You won't neccessarily even get the 10hp they claim from each. Those numbers are usually "up to" 10hp. That means that say you buy a tuner chip, your computer might already be tuned better than someone elses, because of difference in elavation, type of gas, etc. And add intake, same thing, maybe your car already was breathing fairly good, you might get 5hp from that. Exhaust, maybe you get 12. Those numbers arent going to be exact they are just examples. I would be guessing you will get less than A+B+C+D.

EDIT: Those numbers are usually best case scenarios, to make their product look better.

 

I think he's just using those numbers to make it easier, theoretically speaking, lol...

Anyways, I would have to agree with you Mr. Jack the Ripper. For instance I have full exhaust set up with LT's. I've been told many times, especially by my tuner that a 75 mm Tb/Plenum would be a great addition with my good flowing exhaust. Theoretically because of this I may get 10HP from the combo.

If I had stock exhaust set up and added the TB/Plenem I would get only 7HP theoretically.

 

I guess it would depend on what bolt-ons too... do they complement each other? If they are all for more fuel, and exhaust isn't free flowing enough... or if they are all for air, but not enough fuel can get into the engine, etc.

 

yeah, each depends on the other.

example: having a tb/plenum but stock air intake will actually hurt you hp-wise(I read that somewhere)

tuning a stock GT wont do much, whereas tuning one with intake, headers, and exhaust will yield bigger gains.

 

Well it's like most have already said. You will never get the manufactors avd hp from a bolt-on. I run a small perf shop and have a great sunhp3500d dyno. After every bolt-on I.ve been able to pull a run. I've seen anywhere from great to not worth the $ from many parts. My 04 gt runs just @ 303 to the rear with the basics and 93 pump gas. Thats around 340-350 @ the fly. My 99, with a KenneBell 2.2, runs 472 @ the tail.It's more important to ad bolt-ons that work together. Most #'s are @ peak rpm any way and will not give you say 10 hp from idle to 5500. You may not get any until 5000rpm. From my playing around, X-pipe with catback is good for around 12-18hp not the 20-30 most venders will try to sell you on.(slp has been the higher thus far, and no I'm not an SLP dealer...yet) Anyway I could list bolt-ons and hp numbers all day, the trick is to use your head, an engine is an airpump, move more air in and get it out generaly will make more power. Timing is great for any MOD motor(10-14deg).

 

exactly what he said about the air thing.. if you do full exhaust and you have more air flowing out of your engine you would want to do the mods to get more air in. You don't want to bottleneck it anywhere.. for example if you got some sweet cams that really helped to move the air in and out of your engine.. you don't want it to take forever to get the air through your intake and you don't want it to get hung up in your exhaust forever. that's why with mods like that they say you'll see a bigger increase in power with exhaust/intake. same for superchargers.

 

The answer to your question lies in actual dyno results. Take a mustang that had 230 rwhp stock and add the following mods:

UDPs, X pipe, Catback, Headers, CIA, TB, and Plenum.

You will expect to see about 255 - 266 rwhp. So, no, they really do not add up.

 

Yeah, I think you hit the nail on the head. Even with Cam's added to your list it's still probably not going to get you to 300rwhp, but closer. Now if your blown with all of those boltons you probably will get the advertised hp out of them.

 

Now that sounds like a good plan

 

You will hit a deadend with bolt-ons. Around 300hp @ the rear is a good goal. Heads, cams can and have added another 30-50hp. Strocker motors and custom cam grinds are where the big power is without and NOS or huffers. I have an 03 in my shop, stock shortblock Pat stage two heads, custom cams(crane) and the norm bolt-ons and makes over345@ the rear, still runs alittle lean in the upper rpm however...my work is never done.

 

IMO there are 4 things a mustang owner should get(in this order)

1. exhaust... for the sound

2. gears... for the acceleration

3. LT's... for the power to compliment the exhaust

4. supercharger...nuff said


getting pullies, tb/plenum/spacers, CAI, are ok for 5 hp here and there, but the first 3 are things you WILL notice gains from and the 4th is a no-brainer