About Exhaust...or lack there of

**BashamWS6** · 12-19-2010, 08:20 PM

ok so me and a few of my friends are having a little argument..and i figure you guys know best.

they say if you take the exhaust off (example cut it mid y-pipe or just dump it after the stock cats) that it will mess up your engine unless you get a tune

i sided with that it doesnt because some people dont even run a tune after exhaust mods...

am i wrong?

**Mr. Luos** · 12-19-2010, 08:41 PM

Not wrong.
And certainly isn't 'messing up the engine.'

Probably not making anymore power that way, but not breaking/hurting anything.

**BashamWS6** · 12-19-2010, 08:51 PM

^^^
thats what i said
i told them that the only reason for a tune is to maximize the gains of the exhaust
which...frost offers a damn good price nonetheless...

**Davey G** · 12-20-2010, 12:19 PM

if you loose anything it will be a little low end torque by not having a lot of back pressure

**Sarge** · 12-20-2010, 12:28 PM

DaveyG is right on the money. Back pressure = Torque.

**9T8W66** · 12-20-2010, 05:18 PM

Originally Posted by Davey G

if you loose anything it will be a little low end torque by not having a lot of back pressure

Originally Posted by Sarge

DaveyG is right on the money. Back pressure = Torque.

These guys are correct.
I had some personal experience with my old Pontiac 400.
It always seemed to have header leaks at the flange (until I finally solved it). When it did leak you could feel a noticeable difference in torque output from the engine.

**BashamWS6** · 12-20-2010, 05:22 PM

So how do Kooks 1 7/8 LTs 3" ORY and SLP LMII do in terms of torque?
I mean i figure that a dyno would be needed to exacts...but shouldnt it go up?

**Demon_Z28** · 12-20-2010, 06:11 PM

Originally Posted by BashamWS6

So how do Kooks 1 7/8 LTs 3" ORY and SLP LMII do in terms of torque?
I mean i figure that a dyno would be needed to exacts...but shouldnt it go up?

yes you total torque gains will be up in the higher rpms, regardless of losing a little bit of low end off the hit in the power band you will pick up hp and torque in the power band. I have seen this first hand from being stock to full exhaust on the same dyno and picked up more torque a little later in the power band. so the power curve isn't as strong off the hit but it does gain torque.

**35th-ANV-SS** · 12-21-2010, 07:37 AM

Originally Posted by BashamWS6

So how do Kooks 1 7/8 LTs 3" ORY and SLP LMII do in terms of torque?
I mean i figure that a dyno would be needed to exacts...but shouldnt it go up?

That exact set-up is the only power mod I have on my car other than a lid. I'm a M6.

I DYNO'd 330rwhp/342rwtq through a 9" rear end, which is the least efficient rear end there is...so I know I left some on the table.

Those numbers were from a Mustang Dyno too. A DYNOJET would have read higher.

I didn't get a baseline run in with the car stock, but I would assume I gained close to 35/40 from other numbers I've seen on stock cars.

The important thing is that you have a car that is running properly. Don't get caught up in the numbers.