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Discussion Starter · #1 ·
Turbos for the 621cu BBC build. Pair of Garrett 91's. Huge compared to the little Rayjay 301
 

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Highaboosta
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Those should do the job.
What A/R is the turbine housing ?
 

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Discussion Starter · #3 ·
Hot side 1.16
 

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Highaboosta
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Was there any other A/R choices on the turbine housings ?
I guess I would have preferred a T6 flange over the V band for a turbo that large.

On E85 I've been running 1.32 A/R and feel I need to go larger to work with this fuel. The boost is still way above where I want to be.

I checked it yesterday and it was on the rev limiter at 7700 / 26# boost with the wastegates wide open. I certainly need larger gears than the 37s.
 

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Discussion Starter · #5 · (Edited)
I would have prefered a T6 flange also but the price was too good to pass up. Found these on Yellowbullet and they were local to me. Hate to buy something like turbos sight unseen and hope that they don't get wounded during shipping. The hot side housings are made by "Precision" and and are supposed to be 16 lbs. lighter. I don't want to rev that high in mine. I plan to start with 48's and go up from there. You should be able to get 48's in your box without cutting the water jacket, don't need the water anyway. What size blowoff's and wastegates are you running?
 

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hey stevo the turbine housing should be able to be replaced with a v'band to the compressor & t6 to exaust. is the v-band the same size as the rajays to the compressor?
 

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Turbos for the 621cu BBC build. Pair of Garrett 91's. Huge compared to the little Rayjay 301
Sure Steve 'rub it in'. With all the bearing, shaft, seal and wheel improvments over the years, those two Garretts will take less effort to 'spool up' than the ONE 301E ! "Way back we would have to "rope start the blowers (turbos) and then crank up the motor" HA HA ! NICE!
 

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Highaboosta
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I've had friends with roots blowers tell me that after they got it restripped it took a 2' long bar to roll it over :)sphss
That would be a clue to me.......................:)bulb

Compare that to my turbos that are still coasting for 30 seconds after I shut the motor off.
 

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Discussion Starter · #9 ·
hey stevo the turbine housing should be able to be replaced with a v'band to the compressor & t6 to exaust. is the v-band the same size as the rajays to the compressor?
I'm going to fab a transition from exhaust headers to v-band and will actually have more mounting choices. Place to egt and o2 bungs.
 

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Highaboosta
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With E85 even those big diesel turbos are going to go nuts.
I planned on starting out with lower boost too. :)sphss

I just talked to Bullseye power and the tech guy said that with E85 two wastegates per turbo is going to be the only way to get the boost down around 15#.
I questioned about using larger turbos but still the 1.32 A/R turbine housing is the largest available even with larger compressors.
Evidently this is a common problem with ethanol and methanol.

What are you using for headers ?
Put up a pic of them.

You're going to want those O2 bungs after the turbos.
 

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Discussion Starter · #11 ·
I have a pair of cast alum. Drake/Eickert manifolds with 21/8 primaries that I was going to use but if I get that set in spam I will use those. The polished stainless is very unique. I am having a sheet metal intake fabbed now with a burst panel and 2 blow off valves.
 

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I have a pair of cast alum. Drake/Eickert manifolds with 21/8 primaries that I was going to use but if I get that set in spam I will use those. The polished stainless is very unique. I am having a sheet metal intake fabbed now with a burst panel and 2 blow off valves.
stevo , those turbos look as though the lag would be extreme. isn't that too big of a turbo? unless of course your running 60lbs of boost:Djust wondering ,but could be just the picture . i'm thinkin' "fair warning" :|err :D
 

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Those 91's will have no lag with a 621 inch engine!!
 

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Discussion Starter · #15 ·
stevo , those turbos look as though the lag would be extreme. isn't that too big of a turbo? unless of course your running 60lbs of boost:Djust wondering ,but could be just the picture . i'm thinkin' "fair warning" :|err :D
Paulie, how is your deal coming? Sucks about the crack in the hull. With the size of the motor burning E-85, more exhaust gases, tall gears in v-drive and takeoff in 2nd gear, I doubt there will be any lag. I'm more worried about breaking driveline parts with the hp available. I could have gone with 88's but a lot of the asphault guys are having good luck with 91's, 94's, and one is trying a pair of 106's. My son says these calculate out to 1360 cfm each. Hope to run controlled boost in the 25-30 lb. range. 2500hp+
 

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Paulie, how is your deal coming? Sucks about the crack in the hull. With the size of the motor burning E-85, more exhaust gases, tall gears in v-drive and takeoff in 2nd gear, I doubt there will be any lag. I'm more worried about breaking driveline parts with the hp available. I could have gone with 88's but a lot of the asphault guys are having good luck with 91's, 94's, and one is trying a pair of 106's. My son says these calculate out to 1360 cfm each. Hope to run controlled boost in the 25-30 lb. range. 2500hp+[/QUOTE]

easilllllyyyyy! its gonna be a monster, forget ever turnin it up to 25lbs of boost, 18-20lbs will be more than nuff to get the job done:)grn

how much for each turbo? i'm gonna do my sbc finally and i'm looking for a 88mm, but shit, a 91mm will do lol
 

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Discussion Starter · #17 ·
Paulie, how is your deal coming? Sucks about the crack in the hull. With the size of the motor burning E-85, more exhaust gases, tall gears in v-drive and takeoff in 2nd gear, I doubt there will be any lag. I'm more worried about breaking driveline parts with the hp available. I could have gone with 88's but a lot of the asphault guys are having good luck with 91's, 94's, and one is trying a pair of 106's. My son says these calculate out to 1360 cfm each. Hope to run controlled boost in the 25-30 lb. range. 2500hp+[/QUOTE]

easilllllyyyyy! its gonna be a monster, forget ever turnin it up to 25lbs of boost, 18-20lbs will be more than nuff to get the job done:)grn

how much for each turbo? i'm gonna do my sbc finally and i'm looking for a 88mm, but shit, a 91mm will do lol
3500 for the pair over on yellowbullet!
 

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Paulie, how is your deal coming? Sucks about the crack in the hull. With the size of the motor burning E-85, more exhaust gases, tall gears in v-drive and takeoff in 2nd gear, I doubt there will be any lag. I'm more worried about breaking driveline parts with the hp available. I could have gone with 88's but a lot of the asphault guys are having good luck with 91's, 94's, and one is trying a pair of 106's. My son says these calculate out to 1360 cfm each. Hope to run controlled boost in the 25-30 lb. range. 2500hp+
well i think he turbos are done ,just waiting on the fabrication of the waiste gate adapters. its gonna be a long wait, they will let me use the crappy adapters if i get the hull done.
 
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