40% is not correct... our trucks are around 20-25%.

A mustang dyno gives a very lower reading in hp compared to a dynojet. They are totally different dynos all together and give different readings.

I had my truck on a dynojet with just my magnaflow catback and put down 238hp. I cant wait to go back next week with my new xcal and electric fans.

With the factory rating of 300hp on my truck and my dyno pull of 238 I am right around 20% loss.... 20% of 300 being 60hp. I did have a exhaust so maybe that was giving me alot extra power... but I also have 13" wide 33's that where hanging off the rollers... so my tires are robbing some power.

 

i know how you feel, i have 38-15.5" tires and my truck is 9 feet tall i have trouble just finding a dyno shop that has a bay door big enough to get my truck threw the door, let alone wide enough for my tires, i have no idea how much power i am losing frome my tires

 

"a lot"


I've heard of people seeing ~30rwhp difference just dynoing on slicks with the pressure dropped vs. radials, high powered combo of course, but quite a difference just running different tires.


For those asking, the Mustang Dyno is a load bearing dyno and applies load against the vehicles attempt to accelerate. The Dynojet is an inertia dyno that simply has a weighted drum and measures how fast you accelerate it. Two very different approaches that give different results. The loaded method is much better for tuning, but most of the world has Dynojets so its hard to compare those numbers against others.

 

How accurate is the weight of your truck too that they entered at 5250 or are they just guessing?

Just wanting to know b/c I'm trying to track down a estimate on how much my truck weighs w/o having to drive to NPR to actually weigh it.

Also, was that tune on the 93 performance or not? 10 hp doesn't seem worth it. Would like to hear Mike's comments.

 

Its a mustang dyno....its useless. No really, they are useless. I wouldnt trust that dyno reading for a second. Go dyno on a dynojet for a real(accurate) reading. Ive dynoed on both and can testify the mustang dyno is junk, I mean who cares about speed of the vehicle. I want to know RPM. Also the fact that they said you have a "5.3" V8 should say something. Are we talking GM engine or the Ford 5.4 lol. I also done the 1/4mile run and it was about as inaccurate as I dont know what. The car ran 13.xx on the mustang dyno and 12.11 consistently. The stang dyno also said I put down 300hp/6xx trq, which I knew was BS because I had the car dynoed at 298hp/385trq 2 yrs before on a dynojet and since then I had replaced the heads/cam/intake/injectors/etc and ran well over a second and half quicker in the 1/4. Mustang dyno = junk.