duhafnusa4

iTrader: (1)

well I was going to turbo my 99 miata, but I got an eaton m90 in good condition for 15 bucks

Heres some pics of my car and such






As for the build, Ill be getting my mounting bracket design from Oreo on here, because he is awesome

Ill need to shorten the snout on the M90 (from a GM 3800) as it is too long (you dont hear that too often




Ill be utilizing my access to a full machine shop (woot for working as a lab tech in the machine tool lab at my University) so ill pop it on the mill and shave dat bitch


injectors will be from the same engine, they are 350cc bosch, got them for free, they are bigger than stock, and same impedance and clip. So triple win.

Tuning will be MS3, that I am building.

Thats where I am at for now, more pics in the future, but this should tide you over

Leafy

iTrader: (1)

Why not just buy a shorter snout from eaton? Making that one shorter is going to be a pita.

cjsafski

iTrader: (2)

M90 seems too big for the BP. Every M90 build I have seen has made the same power as a M62. Also if you are using only 350 cc injectors you will have to spin the blower so slow it will make zero sense to use.

Leafy

iTrader: (1)

Yeah the tiny injectors dont make sense. The reason the M90 builds normally suck is heat. The M90 makes a lot of heat especially when you run it at real boost levels. Its the correct displacement to make real power on a BP but you really need a TVS or twin screw for it to work.

cjsafski

iTrader: (2)

Also the buick blowers are super long. My Buick M62 barely clears the firewall even though I cut it off by the bypass. If you want to keep the bypass (which you need), it will be very difficult to fit since the M90 has a longer rotor section if I remember right. You will need to make the nose be as short as possible.

laguna96

You can always incorporate the bypass remotely. the jackson racing kit is a modular bypass that you could easily unattach and reloacte if you were to alter the arrangement.

Since I've been bugging cjsafski to do this build and he keeps procrastinating every time we see one in the JY about how he doesn't want to spend the time to do it, I call shennanigans on him. Do it.

duhafnusa4

iTrader: (1)

So to answer all these concerns and comments

what are you basing the 350cc injectors being too small on? do you have relevant data or just going off of what others have said and done?

The supercharger being long isnt as issue, ive been machining for quite a long time and making a new shaft and shortening the housing is cake. PITA not so much

bypass will be a bosch valve, i already own it and it will work like a champ.

The eaton m90 creates excess heat at higher rpms.

based on the flow maps that are provided my eaton, my pulley size and max psi calcs, i wont be having issues there. Yes it may not be making the max cfm that the m90 is capable but for what I am going for it will work fine.

Thanks laguna for the support. Ill do it. Tomorrow night I work at the Machine tool lab, and will be machining down the snout. Haha i am getting paid to do this

cjsafski

iTrader: (2)

There is a calculator out there that will tell you. But from experience:

Stock(295?): Maxed out at 5 psi on an m45
440s: ~80% DC 8 psi M45
550s: Maxed 13 psi M62
1000: 60% DC 13 psi M62

I consider injectors maxed above 90 percent. Any worthwhile pulley ratio on an m90 will use a lot more than the 350s can do.

If you mean this unit for the bypass then it will not work with a roots type blower. Read around everywhere and you need the butterfly type. Hell I even tried to go against that advice when my bypass actuator failed and the unhappy noises that come from the blower...

duhafnusa4

iTrader: (1)

is this the calculator you are talking about?

Fuel Injector Calculator from WitchHunter Performance

if so, 220 crank hp, bsfc of .6, 4 injectors, and 90 % DC as you say, injector size is 385.

Now I am not stuck on the injectors that I have, just that I have them, and will initially use them.

On the BPV, thats fine, no problem using a butterfly type. Good to know that the bosch unit wont work.


anything else to be considered?

cjsafski

iTrader: (2)

I thought about trying the unit from the Mini Cooper S when I wanted to relocate mine but never really needed to.



The bypass from the Thunderbird SC is not part of the blower either and could be possibly be made to work.

Leafy

iTrader: (1)

Depends on the injector, I would run an EV1 over 80% or an EV6 over 85%. And even at 90% they're going to be wicked marginal on a blower that you're going to have to dump fuel at.

Godless Commie

iTrader: (2)

Using 650cc EV14 Bosch injectors on an MP62 running at 14-16 psi here.
Max duty cycle is 72% IIRC.
150/65 mm pulley setup.

duhafnusa4

iTrader: (1)

Thanks for the info people, the more hard data I have the better.

laguna96

This bypass would be WAY better for anything close to and over 10psi... the bypass on the 45 and 62 units is about 1-1/4" dia, the mini cooper one is like 2-1/4" dia. They run at 9-10psi stock and upgrades up to 17 on factory parts so they engineered that to have a bit more flow. Otherwise you'll need a BOV of sorts to compensate.

Leafy

iTrader: (1)

I dont see why. you dont even NEED a bypass, its just there so you arent drawing power and heating the air when not in boost. And also for NHV (blowers without bypasses make some funny noises at low loads. All those blowers you see on muscle cars dont have bypasses because they dont give a **** about fuel mileage or NHV. There's no need to blow off with a blower on throttle closing since the TB is before the blower, not that they have any issue with surge anyways. In other words, flow through the bpv doesnt really matter as long as its sufficient for low load situations (mainly being able to flow enough air for the engine during cruise).

Godless Commie

iTrader: (2)

This.

duhafnusa4

iTrader: (1)

so random Q, if you have the throttle body after the supercharger, with the bpv removed. It would work fine with a bov system?

Godless Commie

iTrader: (2)

It will, but the noise will kill you.
Dual TB is absolutely the best way to go.

duhafnusa4

iTrader: (1)

ill be uploading pics shortly, but I got the nose shortened, along with making a new shaft to go inside.

woot that was fun.

Godless Commie

iTrader: (2)

Would you be willing to make an input shaft for my blower?
Mine is pretty chewed up right where the bearing rides.
I had to make do with a sleeve - made out if a wrist pin - for the time being.