CT9 Turbo from EP82 GT Starlet on a D15

Going to take a DIY manifold hack probably, and a good tuner, but i see no reason you couldn't make it work with some patience and elbow grease. Just depends on how much your time is worth i guess.

slo_eg8 said:

starlet ct9 turbo - Miata Turbo Forum - Boost cars, acquire cats.

"compressor:
exducer: 48mm
inducer: 34mm

turbine wheel:
exducer: 36mm
inducer: 46mm

22 minimum airflow (Kg/s)


130 maximum airflow (Kg/s)


1.53/20 pressure ratio/ temperature


60% efficiency at maximum

"


Turbocharger Compressor Calculations

note: I fucking hate myself for going through all that effort for you. your turn to do the math

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I really appreciate it man I'll do it next time I promise

Oldcivicjoe said:

Going to take a DIY manifold hack probably, and a good tuner, but i see no reason you couldn't make it work with some patience and elbow grease. Just depends on how much your time is worth i guess.

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I figured that I'd have to make a custom manifold. Thanks for your reply. T3/T4 or TD04 setup might just be a little bit better

For a low power build find a .50 trim t3 on a .48 a/r turbine housing, run a log type external wastegate type manifold to maintain ac and ps, shouldnt need more than 7 psi to get to your 160hp goal. a rising rate fpr will help with low load drivability, but you will probably want to tear that motor apart and at the very least re-ring it with mains, send the head out for a valve job with guide replacement, use a nice head gasket and arp studs. These low power dd builds are something I've been doing for 20 years, though the current dyno queen movement has made sourcing the turbo and smaller intercooler that accompanies it difficult at times. Find a good tuner near you and ask what their preferred tuning solution is, no sense needing to drive 150 miles every time you need a tuning tweak from a minor change.

Oldcivicjoe said:

For a low power build find a .50 trim t3 on a .48 a/r turbine housing, run a log type external wastegate type manifold to maintain ac and ps, shouldnt need more than 7 psi to get to your 160hp goal. a rising rate fpr will help with low load drivability, but you will probably want to tear that motor apart and at the very least re-ring it with mains, send the head out for a valve job with guide replacement, use a nice head gasket and arp studs. These low power dd builds are something I've been doing for 20 years, though the current dyno queen movement has made sourcing the turbo and smaller intercooler that accompanies it difficult at times. Find a good tuner near you and ask what their preferred tuning solution is, no sense needing to drive 150 miles every time you need a tuning tweak from a minor change.

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Thanks for your advice! Can't wait to get everything started. D-series seem really affordable

At around 2600 for a motor build that will handle up to 200whp (provided your machine shop is good) they arent expensive, more power means more expense though, above 200hp you will need things like rods, pistons, deck closing, springs, valves ect to stand up to the abuse. I've seen many a stock d series running small turbos last well into 100k miles, just takes good maintenance habits and getting all your t's crossed and i's dotted throughout the build and tune. Check out zealautowerks d series compression calculator for piston and head info if you are thinking a total build up.

Alright, we have about two main machine shops in my area. I don't know their expertise so I'll have to go and find out how good they are.

The engine is a D15Z4. I know most of the posts on this forum recommend getting a D15Y*. The D15Z4 is all I've got at the moment, though the D15Y* is stronger. I'll do some research on what is involved in a motor build. I'd love to have the engine has strong and healthy as possible to avoid blowing up on the road. If there's any little info you could give in regards to the D15Z4 and its strength, I'd appreciate it.

Eventually the plan will be to upgrade the rods and pistons and add more boost. Not too much power, the car will be streetable. 350 HP -- but I'm just calling numbers here. We'll will see as the build goes on.

Oldcivicjoe said:

re-ring it with mains

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I'll assume you mean piston rings and change the main bearings

Yes a re-ring generally involves piston rings and rod bearings, im saying do the mains while you are in there. but if you are thinking of building it then the shop is going to want to refinish the journals, install new bearings, and bore the block to match the pistons any way.
Since its a 96-2000 block im thinking its the oiling system that has brought durability under question, if thats the case sourcing a b2/7 crank may fix this issue but that would need research to verify the solve and fitment.

Oh thanks man! Really helpful

I'll try and source a refurbished crankshaft online once i get the fitment. If I got any more questions I'll ask them. Might start a build thread for starting a build thread's sake since there's nothing really special about this project.

Sometimes nothing special is exactly whats called for, a fun, reliable dd doesn't need to be fancy, and it dosent need 400whp either. Often times a smaller faster spooling setup that makes less power but makes it lower down is more fun as a dd.