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Alunox Manifold with EFR 6258-G Twin scroll Turbo upgrade - Induction/Turbo/Chargecooler/Manifold/Exhaust - The Lotus Forums Jump to content
MarkKassim

Alunox Manifold with EFR 6258-G Twin scroll Turbo upgrade

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Thanks for the detailed post, Mark

Did you have access to a load holding dyno to establish the minimum best ignition timing?  I'd be curious to see your timing map, as my EFR/Alunox setup has only been road-tuned with an approximation of the OEM distributor data and some knock data-logging.  Unfortunately I don't have a Karl....

My install is much milder in deference to the Citroen gears, & just used a T3>T4 adapter to work with a first gen. Alunox manifold.

 

EngineInstallReadyCrop.jpg

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Hi Thomas, Yes it is an expensive dyno that can hold static loads and so tune each speed site or cell in turn.  During part of the video you could hear him holding constant RPMs while he dialled in the speed sites. I think this formed part of the base mapping

55871919_IgnitionMap.PNG.84202789c735a53fffa72a833dd45883.PNG

Later on the power runs he tunes the Boost control. I'm not running a Knock sensor so its pretty much tuned under load avoiding detonation (knock), so it may not be as close minimum you are looking for.

I forgot to mention I am running a wide band lambda sensor and EGT sensor (PLX)

Just out of interest what ECU are you running.

Hope the table helps

Mark

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I'm running a Megasquirt MS3 kit with MS3X daughter board, clock and knock boards & baro/MAP combo sensor. Full sequential with coil per plug. Unfortunately I'm running a speed density tune with MAP as the load variable so I don't know that I can translate the timing map, but thank you and I'll give it a look.

This is my garage DIY, still tuning little things like cold starts after four years... 

https://www.lotustalk.com/forums/f164/910-megasquirt-339834/

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@MarkKassim, so is this a twin scroll manifold? :

257545263_TurboMockup.jpg.900ac6c54a09aa

 

Does it only vary from the single scroll manifold in the final section to the turbo?

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Same manifold as on yours I believe  @RobinB5

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Only here once

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Hi Robin, Yes that is a twin scroll manifold and if you have the normal Alunox manifold it is also a twin scroll as Barry has stated. My particular manifold design has been adapted in the final section (Collector) for the T4 turbo instead of the standard T3.

This is the size of the T3 Flange vs the T4 Flange

488975210_T4T32.jpg.1fa1af8900488c784e7d1c16f5e98312.jpg

Sorry its not the best picture, the Collector design has been enlarged to match the bigger port sizes of the T4 flange. 

IMG_2870.JPG.a0e57a4ce6d577cf40fb2092ae152c8f.JPG

 

Hope this helps,

Mark

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That must mean that there are separate internal pipes for the 2+3 and 1+4 up to the final join at the turbo? (I've not removed and inspected the manifold internals). I would have assumed that all 4 would have been combined into 1 by the turbo stage. So in theory I could replace the stock turbo and with a twin scroll turbo without having to replace the manifold?

Thanks @MarkKassimand @Barrykearley!

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Yup I believe so... 👍


Only here once

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Yes, the tubes are 4 into 2 into a split collector at the flange. But as the turbo discussed here is a T4 flange and your manifold is a T3, you face the choice of modifying the flange and/or collector tubes on your pretty, expensive manifold or adding an adapter to it. I went the adapter route, which moves the turbo up and back a bit, which may need to be addressed as far as lining up with the existing charge cooler plumbing and exhaust exit.

Cost-no-object, best performance option is sell your popular, limited supply T3 manifold to another enthusiast and buy the new T4 version if you wish to go with the EFR turbo. Our maybe Alunox could be talked into modifying yours? I'm guessing not.

T3 T4Adapter.jpg

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Mark,

Congratulation on the job well done !

Fascinating project and great execution.

Have you done anything to strengthen your transmission and clutch?

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Thanks guys for your great feedback, your comments are much appreciated.

The transition is unmodified but the clutch is uprated, Dave helped me out with the specification of this putting together some of his old parts. The pressure plate and friction plate are AP capable of holding 330 lb/ft. I may be pushing my look if I go much further with the transmission.

Mark K

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RobinB5- Another option is to build a Garrett turbo (yours?) around a T3 twinscroll housing. They are available for various models, the GT3071 seems popular.

https://www.atpturbo.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=GTHGT30-T3divided

But the EFR has quite a feature set....

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