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So begins the insanity *Gathering ideas*


Twitch de la Brat
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This is going to be the official build thread for my 85' BRAT.

I'm building it into a Twin Turbocharged EA81 Beast!!! :banana:

Its mostly going to be seeing RallyX and the like, so I figured Racing would be

the best forum for it.

 

I'm currently fabbing ideas in my head but have a general idea of what the

engine bay is going to look like.

I'll have pics soon, so bear with me through my description.

I'm going to have two intakes feeding two turbos, located behind the engine,

on each side of the tranny.

Those will be blowing into an intercooler, mounted directly above and slightly

behind the engine.

That will pipe into a pair of carbs connected to a custom intake manifold.

 

Got a good idea now?

Hope so, cuz I need some more.

I'm currently researching the best carb for the job, and I'm currently looking

up pricing on an intercooler system that will fit my needs.

 

If anybody has any experience with this sort of thing, I would be extremely

grateful for their knowledge and maybe even some assistance? :D

 

Thanks for sharing in my insanity and hope to see you on the flipside!

 

Twitch

 

PS: Pics to come soon!!!

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After gathering some much needed research, I'm partly on my way to

getting parts and the like for this project.

I've found a brand of carbs that are already sealed, but I don't know about

their quality or tuneability.

The brand is dellorto, and I did a little research on them, and it seems that

really the majority of the carbs they have are for motorcycles.

Its no problem as long as they can provide the needed amount of fuel, as I

am building a custom intake manifold.

Does anybody have any experience building or tweaking these carburetors?

Is there any other online resources I could use for carb tweaking or more

info on sealed/sealing carburetors? (I got my info from

http://www.dune-buggy.com/turbo/index.htm)

 

Twitch

Edited by Twitch de la Brat
Proper website and spelling
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I'll have engine pics as soon as it is out of the car...

 

Anyway, here's the official dellorto site, and the specs.

I have yet to check the jets and barrel diameters on my stock hitachi, but

if anybody could help me if they already have the stock numbers...

I'm looking to go bigger, but a lot of the info they list is greek to me :confused:

GD, or anybody for that matter, please give me a little guidance on these carbs,

I know I bit off more than I could chew, but I'm willing and need to learn this

stuff.

 

I'm currently trying to get some specs from RAM performance, but I have to wait until tomorrow to find anything out. :-\

Thanks in advance for any and all support!

 

Twitch(ing)

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  • 1 year later...
I thought I'd honor this thread about my favorite Subaru in the world with my 100th post. :D Plus I'm curious if any new ideas have formed about it :banana: Figured it wouldn't hurt to draw everyone's attention back to this thread... ;)

 

Thanks for dragging a bunch of attention to a current failure.

Thanks.

 

Twitch

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Oh nos! Its teh drama llama! :lol:

Attempted public humiliation = fail. :rolleyes:

Ideas only fail when you let them die. An idea doesn't have to become reality. It's still a good idea. That's the great thing about ideas too. You can change them and it doesn't cost a penny! ;)

 

ANYWAY

So are your ideas the same? or have you tweaked them a little since you posted these? Just wondering still. :)

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A few years ago, I was working with Sean at RalliTek as we were thinking about building an EA81TT for my old '79 wagon.

 

Unfortunatly, nothing really panned out as finding aftermarket parts to handle any sort of power for an EA81T is almost impossible which is why we ended up abandoning the idea.

 

I still have the complete EA81T with harness, ECU and a few other parts I believe at my parent's house still but last time I saw everything was about 4 years ago so I'm not sure if its still around...

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A few years ago, I was working with Sean at RalliTek as we were thinking about building an EA81TT for my old '79 wagon.

 

Unfortunatly, nothing really panned out as finding aftermarket parts to handle any sort of power for an EA81T is almost impossible which is why we ended up abandoning the idea.

 

I still have the complete EA81T with harness, ECU and a few other parts I believe at my parent's house still but last time I saw everything was about 4 years ago so I'm not sure if its still around...

 

What did you discover about how the stock pistons, rods and rings handle boost pressures around 15psi?

Or did you not get that far?

Also, design-wise, I was looking at putting in basically 2 separate intakes, one per head.

Did you look into that design, or were you sticking with the basic single intake?

 

 

If I ever get enough money put together I might come knocking on your door.

I have decided to go with FI over carb, as tuning a carb under pressure can be a real beast.

 

Twitch

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  • 2 weeks later...

Just curious why you would go through the extra cost and effort to go twin turbo? I don't mean to discourage you, it would be pretty sweet. But I think you could make more power than an ea81 can handle with a single turbo. Also don't think it would need to be so big that it spools too slow or has a peaky power curve @15psi.

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Just curious why you would go through the extra cost and effort to go twin turbo? I don't mean to discourage you, it would be pretty sweet. But I think you could make more power than an ea81 can handle with a single turbo. Also don't think it would need to be so big that it spools too slow or has a peaky power curve @15psi.

 

Simplicity my friend.

EA81's only have a single port per side, and they have 2 sides of the engine.

No fancy up-pipe required with all of its inherent flow losses, nor any fancy

down-pipe.

I'll basically be able to run equal length piping each head to a turbo, mounted

wherever I please, because I don't have to worry about pipe length from

either side, with separate, dual intakes to increase flow.

Its all about simplicity and symmetry.

I'm not running a sequential setup, just a simple siamese turbo setup.

True dual exhaust after the turbos as well, unless an x-pipe proves to be

better for power bands.

 

Twitch

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  • 1 month later...
My guess for the internals, probably about as good as an EA82T:rolleyes:

 

I know the EA82T isn't renowned for it's strength, but the blocks are a LOT less likely to give out than the heads.

So I figure with the increased strength allotted by the stronger design, I should be reliable running @ 15 psi.

 

Twitch

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I'm just throwing this out there as you're looking at going for FI. Do what you want with this idea:

 

Ever thought about a supercharger? A toyota SC12 or SC14 would be a great upgrade to the EA81 especially if you're going with FI!

 

Advantages are boost off the line, you can set it up so that the supercharger is on or off via a toggle switch on the dash if you get the unit with the clutched pulley.

 

Not meaning to throw a spanner in the works for you. It does seem like an interesting build. I'd be keen to see some pics!

 

Cheers

 

Bennie

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I have thought about the S.C. Idea.

There was one on CL a year or two ago with clutch pulley, wiring setup and all that good stuff.

It was only $300 or so and unboxed but new.

I thought long and hard about buying it, but the efficiency of the turbos just keeps bringing me back to them.

I did have an idea of dual superchargers for a while, but the drag on the engine would have killed base power and fuel mileage.

And I really want to go with a dual intake setup.

Not to mention, where would I put my alt?

Never mind, I know where that would go, as the air cleaner would be gone, but still...

 

Twitch

 

PS: The turbo's I'm looking at are massively quick spooling garrett GT 10's.

They will be just about perfect for a torque build like I want.

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I did have an idea of dual superchargers for a while, but the drag on the engine would have killed base power and fuel mileage.

 

This is absolutely a myth. Superchargers have almost no more restriction on an engine than a turbo. I don't remember any of the numbers off the top of my head, but reddevil's supercharged 2.2 made essentially the same power as a turbo'd 2.2 running the same amount of boost.

 

AND, if you use the Mercedes-version of the Eaton M62, you have the clutched pulley, so when you're out of boost, it has no more drag than an idler pulley.

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Hmmmmm...

And I could keep carbs temporarily until I could afford (and have the skills) to drop in a FI system.

Anybody want to help me get some old mercedes "kompressors"?

I'll have to build an adapter tube, but that's no big deal once I get my hands on a welder and some scrap steel.

 

Not to mention the reduced complexity of running the extra tubing.

I'll just need intake and opened exhaust.

Hmmmm

 

Twitch

 

PS: The fuel consumption was kind of suspect as there are reports of supercharged 3.8's getting better mileage than NA 3.8's.

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Hmmmmm...

And I could keep carbs temporarily until I could afford (and have the skills) to drop in a FI system.

Anybody want to help me get some old mercedes "kompressors"?

I'll have to build an adapter tube, but that's no big deal once I get my hands on a welder and some scrap steel.

 

Not to mention the reduced complexity of running the extra tubing.

I'll just need intake and opened exhaust.

Hmmmm

 

Oh-o... What have I started now?? :D :D

 

The fuel consumption was kind of suspect as there are reports of supercharged 3.8's getting better mileage than NA 3.8's.

 

Very true as the engine is worked in its torque range meaning less revs for the same momentum build compared to an NA that would rev higher to get the same momentum built up... That's the raw basic idea anyway. You just need to drive it with a light foot - once you plant it you can kiss your fuel economy goodbye!

 

Cheers

 

Bennie

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