Hi guys,

I'm building a turbo setup on my 2001 B6 NBB miata with:
Greddy exhaust manifold (allready hav cuts to prevent cracks)
T25 turbo from an nissan.
a 18" intercooler with 3" couplers.

My first goal with the turbo is to run about 6psi, so everything else can be stock for a time. Then I can save money for a other clutch , injectors and diff.

So far I'm running on adaptronic engine management and have made the tubing at cold side of the intercooler to the TB.

Today I've mounted the manifold and turbo to measure the hot side tubes.
The tubing kits I see on Ebay are mostly 2,5" but..... the way I see it 2" will fit a lot easier because the turbine outlet is 2" and I can get the tubes a lot easier crossing the PS lines and the cooling return line.

I have read the DIY FAQ. Is my conclusion right that the size of the tubes dosn't matter that much?

My question is there a downside to using 2" instead of 2,5" at the hot side?
If there isn't I'm going for 2".

Thanks Martijn

 

Made a choice:
Hot side is going to be 2,5".
This week I'll go order some steel pipes.

 

how'd you get a greedy manifold to fit a 1.8 head? They're made for the 1.6

 

 

he said b6.... he's in the netherlands.... its a 1.6 nb. they used the b6 LONG after 93 overseas.

would love to see some pix. yours is a RHD, correct? hot side should be a cakewalk for you without all those pesky hydraulics in the way.

 

martijn, how are you going to route the hot side pipe? I routed mine through the left wheel fender. It's easier and you don't have to worry about PS/AC lines.

 

Nope, they drive on the same side of the road as us. Nice looking on the profile

 

Okay, I can understand the request for pics.

Here are a few:


























The pipe between the TB and the intercooler is 3" (75mm)
The pipe between the turbo and the intercooler is going to be 2,5" (64mm)

So far I removed the PS cooler to make room for the intercooler, and placed the AC fan parrallel with the standard fan ( I don't have AC) for extra air movement.

I'm planning to order a turbocover at FM for the greddy manifold. And if that is not enough for heat protection I'll mount some heatwrap to make sure I'll keep my brakes.



If anyone knows the exact type of the turbo info is welcome!

For now my first step is to make the pipe between the turbo and the intercooler.
secondstep is the downpipe. Plans are to make it aproxx. 2,5"
third step is to tap the oilreturn line.

 

Okay, I've made the pipe between the intercooler and the turbo

Next step the downpipe! I've orderd the parts needed.





The size of the pipe I've used is 60mm (about 2.4inch)

 

Maybe a strange question for you?

Is it possible to fit 2,5"elbow to a t25 exhaust flange?
I have them in ta house, but is seems that when I'll connect the elbow it is going to be impossible to mount the nuts.

I also have a garret downpipe, with a flange that isn't going to fit.

Is it a better option for me to chop the wrong flange and weld the downpipe to the t25 flange. And than I can chop the flange at the bottom of the downpipe to connect a 2,5" pipe to the end of the car?

I don't get it, if I'm right i read that you guys created an 2,5" downpipe.
Do I have a problem when the first 10 inches are 2" instead of 2,5" ?

Thx

 

You will not have a "problem" per say. But you will lose power compared to a 2.5"

 

You will essentially make your ENTIRE exhaust a 2'' exhaust if you have a 2'' bottleneck ;p (the 10'' up front) Go 2.5 MINIMUM, growing to 3'' or go full 3''



Keep bends down to a minimum, as well.

 

Thx for the replyes!

Did some work today for the downpipe.
I can't weld. If everything goes well a friend of me will weld my downpipe for me, so I made today only some connections.

I all ready did some bending on the coolantpipe, but today I mounted a 90dgrs knee.


The first part of the downpipe. the first is a piece that is 2" to 2,5" wich we chopped to the minumum. second is a 90dgrs 2,5"pipe


Now I've connected a 45dgrs pipe


Here I mounted about 6" of 2,5" pipe, and a 45 dgrs pipe


Here is what I did today mounted in the car.


If everything goes well I can remove the original downpipe (incl. the cat) friday. Then I can finish the downpipe.
I'll hope that my friend can weld my downpipe coming saturday.

I'm getting there bit by bit

 

Okay, my downpipe is finished!!!





Now its waiting for a gasket and some coolant banjos, then its tapping time to make the setup work.

 

Okay, the car is running with the turbo.
Currently I'm running 40kPa boost (about 6 psi).

This is fun





Still have some items to adjust, but info on that will follow.

In short my setup:
Miata nbb with B6 engine
greddy exhaust manifold
garrett tb2525 (from a S13)
DIY 2.5 inch downpipe
2.5 inch piping at hotside of the intercooler
3 inch piping at coldside of the intercooler
18 inch intercooler
LC-1 wideband
Adaptronic E420c ECU with loom
ACfan as an extra fan in parrallel with the stock

Short list with adjustments still to do:
- adjust my turbo heatshield, so it will fit (its a FM greddy heatshield)
- adjust the coolant lines and one banjo (because now they are standard rubber and I'm not sure they will last)
- If the heatshield don't bring enough protection to the heaterlines and the brakelines, I'm considering a turbo blanket or heatshields for the lines and reservior.
- On the long term: a high flow cat and a magnaflow mufler for a mazdaspeed
- place a adjustible 7 psi actuator with bracket instead of the crappy actuator that I have now.

If I'm forgeting something, please feel free to tell me.

 

Okay, did a little mod.
I reroute the coolant hoses to the turbo, insulated them with heatsleeves and placed a FM heat shield for a greddy kit (a little bending was neccesary because I use a diferrent turbo).

The breakfluid reservior is less hot, and the coolant lines look nicer.

 

Wow! Congrats man!

The car looks great.

 

Nice work martijn; it sure is fun, isn't it?

Wait until you turn up the boost You'll see the true meaning of fun!

 

I was un aware that these fit the greddy mani's

 

the garrett tb2525