hey whats up i have a 92 rs that im swapping a 350 tpi from a 88 roc and i want to turbo it now i heard the sd if more preferred for boost is that true.i have the entire harness and ecm for 88 and i really don't wanna butcher it up if i don't haveto . can i run boost with maf and if so were should i put maf on the setup before the turbo or after i want run 15- 20 psi of boost max i don't think the a stock maf supports that does any one have a suggestion for like a 2 bar maf if they have one please help

 

i believe if you want to run that much boost you will need to rebuild your engine with lower compressor and forged pistons. I would put the maf on after the turbo

 

i am goin to rebuild it probably gunna get AFR 180 cc head custom comp cam hydraulic roller slightly ported tpi forged rod and piston and a 8 to 1 compression ratio and the turbo is a t70 and some other goodies =)

 

You may want to run an aftermarket tpi or better yet a stealth ram. A turbo 350 is way too much for a "slightly ported" tuned port.
She wont get enough air

 

i believe his name is zz astro on here he has a stock tip and he's runing i think 12 psi or on a stock tip how come it is too much my goal is 400 ***** at the wheels zzastro is at 300 stock with a turbo

 

Turbos FORCE air in. The tpi manifold will be fine. And rookie24, you can run boost on a maf system. A friend of mine had a supercharged '88 IROC with the stock maf system and 12psi and it ran great with just an FMU as an add on. Since you're doing heads, cam and forged bits, you're probably better off with a stand alone system. I'm planing to turbo my tpi as well and am debating using the maf or going stand alone but I think my build will be a little more tame than yours. If you can budget the stand alone in, go with that.

 

He may be able to do it for a while, but those forged parts are very good insurance. And they will be able to handle nitrous and more boost with out a problem, if you feel the need for more power

 

mass air flow sensor should be installed on the inlet side of the turbo.

 

Yes you can use a MAF and stock 165 ecm with a turbo.

It can be done either as blow through or draw through set-up, but I would suggest blow through to help minimize the turbo's inlet flow restriction, reduce plumbing complexity and to reduce any transport delays.

Locate the maf downsteam of intercoolers and any bov or bypass valves.

A maf conversion and corresponding tune from Blowerworks.net will support your fueling needs provided that the rest fuel system is equally matched and compensated for in the tune. 63 or 80 lb. injectors and appropriate fuel pumps would be required depending upon ultimate power goals. No need for an fmu with this approach.

 

Yea, sure...

The worst flowing part of a _stock_ TPI flows about 200cfm, which assuming that a 350 is at about 85% VE at redline is enough to feed it till almost 6500rpm, there is no way that a 350TPI motor will turn to that. The stock heads and exhaust are a limitation well before that. Adding boost doesn't increase volume flow, just the pressure/density of the flow through the intake, you get roughly the same flow of more dense air.

As far as the maf goes, there is no technical reason that it shouldn't work if you can get the programming right, of course, I haven't spent the time/effort to figure that end out...

 

Look at that, thanks for correcting me.
I was just assuming that if he wants to make power, the tpi is the limitation before the heads and exhaust. Sure the turbo forces air down the intake, however, if you have wimpy ports how much power are you losing by bolting on a stock tpi.

But if you guys have done it before, listen to them. I'm just running a NA 385.

 

You have a choice. Either butcher that harness to change to SD, or butcher that engine with 15-20 PSI and MAF. To convert to MAP requires minimal changes to the harness.

 

Unless you convert with a 3bar MAP sensor and run code $59 I don't see how a SD conversion with the stock F-body code is any better than a MAF. It seems like with either MAF or SD you can use the PE and AE tables to get the fuel you need. I've worked with MAF more than I have SD, but I think you could safely fuel a turbo MAF setup even after you've passed 255gm/s.... it is not the optimal setup, but I think it would work well and be safe. I'm in the process of exploring a turbo setup for a MAF TPI 350, so I'm still reading up on this topic. If I'm missing something please correct me.

 

For low boost it doesn't matter. You can stretch either the MAF or MAP using PE MODE. The person posting said 15-20 PSI which is too much to try and cover with PE MODE. It would require SD with appropriate MAP sensor and code/BIN.

Have you thought about putting a 3" pipe in parallel with your current MAF and scaling the code tables?

 

I have thought of that many times before. The problem is that it's impossible to tell how much air will go through the bypass tube at any given time. I'm afraid a bypass tube would cause you to loose so much MAF resolution that it would never run correctly. The better option is to put the maf guts in a larger tube and re-scale which has been done by some on here, DOC is the chief among them. The problem is you have to cut up a MAF to do this and then you have created a 'non-replaceable' part that could strand you until you make another one.