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want bigger turbo for my 86xt but don't kmow what will interchange


dj72
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You can frankenstien together a turbo from parts of your existing turbo and parts of a legacy turbo to get a larger turbo that will bolt in. There may be a few modifications neccesary other than that to the pipeing. There's others of the board that know more than I - but I remember hearing about it here. Do some searching of old posts and I bet you'll find what I talking about. The larger injector thing has also been discussed in the past - not sure about that, but I'm sure you can find that in old posts as well.

 

Also - you have to realize that a larger turbo is not neccesarily a good thing. It will take longer to spool, and probably give you worse off the line performance. There's a lot more that goes into a proper turbo setup that just "bigger is better". This is why many high performance cars have gone to twin turbo's - one small one, and one larger one - to get the spooling effect more even, and a flatter torque curve.

 

GD

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Ok, here is the skinny.

 

Legacy turbo will bolt directly to the stock crossover pipe. However, it will not bolt to the stock downpipe. It will bolt to a stock WRX downpipe.

 

A WRX turbo will need a bit of fabrication to get to work. Don't even attempt it unless you have the spider intake. Needs a new flange on the crossover pipe. Needs WRX downpipe.

 

I've also heard that perhaps the Mitsubishi TD04 will work. But, i haven't played around with that.

 

Nor have I played around with the others. This is just information I have groomed from many sources.

 

And remember, bigger isn't always better. Higher PSI isn't always better either. A legacy turbo will push more air at 10psi than a stock turbo will at 10psi. Keep that in mind.

 

For injectors, not sure about drop-ins... I'd get a spare set (junkyard) and send them to a place in Cali, called RC Engineering. Look them up in google. Probally run about ~$50 an injector to get it flowed, cleaned, maybe then can open them up some. Who knows.

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i have the legacy unit on my car...been told its a VF11 that came on the 91-94? USDM legacy turbos.

 

it flows way more than the stock sorry excuse for a turbo...the extent of it however has yet to be seen because the thing never really ran right, hopefully that will change by the end of the week. what ive seen so far has been quite impressive, big power increase, more torque, and way more top end...will only get better once the car is tuned.

 

the mitsu TD05 tex is talking about is a 16G turbocharger found on 93-97 jap spec STIs, and are pretty tough to come by, the ones found on USDM mitsubishis are very different in terms of flanges and bolting it on. the ones we would use can be located on ebay once in a while but are usually priced sky high. also, some mods will be necessary for the coolant pipes. ive heard from people on the legacy central forums that this turbo doesnt produce any better than the VF11 until about 16PSI...and riding around daily with that kind of boost in our cars is crazy, wouldnt be bad on race gas though.

 

id find a legacy turbo and buy some cheap aftermarket WRX exhaust system off of iclub or ebay...at 15PSI, a full turbo-back and an intercooler, youll probably be touching in on 190-200hp at the crank.

 

as far as injectors, im clueless...

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Thanks guys for all the info, i got some research to do now that i have an idea of what i can do. By the way read the post update 86 turbo xt mods as thats my car and i have moded it pretty good already, just need a bigger turbo to kick even harder butt. I'm just a plain old speedfreak and i can't leave anything alone. thanks again, Dean.

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what part of Canada do you live ? i live in Kelowna B.C. and i'm part of the Okanagan Subaru Club , i have 5 Subarus my self and all turboed some modified so they are actuily fast ! :D

if you are close i could help out in that department also i have club members in Alberta / Calgary that know a lot . let me know if you want ?

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ALSO! you can stick a t-birt turbo on there. they came with 2or3 different ones. the biggest one is the one you want, i think its even an upgrade for the lecacies. the t-birds were something like 3.0s i think? so its bigger.

you just pull the exhaust housing off and swap them. there might be a tiny bit of plumbing differences, butnow is a time for an intercooler anyway.

 

if you have a bigger turbo, and boost the same amount of lbs you will make more hp. more reliable, cooler boost too. and it will spool up the same, because it uses the same exhaust housing.

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Yes - but the hybrid principle might not actually help you - a smaller exhaust will only make the problem worse - since the diameter of the exhaust impeller is smaller, it will have less rotational torque, and take longer to spin up a heavier intake side. It's just like using a small breaker bar vs. a large, very long breaker bar - it's easier to use the larger one. Same goes for the exhaust side - it will be easier to spin up a smaller exhaust side, but at the same time it will also be more difficult if that is hooked up to a larger diameter intake side. What I'm trying to say is that the smaller exhaust impeller is going to "inherit" the large inertia of the intake side, and also not have good torque due to it's smaller diameter - you lose in both respects.

 

This is of course all very acedemic, and who knows how much it will actually affect the performance - some experiments are in order. Discussion is great, but some charts and graphs of impeller sizes / and exhaust flow rates over time are in order I think....

 

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  • 5 months later...

I thought the exhaust housings (exducer) of the legacy turbo and the stock EA82T turbo where the same size. I discussed this with Subspeed a long time ago. Here is part of an email I got from him:

 

The turbo from a Legacy does not have the same bolt pattern as that of the EA82T. It is similar but not the same. Pipes that are made for one will not just bolt right up to the other. I too have heard of enthusiasts swapping the turbo from a Legacy to their EA82T powers cars. I do not doubt for a minute that the Legacy turbo is a larger, somewhat. However, it is interesting to note that the exducer of the turbine is the same size on both units.

Can somebody please verify!

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i got em both, and the ea82 is a bit smaller, and different mounting flanges.

bigger turbos rule! it will lag a bit more, but give you lots MORE COOLER air.

im workin on a high comp lower end, with a legacy turbo, fmic, with stock boost. high comp to get you off the line, and big turbo for power past 3k

 

and maybe gd learned something since that last post, because a hybrid turbo will spool up lots faster than the larger turbo alone

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so the hybrid turbo will have less lag than the legacy VF11 turbo, but yet it will make more power than the stock EA82 turbo. Will it make the same amount of power as the VF11? It seems like that is the way to go for the EA82T (best of both worlds).

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