OK so I received a PM from a "somebody" and I guess to prove a point, I'd like to see a little discussion here:

So I reply and let this "somebody" know that my setup is about as good as it'll go since there's no car I know running my equivalent cam (NA, stock 853 heads, TR230/224 568/573) that's bumpin any more than slightly over 400 rwhp. But he seems to think I have more left in my motor and that a cutout will get me there (like ~40 horses more )

So then, after trying to explain that it's not gonna happen, I get this response:

My point in posting this is not to "flame" this guy, but more for educational purposes. The NA graph (small) shows a 37 hp gain, and peaks at 400. Now wouldn't folks agree, and cammed LS1 that's making 363 has got some RESTRICTIVE *** exhaust, in order to gain that much from opening cutouts?

Hell, I made 362/368 with cats during my full bolt-on phase. But I certainly will not gain ~40 horses if I do a cutout right? My argument to this gentleman was that cutouts or catback, it won't matter, for an NA 346 LS1 it's gonna all be in the same ballpark.

 

On cars with restrictive exhaust systems, I have seen some impressive gains with open vs. closed cutouts (though never 40 rwhp). However, if you have a free-flowing exhaust system, the gains are minimal.

For example, my Corvette exhaust system consists of long tube headers, no cats, an x-pipe, QTEC electric cutouts, and a pair of very efficient MagnaFlow mufflers. In numerous dyno sessions, we have never seen more than a 1-2 rwhp gain and no change in the torque numbers between my dual electric cutouts being open vs. closed.

 

40 horses on top of your setup? I think you're just about one of the better TR 230 cars out there, just by looking at your dyno...

 

I saw with my own two eyes "Jlaw's" car off this board gain like 20rwhp over a Y pipe thru a bullet dumped at the rear when he opened up his dual cutouts. That really impressed me... but that was on a H/C car. Maybe you can PM him and he'll have the exact numbers for you.

 

Hmmm... I don't where to go with this...

It is hard to standardize a "for sure" formula, when these cars (LS1s) can perform so differently to the same mods...

I removed my cats (obviously not as good as doing cut-outs) and got 1rwhp and 1.8rwtq. Needless to say I put them back on and I still hit 450rwhp (SAE).

For me running with cats is no loss…

 

you know,no matter what you do,there's always somebody that says they know so and so that did better or their car did better or whatever.i know a mustang guy who thinks he knows more about my car than me.told me i would gain 30hp with a flowmaster muffler on stock manifolds. you have a stout combo,the 115mph trap speed impresses me more than the dyno sheet.

 

Dang man, you know my first p.m. was just questioning you if you had tried it. Obviously, you took my p.m.s the wrong way.

I know your not going to pull 40rwhp with cut-outs. The dyno and profile specs I sent you were used with cut-outs Or thru his y pipe/flowmaster catback. Definetly, this is where the gain was.

Dual exhaust can show a decent gain. I'm sure you have seen the comparo's in the external section.

Yes, I was impressed with your dyno of the TR230/224. A very strong torque curve for that profile. One that isn't seen as much with that grind.... From what I have seen. You made like 350 @ 3000 I think it was? Searched thru your website and noticed you did this with a y pipe and a cat-back. So, I continued thinking, "Damn, what would happen thru dual exhaust/cut-outs?" I did mention in a p.m. I sent you, "What will happen, anything or nothing", so I'm not the idiot you make me out to be. Your gain; if any, would depend on your exhaust lay out. You mentioned that the Borla I?... Is a cut-out? Didn't know that.

Actually, here is the last p.m. I sent you. You can see, I'm not totally optimistic and think you will gain 40rwhp.

Your last p.m. was more reasonable and you actually treated me like a human so I thought we were straight. I was going to send you a p.m. to clear the air because it seemed this was just a misunderstanding. In no way, was I trying to tell you what to do. After reading 66deuce's post, I can see where it might of seemed like those were my intentions. No way!

No big deal. I was definetly being a bit giddy and over exaggerated the gains you might see. I didn't expect the p.m.s you sent me however or I'd just asked, if you had tried a different exhaust routing. It's my mistake.

Kyle

 

Interesting, but this discussion is about the performance value of cutouts, not cats.

 

I talk from personal experience here.

I gained over 13rwhp at peak with dual electric cut outs and over 35rwhp and 37rwtq in some areas bellow the curve. I had cats and a hooker aeromax muffler and gained a lot of power.

It may not have shown your 40rwhp at peak, but my numbers under the curve sure speak loud and clear.

My set up was
01 SS M6
Lid
Filter
FTRA
TR236 cam
Pacesetter headers
Dual QTP cut outs



Also in a week or so, you will see another dyno from a buddy of mine. He is using a Y-pipe similar to my old set up. But his car is a little more radical than mine was (depending how you lok at it)

G1 cam
MTI stage 2 heads
QTP 1 7/8 headers with HVMC's

This runs in to dual cut outs before the cats again.

 

Very decent gains LIL SS.

I'd like to hear of a reverse patterned profile that has not shown gains by swapping his/her restrictive exhaust for something efficient. On stock heads of course w/ full bolt ons. This may not hold true with ported heads where the flow ratio has changed.

What would be interesting is take a large, exhaust bias profile with 3'' duals. Dyno it. Replace it with 2'' duals. Would you gain area under the curve? Well, if not the exhaust bias profile was more than likely needed to support the setup.

 

Going from what I have seen, read and heard the reverse split duration cams need the best exhaust possible to get the best results.
I am going to say that the gain from adding a dual cutout could go anywhere from little gain to 30+HP gain. It is all about the current exhaust combo used.
Cutout's work great on cams like the 230/224 cam. Now if you have a true dual setup that dumps before the back tires and is designed correctly you gain will be VEry little if any at all.
Look at the cheater cam thunder came out with.
It was designed for those using stock exhaust. Te cheater cam, LS1 cam, Z06 cam, LS2 cam are all very similar with the hugh split in duration. That is the same thing thunder did. Now when you have a cam that is backwards to these cams about you need the best flowing exhaust possible.
With you setup there is probaly some power to be gained.
10HP maybe at best, but for 250 dollars I would give it a try.

 

Obviously, you did not see the part about..

Please take a chill pill... we don't need forum police...

 

Yeah exhaust can be a gray area sometimes. I've seen first hand cars actually lose power with cutouts. I don't think I've ever seen an LS1 lose power... the car I saw was an LT1 F-body with heads/cam. It literally lost 20rwhp... probably a velocity issue. But yeah, exhaust is fun

 

that was before cats and an alumy flywheel... best trap back then was 116, so I'm thinking a little more with the current setup.

 

OK, good discussion people. Here's my final point:

Looking at MY setup, cutouts vs duals vs catback probably won't do didly bit of difference for considering that for a TR 230 cam only car, I'm not leaving a whole lot out. I agree that cars who have more in their setups can gain from exhaust mods, especially if their exhaust is restrictive.

But you MUST understand that the gain doesn't come from just the cutout/s alone. The gain is from the cutout allowing other mods (headers, cam, intake, etc) to realize the most absolute power they can make.

Sportside: Again, wasn't trying to flame you, but when you come to me with the idea of me gaining ~40 horses on top of my already well flowing, near max power setup, from just adding cutouts, i gotta set things straight. Educational purposes here only.

 

Umm........

1. The mere mention of cats doesn't change the topic which is the effectiveness or lack thereof in the use of cutouts. Try rereading the thread.

2. I put a smiley face after my comment, indicating it as a "tease," but apparently your understanding of intent is no better than your reading comprehension.

Have a nice day.

 

Dude must you always police everyone’s threads... you are retired... take the badge off.. put the gun away.. and relax....

 

Sidestep, is this with the current combination? I think I remember you doing some changing of parts. Thanks.

 

 

I just hate it when people tell me how to make MY car faster by doing stuff thats already done, and when I tell them that they say I have it set up wrong. Then they dont belive I trapped 119 with the mods I do have.