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Dreaded Prior Owner
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Discussion Starter #1
I'm looking for a internal wastegate turbo to replace my existing chunk of external wastegate iron.
Has anyone looked over the divided scroll B/W 6258? Small lightweight wheels with modern aero, water cooled ceramic ball bearings, integrated blowoff and a stainless steel divided scroll turbine housing ticks all the boxes for me. The offset turbine outlet should give me room for a T3 > T4 adapter also. Putting it on a Alunox divided exhaust manifold, but not looking to grenade my Citroen transaxle with more power, just to simplify and add lightness by losing all the cast iron in the external wastegate / exhaust manifold assembly, and maybe pick up a little bit faster bottom end boost response.

http://www.turbos.bwauto.com/files/pdf/179359-EFRTechPages.pdf

It seems the new item (P/N 11589880036) is shipping with a .80 a/r divided scroll rather than the listed .92, so the above link may be out of date.

Maps on BorgWarners MatchBot app seem to make it look feasable:
(hang on, this is a monster URL)

BorgWarner MatchBot
 

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Wingless Wonder
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5,526 Posts
Might want to PM S2KSeven, that is his area of expertise.

Make sure you mention your car's year (he currently owns a V8 but has owned 4 bangers in the past).
 

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935 Posts
re: Turbo for a 910

You did a lot of work with the sizing tool!

Just some general comments....

If anything 6258 is on the small size i.e. will give instant response but constrain the motor at top end.

7163 makes a good fit, also.

Were you getting any boost at 2000RPM before? There may not be enough energy in the exhaust to spin the turbo. This depends on the camshaft and motor. I know little about 910...

I like EFR's. (I own 7670 on a race K20 motor). The packaging is great!!! No more separate BOV's and WG's... However, they were designed to be more of a high-pressure turbo... I would check Garrett, also. Also, more turbine housing choices, there....

Anton
 

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I would suggest the 6758 unless you plan on staying under 15psi.

Also, make sure you get the tightest actuator you can because these turbos have a tendency to blow open the wastegate doors at high RPM unless you run the tight spring, or have a lot of preload on the actuator bar.
 

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Dreaded Prior Owner
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673 Posts
Discussion Starter #6
I have a 1985 with the weak transaxle, so I'm looking at the small size for good response on the bottom end. Boost will have to stay low, because if the motor or transaxle goes away, I'd have to seriously consider replacing everything between the rear wheels with sturdier stuff I can get parts for.

However these turbos seem to be used more for high boost and after looking at the wastegate canister info sheet I'm concerned that even the low boost wastegate canister might not clamp down to near stock boost (7-8psi). I'm thinking of forged pistons while the motor's out for general freshening this winter if I can find them for a reasonable price.
 

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Cal H
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982 Posts
I have a 1985 with the weak transaxle, so I'm looking at the small size for good response on the bottom end. Boost will have to stay low, because if the motor or transaxle goes away, I'd have to seriously consider replacing everything between the rear wheels with sturdier stuff I can get parts for.

However these turbos seem to be used more for high boost and after looking at the wastegate canister info sheet I'm concerned that even the low boost wastegate canister might not clamp down to near stock boost (7-8psi). I'm thinking of forged pistons while the motor's out for general freshening this winter if I can find them for a reasonable price.
We get our parts from JAE, its a good place to get rebuild parts for the winter project. Its a good thing you are going forged as it is only a matter of time before the stock pistons crack and fall apart. More a matter of when and not if as there is known weakness of the stock piston. Trying for more boost out of the pre 86 cars is a big mistake unless the engine has been upgraded.

Remember to plan ahead for your rebuild parts as Tim has informed all of us that JAE will close for the holidays from Dec 16th to Jan 4th. Jeff has retired so when Jay takes off there is no one to cover the shop.
 

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We get our parts from JAE, its a good place to get rebuild parts for the winter project. Its a good thing you are going forged as it is only a matter of time before the stock pistons crack and fall apart. More a matter of when and not if as there is known weakness of the stock piston. Trying for more boost out of the pre 86 cars is a big mistake unless the engine has been upgraded.

Remember to plan ahead for your rebuild parts as Tim has informed all of us that JAE will close for the holidays from Dec 16th to Jan 4th. Jeff has retired so when Jay takes off there is no one to cover the shop.
Love Jay... but a sad day for us that Jeff retired. He piled off to Australia where his wife hailed from... and is traveling the globe to boot. I got rather spoiled on that access to knowledge! LOL

Cameron
 

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Hey if you are (maybe) interested. I do have a stock 89 Turbo compressor with less than 29k miles. It's clean and very tight. No shaft play and it already has the built-in Waste Gate!

Let me know? PM me if you like.

JG
 

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Dreaded Prior Owner
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Discussion Starter #10
Thanks myespritgt, but the timings off, as I just received my EFR 6258, much as the recommendations for the EFR 6758 came the day after I shipped one received in error back to Full Race.
A month ago I might have gone for the '89 turbo at the right price, but all I was seeing at the time was (rebuildable?) lumps of rust for $600 with ungodly UK shipping.
 

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Dreaded Prior Owner
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673 Posts
Discussion Starter #11 (Edited)
Boost response for the EFR. Not an optimal tune, but a rough idea of when the boost comes on.
EFR 6258 on an Alunox exhaust manifold, 2.5" exhaust, charge cooled EFI motor.
Boost control was set at 160Kpa (~10psi), but settings need work. :shrug:

Turbo certainly wants to give more than I need for a Sunday driver, and the 910's 107 cams are going to give up before the EFR chokes off on top anyway.
 

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