68 Yellow 468

It seems I have read a few comments about sidepipes not allowing high horsepower motors to 'breath' properly.

At the same time, I recall reading an article in a recent vette magazine (corvette fever I believe) that showed numbers from a high HP small block: numbers with an aftermarket full exhaust system, numbers with sidepipes and inserts, and numbers with sidepipes w/o inserts. This particular article showed the sidepipes w/ inserts to product slightly better numbers than the full exhaust. Obviously, the sidepipes w/o inserts showed by far the best results.

I really want to pull the trigger on the sidepipes to pick up some ground clearance with my BB, but I would hate to do that at the expense of horsepower.

So, my question is, do sidepipes kill power?


Bryan

mlub

ive heard some say on here that you lose some low-end torque because of loss of back-pressure, but i dont know...i'm interested to hear also

SteveG75

If you use the Hooker reverse flow mufflers, you will lose a lot of HP. The JCL Spiral Turbo baffles are the way to go.

cmashark

hmmm, i think i'll wait to order my hookers. i hope i don't have to resort to the undercar chambered to keep the low-end torque.

chris

LOTAHP

Header for header...A standard header will give you more HP than a sidepipe header, simply because of the distance the exhaust has to travel (on a sidepipe header) compared to header that ends under the car. As far as after the header, a 4" open pipe (sidepipe) will make up the difference compared to almost any exhaust system you will put under the car.

71vetteLT-1

back-pressure, a common misconception, back pressure is bad on ANY 4 stroke engine, what you need is exhaust velocity not back pressure, that's the reason for tuned headers, they have runners at tuned lengths so that the pulses pull on the other tubes creating greater exhaust velocity...

big632

The best sidepipe header is the stahl system. The hookers have too long of runners but will make power above 3000plus,loose a little gain a little. The stahls will make more power everywhere. I like the look of the hookers but with my new exhaust fabbed stahl and my own sidepipes for what I needed.

Wrencher

Yep, Stahl is the way to go for performance, but forget about better ground clearance with any sidepipe. It's worse, unless you have some REALLY low center dump headers.

Hans

Gage

the sidepipes keep the interior cooler too since they run the exhaust out to the side of the car way before the firewall, rather than hot pipes and headers running down the middle of the car. Comes in handy here in Austin.

cmashark

got any pics?

chris

442olds

http://www.et-motorsports.cc/project...aust/index.htm

Here's some pics of the stahls. They fit pretty decent. I ordered them partially assembled to save a little money.

danboback

I understand that the hookers aren't the best headers for performance but I am pretty sure that hookers are going to run better than the stock manifolds that I have bolted on right now, so I will still see an improvement in performance!

MotorHead

Hmmm that's why I bought the Hooker sidepipes, for better performance. Big blocks may be different but there aren't many small block headers out there that come in 1 7/8 in primaries. That and JCL spiral baffles I am looking for a good gain over my 1 5/8 in. primary header and mufflers, I am not buying into any performance loss theory

On big blocks you can probably get the same size primary tube so the gain will not be as great

big632

The BB are 2 1/8 but still have a performance loss over reg tuned headers in a drag car. SB is the same. Not that important on street cars and yes 1 7/8 would be the way to go over smaller pipes.

big632

Email me for pics I have a hard time posting. computer inept. Mine are 2 1/2 x 5inch sidepipes. stainless

LOTAHP

This is why the Forum is so great !!!

I have never seen these Stahl headers before. I just got off the phone and their website. This will be the next thing I will be saving $$$ for. And my Hooker Sidepipes will be the next thing added to my "LOTA PARTS FOR SALE" thread. Thanks Mike & 442

MotorHead

Actually still not sure if the sidepipes are going on, looking at undercar system with electric cutouts, now that would be something

The Dude

I think that same article went out of its way to mention that the Hookers shown in the installation WOULD kill low-end power in small-displacement and/or stock engines. The power gain seen in the CF article was for a slightly built 406 ci engine that was REALLY losing a lot of potential because the "before" setup was simply long tube headers with 1 5/8" primaries.

That particular engine in the article needed and wanted the larger-diameter primaries and exhaust.

Your mileage may very well vary quite a bit.

BB wowbagger

Slap in a bigger cam and be done with it...Remember kids,all can be compensated with a bigger cam

big632

What goes in needs to go out