Single Turbo RX-7's Questions about all aspects of single turbo setups.

just dyno'd precision 6262 .84 on a ported engine

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Old May 31, 2013 | 08:14 PM
  #76  
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If your warping the flange your pouring way to much heat in it. You can put the flange on a belt sander to flatten it out. Just make sure not to take much material off.
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Old Jun 1, 2013 | 01:28 PM
  #77  
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^That dont work for wategate flanges that have a step on the inside. The seat sits in the groove and seals. the only way to fix this issue is to do the copper wire gasket I mentioned or replace the flange
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Old Jun 1, 2013 | 01:50 PM
  #78  
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I am sorry but is not true, you can take a little material off of it. It's not going to hurt, but your can't take more than maybe .40 - .50 thousands off. Look at a full race manifold and you will see where they surfaced the wastegate flanges.
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Old Jun 1, 2013 | 02:51 PM
  #79  
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How do you know if the 2 ports are balance?

I mean how do you know if only one rotor is making the turbo spin of the 2 of them
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Old Jun 5, 2013 | 02:26 PM
  #80  
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so all you guys running the Precision turbos, just stick with journal bearing or is the BB cost really worth the couple of hundred rpm spool?
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Old Jun 5, 2013 | 02:31 PM
  #81  
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Originally Posted by blue93FDproject
so all you guys running the Precision turbos, just stick with journal bearing or is the BB cost really worth the couple of hundred rpm spool?
According to A-Spec, it's the smoother and quicker transient response into boost that is more desireable.
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Old Jun 5, 2013 | 02:32 PM
  #82  
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Originally Posted by blue93FDproject
so all you guys running the Precision turbos, just stick with journal bearing or is the BB cost really worth the couple of hundred rpm spool?
Ball Bearing vs. Journal Bearing
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Old Jun 5, 2013 | 02:43 PM
  #83  
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the real-world application of journal bearing vs BB (same turbo otherwise) is that it's not much of a difference. for autocross or road racing where you need the off-throttle to full-throttle punch response, i could see where people may want to pay the money for it.

personally, i decided to pay 979$ for my precision journal bearing instead of paying $1529 for BB. the 1/4 second better response is not worth $550 to me, and that money was used to purchase two wastegates instead
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Old Jun 5, 2013 | 05:20 PM
  #84  
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I would have done the same great turbo
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Old Jun 5, 2013 | 08:48 PM
  #85  
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Originally Posted by jacobcartmill
the real-world application of journal bearing vs BB (same turbo otherwise) is that it's not much of a difference. for autocross or road racing where you need the off-throttle to full-throttle punch response, i could see where people may want to pay the money for it.

personally, i decided to pay 979$ for my precision journal bearing instead of paying $1529 for BB. the 1/4 second better response is not worth $550 to me, and that money was used to purchase two wastegates instead
I have the TD61 1.0 A/R journal bearing turbo on my FD. I see full torque at about 3750 RPM; 15psi by 3300rpm and its perfect for the track. I even short shift to 3rd gear on some tight turns and still power out of turns no prob. I dont notice lag in between shifts as well. This is with a 3.5 inch DP and cast manifold.

Initially when I bought the jb turbo I was worried about lag. In comparison to a 500r which I have felt prior, I must say the difference in spool time is not really noticeable. A lot of people look at my crooked when I say I have a jb turbo. I guess people are stuck in the old times where most non bb turbos (such as the T04R) were pretty laggy.

I agree with you, even if I had to money to spare, I would keep the $550 difference and put it toward something else. The rebuild price is also much cheaper for jb turbos.
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Old Jun 8, 2013 | 11:23 PM
  #86  
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Originally Posted by blue93FDproject
so all you guys running the Precision turbos, just stick with journal bearing or is the BB cost really worth the couple of hundred rpm spool?
I honestly only experienced ball bearing turbos (except for the stock twins), I figure might as well just go all out and have no regrets...do it once do it right.
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Old Jun 9, 2013 | 01:01 AM
  #87  
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Very interesting thread.

I had a similar problem with a 6262 but I resolved it by going to a 50mm wastegate. Granted this was on a piston engine but I also put down 734whp @ 40psi. Oh yeah, lol the turbo kit was designed to be efficient up to 600hp, so the manifold flow and wastegate both played an issue.

Looking to transfer it to my rx7 one day and run a dual wastegate manifold in hopes for 350-400hp for auto cross use.

From this thread, and many others discussing manifolds, Turblown, full-race, a-spec, and a couple custom manifolds on here, all have the basics covered - dual wastegates, great flow, good turbo/wastegate position.

Interested to hear the figures once your issues are sorted.
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Old Jun 11, 2013 | 10:21 PM
  #88  
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Originally Posted by 86v8rx7
I am sorry but is not true, you can take a little material off of it. It's not going to hurt, but your can't take more than maybe .40 - .50 thousands off. Look at a full race manifold and you will see where they surfaced the wastegate flanges.
I think your thinking of the mounting flange surface and not the sealing step for the wategate insert ring. Once the "step" that it sits in warps there is no way to get it to seal unless you have the proper setup to take a few thousandths off the little lip.
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