OK I am getting serious about getting this car done and have to come to a desision soon.

I am wondering, with all of the infinate knowledge in here, what am I going to gain with a 3" GM MAF?

What are the pros and cons of a GM MAF before or after the turbo?

I am not planning on putting 20+psi into this engine nor do I plan on putting any significant engine management systems in there unless needed.

The car will have all hard pipe (upper, lower and intake). Most everything else will be stock (new joe p is about it). And a 40mm restrictor at the turbo inlet.

Ok lets have it. What do you all think I need to get done to make this a reliable setup.

Thanks,
Dan Moore

Probably not much with that 40mm restrictor plate blocking the turbo.

What are your future mods going to be? Why do you think you need a maft translator?

Do you plan on upgrading your fuel system at all? If not, about the only benefit would be venting and it can SOMETIMES help with fuel cut issues.

Why do you have a 40mm restrictor plate?

I could be wrong here, but I believe this is for his rally car and their are certain restrictions that are now required on turbo'd cars for the Club/Pro Rally.

Dan, correct me if I'm wrong. :)

No correction needed you are right.

I have to run a 40mm restrictor (not plate type) in the inlet side of the turbo for open class. Rules are rules.

I am going to try and make everything as close to stock as possable since I dont actually plan on running this car more than a year and dont want to dump a crap ton of money into things I probably dont need.

My question was actually, do I need a 3"GM MAF with translator or not. What would require me to need one. If I do or dont what is the diffrence of having it before or after the turbo.

Or would I be better off putting a 2g MAF in there.

This car will not have 300+ HP just trying to make it as reliable and efficient as I can.

I do not plan on doing anything to the fuel system other than a walbro pump. And I dont know if I actually need the BOV to dump to atmosphere other than it would make the car sound cooler. IMO.

Here is what the car will/does have. Big 16g.(with restrictor) lower and upper pipes, intake pipe, manual boost controler pushing no more than 16-18psi. walbro fuel pump. 3" turbo back exhaust. completly rebuilt 6bolt. nothing fancy but some porting done to intake and exhaust (gasket matching basicly) and that is about it as far as the engine goes.

Dan

You do not need the gm maf. A stock 1g should be fine for what you stated above. You can hack it if needed. To run 16-18 psi of boost you will need 550's unless you want to run racegas all the time. With 550's you will want an SAFC or atleast a 2g MAS. Hope that helps..

I would think that a stock (or slightly hacked) 1G MAS would flow more than enough for your car.

Just a thought, but if he is running a full 3" IC piping, wouldn't that create some form of a vacuum at the restrictor plate point therefore increasing the overall airflow? Air wants to flow from high pressure to low pressure: high pressure before restrictor plate, lower pressure after the plate= vacuum, right? Think of it like an exhaust system, running a 20G with a stock O2 housing with 3 inch exhaust is going to have an overall better flow than a 20G, stock O2, and 2.5 inch exhaust, right? Wouldn't it be the same concept?

converging like that will make it gain some speed and reduce pressure if thats what you are thinking jake

Full 3" IC piping will probably hurt throttle response and torque.

With the GM maf the system probably would have better overall flow, but if you are only pushing 18psi with a 16G, how much of that flow do you need?

40mm is also smaller than the inducer size of a 14B compressor wheel. 18psi with that restrictor in front of the turbo is not going to flow like a 16G at 18psi would normally be able to. 3" I/C piping is going to be way overkill for that turbo even with if their wasn't a restrictor, but the restrictor is just going to make it even worse. The stock throttle body matches up perfectly with 2.5" OD I/C piping. Most of the piping kits out there are only 2.25" which is more than enough for a 16G.

thanks for all of the response guys. just one thing...I never posted that I was going to run 3" IC pipe. That would be huge for what I need it to do. Just the exhaust will be this size, and this is only because I have it already.

I am planning on going with a 2.25" IC pipe system, probably the same for the intake if I dont end up going the GM route.

Also I would rather run a 14b but no one wants to make a 40mm restrictor for a 44.??mm hole.

Dan

3" gm maf = 3" ic piping

How does that math work? Looking at the Dejon Tool UICP for placement of a 3" GM MAF the pipe is only flaired to 3" at that location and only 2.5 for the rest. Is having that GM MAF in there with the rest of the system being smaller still going to be "over kill"?

Ok lets start over. What would you do to your intake/exhaust/fuel systems if you had a 40mm opening on a B16g turbo? Less than $1000 options please.

Dan

I would probably run the biggest and least amount of exhaust possible. A hacked 1G MAS or stock 2G MAS. And either 550s with an AFC or possibly just try running a high base fuel pressure with a cheap B&M FPR on the stock 450s.

Walbro 255hp $100
used s-afc $200
aeromotive regulator setup w/ gauge $250
550's, used, $200
that gives us $750
2g mas $50
so we are at 800
3" dp, no cats or mufflers,:)
Should be a tad under 1k, lol.

Thats what I am looking for. Thanks and keep it coming if you have ideas.

aeromotive regulator setup w/ gauge $250 What is this ????

Can I vent the BOV to atmosphere with a 2G MAFS ?

Dan

You can vent but your car will still run like shit. It is not the gm maft that lets you vent, it is the translator. The Aeromotive regulator with gauge is an adjustable fuel pressure regulator with a gauge. I have the one at Buschurracing.com. They are nice to have when it comes to tuning.

I would go:
used safc - 200
used 550's - 200
walbro 255 (low pressure) - 100
cheap B&M regualator - 50
catback (used) - 300-350
offroad dp (used) - 200

You would also want a datalogger (100). You could hack your mas if you need to (free).

Stock injectors, rewire fuel pump, no afc, buckle up and let her buck.