turbo questions

[Sewerrat]

I'm thinking of qoing turbo and have been researching much helpful info on the web so I won't ask to many questions. Couple of questions I'm curious on is on a MAF engine, where do you place the sensor? I'm guessing b4 the compressor? Also since the intake system will now be pressurized, what happens to all the vacuum actuated parts like FPR, EGR, and brake booster? A vac. res tank would take care of the B/booster but what about the rest? Thanks in advance.

[El_Diablo]

if you place a MAF before a compressor you'll end up running extremely rich when your blow off valve activates, its best to have it as close to the throttle body as possible

[nocutt]

if you place a MAF before a compressor you'll end up running extremely rich when your blow off valve activates, its best to have it as close to the throttle body as possible

Not if you have the output of the BOV placed back into the intake track after the MAF.

There are two ways to set the MAF up...since you guys run a 'true MAF', then I agree with El_Diablo...it is best to have it at the stock location.

Also since the intake system will now be pressurized, what happens to all the vacuum actuated parts like FPR, EGR, and brake booster? A vac. res tank would take care of the B/booster but what about the rest? Thanks in advance.

FPR is OK with pressure, brake booster should have a factory check valve, evap tank should have check valve, so should the tranny line assuming it is vacuum modulated...

[El_Diablo]

true, but it can still run rich if the compressor isnt able to take in all of the air.... dont ask how i know.....

[nocutt]

true, but it can still run rich if the compressor isnt able to take in all of the air.... dont ask how i know.....

LOL not really a MAF issue then...

[El_Diablo]

lol, true again

[RedZMonte]

boosting threw the maf is how most of the turbo setups run. but you can suck threw. what car is it going on? is it MAF only or does it have a MAP also? i had just a MAF for the first 1.5yrs my car was boosted. then i did a OBDII swap and now i have boot. the stock MAP is only 1bar so it will control most of you fuel untill it maxes out then your fuel control will be strickly done with MAF.

S

[El_Diablo]

a 1 bar MAP will max out at 14.7psi which is atmospheric pressure at sea level... my guess is it will max out pretty quickly, and thats why our cars run a MAF system aswell

[Sewerrat]

Thanks for the inputs. My possible turbo project is my 88 camaro 2.8 5spd. I recently swapped in a 85 2.8 which I rebuilt. I later learned the 85 had smaller valves than my 88 but the machine shop said in my case it wouldn't matter much because it wasn't a race track vehicle. I was hoping for alittle more performance from the rebuilt engine but none was experienced. At least I'm not burning oil anymore and making the neighborhood nauseated.
Alot of people said I should have done a v8 swap and maybe I will someday but for now I'm quite happy with the little V6. I just need alittle more punch when trying to pass on the highway. My goal is aprx 25% more hp. Would you say 6 psi would be safe for a beginner? Im very capable of welding so fabing the pipes isn't a problem. My car is not equipped with a MAP, only MAF for my year. So I guess putting it between the IC and TB but as close to the TB as possible, right? I still don't understand how the brake booster is going to get vacuum. So vacuum does occur within the intake? Even at idle it's still under some sort of boost right? Sorry for the stupid questions but I don't get it. Would a FMU be the simplest way to enrich the stock injectors or would larger ones needed. I'm sure in either case an ecm tune is a must. Thanks again.

[El_Diablo]

simplest would be a rising rate fuel pressure regulator

not to familiar with the older engines but 6psi should be fine and allow you to use a small turbo for better response, and yes, you would want the MAF as close to the tb as possible as stated before

when the throttle body is closed at idle the engine is seeing vacume usually, if your really worried about not having enough braking force then use a vacume reservoir or a vacume pump, or you could always go with a hydroboost unit

[Sewerrat]

Ah, now I'm getting a better picture of it. Just a couple of more questions please.
I've browsed ebay to get an idea turbos sizes. Many of the smaller ones state 20-25 psi max. How do you regulate it down to 6 psi. I don't see a removable spring on the wastegate? On some I don't even see a wastegate. Just a plate with 4 or 5 mounting holes with another hole about 1 1/2".

Because my vehicle is a 5spd, do you recommend a BOV even with just 6psi?

What does the FMU rating mean, e.g. 12-1, 8-2, 3-1?
I really appreciate the input guys. It's pretty obvious you guys have been messing with this stuff for awhile now.

[timg]

Ebay turbo descriptions are infamously inaccurate. They have little bearing on what the turbo actually is or what it is capable of.

Boost is controlled by either an external (Tial, HKS, Turbosmart, Synapse, etc) wastegate or an internal wastegate that's mounted to and a part of the turbo itself.

I do recommend a BOV. They can be had quite cheaply if you're willing to look around. I spent $20 on mine and took it from a 1G DSM.

FMU ratings describe how much pressure the FMU adds to the fuel system per psi of boost. Roughly, the 4-1 is supposed to add 4 psi of fuel pressure for every 1 psi of boost. A 12-1 would add 12 psi of fuel pressure for every 1 psi of boost. 12-1's are definitely overkill, but without tuning your car with a wideband O2 after the turbo is setup, it's impossible to know which one is best.

Tim