kawiguy827

Hey all,

So i'm entertaining the idea of doing an exhaust. The car sounds great, but it is lacking, and i'm having trouble deciding.

I've been looking at the Ford racing by Borla (either S-type or Touring, not there yet) or the MBRP Street exhaust. The reason i'm looking at MBRP is because it's a really good price point (roughly 50% less than the Borla). The issue is that the MBRP is a full 3" system with 4.5" exits, as compared to the borla's 2.5" system with only 3" exits.

I understand, that basic mechanics teach us that the 3" system will reduce backpressure and result in a loss of top end power. The question is, will i be able to notice the loss? Furthermore, will an intake along with the exhaust cure part of the problem? Lastly, will the computer need to be retuned?

I appreciate the help, everyone. Also, if there are things i haven't thought of, please let me know. I want to make the most informed emotional decision i can.

jz78817

you think giving the engine more air flow when it needs it will reduce power?

bluebeastsrt

If you want to purchase the 2.5 inch exhaust because it's a lot cheaper that's a very valid reason. Everyone has a budget. But the 3 inch exhaust will most likely benefit performance. not hurt it.

kawiguy827

Ordinarily, i'd believe that anything that allows air to move more freely would equal more power. However, i have also been told that reduced back pressure inhibits top end performance. Is this incorrect? If it is indeed faulty information, than my decision is close to made.

COMPORNG_15

I disagree with this, without the proper build 3" exhaust is unneeded as the amount of exhaust is already based on the size of your manifold ports. In my experience in the Lightning community in which I had a 700hp whippled lightning, even that was not enough power to warrant a 3" exhaust. I ran a 2.5 on it and it was perfect. too big of exhaust will make more noise but not more power.

with that in mind I am looking at the MBRP race version for my car as it is nice setup and sounds great plus it is very reasonable price wise. my only downfall with it is the fact that they do not make a 2.5" version and only available in 3"

my thinking is unless you are upwards of 750-800 wheel hp 3" exhaust is just for bragging rights.

COMPORNG_15

also, I do believe the loss will be marginal in comparison as the car is still stock and the factory computer parameters should be able to adjust just fine without a tune being needed to update the fuel trims and such.

bluebeastsrt

Exactly there will be no loss of power and the exhaust is now set up for what ever power you intend to throw at it in the future. I believe if your going to mod. Do it once and make it correct for what every you decide to throw at it in the future. I've seen it countless times. People spend money on simple mods to only spend more money down the road when they have outgrown the first round of mods! I understand not everyone builds a low 9 second car like the one in my sig but it doesn't hurt to be prepared.

whatsup62

First off you are incorrect on power loss of larger diameter pipe. It does affect where the power is made. Assuming you have the motor to handle it....and you do...Larger pipe will decrease some bottom end but gain at higher rpms. I went to the MBRP street 3" and noticed no loss of anything. I put some long tubes on and now it is a beast...plus the sound is incredible!!!!! No worries...get r done!

howarmat

I actually think you notice the loss of torque in the low end over the HP.

bluebeastsrt

Your not going to notice 10 pounds of torque lost in the low end any more than you'll notice 10WHP gained on the top end. At least no in a car that's 400 Ft pounds to start.