Basic Supercharging: My M50B25 + Eaton M90

[MaxBell]

Hey guys!

So I just finished my M50B25TU build, and got it running right (finally). I was with a friend a little while ago and he gave me an Eaton M90 from a old Thunderbird.

I've been doing some research about how hard it would be to put it on, and it looks do able!

I have a few questions that maybe you lot could answer.

1. Charge System Setup

What order should everything go in?

Supercharger > Intercooler > Wastegate/BOV > MAF > Throttle Body

Don't get all "this guy's a ricer" on me, but I'd like some noise from my pressure release. Is a BOV doable, since the M50 has a MAF?

2. Pressure Control

Would it be possible to run a wastegate, just before the throttle body and before the MAF that would allow control of the boost level?

That way I could put a tiny pulley on the supercharger, so that it would reduce drag, but I would be still able to waste some of the pressure to keep it down on higher boost.

Would I have to run a BOV/Bypass Valve as well? Where?

3. Intercooler Sizing

Right now, I don't struggle with heat at all. I have a 318i rad, with a 16" blade style SPAL fan. It moves a ton of air. :) However, what size intercooler should I get?

I would like to keep it on the smallish side, since I don't plan on running crazy boost.

I have the option of buying a Dodge SRT-4 intercooler for cheapie cheap. It's got 2.75" inlet/outlets and it's overall dimensions are 23.5" x 5.75" x 2.75". Would this be good for my project? It would fit perfect behind the kidney grills.

[Denny]

Hey

First: I recommend you read the book Supercharged from corky bell....dont be lazy read it :)

second: check my thread out very closely tons of info: http://bmw325e30turbo.blogspot.ca/

Third: A roots type the throttle body needs to be relocated before TRUST me on this been there done that.... the BOV to compensate doesnt work and should not be there and the noise is REALLY bad... much much worst then people think.

Fourth: Pressure control no it doenst work that way...only way is to size the Crank pulley and SC pulley perfect to get the boost you want... my case 4.98| crank on a (1.0L M62 SC) and 2.6" SC pulley gave me 4PSI now with my new 7" crank and sill on a (1.0L M62 SC) and 2.6" SC pulley = 10-12 PSI :) for me am happy with this boost as I got 30# injectors running.

FIFTH: The M90 SC is perfect as long as its the thunderbird one (small size) then the grand prix one its too big to fit.

SIX: check the size of my cooler well that one is good for 12PSI so yours should be good to its all about how your going to put it all together and this is where you should concentrate on first.... building the mount and where things are going to go and fit.....draw it out and measure it all.. make sure the belts align and that you have a tensioner mechanism in place to be able to get the right size belt...


SEVEN: Whats fuel/timing management do you have?

Also warning Get ready its not easy to do it right... people think its slapping on a charger and belt...lol...

Hey guys!

So I just finished my M50B25TU build, and got it running right (finally). I was with a friend a little while ago and he gave me an Eaton M90 from a old Thunderbird.

I've been doing some research about how hard it would be to put it on, and it looks do able!

I have a few questions that maybe you lot could answer.

1. Charge System Setup

What order should everything go in?

Supercharger > Intercooler > Wastegate/BOV > MAF > Throttle Body

Don't get all "this guy's a ricer" on me, but I'd like some noise from my pressure release. Is a BOV doable, since the M50 has a MAF?

2. Pressure Control

Would it be possible to run a wastegate, just before the throttle body and before the MAF that would allow control of the boost level?

That way I could put a tiny pulley on the supercharger, so that it would reduce drag, but I would be still able to waste some of the pressure to keep it down on higher boost.

Would I have to run a BOV/Bypass Valve as well? Where?

3. Intercooler Sizing

Right now, I don't struggle with heat at all. I have a 318i rad, with a 16" blade style SPAL fan. It moves a ton of air. :) However, what size intercooler should I get?

I would like to keep it on the smallish side, since I don't plan on running crazy boost.

I have the option of buying a Dodge SRT-4 intercooler for cheapie cheap. It's got 2.75" inlet/outlets and it's overall dimensions are 23.5" x 5.75" x 2.75". Would this be good for my project? It would fit perfect behind the kidney grills.

[MaxBell]

Ok, I'm coming back to this post with some more knowledge. I've read most of Supercharged, it's fairly informative, but filled with a ton of useless history and crap I don't care about. I just need him to state something, give a reason or two and then move on. :^|

PROBLEM: I'll accept that the TB has to be before the charger (only for roots and twin-screw style blowers, I think), though that complicates everything quite a bit.

(Though many people seem to be able to pull off the TB after the charger. Here for example: http://www.r3vlimited.com/board/showthread.php?t=219806)

That means I have to build a custom manifold that I can mount the charger to?

I found this M50 intake flange that I could build something from: http://kadunza.myshopify.com/product...anifold-flange

Will an aluminum intake manifold be strong enough to hold the blower?

How can I do an inter cooler at that point?

EDIT: If I have the TB after the blower, then the blower is seeing maximum air all the time. (since there's no restrictions before it) If I put a vacuum operated bypass valve to make it recirculate the air back, would that not solve the problem of compressor surge and allow me to put the TB after the charger?

[Plynch2]

you definitely need the TB before the supercharger. my first setup was SC, FMIC, BOV, MAF, TB. when crusing the BOV was constantly blowing off very annoying also very inefficient. Here is my bulid. http://www.r3vlimited.com/board/showthread.php?t=290320

[Q5Quint]

Wouldnt you need just one bov for a charger before tb setup? Everything should be boosting into the intake manifold when tb is open, and when it closes the bov should bypass the charger onto itself so it creates no pressure against the closed tb and blows your intake pipes?

Ie your bov should be allowing intake air to vent past the supercharger so it creates no pressure differential and no boost, not venting into the atmosphere like on a turbo?

So at 6000rpm when you let off the throttle and the plate closes, and the supercharger is pumping tons of air still because the engine is spinning, the bypass bov opens and with ambient air pressure on both sides of the charger it stops making boost. If you just have a vent between the charger and the throttle plate it will just blow out the valve constantly as a boost leak.

This isnt a big deal on a turbo because when you let off the gas the turbine slows down. On a supercharger it will spin at whatever rpm the engine is at ie not slow down, so you have to put ambient air to both sides of the charger so it cant charge anymore even though it is spinning?

[The Dark Side of Will]

1. Charge System Setup

What order should everything go in?

Supercharger > Intercooler > Wastegate/BOV > MAF > Throttle Body

Don't get all "this guy's a ricer" on me, but I'd like some noise from my pressure release. Is a BOV doable, since the M50 has a MAF?

Airflow order:

Filter > MAF/AFM > Throttle > Supercharger > Intercooler > Intake valve

2. Pressure Control

Would it be possible to run a wastegate, just before the throttle body and before the MAF that would allow control of the boost level?

That way I could put a tiny pulley on the supercharger, so that it would reduce drag, but I would be still able to waste some of the pressure to keep it down on higher boost.

Would I have to run a BOV/Bypass Valve as well? Where?

This doesn't make any sense.
Tiny blow pulleys turn the blower faster and increase boost.
For a given engine, the pulley determines the boost pressure.
There is a requirement for a *BYPASS* valve which connects the inlet and outlet of the supercharger when the throttle is less than WOT. This reduces waste heat and parasitic drag from the SC by making sure it's not trying to compress air that was just rarefied by squeezing through the mostly closed throttle.

3. Intercooler Sizing

Right now, I don't struggle with heat at all. I have a 318i rad, with a 16" blade style SPAL fan. It moves a ton of air. :) However, what size intercooler should I get?

I would like to keep it on the smallish side, since I don't plan on running crazy boost.

I have the option of buying a Dodge SRT-4 intercooler for cheapie cheap. It's got 2.75" inlet/outlets and it's overall dimensions are 23.5" x 5.75" x 2.75". Would this be good for my project? It would fit perfect behind the kidney grills.

Air to air on a positive displacement blower is certainly doable, just a little unusual.

[The Dark Side of Will]

would that not solve the problem of compressor surge

Look up the difference between a positive displacement blower and a centrifugal blower.

[MaxBell]

Hey thanks for the help guys, I'm starting to understand the mysteries of this blower.

One last question about the bypass valve. Does it run from between the TB and the S/C to after the S/C?

Would this be correct?



Why would you say an AIR TO AIR IC is unusual? Is it usually an AIR TO WATER IC?

[IRON-E]

You need to go lower and IS lip. ;)

[Ether-D]

Bypass goes from in between the throttle body and supercharger to after the supercharger.

[The Dark Side of Will]

Hey thanks for the help guys, I'm starting to understand the mysteries of this blower.

One last question about the bypass valve. Does it run from between the TB and the S/C to after the S/C?

Would this be correct?



Why would you say an AIR TO AIR IC is unusual? Is it usually an AIR TO WATER IC?

A supercharger is usually tightly integrated with the engine's intake manifold such that there's only space for an AWIC.

Bypass routing in red:

[MaxBell]

Thanks dude. Yes, I have been seeing Ether-D's build and he's doing that.

However, I don't want to build a custom metal manifold for this car, which would be needed since the M50 one is plastic.

[Julien]

my e46 vortec system had a diverter valve from charge piping to behind the maf (so the system stays "closed" and doesn't loose air/confuse the dme)

[The Dark Side of Will]

Thanks dude. Yes, I have been seeing Ether-D's build and he's doing that.

However, I don't want to build a custom metal manifold for this car, which would be needed since the M50 one is plastic.

I understand why you're doing it that way. It's not unprecedented... just an unusual approach.

I'm curious about how well the blower and intake ducting will fit on the exhaust side of the engine, though.

Here's a thread in which a guy does a from-scratch installation of an M90 on a 4.9 liter Cadillac V8 in a Fiero: http://www.fiero.nl/forum/Forum2/HTML/127611.html

[Victell]

Thanks dude. Yes, I have been seeing Ether-D's build and he's doing that.

However, I don't want to build a custom metal manifold for this car, which would be needed since the M50 one is plastic.

As long as you dont need AC then there should be room on the passenger side where the compressor would have been. Then you can run your supercharger outlet pipe from there to a front-mount intercooler and over to your factory plastic intake manifold on the driver's side. Pretty much like in your drawing.