yabadaba

Hi guys, I'm planning on placing an order soon for a set of ARH 1-3/4 long tube headers with catted y-pipe for my 2001 Z28. It's an A4 with 2.73 gears that is stock apart from an SLP lid and GMMG catback. I don't want to go crazy with the mods, but from what I gather this will give me the 'biggest bang for the bucks' performance increase, so seems like the obvious next step. Just got a couple of questions before I finally go for it...

Firstly, I'm in the UK (London) and the shipping cost is huge (about the same price again as the actual headers), so I really want to make sure that if there are any other parts I need to do the job that I order them at the same time (gaskets/o2 extenders?). So, anything else I should be including in the order?

Secondly, what kind of power gain would you expect I'll see? I've had the car on a dyno just the once, to get some baseline figures and it made 298.3 rwhp and 310.0 rwtq. That was on a Dyno Dynamics machine. Not that I really know what the AFR is all about, but as I see people quoting it, the reading was very close to the 12.0 mark throughout, dropping slightly past the 4.5k rpm mark. The guy operating the dyno thought that was probably about right for a stock motor.

Apart from answers to the above any other general advice or comments you may have would be much appreciated.

UGotBeaT

Id opt for the 1 7/8ths headers.

yabadaba

Was aiming for the 1-3/4 because I've got a fear of losing any low range torque and although I know there has been an ongoing debate on this I still don't think the situation is clear. Also, I don't plan on doing too much more so wouldn't think|I'd 'need' the 1-78 ones. having said that, I could stil be persuaded

Anything else I would need, though? I can't just pop out to a local parts store if I forget something - it would have to be another international shipment, i.e. more time and money. From what I can make out I might need O2 sensor cable extenders? Also, there seems to be a lot of mention about different types of gasket. For instance on the web page of one of the sponsors where I've located these headers they have the bit about 'what other people also buy' and I see GM Exhaust manifold gaskets is there, along with prothane engine mounts.

cookba

iTrader: (10)

i have bought most of my parts from Speed Inc. (just saying). get some GM MLS gaskets or the Percy's Seal-4-Good LS1 MLS Header Gaskets. Some Stage 8 header bolts are a good idea too. Contact ARH directly and see if there headers require the use of O2 extensions and make sure they come with all the band clamps required. Spark plugs and wires are a wise idea too.

I would also do the 1 7/8 headers, its a few more hp over the 1 3/4 while still semi-stock, but further down the road your car will love the larger headers. plus our cars can deal with losing a little low-end tq.

yabadaba

Thanks for that. I'll make sure I order one of the GM gaskets and I've emailed ARH about the other stuff, as you suggested. I can see the sense in doing plugs and wires at the same time, but I only did them about a year ago so hopefully they should be fine for a few more years yet.

NAL3231

motor mounts are always a goo idea so your y pipe dont hit the floor. if you think your are or are close to wore out.

heartless_T/A99

iTrader: (1)

when i ordered my ARH headers and y they came with o2 extenders and the necessary hardware and exhaust clamps

ThunderStruk

iTrader: (1)

The American Racing headers are some of the finest headers on the market today. I would definitely recommend getting the exhaust manifold gaskets and some Stage 8 locking header bolts. I would also recommend getting the o2 extensions as well. We have all of those parts on our website. I can definitely get you setup in a package for all of those parts for you. PM me or email me and I will get you set up.

sjsingle1

iTrader: (1)

has any done dyno on 1 3/4 vs 1 7/8 ???

97ta383

iTrader: (5)

I would just replace the plugs any way its only 20 bucks and just a good investment.

RevGTO

iTrader: (12)

If you're looking for the "biggest bang for the buck" in performance, get a torque converter like a Yank SS3600. I'd add a set of 3.42-3.73 gears. The cost for both will be no more than the headers, shipping would probably be less, install might be a little more, but the gain in performance will outshine the LT's by far.

If you go with the headers, you can re-use the stock gaskets. Works perfect.

tillery

iTrader: (4)

Dont know how you send them out but Mine came with the extentions and gaskests. If you dont want to mess the extentions most of us use corvette rear 02s. Same sensor just a longer wire on them. And no you dont need the Stage 8 locking bolts. Ive never seen header bolts back out on a LS engine like the older SBC engines. unless the installer didnt torque them properly.

Shockwave179

iTrader: (7)

Here is a before and after graph. The after is ARH 1-3/4 longtubes with the catted y-pipe and a tune. Money well spent.

Also if you don't already have one I would look into an LS6 intake mani.

studderin

iTrader: (28)

you can reuse the stock bolts and gaskets if there no damage to them. I do it all the time.

yabadaba

Okay, thanks for posting the graph....looks like a healthy gain, I'll just have to find someone who knows how to tune these engines to make sure I get the most out of all this. Did you notice any change in the real low end torque though? This is my daily driver and gets used in town traffic a lot so plenty of stopping and starting....I'd soon noticed any differences lower in the rpm range.

Pretty sure my car already has the LS6 intake, as it's a 2001 model and I think most came with one, plus I remember checking somehow (can't recall how) when I first got it.

Shockwave179

iTrader: (7)

Definitely a lot of low end torque. I honestly don't think its worth spending $1300+ on headers if you don't get a tune. I didn't realize you had an 01 so your right you probably do have the ls6 intake manifold. In that case you will love the ARHs.

Mumbles

iTrader: (5)

I'll second this.

No easier time to get to them than when your exhaust is out of the way.

Also, each LT install I've been a part of, we reused the stock exhaust manifold bolts without an issue.

Good luck with your install, man and let us know how it turns out.

SWEET98SS

iTrader: (8)

If you looking for a tuner, check new era performance in Rochester. They are a sponsor on this board and there going to install my cam and tune it.

kwiker

iTrader: (10)

Don't bother with the 1 7/8 if you aren't going to modify the car past basic bolt-on's. 1 7/8 are for big motors moving a lot of air, a bolt-on 346 really doesn't need them, torque is what you feel, hp is what you see on the graph...what is more important to you? Even if you are going to do heads and a cam, keep the 1 3/4's.

yabadaba

Wish I could....I'm in the UK, so won't have a lot of choice and will no doubt need to travel quite a way.