Do headers make a car any louder and give it a different sound? I have a hi-flo cat, 3in tubing, and 80s Flow will headers make my car any noticably louder? I would be putting on new headers and y-pipe. What should my car be running in the 1/4 with the full exhaust and CAI?

 

yes

 

What should I be running in the 1/4 with a full exhaust and CAI? How much louder do headers make the exhaust? How much power will I gain? As you can see I have many questions before I shell out the cash for headers.

 

Headers won't give you the most power or 1/4 gain as compared to gears, cam, or heads, but without a free flow exhaust no matter what mod you put on the engine will choke and the other mod won't benefit as much.
A good estimate for headers would be 15-20 hp at most and a cat-back probably around 10-15hp.

 

I have the peanut cam so how much HP would I gain for switching it out for one better suited for whats going to be on the car? What will the approx. 1/4 times be with a new cam, free flow exhaust, and CAI? I know I should be running somewhere in the mid 15s before the mods I have done. With the free flow exhaust and CAI I did notice a improvement in power and acceleration. It seems to have more power now than before not to mention it sounds better

 

What kind of gears are in your car?

 

It is the 3:xx?? I forgot but it is 3 something POSI.

 

Louder and better.

 

get headers and a 3" exhaust, then get ur gears, then cam it, then think about some heads (lol nice little guide i have for ya here) o and NEVER EVER get aluminum heads if u have an iron block! EVER! that is the #1 rule of whatever cuz u will blow head gaskets all day long......... some ppl dont know that.... i thought from my experience of seeing ppl come into my shop with no idea why their gaskets kept blowing, id enlighten you.

 

There are a lot of people that run aluminum heads on iron blocks without problems, I'm pretty sure. But I hear once the block overheats once, that's when the problems begin.

 

Isn't a LT1 an aluminium head/iron block combo? I don't think GM would have let that slip by year after year of the LT1's production run if blowing head gaskets was a reoccuring problem.

Just wondering

 

Hahahahaha!

Phunnie

 

The LT1 is aluminum headed with an iron block and so are most of the hi-po crate engines you can buy from GM now-a-days. There is no good logic behind blowing head gaskets daily when using aluminum heads. You shouldn't listen to anything the person who told you that EVER says every again.

 

Yes they make your car a little louder.For best results get a 3in cat back system.I picked up 4 tenths in the 1/4 just by doing those two things.

 

Back to the aluminum heads, if the car overheats it will damage the heads pretty bad, but as long as the car is in normal operating temps there should be no problem.

 

I have a 3" Hooker catback on my car and I just added SLP 1-5/8" headers and a 3" Catco cat this past weekend and it made a HUGE difference. It went from having a nice, low rumble to a deep, wicked growl. You can hear me coming about a mile away now!

 

Another satisfied customer.

 

well seeing as i've never heard this from anyone but seen it with my own eyes id say you probly dont know what your talking about...... i mean if GM manufactures a motor with an iron block and aluminum heads there are things you can do and types of gaskets you can put on to avoid this, but if you are some 16 yr old kid out of bum****, idaho slapping aluminum heads on your 305 with no chip or thermostat to keep the engine cooler..... most likely you will blow a gasket soon.

 

yea i mean if you know what your doing than runnign aluminum heads on iron is fine but you're safer and better off not doing so if it is your daily driver.

 

yea in fact my buddy with a 350 crate in his s-10 just blew a gasket last week and his has aluminum heads with an iron block...... he just sent them out to a machine shop to b e resurfaced cuz they got pretty f'ed up.

 

That's exactly what my brother told me.

 

So what do you suggest to do heads wise for my car? It is a daily driver but I am making it a very high performance daily driver.

 

I have aluminum heads on my 90K mile 93 Z28 that is a daily driver. Not one problem with it in 9 years of daily flogging, long trips and spirited driving. Mind you the fans don't turn on untill the temp is around 260*. All the Chevy GMC 4,8 and 5.3 trucks have aluminum heads, and are towing without problems, including my 01 silverado. The ZZ4 in my chevelle has L98 aluminum heads and it also works fine as a daily driver, as well as a weekend cruiser/racer. The myth about aluminum heads started back when manufacturers tried using iron casting technology to make the aluminum heads. They weren't desiged properly to prevent warping and they had problems. The heads available today are engineered to work on iron blocks, and anyone who tries to sell the idea that head gasket problems are associated with aluminum heads doesn't know very much about them. I've seen many blown head gaskets on iron heads from overheating, so it's not exclusive to aluminum. An iron head cracks, and it's junk. On the other hand, an aluminum head can be repaired. Just my .02

 

I agree. There are many running them with n/p's. Alot with AFR aluminums in all cars and they also seem to do great. Weigh reduction is always cool too.

 

yes what ive been trying to say is GM makes them to work with iron blocks and they are designed to fit and work from the factory......... but the everyday driver who isnt a tech or whatever shouldnt try putting aluminum heads on a block that is iron and came stock with iron heads cuz the block prolly isnt meant for it.

 

The problem with that is, the zz4, is a traditional small block chevy that hasn't changed signifigantly since 1954 when it was first introduced in the 55 car line. The LT1 is for the most part identical as well. The heads themself have been improved, and work fine on just about any application. If someone isn't capable of installing aluminum heads, they shouldn't be installing iron heads either. Sorry for hijacking this post about headers.

 

my dad has a 77 pickup with true dual flowmasters and a nicely built 350. he got ceramic coated long tubes, i noticed no difference in sound.
my friend mike has a 72 dodge dart with a 318, he got hooker competition headers, we noticed no difference in sound
my friend chris with a 67 nova with a 327 got hooker super comps, we noticed no big difference.

i still fail to see where people get that headers make a difference. i mean sure there is like a very small difference in sound, but it doesnt change an exhaust tone completely or makea quiet exhaust loud.

 

VORTEC Heads :hail:

 

Vortec heads are a great performance deal, but keep in mind if he uses them on the 305, he'll have to shave them to keep his compression up. They also don't like a cam with more that .470" lift. They can be modified for higher lift though, and would be killer hipo street heads on that 305 with those mods to them.

 

When the exhaust gases move past the exhaust valve, they are moving at(or near) the speed of sound. Needless to say(but I'm saying it anyways ) this creates miniature "sonic booms" in the primary tubes until the gases have slowed down sufficiently. Cast iron, in addition to having better heat retention and being cheaper to manufacture, does a much better job of dampening the sound than thin-guage tubular steel.

Short answer: yes, headers will make your exhaust louder.

 

about the heads... Aluminum has a higher rate of thermal expansion than does iron, that might be the basis for this whole head gasket thing but plenty of people run them without any problems. If you overheat the engine or have a crappy cooling system, then your in trouble with aluminum heads. Otherwise, their great.

 

An iron head cracks, and it's junk. On the other hand, an aluminum head can be repaired.

This, of course, will come as somewhat of a surprise to all those who've had cracks in their iron heads repaired.

 

Who?

 

I plan on putting a 180' thermostat in, having the fans come on earlier, and putting an aluminum radiator in. Would aluminum heads be ok with my car? I mean the thing will be running cool.

 

It will definately be cool enough, you just have to be careful that something doesn't go bad one day and peg the temperature gauge, just keep an eye on it and you'll be fine. I have a habit of lookin at the temp gauge every minute, guess just cause all the car's I've driven haven't been the most reliable.

 

I know about the heat problems, here in Kentucky we get screwed temp wise. We can be 0* in the winter and 110* in the summer. It's 91* right now!!!. Just wired my fans to an in dash switch so I can turn them on when I want to. And as far as the header discussion, I did notice quite a difference on my car when I added my headers. Cut the cat out and noticed even more. Ran 3" all the way and made even more of a diference!! Gonna get a set of one chamber flows and see how they sound AFTER I get my aluminum heads installed!!

 

ZZsmpch,

Several folks I've known. Most notably, an ex-roommate.

After one Christmas holiday he was driving home, and decided the falling oil pressure was probably due to GM's notoriously unreliable oil pressure senders. Unknown to him, a hole in the oil pan was the actual culprit of the decreasing pressure reading. He finally pulled over when loud metallic clunking sounds started coming from the engine(well past the point when the guage was reading 0). Fortunately for him the damge was limited to a broken rocker arm and a bent pushrod, and cracks at the rocker arm stud boss and the top of the pushrod slot. The machinists welded the cracks and these heads(duoble-humpers) are still on his '70 C10.

The irony was that he didn't want to stop because he had to be back on base the following day, or be AWOL. As it was, having to stop in the middle of nowhere and have his truck towed back home caused him to be two days late.

 

I have a 3'' Monza PaceSetter cat back which used to be kidna loud... then I got headers and it got quiter but deeper. Go figure... headers usually make exhaust louder and deeper, but mine got quieter and deeper. Maybe its because the Monza is a POS Poor mans muffler.

 

I have found a way to make my exhaust as loud as want when i want it but back to the Flowmaster sound when I want it as well. I decided on a cut-out.