WHO makes 1 5/8 headers??

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Mar 28, 2004 | 05:03 PM

#21

65Z01

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From: SE NY

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Re: WHO makes 1 5/8 headers?? (Rich B.)

Well Vic'89 recently installed 1 3/4" LTs on his L98 (stock heads & cam with bolt-ons) and picked up over 15chp, according to trap speed increase. I believe his A4 is now set up to shift around 5,200rpm.

You might IM him as I don't think he lost any 60' time, which is a pretty good indicator of what's happening on low end torque.

I realy don't think it's a big deal to run 1 3/4" LTs on a Vette L98. I'm running the Edelbrock TES (1 1/2" & 1 5/8" LTs) on my IROC's LB9 with great success and it's only building about 240 chp.

When we do all the bolt-ons to a late L98 we get near 300chp and cams, heads & LTs will push that number close to 370 chp. Though Lengenfelter says to use 1 5/8" below ~350chp, are you sure you won't want to go higher...

It sounds like we aren't "losing" low end torque but maybe just not "getting" as much low end torque gain with 1 3/4" LTs.

I too love the fun of low end torque but will go with 1 3/4" LTs, when the budget allows it.

Mar 28, 2004 | 05:14 PM

#22

Nathan Plemons

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Re: WHO makes 1 5/8 headers?? (CFI-EFI)

Quote:

You might not have lost low end power (torque) from what you previously had, but DID lose power over what you would have had with smaller headers. Your loss was unrealized, because you never felt the benefits of properly sized headers. In any case, it is good that you are happy. Ignorance IS bliss.

You may be absolutely correct, there might be a little more to be had with the 1 5/8 pipes as far as torque is concerned, but I'm happy. As it is the car will roast the tires from a roll and I have to struggle to get a 2.0 60' at the track. Even more low end would be a curse.

I'm not a fan of extremely high revving imports but there is something to be said for having the power come on a LITTLE later. As it sits, although my car does have a torque peak, you really can't be in the wrong gear. You don't have to think about it too much, if the revs will be reasonable with a downshift than do it. It doesn't matter so much if it puts you at 3000-4000-5000, it's gonna pull STRONG anywhere.

Like I said the 1 3/4 were readily available and they are easy to deal with. It's just one less thing I have to worry about for future mods. :cheers:

Mar 28, 2004 | 05:24 PM

#23

Rich B.

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From: Lockport NY

Re: WHO makes 1 5/8 headers?? (Nathan Plemons)

I imagine 88blackZ-51 has long since gone to sleep :sleep: , so did any of you guys with 1 5/8" or 1 3/4" headers have to dimple the tubes, install special header bolts, or fabricate special alternator/AC brackets for your headers??? :rolleyes:

Mar 28, 2004 | 05:31 PM

#24

65Z01

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From: SE NY

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Re: WHO makes 1 5/8 headers?? (Rich B.)

Yea, this thread has grown similarly to the "160 deg stat" threads but I've found some useful info here, as often happens with the rehashes.

And, IMHO, this topic hasn't yet become redundant.

BTW, some of the things you just mentioned are the reasons I will go with the TPIS LTs, as they overcome most of these problems though "at a price".

Mar 28, 2004 | 06:14 PM

#25

CFI-EFI

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From: The Top of Utah

Re: WHO makes 1 5/8 headers?? (Nathan Plemons)

Quote:

As it is the car will roast the tires from a roll and I have to struggle to get a 2.0 60' at the track. Even more low end would be a curse.

A curse for some, maybe. Imagine your 60's if you can control that torque.

Quote:

It doesn't matter so much if it puts you at 3000-4000-5000, it's gonna pull STRONG anywhere.

Even more so with 1 5/8ths" headers. It isn't like the small tubes stop abruptly at a given rpm and the large tubes start where the small quit. There is a lot of overlap. These engines are only 350 cubic inches. It is a rare 350 that will choke on 1 5/8ths" headers. Very few will process the amount of air the 1 3/4" tubes will precess most efficiently. And if they do, it will take mega rpms. The power, or torque, take your pick, will have more area "under the curve" with the small tubed headers. Besides the engine size, it goes back to coordinating ALL the components and modifications for a common purpose. It is almost like over camming an engine, but with less drastic negative consequences. I AM glad you're happy with them.

RACE ON!!!

Mar 28, 2004 | 06:40 PM

#26

Nathan Plemons

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Re: WHO makes 1 5/8 headers?? (Rich B.)

Quote:

On the LT1 there is one brace that you can't put back because of the header. For the other 2 just use the supplied spacer and one of your stock manifold studs and you can easily re-attach them. Then all you have to do is fabricate a small spacer for the missing bracket and you'll be done.

OEM there are 4 brackets. I ran the car for 2 years without ANY of them in place. Everybody said though that your A/C would cause a terrible vibration though, since I didn't have A/C I didn't worry about it. When I re-installed the A/C system I went ahead and made the brackets work. So far so good, apparently 3 out of 4 brackets is all you really need anyway.

TPIS might solve some of the bracket problems but I really don't like their slip fit collectors. Everybody I know with slip fit exhaust has leaks.

Mar 29, 2004 | 04:02 PM

#27

88BlackZ-51

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Re: WHO makes 1 5/8 headers?? (Nathan Plemons)

thanks guys..............i am still on the fence, but leaning more towards 1 5/8 headers....just makes sense for the street and off the line go!!!

the hedman "elite" series headers seem an improvement.....go to hedman site, and tell me what u think? they don't have the EGR stuff however, so i have to see which way i am going......"i think i am going to have nightmares soon on headers"...lol!