maf size and throttle body

grimreaper_72 · Mar 15, 2015

As in title How big can you go on stock injectors??

ttocs · Mar 15, 2015

not knowing the year of the car or what has been done to it that could not be any more of a loaded question. Welcome to the forum please include as much info on the car as to where it is today and where you want it to go in the future and we can help but until then I would recommend the silver TB, and my maf is black.

grimreaper_72 · Mar 15, 2015

My bad sorry about that has cai, long tube headers, x-pipe, dumps at axles, going to look tomorrow to see if I have pi intake swap or not but it's a 96 GT auto, not looking for crazy horse power just looking for as much without rebuilding

the5.ohh · Mar 17, 2015

Biggest throttlebody I'd do is 70mm. 75-76 if you were running boost.

chris91 · Mar 17, 2015

Stock MAF and if you plan on adding ported PI heads then go with a 75mm throttle body. That's what I'm running on mine and it runs killer.

DropTopPony · Mar 17, 2015

Yes no need to change your maf out and your stock injectors are good for almost any na bolt on you can add so start shopping.

ttocs · Mar 17, 2015

chris91 said:
Stock MAF and if you plan on adding ported PI heads then go with a 75mm throttle body. That's what I'm running on mine and it runs killer.

Just curious is the pi opening on the intake 75mm? I ask only because I was a little surpised to find out that the 94 95 cobra's upper intake is only 70mm even though 75 seems to be the go-to that everyone goes with

chris91 · Mar 17, 2015

Never measured mine as I went to a Dragon Plenum and it was 75mm.

ttocs · Mar 17, 2015

I was curious myself as I know everyeone seems to go for the 75 mm tb on the pushrods as well.

But thankfully on the pushrods that is not so hard to fix.

DropTopPony · Mar 17, 2015

You can port the stock 2V plenum also but an aftermarket isn't that much to buy so not worth the effort unless you have time to kill.

grimreaper_72 · Mar 17, 2015

any particular brand to stay away from or go to brand everyone uses I see them on the internet as low as $140

chris91 · Mar 17, 2015

Im using a ProProducts TB on mine and its been fine.

ttocs · Mar 17, 2015

From what I was told and remember you want to stay away from "weighted" mafs (I think that is the technical term) where they say the maf is calibrated to go with a higher injector size. These are just systems made to trick the computer to try and work with components that it doesn't think it is running. When asking about them when y car was on the dyno he said it was about the same as going on a diet by doing nothing different except weighing yourself on a different scale and HEY I LOST 20 LBS! Some of them do it electronically and others use a different tube that is inserted around the maf element. I am not saying that these are trash or will smoke your motor, just saying that its not the way it was designed to work and just not ideal. People use them obviously as the have been selling for years now but if you look at anyone that is trying to do a good solid build you will not see them.

I use a lightning 90 mm maf which is nice because its good for both suck through and blow through(boosted options) so its good if you add boost later and upgrade but you would need to get the car tuned just to run this maf at this point as well as if you go boosted.

As for tb's I think accufab is considered one of the best but you pay to play.

Michael Plummer · Mar 17, 2015

grimreaper_72 said:
As in title How big can you go on stock injectors??

You want to size your components (Air filter, MAF and throttle body) to the air flow needed to support your HP..... that's it.

Air filter: I like to use an air filter size that supports more than my desired air flow because once the filter gets dirty, the filter will supports less HP. So if you get an air filter that supports 350HP and when it's dirty, it should support my 250HP. I hope that makes sense.

MAF: Only need a MAF size and that's capable of supporting your air flow requirements. If you go to big, you won't have enough air flow at idle to get a good enough reading from your MAF meter and you will have idle issues.......This is important.

Throttle body: Same thing here, you just need something that's big enough to support your air flow needs. EXAMPLE: If you're making 270rwhp, there is no need for a 75mm throttle body when a stock or 65mm will do just fine.

I hope this helps
Michael Plummer