ill start off by saying what i have:

1989 Firebird Formula, (had a stock 305 TPI)
350, bored .030 over
305TPI heads, 58cc, 1.84in valves
.422in valve lift, 204in duration at .050, hydraulic flat tappet cam
completely stock TPI setup
stock LS1 SLP injectors, straight off the SLP website (with custom made clips to hold them in place on the rail)
full edelbrock exhaust

what i want is this:
498in valve lift, 226in duration at .050 hydraulic flat tappet cam
TPIS base and runners
Trick flow 58cc heads off summit, with 1.94in valves

since i am making this switch, i have been told that my stock TPI MAF setup will not work correctly.

1) can i just get a bigger MAF sensor? or do i HAVE to switch over to MAP sensor....
2) can i keep my existing ECM if i change to MAP sensor? or do i HAVE to get a different ECM

sorry this is so long, but i would REALLY appreciate any help you guys could give me. i've been searching the forums, but i just need someone to clarify it a little for my setup. thanks a lot!!!

 

after the switch you'll need some computer tuning.

 

1. A. Yes you can get a bigger MAF. B. No you don't HAVE to convert to MAP, who said that you did?
2. You can keep your existing ECM and run a MAP but I believe it requires alot of chip burning. I personally went with a 730 ECM for my own sake.

 

MAF will normally handle the mods better than S/D. Keep the MAF, you might be suprised that it will run well. You can always change down the road if you really must.

 

another question.... is there anyone that has tried to do what im doing???

also, is there a horespower limit with my setup right now? is that why i have to make MAF change, or switch to speed density? if so, what is it?

thanks!

 

A descreened MAF flows about 658 CFM,, which should be enough air to make 500 Hp at the flywheel.

 

oh... i thought that since i have the stock MAF in my car, if i were to make big changes, up to like 400 hp i would have to get a bigger MAF so it can read the bigger amount of air that the car will be taking in....

 

No, you don't need a bigger MAF. That would be a waste of money, as the stock MAF with the screens intact will outflow the intake.

You don't have to convert to MAP. In fact, you can probably get away with running decent on a stock tune if you stay with MAF. The only thing you need to take care of is changing the injector size in the prom to compensate for the difference between the stock 19 lbs injectors the ECM is expecting, and the 25 lb injectors from SLP.

IF you go with a MAP setup, you cannot reuse your computer, prom, or knock sensor. However, going with MAP will require some prom tuning, as the VE tables will be off significantly.

There is a HP limit with both your current setup, and the one you plan on using. In both cases, its the intake. It has nothing to do with whether you run MAF or MAP.

 

I have the SLP LS1 injectors on my 350 TPI setup, if any of you are farmiliar with them, they are supposed to run at 25 lbs on a stock TPI fuel pressure of somewhere around the 40's. i am going to be going from the following setup, to a different setup that i will list below. Please let me know if the injectors i have, and the mass air flow sensor, and everything else except for the PROM will be fine for the following change!

350 bored .030 over
305 TPI heads 58cc, 1.84in valves
.422in valve lift, 204in duration at .050 hydraulic flat tappet cam

same block
498in valve lift, 226in duration at .050 hydraulic flat tappet cam
TPIS base and runners
Trick flow 58cc heads off summit, with 1.94in valves

also, whats the highest you can go on compression, and still be safe on an N/A motor with 93 octane pump gas??? 10:1???

 

Chief,

You may be missing what's been stated already. The stock MAF should easily support your combination. Obviously, the stock PROM will not. Regardless of what you do, you're going to learn programming.

There is at least one member running a 383 with decent heads (250+ SCFM) and a lot more cam (closer to 0.560" 240° duration) through a MAF and doesn't max out the MAF reading until about 6,000 RPM. Granted, valve timing, head and intake design, and other factors will affect VE, but the guy was running 12's through the MAF. It's tough to argue with that.

The injectors should be designed to run at 3 BAR (43.5 PSIG) like most injectors. The different injector flow rate will require reprogramming. The change in heads and base/runners will alter the VE, and require reprogramming. The cam change will alter VE and will require some reprogramming. Heck, the factory programming with all OEM equipment requires programming, since they are never optimal.

Sorry, I'm really only repeating what 92Blue has already stated. Doc has been telling you the same thing, and everyone else is adding good information. You CAN change if you prefer. You don't NEED to change, however.

 

awsome vader, thanks for that response. i still need to know though, whats the highest my compression can be if i'm running 93 octane pump gas. thanks so much everyone!