Just bought a exhaust cutout recently, and its going on my car reguardless of if it makes a HP difference or not, but will I notice a difference at all? If so, will it be bottom end or all hwy where I notice it.. I tried to look up Dyno differences with open and closed cutouts but couldnt find exactly what I was looking for..

thanks
Kris

 

i noticed a better feel in power without one. It felt like i loss some bottom end torque with it open. I personally didnt like the cutout thats i why i eventually ditched it for a catback. The noise, drone, feel of losing some power all were drawbacks that eventually just got on my nerves.


I have no #'s to prove anything. Seat of the pants feel was more important then some dyno numbers

 

Mine lost a little torque down low but gained a substantial ammount of HP up top. My DMH cut out on the dyno put down 16rwh more with it opened on my AI 200cc heads and cam package. With a cam only I would think you should pick up anywhere from 5-10 ponies. A buddy of mine picked up 5rwh on his 94 M6 with just bolt-on's. In the end you will love it...if it's electric that is.

 

My car picked up 17rwhp with a cut out.

 

You will lose bottom end tq due to loss in backpressure, but you will pick up power in the big end.

With duals right behind the collectors my old LE2 package would pull hard up top. I just have a single in the I pipe now due to clearance issues.

 

It should be noted that you lose only a VERY SMALL amount of low end torque - hardly enough to notice. It's more of a psychological experience, louder exhaust feels slower.

 

Yes, you will gain power and torque with cutouts.
And all of those chiming in with that overused wornout wives tale of "losing torque because of reduced backpressure", go run the tests (intelligently....WITH DATA) for yourselves before regurgitating that crap.
All other factors being equal, reduced backpressure will ALWAYS result in more horsepower and torque.
The increased noise really plays tricks with people's "butt-o-meters" and brains, making them think that they're into the throttle more than they really are just because all that extra noise tells them it just has to be so!
There are other factors like collector length behind the headers that can enhance or reduce output, but again, all other things being equal, the less backpressure the better.
Even with a stock cam, depending on the flow quality of the catback, it's common to see 10 hp, reduced 60' times (that means more lowend torque for you nonbelievers ), and ET/mph improvement of 0.1 sec / 1 mph.

 

I gained 1rwhp on the dyno lol. Still my favorite mod.

 

I cant wait to get it on.. just to hear everyone say, "what did you do to your car?!" lol

thanks for all your .02

Kris

 

It will sound great with a cam

 

We normally see 5-10 rwhp. but there have been larger gains with catbacks that do not seem to flow well.

I gained nothing with mine on the dyno, but I do have a 4" catbacj & I kept it since it does sound wicked open

 

I think my cutout sounded better than my TDs. I kinda feel like getting a new CB with cut outs and dynoing it testing it at the track VS TDs back to back

 

I have an LS1 Magnaflow Catback on my car now... Idk if LS or LT catbacks flow differently..?

Kris

 

I made 9 more hp on the dyno with a magnaflow catback.

 

I got 5hp out of mine with full exhaust.

 

LT1's love cut-outs! More so than LS1's that's for sure. You will notice a slight decrease in low-end grunt but will see a decent gain on the top end. The best $50-$150 mod you can do to an LT1 IMHO.

 

Done...

 

If you put one on I would recommended a DMH Electric. Quality piece and has a lifetime warranty. Electric is the only way to go.

 

yes DMH is what we now use and we have had great luck with them

Magnaflow I will say gains in the 10rwhp range from our experience

 

I unbolted the cutout on my cammed lt1 today for the first time since I installed the cam and it made a noticible difference. I nticed more of a difference unbolting it with the cam than without.

BTW, I'm about to buy an electric valve for my cutout. Does anyone know if summit's electric valve is any good?