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mrbob909
12-26-2005, 03:46 PM
Hey im new to these forums, but i couldnt get on tweecer's forums so im trying this out. I've got a 95 gt auto with an e-303, 70mm throttle body, edelbrock intake, headers, offroad pipe, shift kit, k&n cai.

I just bought a base tweecer, and im thinking i should have gone with the RT but i can still upgrade, so i may do that in a couple weeks when they are back in stock, what would you ghuys suggest for tuning. It runs really rich on the bottom end and i believe i am maxing out my injectors on the top end, i have the stock 19 lb injectors.

I know a guy who runs a race shop that has a dyno, he said i could use it for and hour for 80 bucks.

My real question is if i can change the injectors without changing the maf?
Ive been reading on forums you can change the maf table and such, where would i be able to find a chart for injectors, im looking at 30 lb injectors, because i think im going to go for heads/nitrous in the future. My friend has a scanner tool and he hooked it up to the car b4 i got the throttle body and said the maf was maxing out at WOT near 5k rpms....
The car feels like its leaning out up top... it pulls hard to 4500 and then just starts loosing power.... I know my cam is good past 4500....

Any input is really appreciated, thank you

Steve

QWKSNKE
12-26-2005, 04:08 PM
So you are still using a stock MAF?

To answer your question, if you truly are pegging the MAF at 5k rpm then changing the injectors will not help you. The MAF will still max out with 30's at the same rpm. Only a MAF change will fix that. Changing the MAF curve in the EEC will not fix it either.

With that being said............

With the mods you have listed, you should not need injectors yet. Actually I am surprised you are maxing out the MAF. BUT I am sure you could benefit from an aftermarket MAF

mrbob909
12-26-2005, 04:18 PM
I was just hoping you could change the chart for the voltage-air flow rate. Just really didnt wanna spend $250 on a new maf if i didnt have to ya know:)

QWKSNKE
12-26-2005, 05:35 PM
I was just hoping you could change the chart for the voltage-air flow rate. Just really didnt wanna spend $250 on a new maf if i didnt have to ya know:)


I understand. It is odd to me that you are maxing out the stock 70mm MAF already though. Hopefully Dale or Italian LX will come in and chime some more on this.

mrbob909
12-26-2005, 08:28 PM
See ive always heard that 19# injectors are fine until you have heads.

I just couldnt really believe that. 19# injectors are good to 300 hp at the crank, and you figure the car is supposed to come with like 200 at the wheels, and with all those mods i figured i would have hit it by now, which i obviously have lol..:)

Dale McPeters
12-26-2005, 08:56 PM
You need to find out what the MAF voltage is at the 4500rpm point as I do not think that you are maxing out that MAF yet. Unless it is a large cubic inch
stroker motor, which you did not state above.

It sounds to me like your load calculations are off after all of the modifications that you have done to the engine. Note this is just a guess on
my part as I have no datalog to look at.......

Like I stated above I would find a way to check the MAF voltage output
at 4500rpm either with a digital volt meter or some other means to make
sure what the actual MAF voltage is at that rpm. That will help decide if a
MAF/Injector change is in order. Or possibly a MAFia.......

joker
12-26-2005, 11:01 PM
I have no idea about the maf crap, but I would personally just go with 24 lb injectors. They will be fine with your current mods plus heads. Unless you are planning on running a dry nitrous kit (which 90% of the people I have seen run wet kits) then a nitrous kit has no effect on your choice of injector size due to the fact that the fuel is supplied through a seperate solenoid instead of depending on the fuel system to add it through the injectors.

I believe italian once explained why is is actually best to go with the smallest injectors you can use for your power level due to the fact that when you change injectors it changes the spray pattern as well, thus effecting everday driveability, or maybe it was it effected the idle.