Stock vs High Flow Cats
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Stock vs High Flow Cats
Just bought my Z last night and the guy has Invidia test pipes on it. He's including the stock cats in the purchase. It's a bit too loud for my taste with the test pipes, so I plan to put cats back on it.
This car is my daily driver. I'm not planning on racing it or taking it to the track (well, maybe once or twice just for the hell of it). I'm wondering if the performance gain with high flow cats versus the stock cats is worth the $350 I'd pay for the high flows.
Any opinions?
This car is my daily driver. I'm not planning on racing it or taking it to the track (well, maybe once or twice just for the hell of it). I'm wondering if the performance gain with high flow cats versus the stock cats is worth the $350 I'd pay for the high flows.
Any opinions?
#2
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Just bought my Z last night and the guy has Invidia test pipes on it. He's including the stock cats in the purchase. It's a bit too loud for my taste with the test pipes, so I plan to put cats back on it.
This car is my daily driver. I'm not planning on racing it or taking it to the track (well, maybe once or twice just for the hell of it). I'm wondering if the performance gain with high flow cats versus the stock cats is worth the $350 I'd pay for the high flows.
Any opinions?
This car is my daily driver. I'm not planning on racing it or taking it to the track (well, maybe once or twice just for the hell of it). I'm wondering if the performance gain with high flow cats versus the stock cats is worth the $350 I'd pay for the high flows.
Any opinions?
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my test pipes made quite a difference ( pure butt dyno of course) over the stock cats.. , but from what i hear and read here, stock cats vs hfcs are a very close mix.. not much difference.
Sounds like you jsut dont like the test pipes.. in that case id jsut put the normal cats back on.
But give it a month, you may end up liking the sound better than you do now..... i hated mine the first week, now not so bad.
Sounds like you jsut dont like the test pipes.. in that case id jsut put the normal cats back on.
But give it a month, you may end up liking the sound better than you do now..... i hated mine the first week, now not so bad.
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Without tuning for the change, I look at NA bolt ons as "sound/tone" upgrades and not as "performance" upgrades.
OP, if you don't like the sound, change back out. You won't notice a difference.
Last edited by SparkleCityHop; 04-22-2011 at 02:39 PM.
#6
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I don't think the previous owner touched the ECU. I sent him a text to confirm though. Waiting to hear back.
$350 isn't worth the minimal, if any, power increase to me. The test pipes are just so loud they make the inside of my head throb....lol
Stock cats it is then. Thanks for the responses.
$350 isn't worth the minimal, if any, power increase to me. The test pipes are just so loud they make the inside of my head throb....lol
Stock cats it is then. Thanks for the responses.
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If he never touched the ECU, you have zero to worry about. Swap back out, pocket the money, and enjoy the sound you're looking for.
Last edited by SparkleCityHop; 05-08-2011 at 07:17 PM.
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#9
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Post em both up on the private classifieds on here. You may even want to post the wheels/tires up in your local region as a FT (for trade). Do you know what brand/style/size the wheels & tires are?
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The tires are Falkens. That's all I know at this point. I pick the car up tomorrow. I'll post the deets once I get it.
Edit: I think these are the rims: http://www.wheelsnext.com/wheels-tir...ed%20Blue.html
Edit: I think these are the rims: http://www.wheelsnext.com/wheels-tir...ed%20Blue.html
Last edited by BiffRocko; 04-22-2011 at 03:21 PM.
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Cool. Congrats, man. You're lucky that you're in CA. There are always crazy good deals on used stuff out there. Keep your eyes out on the Private Marketplace and you can get some great deals if you're patient.
The vendors on here are also great and are always helpful when it comes to questions, etc. - so I try to pay them back by sending them my business as well.
Welcome to the community!
The vendors on here are also great and are always helpful when it comes to questions, etc. - so I try to pay them back by sending them my business as well.
Welcome to the community!
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Thanks! I'll keep my eye out for deals.
Just heard back. No ECU changes, so it's probably running rich with the test pipes.
Just heard back. No ECU changes, so it's probably running rich with the test pipes.
Last edited by BiffRocko; 04-22-2011 at 04:46 PM. Reason: corrected assumption that it was running lean to it running rich
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Please explain the running lean comment? Thanks.
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No expert on this but if he re-mapped the ECU for the TP's more than likely he made it run a little leaner. Lean means that your engine is getting less fuel but more air. In combination with the TP I am guessing that that made an increase a little in power. However, running an engine too lean or even lean for that matter can be damaging. One reason is that it would run hotter.
If he did re-tune the ecu then you don't want to go and throw OEM setup on there and have it stay lean as this could be damaging.
On the other hand, a car can run rich which would mean its using too much fuel which can clog it up I believe. (i.e Bogging down etc etc....)
I think I hit that on a real broad, general level. Hopefully someone can confirm/add to what I said.
If he did re-tune the ecu then you don't want to go and throw OEM setup on there and have it stay lean as this could be damaging.
On the other hand, a car can run rich which would mean its using too much fuel which can clog it up I believe. (i.e Bogging down etc etc....)
I think I hit that on a real broad, general level. Hopefully someone can confirm/add to what I said.
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If tuned, it would have been tuned to a richer AFR with the Test Pipes. This is because the TP are less restriction, which means more airflow, which means without a tune, test pipes would run lean. If you tune it richer to make up for the TP, when you put it back to stock cats, the tune would be much richer than it was originally. (You get more power tuning on the leaner side which was made possible reducing restriction.) I'm not going to get into the details of stoich and air fuel ratios.
However, the car was not tuned for the TPs. So it is probably currently running a little lean because there are test pipes in place, which means less restriction, but no tune for the change. Luckily, the stock tune is somewhat on the rich side. Switching back to the stock cats (which the factory tune expects) will bring the car's setup back in line with the stock tune.
Stock Tune
-----------
Stock Cats = Good AFR
Test Pipes = Lean AFR
Lean Tune for TPs
------------------
Test Pipes = Good AFR
Stock Cats = Rich AFR
Last edited by SparkleCityHop; 05-08-2011 at 07:22 PM.
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Yes. If tuned, it would have been tuned to a leaner AFR with the Test Pipes. This is because the TP are less restriction, which means more airflow, which means without a tune, test pipes would run rich. If you tune it leaner to make up for the TP, when you put it back to stock cats, the tune would be much leaner than it was originally. (You get more power tuning on the leaner side which was made possible reducing restriction.) I'm not going to get into the details of stoich and air fuel ratios.
However, the car was not tuned for the TPs. So it is probably currently running a little rich because there are test pipes in place, which means less restriction, but no tune for the change. Switching back to the stock cats (which the factory tune expects) will bring the car's setup back in line with the stock tune.
Stock Tune
-----------
Stock Cats = Good AFR
Test Pipes = Rich AFR
Lean Tune for TPs
------------------
Test Pipes = Good AFR
Stock Cats = Lean AFR
However, the car was not tuned for the TPs. So it is probably currently running a little rich because there are test pipes in place, which means less restriction, but no tune for the change. Switching back to the stock cats (which the factory tune expects) will bring the car's setup back in line with the stock tune.
Stock Tune
-----------
Stock Cats = Good AFR
Test Pipes = Rich AFR
Lean Tune for TPs
------------------
Test Pipes = Good AFR
Stock Cats = Lean AFR
Wouldn't a stock tune with test pipes cause engine to run lean and tuned for test pipes then switching to stock cats cause you to run rich?
Last edited by pss350z; 05-08-2011 at 06:40 PM.
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I went back and corrected my post above. Adding TP's will push you to the lean side, but in my case, the stock tune was so rich that I was still seeing rich AFR numbers in areas of my tune even with the TP's.
Last edited by SparkleCityHop; 05-08-2011 at 07:24 PM.