it’s pretty cool watching you improve the tune on this car little by little! it would be so addicting to keep trying things. looking forward to watching you find the peak.
My Uncle had a 67 Corvette with a 435 hp 427. My Dad would always take it home from our shop on Friday and go out looking for races on Friday nights. We had a few Corvette’s over the years but Camaro’s and Nova’s were our favorites.
Excellent comparison with side exhausts.I'm from back in the day and not that many 1965-67s came with them- they are mostly added on these days. Seeing them on 1963 and 1964s looks silly as they were not an option until 1965. I NEVER LIKED THEM, stepping over them and they make the car look cluttered and 'rob horsepower' thanks for proving my point about power robbing. To each their own. Have fun with whichever you want. Back in the 60s most vettes were daily drivers, mine was, all seasons. That was quite normal back then.
Fun stuff, everyone should have a DIY home dyno. Hard telling without seeing the exhaust but... can't you cut out the crimped/restrictive pipe section and replace it with some full 2 1/2" (if it would mount behind the side pipe shield)?
Personal taste, as for myself I like to hear the engine and transmission winding out through the gears in a convertible 4 spd. (and the radio) LOL I like the 'quiet sleeper' theme-then surprisingly open up the bad boy at the right times.That's just my personal choice. Most mid year Vettes like mine were daily drivers in the '60s.
Imagine buying a brand new Corvette with sidepipes in 67 and lining up against a friend with a non sidepipe car. I think there would be some angry words at the dealership the next day.
I worked at a Corvette restoration shop in St. Louis in the '80s and '90s. The guy who owned it worked on his own '67 435 green side pipe, bolt-on coupe at the Union street plant when it was built. He got a set of aluminum heads through the plant and its been an L89 clone since. He still has it and when I go back home we beat on it like a rented mule. We valve job and and run the shit out if it. I wouldn't want to go much faster on those skinny tires. Trust me, if you knew what you were doing, there wouldn't be any bitching with the dealership. Of course when he had headers it made a lot more power. The fact the factory exhaust is restrictive isn't a mystery. They were making cars that could be driven everyday with a 12/12 warranty, or turned into killers. That technology is 59 years old and it can still hang with any engine made.
@@bigblocklawyer You don't think if you and a friend bought identical new Corvettes (except for the sidepipes) you'd be questioning the dealership why your friends car is always faster than yours? This will probably sound like a lie after your post but my father is the original owner of a 69 L71 (435HP) Corvette. It also happens to be Fathom green even though he ordered it LeMans blue (long story). It got headers and mags the first week he owned it and a cam a bit later. With it's 4:11s and 4 speed I'm aware of the lack of traction on the street.
I had a B&M 144 blown 350 chevy motor and had hooker side pipe headers. When I had the glass pack mufflers it ran great. I bought a set of turbo mufflers for the hooker side pipes. When I bolted them on I swore I somehow knocked of a couple of plug wires the HP drop was so bad. So yes a bad exhaust can kill your HP.
Could you fabricate a set of 3"-3 1/4" straight pipes? Would they fit under the heat shields? Really enjoy your videos. The 67 was always my favorite!!! Do they make baffles that would fit inside the pipes like on motorcycles?106 ain't to shabby for a 400 HP Vette! Nice run!
Mr. Gregory, it's not so much the restrictive mufflers or the I.D. of the pipes, it's moreso the 2 almost 90 degree bends to make it out to the side pipes. Too large a diameter of pipes, DECREASES the velocity of the exhaust flow. A often too common of a mistake. There are spiral core race inserts that can be used successfully, in place of the mufflers.
Man, I'd love to see someone doing some serious work with a DZ 302 , or a 1970 350 LT1 .. oneday perhaps . Hey I've had good luck with those Black Widow mufflers from Jeg's . They actually have a model called the 'NeighbourHater' which I thought was LOLMAO
The big black 4-inch aftermarket pipes can be run three way, with a standard baffled muffler inside, with a glass pack for more sound or open with nothing for a totally ridiculous loud sound althoughthe latter probablywould exceed most noise laws and be illegal.
Know a guy who bought a 69 390 horse brand new with side pipes. People asked him the next day how it ran. He told them "It will go clean outta numbers" don't think the 69 side pipes were holding anything back.
Actually the 69 factory sidepipes were the worst, only 2 inch cross section under those fancy covers. The aftermarket sidepipes are mostly 2.5" and flow better.
I know I'm late to the party but... yeah, those side pipes look cool and sound even cooler, but they're no good for power. The stock "out the back" pipes were actually better flowing. However, just running open manifolds isn't the best way to make power either, you need about a foot of pipe added on to the manifolds to get the most out them. If you are required to run a "full exhaust system", look for a set of factory header side pipes... Chevy actually offered them as a dealer installed option back in the day, and reproductions are still available. Oh, and you need 4.11 gears in that thing... 3.30s are for road racing and fuel economy. LOL
All good, except the real advantage of the side pipes was to reduce the in-cabin heat. The standard pipes ran along the trans tunnel next to your leg. You really don't want that, believe me, with a big block on a warm day. Or any day, really.
We knew back then that side exhaust was a horsepower killer, but we thought they were cool. If we wanted real power we changed them out to something more conducive to high power.
According to Babvvo and Tebbvo laws, sadly soon all combustion cars and trucks including classics will be banned from public streets in entire EU and Scandinavia :-( In Germany the Green Peoples Party gave order to shorten fuel supply from 2025 on by reducing all conventional fuel stations to only one state operated central gas station per city or county. Car washs will be forbidden too because they are climate killers, now they want to slow down all the gas station pumps from 20 litre per minute to 2 litre per minute...From 2027 on in the EU certain car spare parts will be banned too....as exhaust systems, turbo chargers and even some engine and gearbox oils...California and New York will do the same from 2027 on.... So no investments should be done in oil burning cars any longer....They even created a new kind of crime here, called emissions and smoke crime!!!
Factory side pipes are the killer. I make all of our current side pipes. We saw huge gains on the dyno with our own side pipes. We gained nothing on the track though.
@@rogerdodrill4733 They also offered the 3x2 on the 390hp engine and rated it at 400hp. The 435hp engine was a whole 'nother animal compared to the 390/400hp.
Put 4:56's in the ass end and you'll cut your ET by a huge margin. But of course, you know that. But Green Who the fk would paint a 427 Vette green? Yuck.
This car has the hydraulic lifter cam. 4.56's wouldn't help much at all over 3.70 or 4.11 gears which it probably already has. Green was actually the most popular color on '67 Corvettes.
There were 2 versions. One with a solid lifter cam was 435 and one with hydraulic lifter cam was 400 hp. Those were with three 2 barrel carbs and they also had a 4 barrel hydraulic lifter one with 390 hp.
I gave up after you started a dyno test with knowing where the timing is too bad you did not detonate the enine and kick a rod- maybe you learn something.
run the side pipe fender well exit headers that come out the side the Roadster header mufflers that's where you have your biggest gain out the inch and 7/8 primaries into a 3-inch collector in a 3-inch Muffler side pipe exit
What a beauty. 1967 was such a great year for automobile design.
With everyone, the Ford's and everyone had good looking cars from 64-72 they ALL looked great!!!
I'd rather have a 64 convertible Stingray with the 327 375 hp fuel injected.
C2 coupes are total dream corvettes!!! I love every chance I get to see one!!!!!!
it’s pretty cool watching you improve the tune on this car little by little! it would be so addicting to keep trying things. looking forward to watching you find the peak.
We’re trying to keep it fun and not get too serious. But that’s real hard to do!
My Uncle had a 67 Corvette with a 435 hp 427. My Dad would always take it home from our shop on Friday and go out looking for races on Friday nights. We had a few Corvette’s over the years but Camaro’s and Nova’s were our favorites.
67 is the coolest Corvette, bar none.
Excellent comparison with side exhausts.I'm from back in the day and not that many 1965-67s came with them- they are mostly added on these days. Seeing them on 1963 and 1964s looks silly as they were not an option until 1965. I NEVER LIKED THEM, stepping over them and they make the car look cluttered and 'rob horsepower' thanks for proving my point about power robbing. To each their own. Have fun with whichever you want. Back in the 60s most vettes were daily drivers, mine was, all seasons. That was quite normal back then.
Great video and the pic of the 67 running against Donny and his 66 is killer
Great picture for sure! Ryan’s been working on the car and his driving. He says no more pictures of a big block behind a small block!
Love watching the Dyno vids and all the small improvement to make HP.
No doubt!
Had a buddy hang a set on his 'stang...total power loss that grew as he pushed up the tac...
I really enjoy your videos. Thanks.
My favourite Vette, C2 1963-67 Stingray Coupe.
Love the color too
Fun stuff, everyone should have a DIY home dyno. Hard telling without seeing the exhaust but... can't you cut out the crimped/restrictive pipe section and replace it with some full 2 1/2" (if it would mount behind the side pipe shield)?
I'll happily sacrifice a little bit of power for the glorious sound side pipes make :P
Personal taste, as for myself I like to hear the engine and transmission winding out through the gears in a convertible 4 spd. (and the radio) LOL I like the 'quiet sleeper' theme-then surprisingly open up the bad boy at the right times.That's just my personal choice. Most mid year Vettes like mine were daily drivers in the '60s.
Imagine buying a brand new Corvette with sidepipes in 67 and lining up against a friend with a non sidepipe car. I think there would be some angry words at the dealership the next day.
I worked at a Corvette restoration shop in St. Louis in the '80s and '90s. The guy who owned it worked on his own '67 435 green side pipe, bolt-on coupe at the Union street plant when it was built. He got a set of aluminum heads through the plant and its been an L89 clone since. He still has it and when I go back home we beat on it like a rented mule. We valve job and and run the shit out if it. I wouldn't want to go much faster on those skinny tires. Trust me, if you knew what you were doing, there wouldn't be any bitching with the dealership. Of course when he had headers it made a lot more power. The fact the factory exhaust is restrictive isn't a mystery. They were making cars that could be driven everyday with a 12/12 warranty, or turned into killers. That technology is 59 years old and it can still hang with any engine made.
@@bigblocklawyer You don't think if you and a friend bought identical new Corvettes (except for the sidepipes) you'd be questioning the dealership why your friends car is always faster than yours?
This will probably sound like a lie after your post but my father is the original owner of a 69 L71 (435HP) Corvette. It also happens to be Fathom green even though he ordered it LeMans blue (long story). It got headers and mags the first week he owned it and a cam a bit later. With it's 4:11s and 4 speed I'm aware of the lack of traction on the street.
I had a B&M 144 blown 350 chevy motor and had hooker side pipe headers. When I had the glass pack mufflers it ran great. I bought a set of turbo mufflers for the hooker side pipes. When I bolted them on I swore I somehow knocked of a couple of plug wires the HP drop was so bad. So yes a bad exhaust can kill your HP.
Headers with 2 1/2" exhausts
13.1 damn! congrats. Nice job.
Do they bigger diameter side pipes on early C3's lose power as well?
Yes they do. We’ve picked up 6 tenths at the track from side pipes to no side pipes on a c3.
I had said the side pipes ROB hp ,
Thanks for the video
That's bad ass. I love vettes.
Those engines were technically built to run on leaded 101-105 octane pump gas in 67'. The best you can get now is unleaded 91-93 octane.
We run 112 in this car.
@@HorsepowerDepot ✊😁
I never have liked side pipes. What if you guys ditched the tri-power?
That Car is Beautiful
I’d like to see it with the full exhaust the intake ported and a real set of carbs
OK so make the short drive to PSMCDR and join us! Like how you're keeping this one simple/stock Jordan.
Love the 67 C2 coupés, but give me a 327/350 any day for driving.
Run those side pipes with long tube headers and watch what happens.
I have a 406 small block in my c3 that has 2x+ that first hits HP NA though. But my heads flow 315cfm at .600 lift and that helps.
Hey I am thinking could you make these side pipes look stock without baffles?
I think you could. The bullet mufflers I had laying around wouldn’t fit under the side pipe covers.
@@HorsepowerDepot Well I guess we need to use a hole saw and cut out a few of those dimpled baffles in the original ones, lol.
the window track is not a door handle
My kinda guys. I hope to run my 63 soon broke the axle shafts first trip to the track. We run 1/8 round here. Hopin for high 7 sec range.
Could you fabricate a set of 3"-3 1/4" straight pipes? Would they fit under the heat shields? Really enjoy your videos. The 67 was always my favorite!!! Do they make baffles that would fit inside the pipes like on motorcycles?106 ain't to shabby for a 400 HP Vette! Nice run!
Mr. Gregory, it's not so much the restrictive mufflers or the I.D. of the pipes, it's moreso the 2 almost 90 degree bends to make it out to the side pipes. Too large a diameter of pipes, DECREASES the velocity of the exhaust flow. A often too common of a mistake. There are spiral core race inserts that can be used successfully, in place of the mufflers.
Man, I'd love to see someone doing some serious work with a DZ 302 , or a 1970 350 LT1 .. oneday perhaps . Hey I've had good luck with those Black Widow mufflers from Jeg's . They actually have a model called the 'NeighbourHater' which I thought was LOLMAO
The 67vette and 67 Ferrari 250 GTO are the greatest sport cars ever made.
Maybe this is a dumb question. Could you run a straight pipe bent to mimic the side pipe or are mufflers required?
The big black 4-inch aftermarket pipes can be run three way, with a standard baffled muffler inside, with a glass pack for more sound or open with nothing for a totally ridiculous loud sound althoughthe latter probablywould exceed most noise laws and be illegal.
Know a guy who bought a 69 390 horse brand new with side pipes. People asked him the next day how it ran. He told them
"It will go clean outta numbers" don't think the 69 side pipes were holding anything back.
Actually the 69 factory sidepipes were the worst, only 2 inch cross section under those fancy covers. The aftermarket sidepipes are mostly 2.5" and flow better.
I know I'm late to the party but... yeah, those side pipes look cool and sound even cooler, but they're no good for power. The stock "out the back" pipes were actually better flowing. However, just running open manifolds isn't the best way to make power either, you need about a foot of pipe added on to the manifolds to get the most out them. If you are required to run a "full exhaust system", look for a set of factory header side pipes... Chevy actually offered them as a dealer installed option back in the day, and reproductions are still available.
Oh, and you need 4.11 gears in that thing... 3.30s are for road racing and fuel economy. LOL
All good, except the real advantage of the side pipes was to reduce the in-cabin heat. The standard pipes ran along the trans tunnel next to your leg. You really don't want that, believe me, with a big block on a warm day. Or any day, really.
We knew back then that side exhaust was a horsepower killer, but we thought they were cool. If we wanted real power we changed them out to something more conducive to high power.
Is this car a 400 or 435 hp?
400
Couldn't you have brazed a set of jets closed then drilled them smaller? Or is that not allowed?
Did opening up the exhaust lean out the afr?
yes, of course
It should have. But we weren’t able to use the afr guage with the exhaust off of the car.
Did removing the exhaust help the mixture to get a little less rich, you did not say
I would imagine it would a little bit. But we weren’t able to use the afr gauge without the exhaust.
Classic chambered has the bigger inner diameter sidepipes/mufflers you need.
Damn! how much do these cars weigh!
According to Babvvo and Tebbvo laws, sadly soon all combustion cars and trucks including classics will be banned from public streets in entire EU and Scandinavia :-(
In Germany the Green Peoples Party gave order to shorten fuel supply from 2025
on by reducing all conventional fuel stations to only one state operated central gas station per city or county. Car washs will be forbidden too because they are climate killers, now they want to slow down all the gas station pumps from 20 litre per minute to 2 litre per minute...From 2027 on in the EU certain car spare parts will be banned too....as exhaust systems, turbo chargers and even some engine and gearbox oils...California and New York will do the same from 2027 on.... So no investments should be done in oil burning cars any longer....They even created a new kind of crime here, called emissions and smoke crime!!!
Leave it up to goofy mangina liberal men and feminists to screw up everything in the world.
Great and I suppose China and Russia will follow right alongside
Dang, MEAN C2!
Solder up the jets and re bore them.
any altercation to factory exhaust cuts power and mileage
Horsepower isn’t everything, sometimes style points come into play.
What are the "certain mufflers" that cost you HP? Are they a sponsor or something? I don't want to make that mistake on my street car.
Any chambered muffler will cost you HP. Dynomax ultra flo is what we run that doesn’t rob horsepower. Wish we had a muffler sponsor lol!
That's a pretty good gain in the horsepower just saying
Of course side pipes killed horsepower but it was all about the sound
This post from 2 years ago confused me, all your current Corvettes have side pipes.
Factory side pipes are the killer. I make all of our current side pipes. We saw huge gains on the dyno with our own side pipes. We gained nothing on the track though.
If ya like sidepipes, then good enough
Yep. The factory side pipes are extremely restrictive, and poorly tuned.
Throw on a set of the old Hooker 4 into 1 side pipe headers.
Need 456 rear gear
Thats it? these 427s should have made atleast 430hp and revved to atleast 6k
This is actually a 400hp 427. And that’s always rated at the crankshaft.
Advertised 425 hp should put at least 350 to the rear wheels
This is a 400hp car.
@@HorsepowerDepot I thought 3+2s were 435 hp ,or did they make small cam 3+2s?
The 435s had higher compression, solid lifter cam, and square port heads. The rest was the same 400 vs 435 hp engines.
@@rogerdodrill4733
They also offered the 3x2 on the 390hp engine and rated it at 400hp. The 435hp engine was a whole 'nother animal compared to the 390/400hp.
Put 4:56's in the ass end and you'll cut your ET by a huge margin. But of course, you know that. But Green Who the fk would paint a 427 Vette green? Yuck.
Gm painted this car green in 1967 lol.
Greenwood Green. Beautiful color
This car has the hydraulic lifter cam. 4.56's wouldn't help much at all over 3.70 or 4.11 gears which it probably already has. Green was actually the most popular color on '67 Corvettes.
@@mattanacker I believe it was called Goodwood Green on '67 Corvettes.
@@bobthbldr3 Goodwood Green makes more sense. I was close!
the 67 427 had 435 hp.
There were 2 versions. One with a solid lifter cam was 435 and one with hydraulic lifter cam was 400 hp. Those were with three 2 barrel carbs and they also had a 4 barrel hydraulic lifter one with 390 hp.
Yep, 4 different 427s in 67 not counting the L88.
390hp Q-Jet
400hp 3x2
435hp 3x2
435hp 3x2 alum head
I gave up after you started a dyno test with knowing where the timing is too bad you did not detonate the enine and kick a rod- maybe you learn something.
This thing doesn’t make enough power to kick a rod out lol.
long tube large diameter tube headers nutn' less
We cant run those in the class we race. Has to have exhaust manifolds.
So it lost 100 hp 80-100 that's about right so it might make 400 or close at the crank one big Holley would make more power 6 inch tire lol
What vehicle from 1967 WASNT cool looking? they had so much style back then.
Why don't you just run open pipes right thru and out the side pipe spots?? If you want "mufflers just put some glass packs in the side pipe slots!!
Just a regular glass pack doesn’t fit under the side pipe covers. We tried lol.
No need to maximize horsepower on this car. Get smooth idle and transition and drive it. Big block. Done.
Any backpressure is no good
Salut my friend super car super video subscribe subscribe
run the side pipe fender well exit headers that come out the side the Roadster header mufflers that's where you have your biggest gain out the inch and 7/8 primaries into a 3-inch collector in a 3-inch Muffler side pipe exit