Put '01-'02 Manifolds on a '99??!!
Put '01-'02 Manifolds on a '99??!! A friend just did headers etc. on his '01 SS and offered me his stock exhaust pieces for free.
Since the prevailing wisdom is that '01-'02 exhaust manifolds, (despite being cast iron), flow better than the earlier stainless stock manifolds, I was contemplating putting them on my '99. I know, prolly a 5 RWHP gain if I'm lucky... but the only cost will be my time for the install.
Just glancing at them, I see that the A.I.R. tube attaches in a different location and that obviously there is no EGR provision. Has anyone done this? How much of a PITA was it? Any advice? I will also have access to a '01+ SLP Y-pipe to complete the install.
Another gain I see from this is that the later model cat setup will flow a bit better and I will benefit from going to his 20k mile cats from my 47K mile cats, so they should last a little longer.
Since the prevailing wisdom is that '01-'02 exhaust manifolds, (despite being cast iron), flow better than the earlier stainless stock manifolds, I was contemplating putting them on my '99. I know, prolly a 5 RWHP gain if I'm lucky... but the only cost will be my time for the install.
Just glancing at them, I see that the A.I.R. tube attaches in a different location and that obviously there is no EGR provision. Has anyone done this? How much of a PITA was it? Any advice? I will also have access to a '01+ SLP Y-pipe to complete the install.
Another gain I see from this is that the later model cat setup will flow a bit better and I will benefit from going to his 20k mile cats from my 47K mile cats, so they should last a little longer.
Banned
Joined: Mar 2003
Posts: 603
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From: L.I. NY
I say go for it. Port them out a little bit to smoothen them out, especially at the flange area where they hook up to the cats. If you've got the money get them extrude honed. Expensive, but they'll flow pretty good and keep that stealth look.
PS Headers can be quite annoying at times.
PS Headers can be quite annoying at times.
The cat flange (against stock cats) mates fairly
well ('02:'02) but the manifolds intrude into the
exhaust port on the head pretty badly - like 3/16"
or so, top and bottom. This is where a little hand-
hogging can improve things a lot I believe (and I
did). I've got these, plus high-flow RT cats & Y,
ready to go onto mine (since I haven't had much
luck finding shorties to fit, on the cheap).
Thing is on a '98/'99 you may be dealing with a
Y-pipe that doesn't want to go, just like I had
a set of '98-'99 shorties that wouldn't mate to
mine. You might then need the late cats & Y too.
Check your passenger's side flange - flat 3-bolt,
probably OK; ball 2-bolt, not OK.
well ('02:'02) but the manifolds intrude into the
exhaust port on the head pretty badly - like 3/16"
or so, top and bottom. This is where a little hand-
hogging can improve things a lot I believe (and I
did). I've got these, plus high-flow RT cats & Y,
ready to go onto mine (since I haven't had much
luck finding shorties to fit, on the cheap).
Thing is on a '98/'99 you may be dealing with a
Y-pipe that doesn't want to go, just like I had
a set of '98-'99 shorties that wouldn't mate to
mine. You might then need the late cats & Y too.
Check your passenger's side flange - flat 3-bolt,
probably OK; ball 2-bolt, not OK.
Originally Posted by jimmyblue
Thing is on a '98/'99 you may be dealing with a
Y-pipe that doesn't want to go, just like I had
a set of '98-'99 shorties that wouldn't mate to
mine. You might then need the late cats & Y too.
Check your passenger's side flange - flat 3-bolt,
probably OK; ball 2-bolt, not OK.
Y-pipe that doesn't want to go, just like I had
a set of '98-'99 shorties that wouldn't mate to
mine. You might then need the late cats & Y too.
Check your passenger's side flange - flat 3-bolt,
probably OK; ball 2-bolt, not OK.
The only reason I'm doing this is because I can get the '01 pieces for free. There is no plan to put headers on my '99. It's just my driver and the other car goes to the track. I'm not spending any significant amount of money to make it faster, but if I can do it for cheap, I'll do it. However, I don't want to get into a total nightmare. Minor fabbing/modding of parts is fine, but if it's a serious PITA, then it's not worth the extra 5 HP I'll prolly get.
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TECH Fanatic
Joined: Jan 2003
Posts: 1,094
Likes: 0
From: Northern Va
Originally Posted by jimmyblue
... I've got these, plus high-flow RT cats & Y,
ready to go onto mine (since I haven't had much
luck finding shorties to fit, on the cheap)...
ready to go onto mine (since I haven't had much
luck finding shorties to fit, on the cheap)...
On a side note, i'm running a Magnaflow muffler (stock I pipe) and after the new ported stockers and Y/cats were installed the system sounds even better (and a little louder). Also, everything bolted up perfectly. The RT stuff is good quality.