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shorterthanrich
11-07-2011, 12:54 PM
I've mentioned in a few threads that I'm replacing my GT2560s for a number of reasons, and am trying to find the perfect turbo for my goals. I know its out there! I've been going crazy trying to pick the right one, and just can't come to a conclusion.

Build Specs:
Built bottom end
Stock Pistons
2.8 Heads/2.8 Cams
Supertech Inconel Exhaust Valves
Rosten upgraded Valve Springs
Stock Intake Valves
3" DPs
VAST Log Style Manifolds
ER Intercoolers
044 Fuel Pump (probably switching to a DeatschWerks soon since a friend loaned me this)
Stern Firm Mounts all around

Long story short, my current turbos have much too large of an A/R - roughly equivalent to a T25 .86, but it's only a 2560 compressor/turbine, so naturally it spools very slow while only being capable of around 475whp. The car feels very fast once its in boost, but falls out of boost on every shift.

Goals:
500-550whp
FATS: <2.8
>375 wtq at 4,000 RPM
Ball Bearing
Still fun at around-town speeds

Nice to have:
11.X 1/4 mile, preferably around 11.5
Trap around 130mph
Great Road Racing car

Turbo Options so far:
GT2860R-5 (DaveNew used this)
GT2860R-7 (JibberJive is using this)
GT2859 (Not sure how this would perform compared to the 2860R-7)
GT2860RS
GTX2860R (Not yet released, no compressor maps or any data available)
GTX2863R (Billet 2860RS with a larger compressor exducer)
Forced Performance HTA2868 (Basically 2860RS with an HTA68 compressor wheel)
Precision 4828 (http://www.precisionturbo.net/turbochargers/aftermarket-replacement/details/Aftermarket-Replacement-Turbocharger---4828-/73) (Billet wheel)
Precision 5128 (http://www.precisionturbo.net/turbochargers/aftermarket-replacement/details/Aftermarket-Replacement-Turbocharger---5128/75) (Billet wheel)
RS6 Hybrid (Billet wheel)

I've also heard someone may be doing RS6 Hybrids upgraded to a DBB CHRA? Anyone know anything about that?
I'm hesitant to do anything RS6 related since I've gone as far as I have already, and they're journal bearing and not really capable of much more than 500whp without being pushed too hard...

I wont be using an tials for a handful of reasons (nothing against tial at all).

The HTA2868 seems like a good option, but I'm concerned that it's going to make power too late for me to enjoy, since its such a larger wheel than the 2860RS.

I'm very interested in those Precision turbos, since the 4828 is basically a bit smaller than a 2860RS, but with a billet wheel. However, Precision claims it's only good for 340 hp/turbo, which is a bit small for my goal. Hence, the Precision 5128, but that's a larger compressor than the 2860RS...at least on the inducer side.

With both the Forced Performance and the Precision turbos, there's no compressor map to look at, so I have no idea where the surge and choke lines are at all, and I don't have most of the specs on the turbos themselves to compare them to similarly sized Garretts, which is frustrating.

Any discussion and input will be appreciated.

cjk
11-07-2011, 01:03 PM
GT2860R-5 If you like that power band man...then you should go with that turbo. You both are running 2.8l as well...so that would be my pick for ya. Good luck!

NOTORIOUS VR
11-07-2011, 01:04 PM
770's IMO, but I'm guessing you're looking for just a turbo that will bolt on to your existing manifolds it probably won't make much sense to buy a Tial bolt on kit just to go back to OEM manifolds.

034Motorsport
11-07-2011, 01:10 PM
770's IMO, but I'm guessing you're looking for just a turbo that will bolt on to your existing manifolds it probably won't make much sense to buy a Tial bolt on kit just to go back to OEM manifolds.

I think Rich is trying to avoid an eliminator style turbo, although I too agree this is the best choice for basically everyone out there. No big ass turbo setup as more good results.

I think Rich should go for whatever fit's his setup, costs the least amount, and has PROVEN good results. Stay away from anything that is yet to be done; you'll very likely just end up in the same predicament you are in now.

shorterthanrich
11-07-2011, 01:28 PM
I'm not worried about the turbos fitting - I'll do whatever it takes to make them work with my manifolds, including changing the flange. But I won't be using any Tial products (again, tials are awesome, and 770s in particular are fantastic, just not an option for me)

Das General
11-07-2011, 01:37 PM
I think for your desired goals, a smaller turbo will be better. But you will need to be more aggressive in the tune. I wouldn't be too concerned about any noticeable "lag" for driving around town; that can be dealt with by adjusting your driving style.

Capt. Obvious
11-07-2011, 01:47 PM
What about just moving to smaller hotsides on the turbos you have now?

shorterthanrich
11-07-2011, 01:57 PM
What about just moving to smaller hotsides on the turbos you have now?

The turbos I have now will never be doing over 500whp. IMO, for anything less than 500whp, RS6s are the obvious choice. The TQ ramp up is just so incredibly fun on those, and I can get them crazy cheap.

moclakens
11-07-2011, 02:03 PM
Never mind

Capt. Obvious
11-07-2011, 02:50 PM
and I can get them crazy cheap.
Define "crazy cheap". [:)]

NOTORIOUS VR
11-07-2011, 03:02 PM
The turbos I have now will never be doing over 500whp. IMO, for anything less than 500whp, RS6s are the obvious choice. The TQ ramp up is just so incredibly fun on those, and I can get them crazy cheap.

But you listed your goals above as 500-550whp.. so that really isn't RS6 territory anymore unless you're thinking of going with something like a Loba style RS6 hybrid

shorterthanrich
11-07-2011, 03:13 PM
But you listed your goals above as 500-550whp.. so that really isn't RS6 territory anymore unless you're thinking of going with something like a Loba style RS6 hybrid

What I meant was that I wouldn't keep my current turbos, even if I were happy with under 500whp, since I would just switch to RS6s in that case, because they spool so fast and make basically the same power.

shorterthanrich
11-07-2011, 03:14 PM
Define "crazy cheap". [:)]

Hah, cheap enough that if I sold my kit now and switched to RS6s, I'd make most of my money back. And cheap enough that if you or someone you know is looking for a set you should PM me!

splatt
11-07-2011, 05:13 PM
Hah, cheap enough that if I sold my kit now and switched to RS6s, I'd make most of my money back. And cheap enough that if you or someone you know is looking for a set you should PM me!

Define "cheap enough".

I mean I can't really afford shit after my steering rack debacle, but I'm curious!

Highhats
11-07-2011, 05:24 PM
Precision 4828 Looks sick and very reasonably priced.

S4 00 2.7
11-07-2011, 05:40 PM
I also emphasize something that is proven.

jibberjive
11-07-2011, 11:24 PM
Rich, I stick with what I suggested before, the GT2859 if you want to get closer to RS6 spool, or now I suggest the GTX2860 for the larger option over anything else.I wouldn't really consider anything else, but that might just be me.

shorterthanrich
11-08-2011, 07:23 AM
Precision 4828 Looks sick and very reasonably priced.

I agree. Billet wheel and its basically the same size as a 2860rs. But they dont release all of the specs on it, so I don't know the exducer size, comp a/r, comp trim, etc. They also only rated it for 340 hp, which is not quite enough. I'm skeptical, though...since the inducer size is larger than the 2860RS.


I also emphasize something that is proven.

I totally agree. It's hard, because not many setups that people are running exactly meet my goals.


Rich, I stick with what I suggested before, the GT2859 if you want to get closer to RS6 spool, or now I suggest the GTX2860 for the larger option over anything else.I wouldn't really consider anything else, but that might just be me.

It's a really good option, but I'm not sure it will flow enough. Looks like its only good for 310 hp each...which really isn't enough. :/

jibberjive
11-08-2011, 07:36 AM
It's a really good option, but I'm not sure it will flow enough. Looks like its only good for 310 hp each...which really isn't enough. :/The GTX2860? I can guarantee they're good for more than 620bhp.

034Motorsport
11-08-2011, 07:46 AM
I agree. Billet wheel and its basically the same size as a 2860rs. But they dont release all of the specs on it, so I don't know the exducer size, comp a/r, comp trim, etc. They also only rated it for 340 hp, which is not quite enough. I'm skeptical, though...since the inducer size is larger than the 2860RS.



I totally agree. It's hard, because not many setups that people are running exactly meet my goals.



It's a really good option, but I'm not sure it will flow enough. Looks like its only good for 310 hp each...which really isn't enough. :/

The compressor map of the GTX2863R is incredible... Besides being able to match the 28RS, it can hold almost double the boost and flow much more at those high levels.

If the GTX2860R shares any of the benefits of the GTX2863R, then its going to be able to do plenty of power. One of the big benefits of the GTX over the standard wheel profiles is the additional flow at high boost, which can be seen on the compressor map. So while you may be out of the ideal efficiency range with a GTX2860R running high boost on our size of motor, you've got ER intercoolers and you can do meth, so thats not as big of a deal (pushing a lot hotter air, but the turbo is still able to push that pressure and flow.

Whatever you do, I'd really try to go for some v-band flanges. They will allow you infinite clocking of the turbos and more flexibility.

shorterthanrich
11-08-2011, 08:02 AM
The GTX2860? I can guarantee they're good for more than 620bhp.

Sorry, I meant the 2859. I need to stop using pronouns!

TweetsS4Estate
11-08-2011, 12:40 PM
770's, a twin disk or whatever Bortz has for a clutch.. slipping my mind right now, and AMD/EPL fueling, that inline 044 does work dude. I can also say I plan on achieving those goals in my 3.0L 605 car and having torque sooner than that. I will post when I get it broken in. I pick it up friday.

DxC
11-08-2011, 05:13 PM
i say 2868s, but thats just IMHO.

my steering rack exploded in my allroad so im stuck back in s4 land for the time being :( i knew that running those 285 sized tires were gonna be hard on the car sighhh

DiscoPotato
11-08-2011, 07:14 PM
RS6 hybrid ball bearings

Evilevo
11-08-2011, 07:49 PM
770's, a twin disk or whatever Bortz has for a clutch.. slipping my mind right now, and AMD/EPL fueling, that inline 044 does work dude. I can also say I plan on achieving those goals in my 3.0L 605 car and having torque sooner than that. I will post when I get it broken in. I pick it up friday.

I have a Southbend Stage 4 Extreme. Been in the car for like 25k miles now. Still holding strong. :knocks on wood:

shorterthanrich
11-08-2011, 07:53 PM
i say 2868s, but thats just IMHO.

my steering rack exploded in my allroad so im stuck back in s4 land for the time being :( i knew that running those 285 sized tires were gonna be hard on the car sighhh

Nooooo no the LOLroad!

You seem to be the only one advocating the 2868. Most others seem to suggest it will spool too slowly for the 2.7L...It is a pretty big compressor wheel at 53mm inducer and 68mm exducer...


RS6 hybrid ball bearings

Is LOBA the only company producing these? If I can get a set of these made without having to spend $5,000 for turbos only, I might be all for it. Ideally a compressor around the same size as a GT2860RS or a touch smaller inducer, but billet would be awesome.

mjb0023
11-08-2011, 10:06 PM
Run a single turbo setup w a precision 6265

shorterthanrich
11-08-2011, 10:07 PM
i say 2868s, but thats just IMHO.

my steering rack exploded in my allroad so im stuck back in s4 land for the time being :( i knew that running those 285 sized tires were gonna be hard on the car sighhh


Run a single turbo setup w a precision 6265

Hah, yeah, I mean that would be awesome. Unfortunately, I'm just looking to switch to different turbos on my twin setup.

Matador
11-08-2011, 10:52 PM
I can't believe I'm saying this, BUT...

If you're looking for around town "drivability" and running 11.X 1/4 mi, a well planned nitrous setup triggered to specific parameters (WOT, between X1 and X2 RPM, etc) could give a nice blip to the turbos to get them spooling. Then have your meth setup or whatever in the upper RPMs. The usage of nitrous to meth on a protracted timeline would be significantly lower unless you're constantly mashing the pedal at every light.

Moderate sized tank, with valve solenoid and blanket relay controlled by the ignition for auto on/off and open/close... Just a thought.

NOTORIOUS VR
11-09-2011, 06:29 AM
I can't believe I'm saying this, BUT...

If you're looking for around town "drivability" and running 11.X 1/4 mi, a well planned nitrous setup triggered to specific parameters (WOT, between X1 and X2 RPM, etc) could give a nice blip to the turbos to get them spooling. Then have your meth setup or whatever in the upper RPMs. The usage of nitrous to meth on a protracted timeline would be significantly lower unless you're constantly mashing the pedal at every light.

Moderate sized tank, with valve solenoid and blanket relay controlled by the ignition for auto on/off and open/close... Just a thought.

In most places driving on the street with the bottle connected and turned on is illegal, plus it runs out.

In his application it would be just a bandaid

AudiA4_20T
11-09-2011, 06:38 AM
RS6 turbos.

SALES@RSW
11-09-2011, 07:37 AM
Loba Turbos sound like the right choice for you. Shoot me a pm if you are interested in them. I would be more than happy to help you out with them.

Audi_S4
11-09-2011, 08:06 AM
LO600's

Aureus1
11-09-2011, 08:12 AM
Rich if you go RS6s we need to run our cars!

mjb0023
11-09-2011, 11:51 AM
what about the franken turbos?

Evilevo
11-09-2011, 11:53 AM
what about the franken turbos?

HAHAHAHAHAHAHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHHAHA HAHAHA


He wants a turbo that can make 500-550whp.

Not something that maxes out around 450whp.

shorterthanrich
11-09-2011, 01:32 PM
HAHAHAHAHAHAHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHHAHA HAHAHA


He wants a turbo that can make 500-550whp.

Not something that maxes out around 450whp.

No offense, mjb0023, but EvilEvo's right.


EvilEvo and Gearhead, this is specifically for you:

EveilEvo's dyno chart is so so similar to what Gearhead's 770 car did. Per EvilEvos logs - the car is VERY fast, and a 2.3 FATS is amazing for how huge those turbos are.
Since the HTA2868 are smaller than 2871s (53mm inducer, 68mm ex vs 53mm in, 71mm ex) AND are billet with all of the updated flow technology, the 2868 should build power sooner than a 2871, with similar - but more - top end capabilities.

It's because of this that I fail to see why an HTA2868 is too large for our motors. I feel like I must be missing something. If the 2871 can perform as well as it does, why wouldn't the 2868 make power sooner? If the 770s, with their small DSM housing, only built a small amount of torque a very small bit faster than the 2871, why wouldn't the 2868 also build a bit more power a bit sooner than 2871.

If someone can explain this to me, I would be hugely appreciative. It just seems that most of these turbos that I'm looking at (all of the GTs anyway), save the RS6 variations, all have extremely similar power ramp ups +/-30hp for most of the RPM band.

Everything with Precision is just a guess, since no one is really running them at all.

I might just end up doing GT2860rs since they've been done before, will have the capability to swap in the GTX wheel in the future if I want, and apparently the tq ramp up on all of these GTs is almost exactly the same

Evilevo
11-09-2011, 02:13 PM
No offense, mjb0023, but EvilEvo's right.


EvilEvo and Gearhead, this is specifically for you:

EveilEvo's dyno chart is so so similar to what Gearhead's 770 car did. Per EvilEvos logs - the car is VERY fast, and a 2.3 FATS is amazing for how huge those turbos are.
Since the HTA2868 are smaller than 2871s (53mm inducer, 68mm ex vs 51.2mm in, 71mm ex) AND are billet with all of the updated flow technology, the 2868 should build power sooner than a 2871, with similar - but more - top end capabilities.

It's because of this that I fail to see why an HTA2868 is too large for our motors. I feel like I must be missing something. If the 2871 can perform as well as it does, why wouldn't the 2868 make power sooner? If the 770s, with their small DSM housing, only built a small amount of torque a very small bit faster than the 2871, why wouldn't the 2868 also build a bit more power a bit sooner than 2871.

If someone can explain this to me, I would be hugely appreciative. It just seems that most of these turbos that I'm looking at (all of the GTs anyway), save the RS6 variations, all have extremely similar power ramp ups +/-30hp for most of the RPM band.

Everything with Precision is just a guess, since no one is really running them at all.

I might just end up doing GT2860rs since they've been done before, will have the capability to swap in the GTX wheel in the future if I want, and apparently the tq ramp up on all of these GTs is almost exactly the same

While my dyno was very similar to Mikes, his car accelerates a lot harder in the midrange than my car does. Now maybe it is because my tune wasn't running the same as when it was dynoed. But who knows.

BTW, my turbos are 53.1mm Inducer, 71mm Exducer and 53.1mm Turbine.

Kruat
11-09-2011, 02:15 PM
I don't have a dog in the fight, but this is good info to learn. When I get to that point, I'd like to have about 500whp. So I'm thinking RS6's.

Evilevo
11-09-2011, 02:17 PM
I don't have a dog in the fight, but this is good info to learn. When I get to that point, I'd like to have about 500whp. So I'm thinking RS6's.

I would use S605s over RS6s. The 605s are way more happy at high boost.

RS6s are a lower boost turbo designed for a larger motor. They are not happy at 30psi which a turbo of that size will need to run to make 500whp.

Here is a RS6 K04 compressor map overlayed on a K04 compressor map.

http://fbowuq.bay.livefilestore.com/y1p7YWhcP7z3H1O2w9hZxAsXwPUXTwJHtqit9jiWG49D0LZH_-sKncuMBv1cV8IlEglFsChd6NK4X58dXlLmAQ1WQ/k04-0025-28%20overlay.jpg


As you can see. Both only go up to a ~2.6PR which is 1.6BAR effective. So after ~24psi it is off the compressor map. In a very basic way of reading a compressor map.

zdriver
11-09-2011, 02:31 PM
So much good info in here, that simple compressor map overlay was really helpful to me.

Thank you!

jibberjive
11-09-2011, 08:21 PM
Ideally a compressor around the same size as a GT2860RS or a touch smaller inducer, but billet would be awesome.
*cough*GTX2860*cough*

shorterthanrich
11-10-2011, 06:53 AM
*cough*GTX2860*cough*

I knowwww but lord knows when they'll be available! Still haven't even seen a compressor map for them either...

Sure, if they'll be available in January I'd go for it...but I haven't really heard anything on it yet.

Kruat
11-10-2011, 07:35 AM
I would use S605s over RS6s. The 605s are way more happy at high boost.

RS6s are a lower boost turbo designed for a larger motor. They are not happy at 30psi which a turbo of that size will need to run to make 500whp.

Here is a RS6 K04 compressor map overlayed on a K04 compressor map.

http://fbowuq.bay.livefilestore.com/y1p7YWhcP7z3H1O2w9hZxAsXwPUXTwJHtqit9jiWG49D0LZH_-sKncuMBv1cV8IlEglFsChd6NK4X58dXlLmAQ1WQ/k04-0025-28%20overlay.jpg


As you can see. Both only go up to a ~2.6PR which is 1.6BAR effective. So after ~24psi it is off the compressor map. In a very basic way of reading a compressor map.

Thanks Evil.

shorterthanrich
11-10-2011, 07:43 AM
While my dyno was very similar to Mikes, his car accelerates a lot harder in the midrange than my car does. Now maybe it is because my tune wasn't running the same as when it was dynoed. But who knows.

BTW, my turbos are 53.1mm Inducer, 71mm Exducer and 53.1mm Turbine.

Thanks - corrected! I was looking at the wrong 2871.

I'm looking at an overlay of his acceleration vs yours, and I see what you're saying. There is a pretty significant midrange difference there.

Interestingly, yours vs. DaveNew's is very similar in the midrange, even with his E85+meth tune
DaveNew on E85+Meth
http://dave-new.com/S4/IMOLA_2000/LOGS/10_29_2011_E85withMeth/Accel.JPG
EvilEvo on 93+Meth
http://i120.photobucket.com/albums/o169/ajbortz/EPL%2030psi%20Log/image012.png
Gearhead1186 on 93+meth (I believe)
http://i1087.photobucket.com/albums/j461/gearhead1186/OceanPkwy%20March11/AccelerationG.jpg

So, if the HTA2868 would logically come on a bit sooner than EvilEvo's, it would be at least slightly more similar to Gearhead's.

NOTORIOUS VR
11-10-2011, 08:13 AM
http://i1087.photobucket.com/albums/j461/gearhead1186/OceanPkwy%20March11/AccelerationG.jpg

I would just like to say, it's incredible how strong Mike's car was for being a 2.7L...

sherbet
11-10-2011, 09:03 AM
I would just like to say, it's incredible how strong Mike's car was for being a 2.7L...

Probably due in part to how well built and over engineering everything on that car was. This thread is great for someone like me who yearns to learn more detailed info about turbos!


edit**holy shit I hadn't paid attention to the .75g between ~5,000 RPM to ~6,000 RPM. It also seems like Mike's car is seemingly stronger overall than the other cars in the comparo aaaand it has a much larger sweet spot.

Matt Danger
11-10-2011, 09:21 AM
For funsies. Collecting logs to lay it out more nicely.. but you get the idea

http://i.imgur.com/DauZW.png

Matt Danger
11-10-2011, 09:23 AM
w/ Notorious (Sascha) @ 24-25psi. Pardon my poor photoshopping.

http://i.imgur.com/Mw37Z.png

shorterthanrich
11-10-2011, 09:39 AM
For funsies. Collecting logs to lay it out more nicely.. but you get the idea

http://i.imgur.com/DauZW.png

Great image... To my point, even with E85+Meth, the 2860R from dave had no more midrange than Adam's 2871. Not until 4,500+, and thats more the crazy fueling than anything else.

Mike's 770 car rips everything.

sherbet
11-10-2011, 09:45 AM
I would love to get a huge highway lineup of all these cars just once!

DiscoPotato
11-10-2011, 10:45 AM
Is LOBA the only company producing these? If I can get a set of these made without having to spend $5,000 for turbos only, I might be all for it. Ideally a compressor around the same size as a GT2860RS or a touch smaller inducer, but billet would be awesome.

Im almost 100% positive Scroll does it for somewhere around 2 grand. Then you would have to get them to modify the snorkels too. I have a guy that has the turbos for cheap shoot me a pm.

shorterthanrich
11-10-2011, 01:24 PM
Regarding the HTA 2868 vs the GT2860RS:

For reference, according the logs in this thread from the 1.8T section, the PSI spool is almost exactly the same: http://www.audizine.com/forum/showthread.php/457235-A4-Experience-with-GT2860RS-vs-HTA2868

While power is naturally going to be higher per PSI, since the wheel is so much larger - 47 lb/min vs thirty something.

DiscoPotato, I'll shoot you a PM definitely.

jibberjive
11-10-2011, 04:39 PM
I knowwww but lord knows when they'll be available!...
Sure, if they'll be available in January I'd go for it...but I haven't really heard anything on it yet.

Very true, I didn't think about the timeframe implications.


Still haven't even seen a compressor map for them either...

Compressor maps and calculations only go so far in the real world. I bet that's part of the reason why Tial doesn't release compressor maps for their 605's and 770's, because too many people would be falsely led to believe that they don't perform (which has been shown that they do). Pure speculation there on my part though. Either way though, based on the real-world performance of the turbos just above and just below them, the GTX2860's seem to be a perfect fit for what you're asking (if price and timeframe aren't considerations).

jibberjive
11-10-2011, 04:41 PM
There's only so much speculation that can be done with calculations and theoretical comparison. I wouldn't pull your hair out about it, I'd just try make the most logical decision and run with it.

shorterthanrich
11-10-2011, 05:47 PM
Very true, I didn't think about the timeframe implications.


Compressor maps and calculations only go so far in the real world. I bet that's part of the reason why Tial doesn't release compressor maps for their 605's and 770's, because too many people would be falsely led to believe that they don't perform (which has been shown that they do). Pure speculation there on my part though. Either way though, based on the real-world performance of the turbos just above and just below them, the GTX2860's seem to be a perfect fit for what you're asking (if price and timeframe aren't considerations).

They don't release all their specs and compressor map data because they don't want to be copied. IP is only as good as your ability to defend it (aka, how much you can pay a lawyer) so I imagine there's very little IP on these designs. That said, it makes sense not to release every spec and compressor map, because it wont be long before there's a china made version.


There's only so much speculation that can be done with calculations and theoretical comparison. I wouldn't pull your hair out about it, I'd just try make the most logical decision and run with it.

I agree, it's just a really difficult call. I look at all of the dyno charts and maps and acceleration graphs, etc, and almost all of the options I'm looking at have the same exact midrange capabilities - except for the 770s which are clearly ahead, and the RS6 which just kick ass in the low and midrange. Since 770s aren't an option for me, I'm trying to find some magic unicorn that will perform as closely to those as possible.

770s are what, a Garrett 76 trim turbine? In a DSM housing, stock size inlet (so smaller than a T25) .50ar. Anyone know what the compressor housing is? And of course a Forced Performance HTA2868 compressor...

jibberjive
11-11-2011, 12:18 AM
They don't release all their specs and compressor map data because they don't want to be copied. IP is only as good as your ability to defend it (aka, how much you can pay a lawyer) so I imagine there's very little IP on these designs. That said, it makes sense not to release every spec and compressor map, because it wont be long before there's a china made version.

Much to Jonathan's credit, a turbo is much more than looking at a compressor map and saying,"Hmm, I think I'd like my turbo to look like that one. I think I'll go throw one together that has a compressor map that looks just like it." Props to anyone who could look at a good compressor map and go build a cheap replica that actually has that same compressor map, because if they can, they're not working in a cheap chinese factory. Releasing a turbo map is by no means a guarantee (a probably not even a big aid, to be honest) if anyone were to try to counterfeit one, and buying a set of 605's (for example) to straight copy would be more likely.

Maybe their biggest concern is IP though, but I have a hard time buying that. I think it's more about marketability and the typical B5 consumer's penchant for overanalyzation[;)]

jasonsowers
11-11-2011, 12:45 AM
I bet this thread ends and he wont pick anything what he already has.

splatt
11-11-2011, 06:23 AM
I bet this thread ends and he wont pick anything what he already has.

http://bbsimg.ngfiles.com/1/23410000/ngbbs4ea2666ddac2d.jpg

shorterthanrich
11-11-2011, 08:47 AM
Very true, I didn't think about the timeframe implications.


Compressor maps and calculations only go so far in the real world. I bet that's part of the reason why Tial doesn't release compressor maps for their 605's and 770's, because too many people would be falsely led to believe that they don't perform (which has been shown that they do). Pure speculation there on my part though. Either way though, based on the real-world performance of the turbos just above and just below them, the GTX2860's seem to be a perfect fit for what you're asking (if price and timeframe aren't considerations).


http://bbsimg.ngfiles.com/1/23410000/ngbbs4ea2666ddac2d.jpg

Haha, thank you Sam.

Still just workin' it all out. Diving further into the details of the HTA6868.

A compressor wheel with 48-51mm Inducer and a 60-65mm exducer, and as small as is reasonable of a hotside are the optimal "specs."

Does anyone know how to calculate what a .50ar on a stock flange is roughly equivalent to on a T25 flange? I really start to get lost there. 770s have made so much power with nice and early torque onset with what appears to be a very small turbine housing. It's still a 76 trim turbine, though, right?