toyota_scion_tc

I don't know much about turbos but I want to hear from experienced people about the differences in these turbos and which is better and why. I know the T3/T4 is ceremic ball bearing. I am dont think the EVO III GT 16G is ball bearing but not sure. Whats the CFM and Max hp that these are suppose to be? I read the EVO III GT 16G is 550 CFM and 400HP Max. Which turbo is better for a turbo kit in the tc? Its going to be a little while before I go boost so I just wanted to get all the research done now. Like I said before I don't know much about turbo or turbo kit. I showed my friend the ZPI Stage 1 kit and he asked me why it has two wastegates? Anyone know the answer to this question? Their is one on the turbo and then one on the charge piping acording to him. Link below and thanks for any and all comments.

http://www.zeropointindustries.net/s...b629513004bbc0

raamaudio

I would not ask your friend for any advice on turbo systems since he does not know the difference between a waste gate and a blow off valve;)

I know you just said you showed him, pics I imagine.

Ok, which turbo is beter, best, etc, depends on many things, what are your ultimate goals for your car, modest boost daily driver, sometimes track car, very serious high HP numbers, drivability, budget, etc, etc.

Rick

GenericUserName

im with raamaudio. dont listen to your friend. besides everyone knows that the company that spends the most on advertising obviously has the better turbo!

GenericUserName

by the way tht was sarcasm.

toyota_scion_tc

if those are blow off valves then why have two? The picture shows two.

BreakTheStatic

There aren't two wastegates OR two BOVs. There is one of each. The wastegate is the one that is attached to the exhaust manifold, and it's purpose is to allow some exhaust gases to bypass the turbine housing and control its speed (and therefore psi level). The blowoff valve is located by the throttle and allows excess boost to be vented in case the throttle is closed prematurely. This prevents the compressed air from returning back through the charge piping into the turbo and causing damage.

zer0

There is a stock internal wastegate on the EVO III GT which is removed because there is no clearance for it with the kit. So the tial wastegate is thrown in.

From the picture, there is 2 wastegates, but you will only recieve 1 Tial Wastegate.
The BOV is on the chargepipe.

MIAPLAYA

Of course I'm partial but the better turbo all around IMHO is the T04E 50 trim/T3 over the 16g. Several reasons. Number one the Turbonetics unit is ceramic ball bearing so you will see boost threshold (the point where yu hit full boost) sooner then in any similarly sized conventional bearing turbo. Numer two and the big one is power production. The T04E 50 trim compressor is good to 470 CHP of air flow (roughly 47 lb/min or air). Of course this is all dependent on supporting mods and the engine but thats a good starting point. I could get into upgradibility, longevity factors, etc. But that would need a books worth of typing.

toyota_scion_tc

Thank you, that answers one of my questions.

raamaudio

Oops, I guess I could of looked at the picture before opening my big mouth, sorry!!!!

yes, that pic shows two wastegates and one BOV.

I am using the EVO III GT on our project car but going with the internal wastegate. This resulted in some mods that most would not want to do in a kit but ours is a one off with no plans to sell the manifold, downpipe, etc.

There are alot of variables to determining which is the best turbo for a particular application and it goes far beyond just bearings, etc.

-Cost
-Planned real power for your particular needs/desires, bigger is not better if you do not plan to develop super high power numbers which cost alot more than just a more expensive turbo.
-Size, bigger may need bearings to reach the desired boost as soon as a smaller turbo does. Sometimes you may not want to reach full boost to suddenly(i.e. turboed autocross cars like ours, to much wheel spin out of the tight turns)
-Manifold design and pipe sizing.
-Wastegate design(internals are generally more reliable but less visually appealing) Some internals are better than others, again by design.
-Longevity, a BB can deffinately last longer, where does that tradeoff over cost fall into place according to your long term plans? But, a water cooled center section non BB turbo with frequent synthetic oil changes can last a very long time.
-MARKETING.
-And many, many more factors of varying significant importance.

Rick

toyota_scion_tc

Thanks for the answers raamaudio. Can you upgrade the EVOIII GT 16G to ball bearings? If not then you helped me make up my mind. Thanks Nick

raamaudio

Not that I know of but I have not looked into it, just not concerned enough to bother.

I have asked some exceptionally knowledgeable people in the industry(not turbo manf) about the real benifits of the BB center sections and the verdict is out, I have recieved answers on both sides of the fence. Mainly it is about what you are after, a real need or use or one of which can be bragging rights which unfortunately far to many of us are more concerned with that than actual real world use.
Massive evidence is found in all the monstor motor projects that have been built, very few of those cars get used for much of anything beyond the dyno as they are to hard to drive for 99.99% of us, to costly to build and maintain. They do have thier place, make big power, bring in customers, marketing toys is the main reason for existance though I know most that build them are very passionate about what they are doing so alot of it is love of the game as well.

retrodrive

I am looking at it this way. T3/T4 is a slower spooling turbo then 16G but it will produce a little more power if you max both out (because of their size). BB option would make T3/T4 spool a little better then it does without BB but then reliability goes down. I like regular turbos because they are more dependible and the difference in spool between BB and regular turbo is not large enough to sacrafice reliability. 2.4 TC engine will spool the 16g faster then T3/T4 so you would get your power sooner and the lag is virtually non existent. If you max out both turbos you would end up with a blown up engine anyway so I would go for smaller one.

raamaudio

Hey Pete!

I agree, why I chose the 16G (Evo III GT) it is all I needed and more.

Rick

InjentC23

I don't remember him asking about Turbonetics, but nice sly way to throw in a plug for Turbonetics.

Cape_Cod_TC

I remember reading the topic title.

InjentC23

shut up, hehe

paul_dezod

Why such generalized statements toward T3/T4 turbos? They all are not laggy what so ever. Some oversized or improperly matched ones with larger A/Rs may very well be. With a properly selected A/R, and exhaust housing, one can acheive a great blend of power, spool & drivability.

In actuality, I feel the tC is really pushing that 16G too hard. In some cases on some lower boost, it is close to the choke point. From some quick and dirty calculations, with a pressure of 10 PSI (1.68 Pressure Ratio), that turbo at 4000-6000 RPMS just continues to plummit from a peak efficiency of 71% at peak TQ and falls off to a bit over 60% by redline. The fall off in efficiency means decent temped compressed air @ peak efficiency then as it falls (RPMS increase here), to really hot condensed air making the intercooler work twice as hard to cool that air. The intercooler only has a limited amount of cooling capacity (most are 75%), this means that your intake temps just got a bit hotter, which in turn means you are getting less power.

Also, the 16G has an Inducer of 1.903" & Exducer of 2.675", turbine exducer of 1.935" & major of 2.205". This turbo with these specs reaches your peak CFM at 25 PSI. What does this mean? It only puts out about 27lbs/min (really rough calculations). Yes out put will increase as PSI increases, but how many people on here are going boost past 15 let alone 25? Probably 5-10%.

I feel the generalization of T3/T4s being too laggy comes from a scenario like the T3/T04E 50 on the tC. The TQ curve is not really that flat, and notice how 'hill like' it is, a mountain if I may:


A flat curve means more area under the curve, which means more useable power.



Note how flat ours is. Now just to make a bit of a comparison and make them seem more alike, I will truncate the T-netics graph from 3700RPMS or so on....





So all in all, our turbo is a T3/T4 and spools failry quickly due to several attributes in the system including turbine A/R. Our peak TQ is made at 3800-4000 RPMS, which is the same as almost any 16G (which is also supposed to a fast spooling smaller turbo) if you want to judge a turbo's merit by when it begins to make boost. That is hardly a good measure.

Cost, build, power goals (I want 5xx HP), power distribution (I want some mid-range and top end vs low to mid-range), warranty info and how well it works with what your doing.....

zucc

what about turbo for an automatic tc? reliablity and speed ill have around 7 grand 2 spend

toyota_scion_tc

Here is another question which turbo will have more usuable hp. What I mean is overall gain not just peak?