open header question

[Theycall_Metue]

some say that you need the back pressure from the exhaust. how come some people go to the drag strip open header? i was just wondering cause me and my brother are taking his celica gts to the strip
mods are intake, exhaust

[Tech5]

Open exhaust just pisses me off!!!!!

at the track I guess its ok but on the street GTFO the street with that crap!

As far as power Back pressure isnt what makes you gain or lose power its the tune you need to make it gain more power from a open exhaust ... If its not tune for that then leave it alone!

[Theycall_Metue]

nah its only for the track

[Tech5]

Make sure he gets it tuned for it, if not he will run lean and could damage the motor.... Hope it doesnt get cold out either.

[81911SC]

Reversion? Savaging? Know anything about either of them?

[CaTcH22]

Reversion? Scavaging? Know anything about either of them?

This man hit it on the dot. You gotta have SOME length to the exhaust pipe. Open header is fine, but if you cannot Scavange your exhaust gases then you will have Reversion inside the combustion chamber. The valves will be workin against each other. This goes for NA and FI. That is the same principle behind adjustable cam gears. The amount of overlap affects reversion, which affects power. NA setups can make alot of power if they set up the exhaust cam to "venturi" the air into the intake.

[Theycall_Metue]

another question, running 100 octane wont hurt a high compression motor will it?

[Vteckidd]

some say that you need the back pressure from the exhaust. how come some people go to the drag strip open header? i was just wondering cause me and my brother are taking his celica gts to the strip
mods are intake, exhaust

Open header is subjective in all honesty.

Usually versus a normal sized exhaust youll pick up 5-10whp TOPS. If you have a properly sized exhaust with no cat, the difference is almost non-existent.

On that particular car, 2.5in exhaust is optimum, so if you dont have that, if you run open header youll feel a tad gain.

It wont really cause any damage because its not going to lean it out that much if any at all. O2 readings are taken after the collecter of the header anyway.

[Theycall_Metue]

its straight piped ( no o2 on down pip )

[Turbodude06]

Well running a stock celica gts with straight header, is going to make it slow as dog... Built cars can run straight headers cause they don't need much back pressure(Just like turbo'd cars too), thats why u always see them at the track cause those cars are actually fast, not some gay honda on the streets that thinks there fast with no exhaust.....

[goi_ek]

Well running a stock celica gts with straight header, is going to make it slow as dog... Built cars can run straight headers cause they don't need much back pressure(Just like turbo'd cars too), thats why u always see them at the track cause those cars are actually fast, not some gay honda on the streets that thinks there fast with no exhaust.....

lol, true

[Vteckidd]

Not true. I've seen stock hondas gain power open header. The whole question is "is his exhaust restrictive"

if it is it will gain power open header. If it's not then numbers won't be that different.

As far as damage or running lean, make sure you're on 93 octane and you'll be fine

[Theycall_Metue]

Not true. I've seen stock hondas gain power open header. The whole question is "is his exhaust restrictive"

if it is it will gain power open header. If it's not then numbers won't be that different.

As far as damage or running lean, make sure you're on 93 octane and you'll be fine

going back to the 100 octane, will it run lean?

[seanrg1116]

^^^^^^^^ in that car 100octane is not going to make much of a difference

[Tech5]

run a open header in the winter and tell me how that car last!

[Vteckidd]

I drove around open header on my old CRX for a year, if someone can explain to me how running open header leans your motor out to the point it blows up id love to hear why.

Its a myth, its a urban legend. Its NOT true at all.

If it blows up, you were on the edge of blowing up anyway.

If its a boosted car, OPEN DOWNPIPE can actually increase boost pressure ONLY IF THERE IS A RESTRICTION PRESENT. Then in that case if you car is tuned for 10 psi and creep to 12,13,14 psi and it isnt tuned for it, then sure, it can cause detonation and damage.

If an NA car is tuned for 14.0 and for some reason it goes 14.2 open header, sure, i guess its POSSIBLE but it would be a very highly modded motor. Not a Stock Celica GTS.

100 octane wont cause your car to run lean, and it wont gain you power. It WILL destroy your factory O2 sensor though

[Tech5]

I drove around open header on my old CRX for a year, if someone can explain to me how running open header leans your motor out to the point it blows up id love to hear why.

Its a myth, its a urban legend. Its NOT true at all.

If it blows up, you were on the edge of blowing up anyway.

If its a boosted car, OPEN DOWNPIPE can actually increase boost pressure ONLY IF THERE IS A RESTRICTION PRESENT. Then in that case if you car is tuned for 10 psi and creep to 12,13,14 psi and it isnt tuned for it, then sure, it can cause detonation and damage.

If an NA car is tuned for 14.0 and for some reason it goes 14.2 open header, sure, i guess its POSSIBLE but it would be a very highly modded motor. Not a Stock Celica GTS.

100 octane wont cause your car to run lean, and it wont gain you power. It WILL destroy your factory O2 sensor though

guess you dont know what cold air sucked into the OPEN / Header exhaust can do to a motor huh?

[punkr6]

guess you dont know what cold air sucked into the OPEN / Header exhaust can do to a motor huh?

oh snap son... Where is the popcorn ?

[Vteckidd]

guess you dont know what cold air sucked into the OPEN / Header exhaust can do to a motor huh?

So sucking in ambient air temp can cause motor failure?

Gee golly willigers, i better not let my engine breath in any air at all.

What temp do you think ENTERS the motor in the first place?

The exhaust gasses leave the combustion chamber with such force that the only time reversion could even take place is under a lift throttle condition. And even then the throttle plate is closed, and the motor is pulling vacuum anyway.

Show me one car where they took their exhaust off and their motor failed from reversion and you have conclusive evidence.

I rode around for over a YEAR OPEN HEADER REVVING TO 10,000 RPMS ON A STOCK BOTTOM END GSR.

[Tech5]

So sucking in ambient air temp can cause motor failure?

Gee golly willigers, i better not let my engine breath in any air at all.

What temp do you think ENTERS the motor in the first place?

The exhaust gasses leave the combustion chamber with such force that the only time reversion could even take place is under a lift throttle condition. And even then the throttle plate is closed, and the motor is pulling vacuum anyway.

Show me one car where they took their exhaust off and their motor failed from reversion and you have conclusive evidence.

I rode around for over a YEAR OPEN HEADER REVVING TO 10,000 RPMS ON A STOCK BOTTOM END GSR.

gsr hummm does it have 1000+ horsepower?

You have your opinion and I have mine i will stick to mine as I pay/buy all my stuff so i do what keeps it running..Not to mention leaving it open header makes more and more people laugh at you and call you a ricer , clean your exhaust tone up and try not to piss people off because your 120 hp toyota celica has a open exhaust...Wanna go fast? get a Big block with 750+ hp and then run it open exhaust . These damn ricer makes me wanna run them over with their open exhaust.
Oh and you want proof , well I been there to see it happen sorry I don't know how I can show you proof when I don't . But this has been said for years longer then you and I been alive.Why ??? Because it has happen

[Vteckidd]

gsr hummm does it have 1000+ horsepower?

You have your opinion and I have mine i will stick to mine as I pay/buy all my stuff so i do what keeps it running..Not to mention leaving it open header makes more and more people laugh at you and call you a ricer , clean your exhaust tone up and try not to piss people off because your 120 hp toyota celica has a open exhaust...Wanna go fast? get a Big block with 750+ hp and then run it open exhaust . These damn ricer makes me wanna run them over with their open exhaust.
Oh and you want proof , well I been there to see it happen sorry I don't know how I can show you proof when I don't . But this has been said for years longer then you and I been alive.Why ??? Because it has happen

You are giving him advice based on experience with a 1000hp car LOL He clearly stated its a STOCK CELICA GTS.

Thats like someone asking if revving to 9000 is bad and you saying "nah man its fine, my outlaw car does it"

You would have to show me a car with a cracked valve from no contact but from some super cooling that "burned an exhaust valve"

Quick question, who on here has EVER seen a BURNED exhaust valve on an NA car?

I never have (unless the headgasket was blown and the engine melted down)

[southside]

Yea I have seen a lot of people running open header on motors like gsr,b16 and sohc,They don't usually mess up at all. Well then again the people I see running open header usually are spraying anyways.So of course you will have damage from that if your car isn't tuned correctly but my friend took his exhaust off his sohc.And it felt alot better from the stock dented and clogged exhaust.And he drove his car for over a year like that shit sounded so annoying though.

[punkr6]

just saying...

[Vteckidd]

You guys throw out big terms like Reversion but do any of you have ANY PROOF what so ever?

How much vacuum does a motor pull at closed throttle? what are the pressure differences on the back side of the exhaust valve?

I guess me and thousands of others are just lucky. Prove to me reversion happens, and it causes motors to blow up strictly from running OPEN HEADER.

Its a myth and its bad information

[Tech5]

You guys throw out big terms like Reversion but do any of you have ANY PROOF what so ever?

How much vacuum does a motor pull at closed throttle? what are the pressure differences on the back side of the exhaust valve?

I guess me and thousands of others are just lucky. Prove to me reversion happens, and it causes motors to blow up strictly from running OPEN HEADER.

Its a myth and its bad information

Seen it happen on many outlaw cars, It happens, google it and you will see others....Its a myth to the import scene but not to the real world.

[Vteckidd]

Seen it happen on many outlaw cars, It happens, google it and you will see others....Its a myth to the import scene but not to the real world.

Did you not read my previous post at all. Here let me clarify it again

If an NA car is tuned for 14.0 and for some reason it goes 14.2 open header, sure, i guess its POSSIBLE but it would be a very highly modded motor. Not a Stock Celica GTS.

So you are comparing an Outlaw car to a stock celica GTS

[Tech5]

Did you not read my previous post at all. Here let me clarify it again




So you are comparing an Outlaw car to a stock celica GTS

OOOPPPSSS I didnt read to that point sorry I jump the gun

[AE86Raptor]

The people who run open header typically also have stiffer valve springs so that they don't end up burning up an exhaust valve so that the valves don't have to necessarily rely on exhaust back-pressure to help close the valves.

[punkr6]

You guys throw out big terms like Reversion but do any of you have ANY PROOF what so ever?

How much vacuum does a motor pull at closed throttle? what are the pressure differences on the back side of the exhaust valve?

I guess me and thousands of others are just lucky. Prove to me reversion happens, and it causes motors to blow up strictly from running OPEN HEADER.

Its a myth and its bad information

I myself would never run an open header, especially on the street. Its just too damn loud and obnoxious. However, I do remember back in the day when vtecKidd ran around with an open header on the old crx with no issues, even on some cold winter nights street racing. As far as power goes I have seen guys at the track unbolt their exhaust trying to lower their times and the reverse happened.

[Vteckidd]

I raced open header in 30 degree weather when it started snowing out, Johnzm can vouch. its a myth, at least on our cars.

You are more likely to blow your car up from an improper tune due to the weather than reversion.

Johnzm and i ran open header for years on our CRXs and EF hatches.

[4DrTeg]

dang 2..look wat u caused..lol

[punkr6]

dang 2..look wat u caused..lol

x2, Hell Yea, I knew this was gonna happen when I seen the post earlier today...

[4DrTeg]

ohh well at least he's getting information

[punkr6]

ohh well at least he's getting information

yea, but he's probably more confussed now then before...

[Warlock]

if your already running a straight pipe just leave it like it is. waste of time taking it off for open header. And it will keep you from getting headaches

[Theycall_Metue]

wow a bunch of gangster fags on i.a
did i ever stated that i run open head on the street? did i stated that the gts is 1000 hp?
did i stated im running at the track during winter when its 30-40 degrees? the track dont even open during winter due to some fag flamers like you guys. it was just a simple question. a punch of grown as men that cant handle something that is posted on the internet.
this tech is already answer so stop bi tching at each other about what you think is true

[Tech5]

wow a bunch of gangster fags on i.a
did i ever stated that i run open head on the street? did i stated that the gts is 1000 hp?
did i stated im running at the track during winter when its 30-40 degrees? the track dont even open during winter due to some fag flamers like you guys. it was just a simple question. a punch of grown as men that cant handle something that is posted on the internet.
this tech is already answer so stop bi tching at each other about what you think is true

This isnt the WL and this requires a BAN!!!!

[punkr6]

This isnt the WL and this requires a BAN!!!!

x2. ban this guy , everyone was simply trying to help him out. Now he's insulting folks....

[stillaneon]

x2. ban this guy , everyone was simply trying to help him out. Now he's insulting folks....

Done

[Gutling]

the 2-3 horsepower picked up from a open header is not worth how shitty it sounds. Its loud, sounds like ass the whole way down the track. Just leave it alone, unless your in some big money competition racing where that extra .001 second off will make you win.