Wondering if anyone has dyno numbers on various mods. I've seen where ported intake without a tune will add 25-30HP, but I'm coming up empty on other mods.

Stock exh manifolds with cat delete?
Shorty headers with/without cats?
Long tube headers with/without cats?
Muffler delete?

I hear people talk about "full bolt on", but there's a lot of variance there. What have you done? How much RWHP are you making....dyno proven. Thinking ported intake plus some sort of exhaust mod should be worth about 300 rwhp, but which exhaust mods? I'd really prefer to retain the cats, or use aftermarket cats, if possible.


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'From what I've read'. Full bolt on mods will get you 280 something rwhp. When I first got my tune, the extra power was great . When I added my long tube headers with a shorty catted x pipe, the extra power was great. Just as much as the tune was. You aren't going to get much of anything from mufflers or catt back exhaust, although their web sites say they will add 15+ horsepower which is a lie .

I was on a quest of 300 rear wheel horsepower, isn't going to happen with what I have They are a few freak v6 Mustangs out there ( a little over 300 rwhp ) and you can be sure they run high 12 second quarter miles. I'm in the low 13's so I figure I'm in the 280 something rwhp

 

Seems like it's the death of the forums that makes this hard to find info about. This is the kind of info that should be in a sticky at the top of the page, but now most have moved to Facebook groups, and it all just gets lost.

Super Six claims 30HP from their ported upper and lower intakes at $500.00, which seems reasonable. Have to wonder how that would do with some exhaust improvements. Others claim only 10-15, so I guess that means Super Six knows something they don't about how to port manifolds.
http://www.supersixmotorsports.com/_...eManifolds.pdf

I'd like to see something documented on the exhaust side that yields similar gains in HP/$$$. If cats are a major restriction, maybe all that's needed is a cat delete, or aftermarket high flow cats? Long tubes obviously make some power, but $1000+ for 25HP is kind of nuts.


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Update for anyone following along.

I found this video showing about a 15HP gain through most of the curve with BBK shorty headers and factory cats.


So, the shortest legal route to 350HP (at the crank) seems to be ported intakes, and shorty headers. Long tubes seem to be worth an additional 5-7 HP at the peak. Mufflers aren't likely to have any real effect with the cats on, that's more of a sound preference I think. I suppose there may be an additional 50HP possible with ported heads, bigger cams, higher compression, but the HP/$ gets up there in a hurry with that stuff, to the point that some sort of boost makes a lot more sense.


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A few years ago K&N panel air filters claimed to add 5 to 7 rear horsepower. They had a dyno pull chart showing the extra horsepower done on every air filter sold for every car. Now they just say "add power" to you car . People have done their own dyno pull with the K&N panel air filter and have lost 2-3 rear horsepower . A dyno can be changed to favor what the company is selling I believe BBK shorty headers will add 15 horsepower but I don't believe you'll get 25-30 rear wheel horsepower with a ported intake. I would believe around 10 added RWHP. Like I said, a dyno can be changed to favor what they are trying to sell . If i ever went to a ported intake I would probably go with supersix but I don't believe their dyno numbers

Just my opinions and giving something to talk about on our dead Mustang Forums

I'm on 10 Mustang Forums and all of them are pretty much dead

 

This is my BBK shorty catted x pipe compared to the factory catts. I've read the factory catts flow great compared to several years ago. So if your thinking about adding shorty headers and changing to high flow catts, isn't going to be worth the money or time. Again, just my opinion

 

Well, I replied earlier but it's gone, so I'll try again.

The only dyno test for deleted cats on stock manifolds I've seen yielded 20HP in the middle of the curve, but they also did a tune on the same test, so hard to say which one made the difference. They also cut the dyno run short at 5000 rpm on the catted test, so we don't know what happened at higher rpms.

Same goes for that intake dyno test I posted. Only ran it to 5300 rpm, and the gains up high were only 10hp, but gains through most of the curve were 30hp. Shorty headers were the same way, bigger gains in the meat of the curve, with 5hp up high.

I'll take a 50hp gain through the meat of the curve all day over peak numbers. Everyone wants that peak number, but it's average power across the curve that matters.


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Your best bet on your quest to 300 rear wheel horsepower is, get the ported upper and lower intakes. Install shorty headers with the factory catts. Tuners can't turn off the rear 02 sensors anymore, it's against the law now, like they did for my long tube headers several years ago . Get a good tune, MPT or Bama are what most of us are using. All the tunes say they add 20-24 rwhp and I believe them. If you have 300 or a little more rwhp, you'll run high 12's in the quarter mile

 

yeah, I think that's about where it's at. Shorties with stock cats and ported intakes. Not too worried about the peak rwhp number at this point, just best bang for the buck, and I'm more into road race stuff, so that mid range power is where it's at for getting off the corners.


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The best mod I did was the Short Tube Headers. Years ago someone put a video up where there was 30 HP and 40 Foot pounds of torque at between 3000 and 3500 rpm.More HP and torque than what BBK had said where the 3.7 needs it most from 2000 RPM to about 4500 RPM.