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Evo 1 2.3l lag issue

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hi guys my own car this time finally got a min to look where I was at with it so here it is

stock block,100mm crank 156mm bridgeway I beams 1400hd pistons pte 1000cc injectors stock inlet stock cooler 26 years old big exhaust manifold with 2.5inch runner for manifold to turbo position was playing around with location turbo well I have no idea it’s one I removed from a 2014 Impreza track car large bb garret tag on core comes back on google search as a 3071r but compressor housing looks more 35 here’s the issue it’s a lag monster and being an early Evo the short short gear ratio makes it useless until it sees 4th then it goes well need ideas I’m wondering if cooler deterioration is the blame or the turbo it’s self or just my make do relocation all help is as always appreciated

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2.5 inch runners will make boost threshold significantly higher due to pulse energy dissipating I would imagine.

All 4 runners on the manifold have a volume of 600cc each based on my crappy math flowing into a t3 flange that then runs a 200mm 2.5” extension to a 2.5” vband into turbo don’t really have to to build a manifold with 4 branches directly to an accumulator at the turbo can’t really see well from the photo

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If you want response/lower boost threshold I think you might be better off starting again with the manifold aiming for tighter runners and less total volume even if they are not perfectly even. If you can pick up a split pulse turbine housing that would help too. Probably not what you want to hear but if a wider torque band is your aim I don't think you have much choice.

For a big track I think I will be fine but as for ten of the best over here I will have no chance on the handling circuit I think I will start working on a manifold and turbo for the engine spec rather than something I through together out of desperation to some seat time maybe a precision 6262 and stick to 500cc per runner as I love these when I run them on customers cars

There is a reason why later evos used twin scroll turbos.