which turbo should I keep?

[phillabaum03]

So I have 2 turbos and I want to know which one is better. Both 16g's. one is a 42 small? 16g ported and clipped with the bigger flapper, and the other is a real evo III 16g but its a 47 so a little bigger. Which one will flow better/give me the most power? thanks in advance fellas

 

[Kevin Jewer]

So I have 2 turbos and I want to know which one is better. Both 16g's. one is a 42 small? 16g ported and clipped with the bigger flapper, and the other is a real evo III 16g but its a 47 so a little bigger. Which one will flow better/give me the most power? thanks in advance fellas

I'm not sure what the 42 and 47 stand for, but the EVO3 16g is the bigger of those two turbos. The small 16g is good for around 36 lbs/min IIRC and the EVO3 will do 43. Any differences in turbine side are fairly irrelevant in this comparison.

 

[xxsupralvrxx]

ummmm what is "IIRC"?

 

[topnotchgsx]

If I Recall Correctly

 

[JusMX141]

So I have 2 turbos and I want to know which one is better. Both 16g's. one is a 42 small? 16g ported and clipped with the bigger flapper, and the other is a real evo III 16g but its a 47 so a little bigger. Which one will flow better/give me the most power? thanks in advance fellas

I believe you mean "42" and "47" as in the part numbers that are on the compressor cover:

49178-01420 = Big 16G
49178-01470 = Evo III 16G

Here are some random facts about the turbos you have:

- They are the SAME SIZE turbo....the only difference is the Evo III has a lighter compressor wheel and turbine assembly in an attempt to decrease rotating pass to aid in spool.

- The Evo III should come with an exhaust housing that features a larger outlet (2.5" versus 2")

- The clipping will allow the Big 16G to flow a bit more freely and less restrictive on the exhaust side, however the clipping will add lag....not much, but it might be noticeable.

- The larger flapper on the Big 16G's exhaust housing WILL BE HARDER TO HOLD SHUT UNDER HIGH BOOST. This mod is generally intended to prevent creep on turbos that run between 15psi and 20psi.

Hope this helps you with your decision.

 

[daren_p]

Here are some random facts about the turbos you have:

- They are the SAME SIZE turbo....the only difference is the Evo III has a lighter compressor wheel and turbine assembly in an attempt to decrease rotating pass to aid in spool.

Technically, they are not the exact same size turbo. The small 16g, big 16g & evoIII all have slightly different sized compressor wheels, with the evoIII being the largest. Another difference is the evoIII turbine housing has more nickle content to withstand cracking better. The clipping should help aid in more airflow uptop on the small 16g (though not sure how it would directly compare to the evoIII) but if it was up to me, I'd go evoIII.

 

[JusMX141]

I believe we've established that his two turbos are a Big 16G ("42") and Evo III 16G ("47"), so any information about the Small 16G is irrelevant toward his decision of which turbo to use.

The higher nickel housing of the Evo III is less resistent to cracking, but the threads are too soft and will normally pull out of the housing the first time it's removed. I would look closely at all the holes of the Evo III's housing....if any of the threads are damaged, you WILL need to install HeliCoils before installing the turbo.

Small 16G = 1.830 inducer, 2.365 exducer
Big 16G = 1.892 inducer, 2.680 exducer
Evo III 16G = 1.902 inducer, 2.680 exducer

I suppose the Evo III's compressor IS bigger....by the thickness of two sheets of notebook paper.

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[daren_p]

I did say, "technically" all 3 compressors are different sizes

While, like you posted the actual difference between the B16g & the evoIII16g are very minimal I would have to say I don't recall ever seeing the flow out of a regular B16g that I have seen out of the evoIII (though maybe they have just haven't been pushed as far being the evoIII seems much more popular over the last while)

Thats strange about the threads being too soft, I don't know of any who have had this issue but I do know of many who have had issues with snapping a bolt, thats still stuck in the evoIII housing (myself included at one time )

My evoIII did have the larger flapper mod & was ported to accommodate it & I was able to run 22psi with it (the highest I tried) but yes if your thinking of running more boost then this, a larger flapper isn't something you want.

 

[JusMX141]

Thats strange about the threads being too soft, I don't know of any who have had this issue but I do know of many who have had issues with snapping a bolt, thats still stuck in the evoIII housing (myself included at one time )

Everytime a used Evo III passes through my shop, it either NEEDS Helicoils installed or HAS HeliCoils in two or more of the manifold / o2 housing flange holes.

In comparison to a plain Mitsu TD05H turbine housing, the Evo III housing is MUCH more resistant to cracking, however. I'd choose the Evo III housing and install HeliCoils in ALL the thread holes in trade for no cracks!

I'm curious to know what would be the better choice....the clipped Big 16G, or the unclipped Evo III. The clipping would be great for high boost, but bad for boost under 20psi. The Evo III would outspool the Big 16G even if it WEREN'T clipped...clipping just makes it even more laggy.

Hmmmm....better try them both and tell us what your favorite is!

 

[Kevin Jewer]

A big 16g will only do 39 lbs/min, so the EVO3 is clearly larger in terms of airflow (43 lbs), which is all that matters in this example.

 

[phillabaum03]

wow! you guys gave me excellent info, more then expected but thanks alot. I think im going to keep the evoIII. thanks fellas!

 

[90laserRSfwd]

I thought the JDM engines came with a "42" turbo that is supposed to be a small 16g. Damn it now I have to tear the turbo off this stupid thing and measure the compressor wheel. Don't want to lie to myself, thinking I have a bigger 16g then I do....

 

[dsm-onster]

Justin, the "hub" of the evo3 16g is smaller in diameter, this allows for more blade surface area and more blade length at the inducer to grab more air.

OP, the bigger evo3 16g has a larger compressor. but a lower flowing turbine. The big 16g has a highere flowing turbine but a smaller compressor. Swap compressors and you'll have two turbos that will match a little better. But that will require balancing both. The evo3 16g spools the same as a big 16g. And the unclipped turbine wheel is plenty for 42lb/min which is the peak flow of an evo3 16g based on the compressor map. So I'd just keep evo3 16g and sell the other.

I don't really condone clipping anyway. It really makes the turbine inefficient. It would be better to get a BEP bolton housing since it flows a litle more if you're really concerned about topend flow with either of these smaller compressors.

 

[damnslowtsi]

So the latest consensus is that a big 16g flows 39lbs and evo3 is good for 42lbs or so? That's cool to hear. The last I 've read was 34lbs for a small 16g, 36 for a big and 39 for evo3.

Also, Matt can you say a bit more about the turbine wheels? I thought they all were tdo5h. What wheel is in a small 16g then? Smaller than even the evo3 one? How do all three turbine wheels compare? Are the three turbine housings cut differently respectively and not interchangeable then? Crap, I thought I know it all about 16g's and will never have to ask another question. Not too long ago I found a big 16g (420) at a junk yard in good shape for 80 bucks. Now I start realizing what kind of gem I 've got. J/K

 

[dsm-onster]

In the OP's particular case. . . all 16g turbos have the td05h turbine and 7cm^2 turbine housing. but his big 16g has a clipped turbine wheel.

The small 16g compressor flows over 38lb/min or 0.29 kg/sec based on the compressor map. The big 16g shows 39 lb/min or 0.27 m^3/sec.

 

[laserspeeddemon]

Wow, you guys really went to war for a bagel. A simple "The EVO III is a better turbo" would have sufficed for the OP.

It really is not worth swapping wheels to make a hybrid 16g turbo.

 

[Kevin Jewer]

I could never get more than 35 or so lbs from small 16gs except for the rare 36 lbs, and the 39 on the big 16g was a rare case too, it was usually less. The EVO does 42 pretty regularly, but the 43 would come in on cold nights. I tested all of these turbos with the WGA vac line disconected. My memory is getting foggy in my old age though, older posts I've made would be more accurate.

It is more than the OP asked for, but it's not all about the OP. Plenty of other people read these threads once they get going.

 

[laserspeeddemon]

Thats in the rare case that they ACTUALLY used the "Search" feature.

What device are you using to pull this figures? DSMLink?

 

[havoc742]

I may be one of the rare one's but I don't know it all so I read about as much as I can so I can better decided what to put on my car and when to do it.

Great info in here.

 

[dsm-onster]

Wow, you guys really went to war for a bagel. A simple "The EVO III is a better turbo" would have sufficed for the OP.

It really is not worth swapping wheels to make a hybrid 16g turbo.

Swapping wheels wouldn't have made it a hybrid. It's possible that he can make more pumpgas power with the clipped big 16g than with the unclipped evo3 16g. You know this . The question is whether he's willing to deal with the lag for a small gain in pumpgas potential.



And I have a stock intake manifold. And just a cam upgrade. I have VERY many 35+ lb/min logs with my small 16g. It can definately push to the limit of the compressor map. Especially since the same hotside used by the small 16g allows an evo3 16g to reach 42lb/min and over 400whp, being that there is no 16g hybrid. As well, I though MHI understates it's compressors on their respective efficiency maps. Look at the results of the evo3 16g. . . Regardless, the below log is with the STOCK 1g maf. It is known to 'drop counts' or show a lower airflow than actual after 30ish lbs/min, which is maf overrun. And you can easily see the maf hertz plane. Yet, you can also see over 35lb/min. This was at 22 psi with a stock head, intake manifold, stroke, rev limit, a smallish FMIC, 272-style cams; nothing special. Seeing the choppy hertz graph, you can clearly understand that the maf was overrunning and the airflow was actually higher. My lm1 went very lean in this instance as well, proving there was more air there than metered: Small 16g at 36lb/min. Also the maf was "under-reporting" because the BoostEst shows under 20 psi when she was actually running 22psi, which held to redline. My 1g maf was hacked. The small 16g is definately capable of reaching whatever it's map reports.

I've never run a big 16g (small 16g to an 18g was a better path for me). But I've seen several 39+ lb/min logs of the big 16g on dsmlink.com forums. 90% of them are clipped.

 

[Kevin Jewer]

I'm not sure I'd trust a hacked MAS too much, but your 36 number isn't exactly out in left field either. All of my numbers came from an untouched 2g MAS with the WGA line removed. I never put much faith in compressor maps anyway.

 

[dsm-onster]

Well, a hacked maf can only read lower than actual, so will one at overrun . . . And yes I agree 100% that a map can be misleading. MHI compressor maps leave out important environment data for sure.

My small 16g has a Peeper's wastegate actuator with an adjustable arm. I did tighten the arm down quite a bit shorter than stock. I could be wrong, but from my experience, I really think the 16g hotside develops alot of pressure and blows even a small flapper open a little. And especially when wringing out the rpms of these 16g turbos, you need all the energy you can get from the exhaust to give it a chance to keep up at 7K.

 

[damnslowtsi]

I know it is off topic and appologize in advance for that What is an 18g wheel rated at since it was mentioned here? I 'm interested in both the 'official' number and the logged one if you 've done it. Now I 'm all confused. I remember a 20g rated at 44lbs/min back in the day and now an evo 3 is pushing it.

 

[dsm-onster]

The 18g has a 43 lb/min compressor map with a missing higher rpm curve, at 145K rpms. The big 16g (evo 1, 2) and evo3 16g along with the evo 4-8 16g all have the same diameter exducer as the 18g and consequently the same tip speed at 145K rpms. So the 18g can probably eak out 2-3 more lb/min.

The 20g has a 47.5 lb/min compressor map (same area as a 50-trim) with the missing 145K rpm curve too. The 20g has the same exducer diameter as the big 16g turbos also, so there's more in this turbo than 47.5 lb/min.

***based on the conversion m^3/sec X 60sec X 35.3CFM = Total CFM; Total CFM X 0.70 = lb/min @ Automotive Standard Temp and Pressure (20*C, 1 ATM)

 

[Kevin Jewer]

FWIW I could never get more than 48.x out of a 20g, on two cars. On some turbos I tested them with the WG flapper wired or welded shut, but after shooting a 14b's turbine wheel out my exhaust and back over the starting line at the track I was less inclined to do that on other turbos. Most turbos survived it just fine though.