BlowenByTwins

iTrader: (6)

I'm sure I'm going to regret asking this,

For example:

Borg Warner offers their S400 series in T4 and T6, would the T4 spool faster and the T6 flow more making more power, given that the two turbos are identical spec except for flange size.

Or am I completely off?

rx72c

iTrader: (8)

The two rear housings couldnt be exactly the same if one has a t04 flange and one has a t6 flange.

I recently swapped from a 1.05 ta flange to a .91 t6 flange, and with the t6 rear housing, the rear housing is huge around the flange area and tapers down.

Yet on the same note, the turbo now spools up worlds faster even with the bigger flange.

I believe the difference in spool between flanges is minimal if you choose the correctly sized rear housing.

BlowenByTwins

iTrader: (6)

^ thanks for the reply

I guess my real question is,

Does the flange alone really dictate any of the power or spool up characteristics?

rx72c

iTrader: (8)

I believe you need to get the correct size a/r housing for your application, and i would choose the smaller flange purely based on space, and in theory it makes sense that having a smaller flange "should" make it spool faster but i am no engineer.

I know the difference between split pulse and single entry is very big, but difference between the 2 split pulse flanges will not be as dramatic.
But still if your trying to chase every little bit of spool, id go the smaller flange.

StavFC

I have a related question to this, so may as well ask on here...

I happen to have a T6 framed turbo, with a GT4202 compressor wheel, but a larger exhaust wheel (10mm over the GT4202 one), and though that sounds big, the turbine is just .86 (undivided).

What would this be like on a ported 13B? Similar to the 4202s people normally run (which seem to be T4 flange but larger a/r), or better/worse?

In my mind I reckon it will probably be similar, but having never ran a GT4202 or a T6 framed turbo on a 13B, im not confident enough to try without asking...

arghx

iTrader: (3)

remember that A/R is just a ratio and it depends on what you are comparing. I really prefer the Holset/Mitsubishi nomenclature of actually naming the area of the housing (16cm^2) etc.

StavFC

Regardless though, it is a damn small a/r and question is still relevant.

Exhaust wheel is 90mm IIRC if that helps

Trots*88TII-AE*

iTrader: (11)

well take this fwiw, but a journal bearing 35R turbo with an O-Trim or P-Trim turbine (74mm) spools up as quick (or quicker) than a ball bearing 35R with the smaller (and newer GT technology) turbine wheel at 68mm. I think rotaries tend to like bigger turbines in general. Once you get up to 90mm, I couldn't tell you though, there may be a point where bigger isn't better.

And what arghx said, .86 A/R T6 is actually bigger than a 1.00 A/R T3, the A/R ratio is just that, a ratio. I think it'll spool damn well and still flow considerable amounts on the top end. what kind of power are you shooting for?

StavFC

Great info, just the kind of thing I wanted, and pretty much what I'd heard in the past

The car is a ported 13B on a T04E (allegedly), and though I dont know the turbine a/r (the car arrived from Japan with the turbo fitted), it is v.large, as big as the compressor, so expect .86 or bigger, most likely 1.00+ to be honest.

The car doesnt give its "proper" power till 5000+ and "really" powerful from 7000rpm+, so I wont be missing any low down power by fitting this big one
Ive driven a PP'd T6 GT47 turbo'd 13B quite a bit, and even that gave great power from 6500, not much higher than mine, but nearly 3 times the power of mine (160mph 1/4mile terminals)!

Mine is just simply not fast enough for me- Currently weighs 1150kg, and from previous experience I know I will be happy enough with anything over 400bhp (fly) per ton, so my goals will be easy to get with this turbo, so as long as it gives power delivery how im expecting, and it seems it will, it will be ideal.

And as I just have this turbo sitting around doing nothing at the mo (its 100% new and unused too), it makes financial sense over spending £1000+ on a different turbo

Trots*88TII-AE*

iTrader: (11)

May as well try, either way it will be good to know where you stand, and worse case scenario try to source a T4 framed divided housing either larger or smaller than you currently have, depending on how well it performed.

Hope you know how to weld a proper manifold or someone who can! No off-the-shelfers for T6, and fitment in a LHD will be tight. FC or FD?

StavFC

FC, RHD, and yeah, its certainly time for a good welder to set to work! I already have a CNC cut stainless T6 to 3.5in round section, which should come in handy.

Other option is rear mount I guess Plenty of room, but something tells me that even with a full ceramic coated and then heatwrapped exhaust spool with an extra 50 inches of exhaust before the turbo will be a bit lacking with the little 13B, wont be quite the spool ive had on V8s in the past, lol

Trots*88TII-AE*

iTrader: (11)

sorry, i meant RHD. I don't think rear mount would even be an option, especially with a turbo that size. You need to take advantage of the heat and velocity coming directly out of the engine if you want any amount of response. I'm sure it's been done before, it'll just take a bit of time getting the fitment right.

StavFC

My friends FD with RHD and T6 frame worked and fitted ok, but looking at my FC, I cant see it fitting.
Shame as this turbo is ideal and just sitting here too.