I see a lot of guys here talking about bolt-on HPs and torque... I recently did some reading and found out the truth differs from what a lot of people think. Ok, ok...I am no expert in technical field, but those guys who publish articles and books cannot be too far from being right.
Here's a general idea: when you are thinking about changing your header, intake, muffler, cat-back, cat, or even any exhuast parts from stock, it doesn't necessarily guarantee that you will gain any horse power by replacing an aftermarket part for stock/OEM. Why? Hard to say, but a lot of factors come into the scene... like the flange, the diameter of the pipe, the design of float... etc. It all depends on how fine the parts combination work together as a whole.
For example, say you have stock header, cat, b-pipe, and the only thing you wanna get is a decent muffler that attracts attention. So you went ahead and bought a muffler with a 115mm tip. Now that the tip is so big you have to gas so hard to get to the speed you used to get up to, and you look at your gauge...hm... 5000 rpm...and you smile because you are happy with the power you've gained. NAH... the fact that the tip is too big and gives you no force feedback is like u trying to blow a balloon about the same size as yourself... tiring isn't it. You've got to give it all out before you can feel the difference.
Another good example is to refer to the June 2002 issue of the Sport Compact Car magazine. Road tests for RSX with different brands of exhuast pipes. I think the charts will help you analyze that bolt-on powers really vary in numerous ways.
Basically you don't gain much from bolt-on's, sometimes even a loss of power. It also vary from high-end power and low-end or even mid-range. Putting on a big muffler, again, may give more torque in high rpm but not necessarily more HP. The power you've lost from lower rpm's probably can't be made up by hitting high rpm's all the time. Sometimes the trick comes in re-adjusting torque/HP in different gear/rpm, you see the numbers move around, the there's probably hardly any HP's gained, or none.
Now I kind of regret getting an SS header, intake, and the muffler. I mean, I think a generic AEM style intake does just about the same as the real AEM CAI. As far as design, filter, weight...can't tell a difference other than what's printed on the pipe. The only reason is that they are brand names and they pay to start the product design in market, research, and pass the carb test...etc. I was glad that I got mine for $35 shipped instead of like $180. Maybe the best bang on the buck so far on my car... but I don't think I am juicing anything extra outta my engine...say...the most 5 HP? I am prolly over estimating

but oh well... it's getting late 'n I dont' know what I am talking about anymore... but I hope you guys get the idea... . Maybe somebody here can explain better than me. I have an auto maybe that makes less of everything I am talking about here... Oh well, it's an Accord, a stylish family car w/ nice ride. Data's how it got its name recognized, not meant for race anyway. I would go w/ civic/tag for race. Anyhow, correct me/re-phrase for me if you would... sorry for the long post...'n I just hope the newbies don't make the same mistake as I did back then, thinking I would gain a 50 HP easy by putting on these parts. Good luck everyone!!

 

i completely agree with you

How much HP you gain depends on what kind of bolt-on part you use. Everything is different.

Can anybody give me an esitimate on how much HP and Torque that I MIGHT have gained from a Injen CAI and a Greddy EVO Catback?

 

ok cliff notes will be good.

 

hmm if i wanted to go race i wouldnt go for a civic...

u'd prolly spend as much if not more money and time on a stock civic to get it going fast as compared to an accord. may be a hatch or a crx cuz its light, but thats about it...even though there may be more aftermarket for the b-series motors, your still gunna hafta do a swap/FI/SC/n20 to go fast.

as for the basic bolt-ons, they let the car 'breathe' better and free up some horses that are lost from restrictive intake/header/exhaust manifolds , the gains may be minimal but thats why some people go beyond the bolt-ons like advancing timing, pulleys,cams, ignition and what not. you gotta start some where, can just slap on a turbo w/ everything else stock... the basic bolt-ons also have good 'looks' for show type people...

i have an aem short ram intake/generic CAI and an apexi ws catback as of now and im waiting for accordsleeper's dc header to be delivered to me. im more of a show type, w/ my basic bolt-ons and my kit im happy w/ the money spent on my car, its a fun hobby...

 

So was the whole point of your post was to say that most mods on our cars don't do much? I don't know, but I thought most people knew that by now. (Not trying to be a jerk here, just stating what I thought.) If you think that getting a new exhuast will gain you 30 or 40 HP, then you need to by a vette. Either way, I have an AEM CAI and APEXi WS and am very satisfied with both. I knew I wouldn't gain much from either, but after each install I could feel the new power from that mod in whatever band. I guess just cause I wasn't expecting much made me that much more satisfied with each mod. I don't think that a generic CAI would be just as good as the AEM, though. The angle and severity of the bends in the pipe, as well as the material it's made from and other factors come into play and I would think (and hope) that AEM does a lot more R&D on their stuff then the generic brands. However, since the gains are pretty small as is, the difference is probably pretty small too. Anyway, I agree with bonestock in that it's just a fun hobby. And it just makes your car look that much prettier to look at :thumbup:

 

The point is not to discourage anyone, but to make a point that these exhaust bolt-on's really don't gain much power for ya. I totally agree that it's a fun hobby and it's been fun to hook up all these parts by myself.
I forgot to state though, I am very satisfied with the status and the sound of my car. It sounds very powerful, although it really isn't. When I first put on that intake myself and drove it out to the streets, I was happy as hell and turned off my radio to hear that little noise that came from the front. And I've been getting into this fantastic car modifying world ever since... I am just disappointed that I didn't know these things didn't give much HP's, and was just changing the low-end torque to mid-range or high... all that.
Overall, it wan't that meaningless because I had fun (that's all we care, isn't it?) and I've learned. I just wanted to post this up so people who just started modifying their cars don't make the same mistakes as I did, thinking these will make the Accord their parents bought would be a super car. (No offense, I really like Accords, both of my cars in my life are Accords.) But again, if I knew and didn't believe on those "advertised" power, I could've saved the money for something more efficient maybe like suspension. IMO lowering the car to transfer them faster to wheels and buying lighter, reasonablely big rims help out more than my header and muffler. But hell ya, regardless of the money, the process of modding cars is fun!

 

this is a big wake up call to the n00bs.

I totally agree with you all, i spent over 800 bucks of mods so far and i'm happy with the outcome.

However:
Import Tuner(recent issue with the red S/C SE-R cover)

Accord V6 Coupe modifications:

AEM Cold Air Intake = 6HP
Dual Greddy EVO Catback = 10HP

16HP GAIN!

subtle or not, these are impressive gains from just bolt-ons