OK, after talkin to people everyone seems to think i single big turbo would be better for my 383 tan twins. So just to see what is out there. whats a good size single turbo? i am looking at:

garrett/air research T6 88 MM inducer 127 MM exducer on the compressor wheel .96 A/R on the compressor housing and 1.50 A/R turbine housing.
TOO BIG?

 

I'd look at the S400 series from Borg-Warner personally, www.majesticturbo.com sells em. Very modern turbo, the version they use for a Detroit will flow up to 94lb/min and they make a modified version with an 88mm wheel that's good for something like 1300hp. The S400s can be had for under $600 in the stock (74mm) form but the price goes up considerably for an 88. Still way cheaper then a precision and the precision is probably similar.

 

I second the Borg S400 for buying a new turbo. I have heard nothing but good things about them in all of the forums. You can't beat them for the price. The stuff on Ebay is going up all of the time for used units. I see 'slightly used' Holset HX35 and HX40 approaching $400. That is a waste of money when the new MPs and Borgs are only $100 to $200 more.

If you never ran a turbo before then you will be more than happy with a S400 sized unit. The giant 88mm, 1.50 A/R exhaust turbo you listed is good for a 420+ ci race smallblock or a 'streetable' big block.

What did the garrett 88mm inducer wheel come off of? I have a garrett 83mm ind., 1.50 A/R unit from a genset and a garrett 85mm ind., 1.39 A/R. I haven't come across an 88mm inducer wheel with 1.50 exahust A/R? Do you have a part number for it? It sounds like a TV81 series with the undesirable 1.50 A/R turbine.

 

If you already have the engine done then you'll want to calculate how much CFM the motor will flow (based of VE%). Then when you know the CFM you can use some of the formulas out there to calculate the Pressure Ratio and then the Density Ratio, and finally whatever CFM at whatever Pressure Ratio. Then you can use those two specs (CFM and Pressure Ratio) to find the right turbo by reading the compressor maps.

 

that wasnt the right turbo... i meant to post this one...

its a T88 "thumper" 88 MM inducer on the compressor wheel .95 A/R on the compressor housing and 1.38 A/R on the turbine housing.

 

i read up on the s400 turbo a bit and it sounds like a really AWESOME turbo...$1500 bucks (500 cheaper than a t88 or t76) and yet produces such a nice power range from 800-1100 hp...i believe i read it can flow 98 lb/min...its a HUGE turbo though but i guess if your sticking with a single setup then youll have space somewhere..

i couldnt find where it was sold on majesticturbo.com does anyone else have links to good prices on these turbos

i was contemplating twins on top of a 406 but now im leaning more toward a single big turbo to save money and ease of build

 

Well, i decided to stay twin turbo, so i can throw you a couple links to garrett T88 if you are interested...

there are a couple used ones for dirt cheap. i was bidding but i learned my dad bought me a set of twin turbo manifolds for an early Xmas present (my sister somehow understood what i was talking about and mentioned it to him) so i am for sure doing a twin turbo setup.

http://motors.search.ebay.com/T88-tu...tsearchZSearch

 

That is good that you didn't buy any of the Ebay turbos and decided to stick with twins. All of the listings do not appear to be real Garrett 88mm inducer wheel turbos. The first listing has the tag knocked off and looks smaller than 88mm and doesn't show measurements.

The second says it is a 88mm when in fact it is a dead ringer for a 76mm unit.

The third is a SSAC knock off that is in the 60mm to 70mm range and will fall apart in no time.

If you ever buy a turbo off of ebay ask for pics of measurements.

I hope the manifold/headers are not SSAC junk.

EDIT: the first and second turbos are being sold from a seller with 67% feedback.......bad idea to buy from someone like that.

 

I dunno what your power goals are but when I was thinking single on a 383 I leaned towards a T76 .96 q trim.........

 

I called Majestic Turbo up just now & spent a few minutes talking with John, here's what he had to say:

* The S400 is pretty popular, he's seen a fair bit of interest in it (probably because it's so affordable).

* That said, as it is right now, it's probably not the best choice for the average car here, because of the constraints imposed by it's physical size - it comes with a 132 housing (forgot to ask if that was 132 mm), & uses a T6 flange. The comment he made was that it would be really good for something like a 508, but even if I were to bore & stroke an SBC, the S400 would likely still be "pretty lazy". (Yes, I did tell him that I too am building a 383...)

* He said that since he's seen this much interest in the S400, what he'd probably do is to go ahead & order one, and see what would be involved with moving the wheels into a smaller housing (maybe a Garrett). He figured that the housing for the Garrett would cost about $200, and there could very well be other costs involved with machining/fabricating/etc.

They're also going to be revamping their website, I'd be surprised if they didn't add some info about the S400 by the time they're done...

I told him that I'd be in touch with him via email, if/when I learn anything else, I'll post in this forum...

Hope this helps someone.

 

Interesting, he said it has a 1.32A/R for a turbine I am guessing and that it is a T6 flange. What size is the flange in inches? 83 Crossfire TA told me that my TV81 and TV75 series Garrett's were not called T6 flanges so I am confused. I thought everyone called them T6 so I did too.

A few people seem to be running the S400 and similiar turbos at Turbomustangs. You might want to check out their setups and spool time, EBP, boost, etc.

Is that the majestic turbo that you called the same as dave@majestic on the Turbomustangs site??

 

Could have been, it's been a while since I've studied up on turbocharging, so I'm going to have brush up on terms again...

Don't know, I didn't ask him that. I was more focused on things like exhaust manifolds, how practical this turbo would be, etc.

I called up the number listed on their website, & was transferred to John. Seemed like good guys to work with from the little bit that I could tell...

Also, checking out the setups on the Turbomustangs site is probably a good idea, but are there many that are running engines in that size range?

 

Anyone have compressor maps for the S400’s?

T6 (T06) flanges vs whatever… I’m either not understanding the issue or missing something here. Garrett/Airreseach used to do T3, T04, T06, T08… turbos. Each one got a larger “frame” and which worked with different housings that tended to have different flanges with larger dimensions.

Most of the performance market centered around the T3’s and T04’s, and the larger turbos tended to use compressors/wheels from the T06’s… fitted into the T04 housings or onto the T04 frames, and from there people started fitting wheels and housings from other lines of turbos.

If I remember our previous conversation about this it was about the GT series, and possibly the TV series. These are their own turbos. They’re not T04’s, T06’s…, at least not in their original form… of course, if you deal with the aftermarket suppliers, they’re using these wheels and housings just like the ones before them, and you can get say a GT42 or GT45 with a T04 or T06 housing/flange, as well as the way that they came from Garrett.

Does this make sense/answer the question any or is this just making things worse?

Now to be honest, I hate dealing with say a T06 flanged GT42, or some of the other ‘bastard’ turbos, because what you have, and if there are even any GT42 parts on it depends on who put the thing together (as far as I know one without any GT42 parts at all doesn’t exist yet, but it has happened with the older turbos). At that point a GT42 map becomes just an approximation of what it will do. I’m much happier knowing that I have something like a Detroit GT4202 or whatever, knowing what parts are in it, what dimensions everything will have…