dancam

I just bought a 70 mm throttlebody with spacer, for my 90' 5.0. I currently have stock manifold on it and dont know if I need to port them to match. Does anyone know what the stock manifold port size is? Thanks

PRO50SC

Yes, you will. Honestly, you're not gonna see much out of the t/b on an all stock set up. What else is done to the car? Exhaust, gears? If not, that money spent would have been better served on items like those.

dancam

I will be installing bigger injectors , I have a 10psi vortech on it now .

dancam

I do have 3:73 gears and exhaust done to it.

PRO50SC

Oh OK. See it helps to know all the info when asking opinions. saves us time and trouble. What size injectors are you going up to and what mass air are you planning on running? I think the stock is 65mm.

dancam

I was going to go with 42lbs but now i'm leaning towards 30lbs. I was told that 30lbs are good up to 430 hp supercharged and 500+ nat. aspirated. Also the 30lbs are self tunable. Do you agree?

PRO50SC

To a point. I have 42's in mine. i had issues when running 30's. I had a custom multi tune chip burned and it pretty much solve my issues. (no need for an fmu either) Again, what mass air are you gonna run. I would recomend the p-mas 3" blow thru. Works great for me.

dancam

vortech recommends a recalibration kit for the fmu according to which injectors you run. So I'll try that with the new injectors / mass air meter/sensor and throttle body. Hopefully it will run alright!

rebel_yell

i just put a mac 70mm tb on my car with stock manifold I/H/E and i saw a big improvement in all ranges in torque and a medium gain of high rpm horsepower
i had a firend modify it to make it flow lust a bit better i have pics of it here. and i port match the manifold slightly but im working on gettign a new intake manifold so i didnt try so hard.

dancam

thanks i apreciate the info