Lose The Rear Cats, Lose Torque.

[300bhp/ton]

1. By removing exhaust restrictions YOU DO NOT LOOSE TORQUE. It simply moves the PEAK torque up the rpms.

Remember BHP is a calculation of torque x rpm/5252 So even if you torque number does not increase but moves 500rpm up the rev range it will INCREASE your BHP.

2. This whole thing doesn't add up. If it's bogging in 1st then it should in 2nd. It's the same engine going thru the same rev range isn't it.

In addition due to gearing you would not need as much torque in 1st as you do in 2nd becuase there is less load on the engine.

The engine will be (should be!) producing EXACTLY the same HP/Torque curves in every gear.

So if it has a lack of power in 1st gear only you have a different problem on your hands.

 

[jimfitzgerald]

Those of us who live in smog land have no choice. I had 6 cats on my car and I now have 2. They are hi-flows and still pass emissions. Big difference it made in performance. Pulls harder in the upper rpms and especially noticable in 3rd & 4th gear. Of course, if we didn't have to battle emissions (and the fine for no cats wasn't several thousand dollars) I would gladly swap to O/R X pipe.

We have emissions testing in Atlanta also, but they just check for codes. Just get an O/R X-pipe and keep your stock H-pipe with cats for the emissions test. By the way, the fine is a Federal EPA thing that we are all subject to. It doesn't matter what state you live in.

 

[timeless2]

By the way, the fine is a Federal EPA thing that we are all subject to. It doesn't matter what state you live in.

How could I be subject to a fine if my state doesn't have inspections? Are you referring to being pulled over for a noise violation, resulting in an inspection and subsequent fine?

 

[jimfitzgerald]

How could I be subject to a fine if my state doesn't have inspections? Are you referring to being pulled over for a noise violation, resulting in an inspection and subsequent fine?

It is a federal offense to remove working cats from your car. It's an EPA requirement subject to fines as much as $5,000. Has nothing to do with state inspections or noise.

 

[timeless2]

It is a federal offense to remove working cats from your car. It's an EPA requirement subject to fines as much as $5,000. Has nothing to do with state inspections or noise.

Interesting factoid. Where would one be subjected to scrutiny and result in such a fine without an inspection though? In other words, if no one looks/tests/inspects, how can a citation of any sort be served?

(I'm not ribbing, just trying to figure out how this is censured.)

 

[vld]

1. By removing exhaust restrictions YOU DO NOT LOOSE TORQUE. It simply moves the PEAK torque up the rpms.

Remember BHP is a calculation of torque x rpm/5252 So even if you torque number does not increase but moves 500rpm up the rev range it will INCREASE your BHP.

2. This whole thing doesn't add up. If it's bogging in 1st then it should in 2nd. It's the same engine going thru the same rev range isn't it.

In addition due to gearing you would not need as much torque in 1st as you do in 2nd becuase there is less load on the engine.

The engine will be (should be!) producing EXACTLY the same HP/Torque curves in every gear.

So if it has a lack of power in 1st gear only you have a different problem on your hands.

any ideas what that may be? it could be simply that I am not used to the driving dynamics of the car yet. my last mustang was a stock auto 95gt. she tore through first lost a little in second and went steady down hill from there. this one is the exact opposite. at least thats what it 'feels' like to me. have put her against anyone yet and dont have anykind of dyno #s. to my knowledge the only mods she has are kn fipk (with a clean filter and maf sensor) and the cats and mufflers. she sounds great, runs strong, just seems to me like she is sluggish in #1. any ideas what could cause that? i guess i am just over reacting, just want to make sure that my new baby is healthy. thanks for all the input yall.

 

[vld]

just realized i left out a vital bit of info: shes an auto

 

[jimfitzgerald]

Interesting factoid. Where would one be subjected to scrutiny and result in such a fine without an inspection though? In other words, if no one looks/tests/inspects, how can a citation of any sort be served?

(I'm not ribbing, just trying to figure out how this is censured.)

Who knows? If a tree falls in the forest and no one is there to hear it, does it make a sound? Maybe Homeland Security? Maybe your neighbor will turn you in. I'm just telling you what the law IS.

 

[BLUE03GT]

i believe diversity is an ooold wooden ship.....

 

[topless98gt]

Here's a test for everyone to try: remove your mid-pipe and your cat-back. Drive your car and see how sluggish it is.

 

[topless98gt]

just realized i left out a vital bit of info: shes an auto

Is it just slow when the A/C is on? Or off as well?

My car slows down a lot in first when the A/C is on. But after 2nd it is fine.

 

[vld]

A/C on or off makes little or no difference.

 

[vld]

if i get the chance tommorow i am going to try and find a nice empty straight and time my run through first. hardly scientific i know but i guess it is at least something that could be compared.

 

[vld]

roughly 5.5 to second gear. 6.5 to 60.

 

[40th GT]

roughly 5.5 to second gear. 6.5 to 60.

If you could, you should record yourself doing the run and it'll be easier to find out your 0-60 times by watching replays.

 

[Kilgore Trout]

 

[40th GT]

 

[Barrier]

A/C on or off makes little or no difference.

Umm... aside from being on the belt and thus making the crankshaft allocate power to turning it instead of the tires?

 

[Kilgore Trout]

At WOT the a/c is cut off automatically regardless.

Also, the a/c pully spins free when the a/c is turned off and the a/c clutch is disengaged.

 

[back_in_black]

1. By removing exhaust restrictions YOU DO NOT LOOSE TORQUE. It simply moves the PEAK torque up the rpms.

Remember BHP is a calculation of torque x rpm/5252 So even if you torque number does not increase but moves 500rpm up the rev range it will INCREASE your BHP.

2. This whole thing doesn't add up. If it's bogging in 1st then it should in 2nd. It's the same engine going thru the same rev range isn't it.

In addition due to gearing you would not need as much torque in 1st as you do in 2nd becuase there is less load on the engine.

The engine will be (should be!) producing EXACTLY the same HP/Torque curves in every gear.

So if it has a lack of power in 1st gear only you have a different problem on your hands.

I don't agree, no offense, but I felt a loss of low end torque with my butt o meter when I installed long tubes and a catted h pipe and I was told that when I installed my cams that I loss some low end torque and it was replaced up top, this was observed by my tuner that had performed a tune before and after the cam install and confirmed on the dyno. Scott winger who just had his 2001 cobra in mm/ff also saw on his dyno a gain in hp and tq when putting his cats back on.