[40thmustanggt]

ive posted this before and ive read alot of post with this but this is what i want to know before i go ahead and order it.. accufab 70mm and 75mm some say if you stay n/a go with 70mm and others say go ahead and get the 75mm it wont hurt you.. but will i see any gains with a 75mm??..

im not planning on s/c or t/c my car but i do plan on heads and cams so what would be the best for me 70mm or 75mm?? i want whats going to give me the most hp for my money.. and heads and cams wont be here for another year...

[06RedfireGT]

75mm.

Almost everybody runs that size whether the are n/a or fi.

[gsjohnson]

I too have pondered that one and have read quite a bit of data (flow charts & dyno sheets) as of late. It appears with the 5.0s there were big gains when jumping from 70 mm to 75 mm T/Bs. I think this same thought process transended to the 4.6s when they came out. But when looking at real numbers, the gains are minimal between the two. I even question whether there are any signifcant gains when utilizing a blower. I think it's a safe statement, "That it won't hurt you". I'm far from an expert...Just been reading & talking to a few so called experts. But are there any gains? I think minimal at best. Just my .02

[40thmustanggt]

no more info then this??? come on guys tell me what you think is better..

[2kGT]

Get the 75.......go look at the accufab website - they show the numbers with various combinations of sizes and brands of tb's and plenums. Even stock the 75 does better than the 70.

[gsjohnson]

I looked at that chart as well, and there is no question that Accufab shows the better gains than the others. But if you drill down a little deeper, the 5.0s were gaining 120 to 135 CFMs from the 70 mm to 75 mm T/Bs. When comparing the 4.6 2V T/B flow numbers, the gains were 3 to 50 CFMs. And in some cases there were no gains depending on the Plenum. Good chart though when trying to decide the plenum T/B combo. I talked to John Mihovetz last weekend about this vary subject, so some of what I stated was regurgitated from him. One of the buildings he rents is in the same complex as the shop that I and a couple of friends rent for our projects. One of my so called experts I spoke with. Good guy.