B2 as bottom turbo.

[RonA]

I keep hearing about the HT3B versus the B2 as a bottom turbo in twins. Some say the B2 spools faster due to more modern design, some say no way because it is 1500cfm versus 1100cfm for HT3B. So if anyone has tried both with the same top turbo and motor I'd sure like to know the result.

 

[metal tech]

This could change the plans for twins for some of us. I was sold on experience alone that the ht3b would be fine. Then you hear the B2 will flow more air + spool faster. Ron, in another thread someone posted that the ht3b's efficiency was like 61. 5% at a p/r 3. 9. Makes you wonder what the efficiency island looks like on a B2.



Al

 

[Jim Fulmer]

Makes you wonder what the efficiency island looks like on a B2.



And you will never find that data out because it's not there, if you notice the people that say a B-2 is so much better than a 3B are also selling them. I only know of one person that has run both on the same truck and same setup but he has limited before and after data.



Jim

 

[wsteffes]

Another option maybe?

Non ball bearing model gt42-2 for under $1000.

74% at p/r of 4 and flows 96 lbs air.

 

[RonA]

The amount of air the B2 moves isn't the part that interests me. It is the "spools easier than an HT3b" part I like. I know that the only way to verify this will be to try it. It would be an expensive experiment.

Ron

 

[McDowra]

Jim, you have a PM, maybe let me know if you didnt get it.



jason

 

[Jim Fulmer]

I got the PM I just don't know much about maps... ... ... never got that schooling.



Jim

 

[RonA]

Nice talk with Jason. B2 does spool a little quicker. If I was starting out from scratch I would use it. But probably not worth making a new set of twins. I'd only get 35 to 40 cents on the dollar if I sold the set I have. Thank you all.

Ron Allen

 

[CumminFast]

I have never owned a B-series turbo, but I think the price of the turbos is ridiculous. Somebody is making some serious money on mark-up. An S300 turbo which I believe is very similar to a B1 costs $460 brand new. I called a vendor about a Big Brother turbo and a B52 turbo. $1700 for the BB and $2700 for the B52. I guess that is expensive machine work. I don't really know, but I bet the turbos that are being modified to be BBs and B52s are probably around the $1000 price range new.

 

[Hohn]

I agree. There would have to be EXTENSIVE re-working involved in order to justify the seemingly high markup.



jlh

 

[kbond]

The big-bro and B52 are far more expensive then the B2. I think I paid right around $500 for the B2.

 

[Jim Fulmer]

I like the B/B and it works well for me but it's not for everyone, If I were to go to a bigger setup it would be the top turbo change and not the bottom, just can't see a need for the B-52 unless it was in sled pulling in the unlimited class.



Jim

 

[McDowra]

Jim how much trouble did you have making the B/B fit?



-Jason

 

[Jim Fulmer]

ALLOT... ... . remember the 40 uses the internal gate so it's up against the manifold and that mixed with the reverse rotation it's real hard to make it fit in that hole, a 3B can be stuffed under the manifold as you know. The trick is to make the hot pipe long enough and have the right kick out on the bottom of the pipe, meaning it doesn't hang straight down under the top turbo, mine has some but when it was done I still had to egg the frame just a tad so the compressor housing wouldn't hit under acceleration.



I had the 40's housing, hot pipe and B/B in and out 8 times... ... what a pain, no way would I ever build Twins like that for a living.



Jim

 

[Old Smoky]

Just for clairification, the 3B flows 0. 73Kg/s, 96. 6Lb/min, or 1373cfm, however you want to look at it.



Mike

 

[Idaho CTD]

Just for clairification, the 3B flows 0. 73Kg/s, 96. 6Lb/min, or 1373cfm, however you want to look at it.



Mike

Not all 3B's are the same though.

 

[Old Smoky]

I was referring to the most commonly used version of the 3B. Kind of like the HX40, there are several different versions, but one is used much more than the others.



Mike

 

[CumminFast]

Wow, 1373 cfm does not really sound that bad. Does the size of the exhaust housing play a part in cfm?

 

[Idaho CTD]

Wow, 1373 cfm does not really sound that bad. Does the size of the exhaust housing play a part in cfm?

Nope. Some turbos have a exhaust flow rating based on the size of the housing but I've never seen one for a Holset.



Mike,



From what I've seen the most common 3B used seems to be a more middle of the road size when it comes to compressor wheels. The largest I've seen is 4. 25" (I've only seen one) but most seem to be around 4" and some down to 3. 75" or so. A B2 is 4. 12". The inducer on the B2 also seems to be larger on average compared to the 3B's.



Nathan

 

[justinp20012500]

Box stock Garrett BHT3B compressor wheel





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From the parallax of the camera, the tape says 4. 25"



Justin