OPINIONS WANTED:

what was supposed to be a mild tune up/once over has turned into pretty much an all out build and I would love some input turbo wise

heres what we are working with.

-NA 6 rolling chassis
-NA 5 speed trans

-Engine is an EUDM BP5A (bpw4 with the Mazda speed Miata intake cam from what I’ve gathered)

-JDM flat top intake with skunk2 throttle body

-FM manifold to a full 3 inch with the Miata turbo approved magnaflow

-flow force 640 injectors

-megasquirt engine management

I purchased the car with the 1.6 and an old school greddy kit with the msd box/ vortech fmu (now for sale) After finding out about the dreaded keyway rot I purchased the new motor with the intensions of reusing the greddy td04H turbo as it’s in great condition.

now that I have spent all this money on engine/intake etc etc, what are thoughts on a turbo to use for a (250+ HP street car?
should I save the money on a turbo/downpipe and just run the td04 with a custom downpipe (I would prefer this option for the budget and the Wife will kill me if I spend too much more on this car) Should I try to find a disco potato 2860 or another variant and go with the fm downpipe? It’s a Street car so I don’t want a huge turbo that spools really Late but I’d love the ability to hit 300hp.

thanks for any input

 

Stick with the td04 and a 3 inch down pipe. You will want to do some grinding work for better flow at the wastegate.

 

I like that idea, any advice on cleaning up the wastegate?

 

If you did not open the engine and are running standard connecting rods, I think you will have plenty of turbo for the engine.
As for waste gate porting: open up the hole and smooth the path of the gasses.
With some googling you should be able to find pictures on this forum.

 

^^^^^^^^^^^
Yup, this. Beat me to it.
You can also use a basketball/soccer ball pump with gauge to set waste gate opening pressure.

 

My friend is running an old greddy TD04 on a kraken manifold with a custom downpipe. It's plenty for a stock engine car, but would be you are going to be limited to arround 220-230hp at the wheels (which is just about perfect). That said, he did a 19T compressor wheel and housing when he rebuilt it. I want to say he went with the 6+6 wheel? It makes boost stupid quick, even on a 1.6.

The 19T shoooould be able to flow enough for 270-280rwhp, but I have no idea if the turbine will.

 

Thank you guys, more googling to ensue to clean up the wastegate.

thoughts on downpipe? Reading up on them on here and it’s mixed opinion of divorced and bellmount downpipes. I found both style flanges on eBay I could start with. Regardless I want it to be 3 inches as quickly as possible. Thanks for the help!

 

I know there was some debate over the superior design, but for a stock motor build, you won't be pushing nearly enough air to notice a difference. Especially if you're running 3in out the back.

Go with whatever is easiest to fabricate, which I imagine is the bellmouth.