1 3/4 vs 1 7/8 headers
1 3/4 vs 1 7/8 headers I'm going to get QTP or Kooks, I know that.... But.... the deciding factor... will be the size... I have a stock motor for now, and eventually I'll have a 402 or some other big bore motor which will need 1 7/8 headers.... So...
How much will the 1 7/8 headers hurt my HP with a stock motor?
How much will the 1 7/8 headers hurt my HP with a stock motor?
Originally Posted by FCar2000TA
I'm going to get QTP or Kooks, I know that.... But.... the deciding factor... will be the size... I have a stock motor for now, and eventually I'll have a 402 or some other big bore motor which will need 1 7/8 headers.... So...
How much will the 1 7/8 headers hurt my HP with a stock motor?
How much will the 1 7/8 headers hurt my HP with a stock motor?
i jsut got my QTP 1 3/4" LTs shipped to me for $700. The advantages with qtp over kooks is that qtp has a better merge when the tubes go into the collector, also it is a little bit longer of a LT as well.
For you application it all depends. if you bore/stroke it with a big cam then go 1 7/8" if your application is going to be sort of stock then the 1 3/4" will be perfect..
if you get the 1 7/8" LTs on your stock motor you will kill low end tq just an FYI..
Good Luck
Originally Posted by TORCHD 02 TA
i jsut got my QTP 1 3/4" LTs shipped to me for $700. The advantages with qtp over kooks is that qtp has a better merge when the tubes go into the collector, also it is a little bit longer of a LT as well.
For you application it all depends. if you bore/stroke it with a big cam then go 1 7/8" if your application is going to be sort of stock then the 1 3/4" will be perfect..
if you get the 1 7/8" LTs on your stock motor you will kill low end tq just an FYI..
Good Luck
For you application it all depends. if you bore/stroke it with a big cam then go 1 7/8" if your application is going to be sort of stock then the 1 3/4" will be perfect..
if you get the 1 7/8" LTs on your stock motor you will kill low end tq just an FYI..
Good Luck
Originally Posted by FCar2000TA
according to QTP, their 1 3/4 headers work well on a 500RWHP 402.
i am sure it will, but if the guy does a 402 with a cam that is over 500HP hence he will need 1 7/8" LTs.
what size header he goes with all depends on his applicatioins in the future
Originally Posted by FCar2000TA
I have a stock motor for now, and eventually I'll have a 402 or some other big bore motor which will need 1 7/8 headers.... So...
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You need to wait a couple more months until LG releases their F-bod extreme long tube header and it will put even the QTP to shame in the torque dept probibly not much in peak Hp.
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I asked aorund as I'm building a larger CI motor, and the consensus is that if you have 1 3/4 headers already, don't bother buying another set as the gains are som nominal, it's not wirth the $... it's only about 5 to 10 hp peak, and the bottom end actually will be slightly weaker with 1 7/8 headers, and this is on a pretty stoutly built larger CI motor, with a 6 speed, we're talking over 550 rwhp. The 1 3/4 will be better up until about 4800 rpm, at about that point, you will see the larger header start to surpass the smaller one, but again, we're only talking 5 to 10 hp at best (header change only, nevermind the rest of the exhaust, as that all makes as much or more of a difference)
You can do 1 7/8 on a stock CI motor, just expect there to be little to no gains down low to midrange from stock. The header is not gonna make worse power then the manafolds at any point, jsut won't be any real improvment until in the upper rpm range (say 4500 and above)
Which to buy? Depends on how serous of a build you plan on down the road, for a street, car the 1 3/4 will be fine regardless, for a all out track build, my only advise, is spare no expense, and go as big as your wallet will allow, at every point. It will only help.
You can do 1 7/8 on a stock CI motor, just expect there to be little to no gains down low to midrange from stock. The header is not gonna make worse power then the manafolds at any point, jsut won't be any real improvment until in the upper rpm range (say 4500 and above)
Which to buy? Depends on how serous of a build you plan on down the road, for a street, car the 1 3/4 will be fine regardless, for a all out track build, my only advise, is spare no expense, and go as big as your wallet will allow, at every point. It will only help.
Tech Resident
Joined: Jan 2006
Posts: 5,117
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From: Philly
i say get the 1 7/8 headers. i've heard from many people that 1 7/8 will make more power even on a stock cube motor. that's why people get edelbrock's. their stepped 1 7/8 headers are better.
plus you're future-proofed. i say do it right or don't do it at all. you'll mod your car and for the rest of your life realize you coulda had more power, you coulda had more power, you coulda had more power.
plus you're future-proofed. i say do it right or don't do it at all. you'll mod your car and for the rest of your life realize you coulda had more power, you coulda had more power, you coulda had more power.
I do not agree that stock cubed motors will not benifit from larger headers than 1 3/4".
On my stock 346 w/T-rex and stock 241 heads my car picked up a good amount from Hooker 1 3/4 LT's 3" X-pipe duals w/4x9 3" Magnaflows dumped at the axles changing to Edelbrock 1 3/4 - 1 7/8 slip on colectors and 4x9 3" Magnaflows off the header. I haven't put it on the dyno to see the power difference, but it's deffinately there according to the track times. There are no other changes other than the exhaust in the following times and I have corrected them to 0 DA to factor out the weather....
5/12/06 +728 DA
60'___1.53
1/8___7.054@96.98
Corrected to 0 DA = 7.0@97.72mph
6/16/06 +3358 DA
60'____1.52
1/6____7.085@97.68
Corrected to 0 DA = 6.8@101.63mph
So for me there was a differnce of 2 tenths and 3.9 mph!!!!!!
On my stock 346 w/T-rex and stock 241 heads my car picked up a good amount from Hooker 1 3/4 LT's 3" X-pipe duals w/4x9 3" Magnaflows dumped at the axles changing to Edelbrock 1 3/4 - 1 7/8 slip on colectors and 4x9 3" Magnaflows off the header. I haven't put it on the dyno to see the power difference, but it's deffinately there according to the track times. There are no other changes other than the exhaust in the following times and I have corrected them to 0 DA to factor out the weather....
5/12/06 +728 DA
60'___1.53
1/8___7.054@96.98
Corrected to 0 DA = 7.0@97.72mph
6/16/06 +3358 DA
60'____1.52
1/6____7.085@97.68
Corrected to 0 DA = 6.8@101.63mph
So for me there was a differnce of 2 tenths and 3.9 mph!!!!!!
Originally Posted by BAIN
I do not agree that stock cubed motors will not benifit from larger headers than 1 3/4".
On my stock 346 w/T-rex and stock 241 heads my car picked up a good amount from Hooker 1 3/4 LT's 3" X-pipe duals w/4x9 3" Magnaflows dumped at the axles changing to Edelbrock 1 3/4 - 1 7/8 slip on colectors and 4x9 3" Magnaflows off the header. I haven't put it on the dyno to see the power difference, but it's deffinately there according to the track times. There are no other changes other than the exhaust in the following times and I have corrected them to 0 DA to factor out the weather....
5/12/06 +728 DA
60'___1.53
1/8___7.054@96.98
Corrected to 0 DA = 7.0@97.72mph
6/16/06 +3358 DA
60'____1.52
1/6____7.085@97.68
Corrected to 0 DA = 6.8@101.63mph
So for me there was a differnce of 2 tenths and 3.9 mph!!!!!!
On my stock 346 w/T-rex and stock 241 heads my car picked up a good amount from Hooker 1 3/4 LT's 3" X-pipe duals w/4x9 3" Magnaflows dumped at the axles changing to Edelbrock 1 3/4 - 1 7/8 slip on colectors and 4x9 3" Magnaflows off the header. I haven't put it on the dyno to see the power difference, but it's deffinately there according to the track times. There are no other changes other than the exhaust in the following times and I have corrected them to 0 DA to factor out the weather....
5/12/06 +728 DA
60'___1.53
1/8___7.054@96.98
Corrected to 0 DA = 7.0@97.72mph
6/16/06 +3358 DA
60'____1.52
1/6____7.085@97.68
Corrected to 0 DA = 6.8@101.63mph
So for me there was a differnce of 2 tenths and 3.9 mph!!!!!!
Originally Posted by BAIN
I have no idea. I just know what gains I have seen on my personal car with the 1 3/4 - 1 7/8. 
me too bro ! i think some combos make more/less with different exhaust valves also.say 1.56 v/s 1.6 