings and turbine wheels to support the higher hp? Still the same A/R but on a larger scale. I ask because I am still getting people elsewhere telling me the 84-85 GN .63 housings are too small for my 396.

 

[charlief1]

The 86-87 turbo is the one you really want instead of the smaller one. It flows about 600-650 CFW per turbo and the 84-85 is less than 400 CFM. You have to remember that you have a "hot" side (exducer) and a "cold" side (inducer) and both of them have an AR rating. You need to know both of them before you try and make it work.

 

[LemansWagon]

Are those flow numbers on the compressor or exhaust side? I'm really only talking about the turbines here. I plan to run TO4B V-trim compressors that should support at least 400 hp each. A friend dumped a pile of turbo parts in my lap for free. Well, not 100% for free, I have to tune the ecu in his car for him since I have the software for it. Anyway it included more than half a dozen Ford & Buick T3's as well as a diesel T4 and 2 spare diesel T4 compressor housings. I already had 3 84-85 buick T3's and 2 Ford T3's. I plan to use the T4 compressor & wheel (2.18 min dia & 2.75 maj dia which matches a 55 mm V-trim) then buy another matching wheel and machine one of the spare T4 housings to match (they have smaller inlets but also .60 A/R).

So my main concern is whether the 84-85 buick (or ford t-bird 5 speed) .63 turbines can support my goals or will they limit my top end. The 396 already makes 425 bhp and spins to 6000 rpm in n/a trim. The goal is to make about 500 rwhp at a hp peak of between 5500 & 6000. I figure 6-8 psi.

Now the pile of parts came with two carbed turbos that have the .82 A/R turbines so I was thinking that it might be better to run those wheels and housings instead of the .63. Only thing is they have a funky bolt pattern on the outlet and use weird 45 degree exhaust elbows. So with all the spare .63 parts I have (numerous elbows) I would rather stay with those if possible.

 

[charlief1]

That's for the inducer side. If you plan on changing it to a better flowing one then you should be ok but if you want the easiest wat to do it then get 2 of the 86-87 turbos. In the Buick desigh it can support 400 HP easily so 2 of them should get you somewhere around 600 to 700 HP and maybe more.

 

[LemansWagon]

So then you are saying that yes the turbine housings and wheels are larger on the 86-87 than on the 84-85?

 

[LemansWagon]

Surprise, sorprise. I finally got around to inspecting the two carbed buick turbos I got more closely and one is actually a TTA 301 turbo. I took the carb adapter off to find the larger compressor wheel staring at me. So now my plan of using the two .82 A/R exhaust housings and turbine wheels is out because they are not the same. One is from a 3.8 and the other from a 301.

 

[charlief1]

Please re-read the turbo thread. The 301 TTA is much bigger on the intake side and the 86-87 exhaust side will give you more than you need as far as spool. Going with the .82 will make it really laggy and you won't be happy with it.

 

[LemansWagon]

Thanks. Is there any way you can give me the actual diameter of the stock 86-87 turbine wheel (major and minor)? I can't find it anywhere and I'd like to know just how much bigger it is than the "standard" T3 wheel in the 84-85 turbos that I have. Give me an idea of exactly how much more air it can flow. In that thread you only show/discuss the early 3.8 & TTA .82 wheels and the 86-87. No mention of the 84-85.

Given that I don't have 2 matching .82 housings I may just start mocking things up with the 84-85 turbos with the T4 compressor housings bolted on. In the mean time I can start hunting for either 2 complete 86-87 turbos or at least the turbines & housings. I can always try the setup with the standard T3 turbine and if it chokes off the engine upgrading to 86-87 turbines & housings (or even aftermarket ones) will be an easy bolt on with no fabbing. Where as the .82 housings, with their different exhaust elbow bolt pattern, would require changing the elbow and/or piping.

Although I am curious just how bad the lag would be with the .82 housings. I have a 2700 stall converter in the car and currently the engine doesn't come on cam until about 3000 rpm. (It really needs about a 3200 stall converter). So I am dealling with a bit of "lag" already.

 

[LemansWagon]

Another thought...since I will be running fairly low boost (6-10 psi) couldn't I run larger aftermarket wastegates to increase the exhaust flow capacity of the turbines?

 

[charlief1]

Thanks. Is there any way you can give me the actual diameter of the stock 86-87 turbine wheel (major and minor)? I can't find it anywhere and I'd like to know just how much bigger it is than the "standard" T3 wheel in the 84-85 turbos that I have. Give me an idea of exactly how much more air it can flow. In that thread you only show/discuss the early 3.8 & TTA .82 wheels and the 86-87. No mention of the 84-85.

Given that I don't have 2 matching .82 housings I may just start mocking things up with the 84-85 turbos with the T4 compressor housings bolted on. In the mean time I can start hunting for either 2 complete 86-87 turbos or at least the turbines & housings. I can always try the setup with the standard T3 turbine and if it chokes off the engine upgrading to 86-87 turbines & housings (or even aftermarket ones) will be an easy bolt on with no fabbing. Where as the .82 housings, with their different exhaust elbow bolt pattern, would require changing the elbow and/or piping.

Although I am curious just how bad the lag would be with the .82 housings. I have a 2700 stall converter in the car and currently the engine doesn't come on cam until about 3000 rpm. (It really needs about a 3200 stall converter). So I am dealling with a bit of "lag" already.

By turbine do you mean the exducer? The whole thing is basically a turbine. The inducer is the cold side and the exducer is the exhaust/hot side. Not sure which one you mean here.

Another thought...since I will be running fairly low boost (6-10 psi) couldn't I run larger aftermarket wastegates to increase the exhaust flow capacity of the turbines?

A waste gate is how the turbo is kept at a certain pressure level. It really has nothing to do with the exhaust flow. You need some back pressure in the system before the turbo to make it work. If you're using 2 turbos then you have to figure on 1/2 of the engine displacement to make it spool. the .63 housing will give the the best spool effort without having a slow reaction time. The bigger the wheels (both sides of it) the harder it is to get it to spin quickly.

 

[LemansWagon]

I see where things have been getting mixed up in our communication now. This is how I understand it:

The term turbine exclusively refers to the exhaust side. The inlet side is not really a turbine but a compressor or impeller because a turbine is "driven" by a fluid. Or in other words the fluid does work on the wheel. Whereas an impeller/compressor does work on the fluid by transferring kinetic energy and also compressing it in the case of a gas. And the terms inducer and exducer do not refer to compressor and turbine sides exclusively. Both sides of the turbo actually have an inducer and an exducer but they are opposite. On the turbine side the exducer is the smaller, or minor diameter of the wheel where the exhaust gas exits and the inducer is the larger, or major diameter, where the exhaust gas enters. On the compressor side it's the exact opposite with the inducer being the minor diameter and the exducer being where the compressed gas exits.

So what I've been unsuccessfully trying to find out is both the major and minor diameter of the turbine wheel on an 86-87 turbo to see how it compares to the wheel on an 84-85 turbo. See how big the difference really is. I have the 84-85 but can't find the dimensions of the 86-87 anywhere on the internet. Up until now I thought the turbine side of the 84-85 and 86-87 were identical since they were both .63 A/R. So I want to know the radius of both wheels so I can calculate the percentage difference in area inside the housing. This percentage difference should be proportional to the flow capability of the respective turbine housings and give me an idea how much more cfm the exhaust turbine of an 86-87 can handle over the 84-85.

 

[charlief1]

Now that I understand what you're asking I can help you more. I'll see about taking some measurements in the morning for you. Not sure but I think I also have this info in the turbo thread.

 

[LemansWagon]

Thanks. I looked through that entire thread but there is a lot to wade through. If there are measurements I easily could have missed them. I know you have photos of the turbines but not next to an 84-85. You show the TTA turbine, an earlier carbed .82 turbine, and the 86-87 but I couldn't find dimensions. I was hoping you hadn't already bolted the turbo together so you could still take some measurements.