SLEEPERBUSA

Thanks Doug.

illenema

Get out the high speed cutter.

gkull

It is really Dumb to use the stock small holes through the cross member.......... You have to think about how can I improve on this

mvette76

This was just temperary to get me rolling again the plan was to go with either moding my crossmember or a new one and a 3" exhaust but the hooker side pipes really look kick ***

worship79

My 383 SBC produces 450 hp (flywheel, chassisdyno 30% correction for TH350) with Hooker Super Comp headers (huge collectors) & 4" sidepipes.

Inserts are modified max flows: reduced diameter on the perforated inner tube, removed outer tube and fully packed sidepipes with ceramic dampening material (doesn't burn out). Still 120.6 dB(A) at WOT...

Great fun though and the sound level evens out eventually

minitech

Personal preference but for me I wouldn't like the loud sound every time and all the time I was driving the car. On one of my C5s it came with a Magnaflow exhaust but I changed it to stock knowing I would lose a few HP but it was so loud it caused a headache driving it.

Has anyone thought about rear exhaust with remote operated cutouts? Then can go to open exhaust when you want to but quiet for comfort.

mvette76

For all people saying they rob hp what are we talking about 5 10 or 50 plus hp if it's like 5 or 10 hp if wouldn't be the world ! And thanks for all the input

bashcraft

With the max flo inserts you won't lose any.

TheSkunkWorks

I may well have strayed off course on this topic earlier in my compromised state, but as long you have excess power enough to bring traction limitations into play on acceleration (whether on corner exit or during launch), IMHO it's somewhat moot to worry about how much more HP might have been given up once you pass the point of diminishing returns.

7t9l82

it isn't significant and what were they comparing too, this type of side pipe is a full exhaust system, are they comparing to open headers? in which case yeah there is a power loss are they comparing to a complete system with mufflers? if that the case id call B.S on that. there is no way it would be a big loss. i don't know where this crap starts , but someone says something no mater how stupid and its accepted as race track tested Dyno verified fact.

LS4 PILOT

Cons to the N11 factory pipes and covers .

Is the cost .....much as some C3 sell for

Once you hang them on your car ......it's worth the wrath of the old lady for spending so much money ....Love Love Love

Cool factor is off the scale for C2 and C3 corvettes ...the slim wast line and sexy body was meant to wear a set of side exhaust

ezobens

Holy crap that's a big restriction!
I didn't realize BB headers came so much further back than SB headers.
You'd think header manufacturers would at least angle the collector so that you can remotely try to fit a pipe close to the existing pipe locations without needing two 90 degree bends right out of the collector.
Bogus...

augiedoggy

The factory sidepipes were actually very restrictive..(but the car is as much about show as go from the factory if not more ) It was designed as a sportscar not a racecar and the c3's were more of a grand tourer as the mid seventies approached. Apples to oranges comparing them to hooker/obx style...

Amelio

Oh ok you wrapped your pipe prior to putting on the shield..... That makes perfect sense...... I got the heat shields from Summit today...... I didn't they they would absorb any heat it's just a piece of metal.

Thanks!

augiedoggy

Not really, I wrapped two strips around the pipe multiple layers thick and mounted the stainless clamps that it bolted to on top of the wrap so the direct heat is insultaed from traveling from the pipe to heat shield. This also creates dead air space between the pipe and heat shields... the two strips are only a single header wrap thickness wide.. It is cool to the touch after a good drive.

Postal123

this topic always seems to come full circle with a lot of misinformed comments...consider this:

--Hooker/OBX and factory sidepipes are vastly different designs...any blanket statement is a telling story and I'd caution heeding the advice

--Hooker/OBX flow varies greatly dependent upon the inserts...mild to wild here

--Hooker/OBX primaries are larger diameter than generic off-the-shelf headers and best suited for large cube or high RPM motors...so as with all things in the powermaking business it depends and it's dependent on properly matched parts...think 327, 350, 383, 406, 421, 427, 434 in the small block arena...now think choked late '70s stocker to highly modified bruiser...now make a blanket statement that describes your personal experience...I realize the OP regards a 454 so my example is only for clarity...a performance 454 can benefit greatly from high flow Hooker/OBX

Is it ignorance or narcissism? I don't mean to rant, but sometimes I cringe reading some of the comments...and to make it worse, if something has been written enough times it somehow gains some type of cyber momentum and misleads those looking for guidance on a particular application. I realize that to tell the whole story takes a lot of time, but I think we can do better.

d555

I lose about 60 hp on my car. It's more about loss of average tq/hp

About .3 in et and 3mph. The stronger the motor, the more the loss.

Under chassis headers will deliver HP. Side pipes have the look, if that's the look your going for.

I use the side pipes to slow the car down for 10.50 Heads up races.
Love the access to the under side of car for service work as well as the much cooler interior . A 20 mile drive is hell on hearing. The best inserts for MPH I have run are the STS and currently have a set of 3" core that have great sound compared to the spiral baffles.

Have run 4 types of inserts all perf versions. Have not seen one that will not lose hp/tq with side pipes. Though car has run deep in to the 9's with both under chassis as well as the Hooker side pipes...in street trim.... my vote if noise isn't a issue, would be side pipes.

Dave

Dave

augiedoggy

While I can only speak for the SBC version I can confidently say that the hooker, x-s power and obx pipes are in fact clones of one another with the same exact pipe routing, lengths and primary size.

They share the exact mounting issues and touch or come close in the exact spots, they use the exact same mounting hardware and inserts.

At some point hooker appears to have changed their design as the very old pipes have an extra long #1 cylinder pipe.... the newer units hooker sells have the drivers side pipes routed differently... perhaps they snuck a redesign in there for better tuning?

As far as the factory pipes go they sound great but the performance was less than the standard factory under car exhaust... they are very restrictive with openings less than 2".... somewhere around 1 1/4 or an inch and a half it I remember right....

Amelio

Understood...thank you!

augiedoggy

no problem... I hope it works out for you... I just received my baffle sound deading wrap today for my sweet thunder inserts... they sound great but are still a bit too loud at WOT and I want to quiet them a bit so I got two of these.

http://www.ebay.com/itm/141382310772?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AITthey just showed up so I will install them today.