teslafan

At what point does the factory intake and exhaust become a restriction?

BadCon

That's a hard question to answer as there are many variables, but the stock stuff will be plenty for bolt-on power levels with a tune. The truck intake manifold is geared towards torque and people have reported good gains with the mustang manifold and a tune that revs out past 7000rpm, but that is still utilizing the stock cold air intake.

The stock exhaust is not ideal for big power levels but is plenty for bolt on levels, and there are guys like me putting out over 600hp through basically stock exhaust. If you compare the advertised power differences between the Mustang Roush supercharger kits and the F150 Roush supercharger kits, you'll get a good idea for how much power is being eaten by the stock exhaust. For reference, the Mustang 5.0's come with a better exhaust manifold and true dual exhaust that's about 2.75" give or take all the way back, while the trucks get log style manifolds and a single 2.75" system (give or take) all the way back. The Roush stage 1 kits for the 2018 F150 and Mustang are advertised as 650hp and 700hp respectively, so a ROUGH estimate is about 50hp or so lost in the exhaust between the two platforms as the intakes should be very similar.

That's a rough estimate, as there are tuning differences, cam differences, and more driveline loss on the F150's as the wheels and tires are bigger, etc.

teslafan

Thanks.... I'm thinking of getting a tune for this truck and was trying to decide if it would be worthwhile to add cold air and exhaust. I am mainly interested in cleaning up throttle response and shifting strategies. I really don't like the throttle lag at all and any more horsepower I can gain through a tune would be great. It would be nice to remove speed limiter as well. If the gains of cold air and exhaust are not there then I'd rather leave it as factory as possible. I feel like there are a lot of high paid engineers designing this truck and only want to change things if there is a definite gain in doing so.

TX-Ripper

BadCon

As for the speed limiter, there are other factors at play that determine what a vehicles speed is limited too, including tire ratings, driveshaft ratings, and even emissions catalyst temperature limits. So before you go removing the speed limiter, make sure the tires are up to the task, and understand that every mile per hour above the limiter you go, you are that much closer to the unknown number at which the driveshaft will grenade. Be safe!

UNBROKEN

iTrader: (1)

teslafan

I'll have the tires covered not sure about the driveshaft. What are the rpm limits on that? I have 3.31 gear and I'm going to stay with as close to the same tire diameter as stock.

BadCon

Your guess is as good as anyones lol, as it is not clearly defined. It doesn't help that there are several driveshaft configurations based on 4x4 and chassis length. I'm a regular cab shortbed with 4x4, so I have a single piece steel driveshaft, and it was spun to 150mph on a chassis dyno and didn't explode, but that is not real world loads either so who knows (that's a little over 6000rpm shaft speed with 3.73 gears). I've personally limited myself to about 120mph, which is all I need to complete the 1/4th mile. Eventually I'll get a nice shaft built, but until then no high speed runs for me.