RX-S7V7N

.

Iīm preparing a 13B NA S5, 6 ports, and i have a TA4122 turbo for about 50$,
looking for 250~350rwhp.


This turbo is from a Mercedes diesel engine with about 280kW, 381HP, need
opinions if this work for the power range iīm looking.

Donīt know much about turbos, i have read and try to learn.




Garrett TB4122 PN 466214-25, it uses parts from T04B, T04E (TB is old type).


Compressor
TO4E 6 blades

446618-0014


Wheel diameter mm (A) 82,00

Inducer diameter mm (B) 48,45

Tip height mm (C) 2,50 (or 4mm)

Wheel bore diameter mm 6,25

TRIM 35

A/R .50






Garrett T04B T04E Turbo Turbine Wheel
OE NO 446905-0004 / 410188-0029 / 410188-0048

DIAMETER (A/B) 58.3 mm / 74.2 mm

TIP HEIGHT (C) 9.6 mm

JOURNAL BEARING (D) 10.16 mm

COMP. WHEEL BORE (E) 6.32 mm

BLADES 11

A/R 1.00



Questions.


The 48,45mm of the compressor is too small ?
Trim 35 is lower than i read about 13b turbos, will it work or no top end ?
What kind of response have this type of turbo ?
The turbine size 58.3mm is ok for a rotary engine ?


Please advise, and understand that iīm no expert.


Tanks in advance

RX-S7V7N

.

Here are some pictures from the same turbo, only this one is made in china, and
the one i will get is original from Garret.

I hope that someone can give me opinion about this turbo, i know that
many members know about turbos, and can give me some help.

cBigganz

I'm no expert but judging by the specs it shouldn't be too restricting exhaust wise. Might even be a little to big of you're leaving the motor unported. The compressor is very small though. Since its going on a 6 port it may be all right if you're not looking for crazy power. The additional compression will make it preform better than it would on a 4 port.

IRPerformance

iTrader: (41)

Compressor is very small for a rotary, but then again your power goals are very conservative. Going to be interesting getting a flange like that for the downpipe.

RX-S7V7N

Hello, tanks for your opinion, i only clean the exhaust port, and maybe will lower
the port 2mm, other than that just smooth and polish the the intake and inside
the ports.

This turbo is used on a 12,7 L engine, but with only ~2000rpm max, i have read
that one turbo that makes for example 200hp on a diesel engine, if used on a
petrol car it will make over 280hp.

So, if i plan from 250~350hp maybe i will be somewhere on the middle.

Tanks.

RX-S7V7N

Hello, i also consider that, but small is only the inducer, the exducer is 82mm.


This turbo may not be good for this application, but for shore it can make 380HP and big torque on a diesel engine.

From what i have understand about the trim is, if higher like 70, than
more lag, and more top end, if small better spool and less top.

If iīm not wrong, this turbo is bigger than the stock TII


Stock TII turbo specs


Turbine major: (63.75 mm) 74.2 mm more 10.45mm difference
Turbine exducer: (54.61 mm) 58.3 mm more 3.59mm difference

Compressor inducer: (43.68 mm) 48,45 mm more 4,77mm
Compressor exducer: (63 mm) 82,00 mm more 19mm

So, in theory it will perfom better than the stock TII on a S4 engine,
correct me if iīm wrong


The relation of the A/R i donīt understand what is the best on a rotary engine.

About the flange, still didnīt think about it, if you mean get one, donīt
worry, if need i will make one, the engine is still open, but for shore i
will post some photos for you to see how it goes.


Tanks for your replay, waiting for more opinions about this.

Regards

lastphaseofthis

iTrader: (8)

a 400 piston turbo is good for .7 on a rotary. = 280hp
so 280 times .7 = 196.

compare the sizes to a known 300 hp turbo... the bnr stage 3.

RX-S7V7N

To calculate the final you have to times .7 twice ?
Sorry if i understand it wrong.


About the BNR stage 3, 60-1 hifi wheel is 59/76mm with .60 A/R cover.

Yes, big difference, more 10mm on the inducer and less 6mm on the exducer.




I have found this about a T4 T70.

T4 T70 Turbo 600hp+ .68 A/R GT35 turbocharger


T4 T70 --------------- TB4122
.70ar cold side --------- A/R .50
ind: 51.99mm --------- 48.54mm
exd: 81.74mm --------- 82mm
trim 40 ------------- Trim 35


.68ar hot side --------- A/R 1.00
ind:73.42 ------------ 74.2mm
exd: 57.97 --------- 58.3mm

This is a piston 600hp turbo, numbers are very close, only the A/R that i donīt understand
the efect, only this are different, and the 4mm different on the ind. compressor.

Base on the numbers the Garret TB4122 maybe is close to 450~500hp, so
assuming times .7, 450hp times .7 = 315hp.


But if it makes 280hp, no problem at all, i still be happy with a 50$ turbo.


The reason iīm asking opinions, is just to not waste time and money if someone
explains that this tubo is not good for this setup and hp that iīm looking.

Tanks

cBigganz

Do you have a compressor map for this turbo? It could be helpful for comparison to a more commonly used turbo. There was an explanation on how to use compressor maps to calculate output for a turbo on a rotary. Will see if I can find it.

cBigganz

https://www.rx7club.com/showthread.php?t=888852

Here's the one I was talking about. I'd suggest checking out the post on reading compressor maps too if you are unsure how they work.

Summary: in a perfect scenario turbos will make approx 30% less than rated power on a rotary. Ex. A 700 hp turbo will only make 490 hp on a rotary. This could be slightly better on a 6 port engine due to increased airflow ability and higher compression.


I haven't been able to test this myself (though I'm getting close). All this info is from various sources on the site.

RX-S7V7N

Hello, no, i donīt have the compressor map, try to find it, but no success.

About the 30% less power, yes i understand, there is also a relation
from diesel and petrol engines, were the same turbo will make more
power on petrol than it will make on diesel.



from this page. turbo_RHE-RHF



The RHF6 if used on a diesel engine with 6L can go from
154hp to 240hp, the same turbo used on a petrol engine
with 3L, can go from 177 to 270hp, but on high power engine
it range from ~220hp to 322hp, more 82hp and that is about more
34%.


Now, assuming that the TB4122 can make 380hp on diesel, if we
add 34% it will make 509hp on petrol, taking out the 30% because
it is a rotary will get about 356hp. removing the extra, maybe i will get
something close to 300hp.

Now, this is only in theory, because many other factors are included,
trim, A/R, etc etc, also this turbo may be out of range in RPM
performance for the rotary, the surge for example.




What is A/R? - Concepts - Turbos - TurboMaster

Found this about the A/R, and i understand now that for the rotary
near A/R 1.00 is ok for the hot side, and A/R .50 i also ok for the
cold side


What is A/R?



Turbocharger Diagram showing the relatiosnhip between Area A and Radio R


The A/R in a relationship that is obtained when dividing the interior area of the
turbine where the inner walls are found, through the turbine housing radio from
the center to the tongue as the illustration indicates.

A/R values are expressed as .35, .47, .68, .84, 1.00, 1.15, etc.

A small A/R indicates a small interior volume in the small turbine and a large A/R
indicates a greater volume.

At a minimum A/R the motor's response is produced at small revolutions per
minute but at high revolutions we will not achieve an adacuate caudal.
We should always find a compromise between achieving the lowest response
possible and have enough caudal at high revolutions.

Regards

cBigganz

So overall this turbo should be fine for around 300 hp and won't cause to much exhaust restriction. I'd say go for it.

RX-S7V7N

Yes, thats what was trying to make shore, the size suggest it can make
250hp to 300hp, but like i say, since it is for a 12,7L engine with low
RPM, than on a rotary the power band may not be suitable.


About the restriction, at least it is bigger than the original Turbo III,
but again, this is a high compression engine not a low compression.


In fact already ask for my friend to send it to me, one more week and
i will have here with me, will post some pictures of it if i have time.

Tanks for all replays, if anyone still wants to give his opinion, it will
be welcome.


Regards

Trots*88TII-AE*

iTrader: (11)

My first turbo upgrade on my TII was an HKS Sports turbo which used a T04E 57 compressor wheel and O-Trim exhaust (T4 framed, 0.82 A/R).

There was no appreciable loss of spool from stock TII turbo to this setup. By the spec size, it looks like the turbo you have listed uses the same O-Trim exhaust wheel, and I think you will be very happy with the performance on the exhaust side (you could even go down in A/R to 0.82 divided without too much restriction for your goals). The 57 trim, however used a 57mm inducer vs your 48.5mm, and was good for up to ~350 whp rotary if I recall.

As far as compressors go, Inducer has considerably more impact on the capability of the turbo than the exducer, and should be the main measurement used when comparing performance. I see no benefit in using the smaller 48.5mm inducer compressor wheel like you have listed over something along the lines of a 50 or 57 trim, or a even as large as a 35R compressor wheel. It will not noticably improve your spool, but will really restrict you. Maxing out a compressor wheel is not an ideal setup, and although I can't find a compressor map (or even a listing) for a 35 Trim, I can't foresee it flowing enough at even 1 Bar to keep up with the engine, let alone doing it efficiently (and the last thing you need in a high comp turbo is hot air).

The good news is, with that turbo frame you can quite easily change out the compressor wheel, backing plate and compressor housing with something larger from the same family, and will only require a re-balance of the shaft/wheels. I would strongly consider doing this if you've already purchased (I did this using a used SC6152e turbo from Precision Turbo on the above listed turbo), as you will gain a more efficient (cooler) air charge and still keep on budget. You can then combine the remaining parts and sell the turbo off to recoup costs.

Remember, when the exhaust side restriction remains constant, an engine can only take in so much air at a certain boost. Changing the compressor wheel in this situation will only affect spool time (marginally) and charge temperature(density). I guarantee you would not be disappointed with the spool time of a 50 or 57 trim wheel on that same exhaust, but your engine would thank you for the cooler charge.

How much boost are you planning on running?

Tem120

iTrader: (5)

According to that little chart and math , That truck makes 380 crank . Ok that multiplied by 1.34

is 509.2 multiplied by .7 for rotary inefficiency factor 356.44 then drivetrain loss of 13% 310WHP at the same boost rating ...


now that 380 at what PSI was that ? can you increase the PSI safely from that turbo say if it ran at 8 pSI on the deisel , But its safe to up it to 12 PSI . you should have more then enough flow for your goal .

But the X factor PSI is missing in my equation .

RX-S7V7N

Hello Tem120,



From what i know, and i will confirm it, this trucks run at 0.8 bar that is 11.6 PSI,
most turbos, including small ones can go from 9PSI to 14PSI, so i think from 11 to
15PSI is not a problem for this original Garrett unit.

Remember, this is a 6 Port high compression engine, the amount of pressure for
the same hp is different than with TII engines.



Regards.
-

RX-S7V7N

------------


Here is the Garret unit that i talk about.










Here is the Garret TB4122 and Holset HX50 from Scania 124 (diesel truck wiht 420hp)




The Holset come for free, and it is larger.























Now, the question is, for the same engine 6 port high compression, still ok to
use this large HX50 ?

Or is better to get low compression rotors ?

Using this large Holset i will get more HP, sitll donīt want to go over 400hp, but
also donīt want big lag.

Will open the HX50 for cleaning and verification, need to know compressor and
turbine sizes, maybe it will boost only after 4k rpm.

Any opinions and suggestions are welcome about using the Holset instead of the Garret.


Tanks in advance.

-

RX-S7V7N

-


Ok, so you all may think that iīm confuse, yep, you are right, with so many turbos i must start to look like a turbotard.

So i make my decision, with my last acquisition the Holset HX40 will be my choice, the TB4122 is small, and the HX50 is way to big for what i want.

And the HX40 is the one in better condition, used, but the best fit.


T4 T70 ----------------- TB4122-----------HX40
.70ar cold side ------- A/R .50-----------not shore
ind: 51.99mm -------- 48.54mm---------53,97mm
exd: 81.74mm ------- 82mm-------------81,32mm
trim 40 ----------------- Trim 35-----------trim 42 (8 blades)

.68ar hot side --------- A/R 1.00--------donīt know, there is a 16 inside
ind:73.42 ------------ 74.2mm------------75,96mm
exd: 57.97 --------- 58.3mm-------------64mm


The HX40 is in all cases bigger than the the T4 T70 (GT35), many people use this turbo on the 13B engine, the hot side is not V-Band, but how can i complain
if it only cost me 25$ ?


So, this turbo on the 13B 6 Port high compression, with a small porting (just cleaning and matching) inserts cut etc, will i be on the 300~350rwhp range ?


Any opinions or advise using the HX40 ?

Next some pictures of the 3 units, the HX50 is tempting, but i donīt want that much, also the lag will be bigger.

Starting with the elected one.





















All above are from the HX40









.

John Huijben

iTrader: (1)

I would go with the HX40, what's the exhaust housing size? Should be stamped on the inside of one of the 2 runners in the housing.

RX-S7V7N

.

I have already left it on the details, , it have the 16 inside, and from what i have read it is 1.13 or 1.21 A/R.


Can you confirm it please.

.

John Huijben

iTrader: (1)

Right, I missed it.
That 16 refers to 16cm^3, holset doesn't use A/R but cm^3 with turbine housing sizes. It doesn't say a lot about the A/R though, it's just the area of the turbine inlet. It's a pretty decent size though, it's bigger than you need for 300 - 350hp, so it will spool a little late but make great top-end power. A holset hx35 will probably also do for your goals, and they spool a little faster (most of them have a 12cm^2 housing).

The problem with $50 turbo's usually isn't the turbo, but that the rest of the setup is also cheap :-). You are aware of all the other stuff you need to actually make this work well and reliable right?

RX-S7V7N

Hi, about it be a little big, yes you are right, but is what comes with the unit, on the
other side this will be a 13B 6 Port with high compression, and will make power with lesse pressure,
also limiting the exhaust isnīt good, if i find a small housing i will change it.

The title is $50 turbo, but that one was the Garret TB4122, that i will send it back, the holset hx50 comes from a truck,
were they change the turbo, but it was not turbo problems, and this one comes for free.

Now, the HX40 only cost $25, it comes from a junkyard engine, the other stuff,
i think iīm aware, next the list of things that i remember that need for all this.


Megasquirt, already running the 12A engine
Turbo II oil pump, also gear box and related to fit the N/A engine.
Bearings with grouve and 3 passages
Oil pressure regulator for more than stock
Jets for cooling the rotors
fuel pump and lines modification, also pressure regulator
Injectors for the power in question
Wideband
Air Intercooler and oil cooler
Small porting and sleeves removed
Clutch for the same power
Water-Met injection,, maybe not need for this power,,, still on the list
Exhaust line 3" or 4"
EGT sensor
Rotary Aviation complet kit with seals gaskets etc (already have this).
Waste-gate 2x38mm or one 50mm, still to decide

FC ignition coils,,,, ----this i donīt know if i need to upgrade-------
Dwell the engine, from what i have read is for setups for more than 300hp per rotor, so maybe will not do this, also here in Europe not easy to find, and the price is high.


From what i remember this are the things that i need to do on the engine, maybe there is other things just donīt remember to list it.


Any advice is welcome, fell free to comment, keep in mind that this is my first engine, already have play with the 12A, but only outside, by converting it from
carb to CBR600RR complet intake, to get 186hp crank.

Regards


-

John Huijben

iTrader: (1)

Wow, nice finds on the turbos by the way! I'm also located in europe, but I never come across deals like that !

You seem to be well on your way to actually make this work, I'm impressed!
The FC coils will work, don't change them. if your engine is from an european S5 you shouldn't have the rotating sleeves, but butterfly valves in the lower intake manifold to activate the aux ports. Hooking up the actuators to a nipple on the LIM that sees boost works pretty well and may even help with spooling the turbo. (the much much more awesome thing to do is to fit those CBR600RR throttlebodies to this engine, and make some sort of plenum that goes beween the trottlebodies and the turbo, the n/a intake is pretty restrictive)
Water/meth injection isn't really needed for 300-350hp as long as it's tuned and cooled properly. I'm not sure if the S5 n/a engines in europe had the rear irons with the thick or the thin casting near the oil filter. All S5 rear irons I have got the thick casting, but they are all turbo ones, if yours has the thin casting than that will probably be the weak spot of the engine. It's been said that it's good to 400hp or so, but it depends on more stuff than just hp.

RX-S7V7N

-
Me also, it is the first time i get deals like this, but it was the last turbo that was
the best one, the garret was too small, and the HX50 too big, also get a spare
HX50 with the compressor wheel damage.


I hope i manage to get what is missing, and put it all together, never done this before.




Yes it is the S5 European, but in contrast this engine come to my hand with the USA intake system, it was supposed to use the sleeves, but since the irons
donīt use it, they close the 5 and 6 port with some rubber.

So i have to add the butterfly to close this ports at low load.

See the pictures here, the engine was stop for some years, a lot of rust but the
internals were ok and in good conditions, at the moment all that rust is cleaned
and it looks much better, i also canīt complain, it cost 300€ with gear box.

https://www.rx7club.com/build-thread...-dust-1051040/




I didnīt think about it, but it is possible to do, also use 2 butterfly's for primary ports and the other 2 only for secondary, still using an actuator to control the
5 and 6 port.

But i was thinking about open the original intake, so i can leave as close to stock as possible, also without the turbo come in it will do as a normal engine,
do you think that because of restriction it is hard to get 300 or 350hp ?

Take a look at the CBR600 system installed on the 12A engine

https://www.rx7club.com/megasquirt-f...-835786/page3/





Water/meth may be a must, this is a high compression engine, will read more about it.

From some pictures i come to the conclusion it have the thin casting, but it will not be easy to get the rear iron with the same type of port as i have,,, the better
is leave it under 400hp, for more than that i have the HX50,, that i will never use.


I already notice that you do some crazy stuff, impressed with your work.



Regards

-

John Huijben

iTrader: (1)

Wow, that 12a with the motorbike tb's looks nice!, and just look at that dyno curve, torque doesnt even begin to fall off at the limiter, you need to give that engine more rpm's ;-). Well if you want too keep it simple and dont want to make over 350 I guess the na intake will work, and the butterfly valves arent really needed, but they do work. Where in europe are you?, I have a few s4 lim's with butterfly valves sitting that Im willing to donate, not sure if it fits an s5 though.