I'm coming from the G8 forums, where everyone is talking about adding an CAI and exhaust with a engine tune to the L76 and saying that they will be getting 50 rwhp from just that.

I'm not a terribly experienced engines guy, in fact my work with them has always been limited to outside the engine. But in my experience, adding a Cold Air Intake does little to nothing for an engine. In example, I once assisted a neighbor in adding an AEM Brute Force Intake to his LQ9 Silverado SS. He later dynoed it, and gained absolutely nothing at the wheels compared to his first dyno with the stock airbox.

Encouraged by the people at the dyno shop, he later added a cat-back exhaust and headers, at which point the dyno showed a whopping 4 hp increase over stock.

And in numerous other cars I've seen the same results. In a 98 Grand Prix we added a CAI, headers, exhaust, and aftermarket MAF sensor. We did not have a dyno to use on it, but instead we recorded quarter mile times down an usually empty stretch of backroads. Before and after the results were the same.

So I'm of the crowd that says external bolt ons do not add performance to engines. Sure, shops and suppliers will be glad to tell you they do, but I've never seen a benefit. The greatest increase I've ever seen on simple headers/cat-back-exhaust/CAI and no internal work was 14 hp, and it was on a 1993 Nissan 240SX.

I've always thought the reason behind it was because of the catalytic converter: its a bottleneck for the whole system. Without modifications to it, doing anything to the rest of the plumbing is worthless.

But G8Boards seems to believe quite handily in after-market air boxes and cat-back exhausts. Are they worth it at all? I got one person who responded that due to displacement and reduced NVH that on LS engines it would give better power, but I find that quite hard to believe. The stock air box and exhaust are tuned to work optimally with the cats and engine, not restrict the flow, and I know the history of the LS, but that history does not make it more prone to increases off of bolt ons than any other engine.

 

V8s love to breathe .
I can tell you first hand on my 00 TA the first time I took it to a dyno a few years back it only had a SLP air lid , a ported throttle body and a set of Mac mid headers duals dumped before the rear .
First pull 340 rwhp second pull 348rwhp and 355 on the torque all with a LS1 intake . No jive even posted it up in the dyno though not sure what happened to my pic .
https://ls1tech.com/forums/showthrea...t=#post2747111
It also had a smooth bellow and throttle body bypass done to it . I had some tuning done after the dyno since it was running lean then .

 

I've heard the new computers pull so much timing for little bullshit things, like intake temp being a little too high or something.

A tune will net you the most power out of everything you listed.

From the factory, lots of cars' PE ratios are too high, dump too much fuel at WOT, slowing the car down from its potential.

EDIT- LOL! the stock air box is designed to be quiet and not rattle, nothing more. It has nothing to do with moving air efficiently. Look at a factory air box for an f-body. They have the huge baffle things on either side of the pipe, which disrupts airflow so there isn't a "WOOSH" sound when the car is idling. CAIs are less about actual cold air as much as they are about straightening out the airflow, so it flows smoothly into the engine.

 

i wouldn't say bolt ons are great for all cars, but lsx's for sure. My ta went from a lid and running 13.6, to after longtubes, exhuast, gear, intake mani, tb maf to running 12.7's with traction problems. With a better tire, i feel my car definatly has a low 12 in it, and definatly had the mph for it. My mph went up almost 7mph from bolt ons. The best things about bolts ons is the more you do the better they work together. If you add a cam or heads, the bigger intake and better flowing exhuast will only work that much better. Is a cai on a civic going to make the 15-20rwhp that they claim, no....


Chris

 

My 01SS M6 ran 13.6 @ 104mph completly stock w/ 500miles on it, with a few bolt ons see sig, less than $1000. in mods. I have run numerous mid 12's.

 

yea you have to have a bigger engine to see gains with bolt ons.

one of my friends has a focus that he's put pretty much every bolt on in the book on down to the head, and is now thinking about cams, and he's only putting out about 20rwhp over stock. the cams he is getting are only about a 20rwhp upgrade too, and they're fairly aggressive (think 224-228).

 

you have probably gotten better at driving too

 

R whp from a focus

 

LOL maybe its the infamous V8 swapped focus that runs 13's ...

well i guess in his defense... 20 Whp means more in a 2000 lb car then a 3500 lb car... but still... i wouldnt want to be there...

as far as "bolt-ons" go ... i feel there worth it, and if you plan to do much of ne thing ie, cam, cam and heads, blower, etc the bolts ons turn into "supporting mods" and allow you do take full adantage of your setup.

 

Lg motorsports just did a headers, high flow cats and aftermarket mufflers on a 07 vette and it gained 29 rwhp. The car also showed a good increase in torque as well so for 1495 that is a good deal in my book. They showed before and after dyno. I think it was sep vette magazine. Def worth the bolt on in this case. I agree, the bigger the motor and the better it breathes, the more real hp will be gained by bolt ons.