JBA header???'s

[big T]

I ordered the JBA mid length headers and noticed that they come in 2 diff tube sizes. I have the 1-3/4" tube, but they also have the 1-5/8" tubes on thier web site. Does it matter between the 2 sizes. May be a tighter fit in the engine bay is the only thing I could think of and hope they dont rub against anything. I measured the sizes on a ruler and the 3/4 is a fraction bigger, just wondering whey they sell 2 sizes in the tubes. THX.

 

[helty]

i asked this same question about 2 weeks ago. with the 1.75" its gonna cost you some power, unless you're putting a lot down.

http://forums.stangnet.com/showthread.php?t=640846

maybe it wont make a big difference, I hope it doesnt cause any problems for you/

 

[trailblazr81]

Like most all other intake and exhaust components, bigger is for high power so it could hurt ya if your not making enough power for the bigger tubes.

 

[03ghoststang]

yeah the bigger size is for higher power numbers. The 1 5/8" is for most street cars and the 1 3/4" for the higher HP streetable cars

 

[big T]

i asked this same question about 2 weeks ago. with the 1.75" its gonna cost you some power, unless you're putting a lot down.

http://forums.stangnet.com/showthread.php?t=640846

maybe it wont make a big difference, I hope it doesnt cause any problems for you/

How much power should I be making to run them? I will be adding vt stage 2's in the near future and maybe thats why the sales person sold me the 3/4". Man, I hope I dont lose too much power cause Im not making that much as it is. My main concern is that the tubes dont rub against anything cause I can add more power as needed. I read that thread too, so basically I dont lose power out right, just moves hp/trq up the power band so the low end might be a bit soft. Hopefully if that is the case, my gears and converter makes up a bit of the low end feel. Thx again.

 

[QDRHRSE]

If it is any consolation, I'm making at least 450RWHP with my Lightning and I run the 1 5/8's JBA's. For some reason (this is my experience) Mod motors seem to need a little back pressure. I put off road mid pipes on the L and it slowed down until I pullied up the blower some more.

 

[helty]

I dont know what to tell you, as far as how much power you need to be making w/o sacrificing down low torque. When I asked the question, it was asked under the assumption that I would have a Novi 2K putting down about 380, and even then I was told they're too much.

However, SLP LT's for 4V's are made 1.75", and they arent putting down any more than 390(flywheel) stock, and thats for the Terminators. The N/A 4V's are what, 305, 320? Whether they hurt performance or not, I dont know.

 

[big T]

I dont know what to tell you, as far as how much power you need to be making w/o sacrificing down low torque. When I asked the question, it was asked under the assumption that I would have a Novi 2K putting down about 380, and even then I was told they're too much.

However, SLP LT's for 4V's are made 1.75", and they arent putting down any more than 390(flywheel) stock, and thats for the Terminators. The N/A 4V's are what, 305, 320? Whether they hurt performance or not, I dont know.

Thx helty, you always try to give as much info as possible. What the heck, I have them already so might as well use them. I cant see it hurting me too much and I figure that they are only mid length and not 1-3/4" long tubes cause I know those would be an overkill.

 

[Stang|ess]

There's actually not a lot of power difference between midlengths and longtubes, as long as the primary tubes are linger than 15" or so. I don't have the exact number, but I'm sure someone can chime in.

It should still feel alright since you got 4.10s

 

[hognutz]

they sell the different sizes because at different power levels you need different primary tubes to optimize hp. 4.6L 2v n/a I would use the 1 5/8 set. If you plan to boost you would consider larger tubes at a certain hp level. since you already have them though I don't know what to tell you there.

even a 2v with heads, cams, and intake mods probably still does not need 1 3/4 primary tubes.

a 4v for example is a higher reving egnine with more valve area in the cylinder bore. it is going to react better to larger tubes than a 2v IMO.

the more rpms you turn though the better the 1 3/4 tubes will shine most likely. It may be okay since the salesman told you so but most of the logic I posses about engines tells me that a 2v with stock heads and intake is going to suffer a bit with 1 3/4 primary tubes.

 

[squares98]

Definitaly
+1

 

[big T]

There's actually not a lot of power difference between midlengths and longtubes, as long as the primary tubes are linger than 15" or so. I don't have the exact number, but I'm sure someone can chime in.

It should still feel alright since you got 4.10s

Hope so dude. Rob at exhaust sys/kailua told me that he liked the 1-3/4" better anyway and it wont be a problem. Said that my power would move up a bit in the rpm range and since Im adding cams after along with a tune should be fine. Said the gears/cnvrtr will take care of the bottom and I would actually pull a bit better up top. PM me cause Id meet u one day if u wanted. I work in kalihi as well.