Non-restricted exhaust
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- Posts: 523
- Joined: Sat Dec 14, 2013 1:24 pm
- Your car is a: 1978 124 spider
- Location: Winston-Salem, NC
Non-restricted exhaust
One of our club members mentioned today that I should look at a non-restricted exhaust. We were all kind of in a hurry so I didn't have time for him to explain what it is. Does anyone have any experience with this and explain what it is and how it works. I have a 77 spider.
Gene
North Carolina
North Carolina
- aevansgatech
- Posts: 346
- Joined: Mon Jul 27, 2015 2:51 pm
- Your car is a: 1982 Spider 2000
Re: Non-restricted exhaust
He probably meant removing the catalytic converter and replacing it with a "test-pipe" or straight through exhaust. Removing the catalytic converter results in a less restricted exhaust flow, but will also make the car louder, possibly smell worse/different, and won't give you much hp benefit in my opinion.
If you think your exhaust or converter are shot, then consider it, but if your exhaust is in good shape I wouldn't modify it.
If you think your exhaust or converter are shot, then consider it, but if your exhaust is in good shape I wouldn't modify it.
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)
- focodave
- Patron 2018
- Posts: 704
- Joined: Sat Jun 30, 2012 10:35 am
- Your car is a: 1980 Spider 2000 F.I.
- Location: Fort Collins, CO
Re: Non-restricted exhaust
If you want to hear what it may sound like without the cat in place, I made a video of mine with no cat, no rear muffler, and just the center resonator in place: https://youtu.be/zxc9TEcS1Eg
1980 Spider 2000 F.I. (my hobby)
1970 MGB GT (my other hobby)
2008 Ford Expedition (daily driver)
2019 Harley-Davidson Electra Glide Standard
2019 Harley-Davidson Iron 883 Sportster
1970 MGB GT (my other hobby)
2008 Ford Expedition (daily driver)
2019 Harley-Davidson Electra Glide Standard
2019 Harley-Davidson Iron 883 Sportster
Re: Non-restricted exhaust
free-flow exhausts are important for power increases, I can't imagine why in your opinion they aren't worthwhile? Exhaust systems with back pressure cause reversion to enter the cylinder during overlap, sapping hp.
Would you care to offer some proof to back up your opinion?
Would you care to offer some proof to back up your opinion?
- RRoller123
- Patron 2020
- Posts: 8179
- Joined: Sun Nov 13, 2011 2:04 pm
- Your car is a: 1980 FI SPIDER 2000
- Location: SAGAMORE BEACH, MA USA
Re: Non-restricted exhaust
I put a Test Pipe in my 80FI, and noticed a great improvement in Mid-Range Torque, whereas before I would climb a long moderate hill at speed but would have to shift down to 4th or 3rd, I could absolutely now stay in 4th, and often stay in 5th. Big difference with just the pipe.aevansgatech wrote:He probably meant removing the catalytic converter and replacing it with a "test-pipe" or straight through exhaust. Removing the catalytic converter results in a less restricted exhaust flow, but will also make the car louder, possibly smell worse/different, and won't give you much hp benefit in my opinion.
If you think your exhaust or converter are shot, then consider it, but if your exhaust is in good shape I wouldn't modify it.
Pete
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
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- Posts: 523
- Joined: Sat Dec 14, 2013 1:24 pm
- Your car is a: 1978 124 spider
- Location: Winston-Salem, NC
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- Posts: 523
- Joined: Sat Dec 14, 2013 1:24 pm
- Your car is a: 1978 124 spider
- Location: Winston-Salem, NC
Re: Non-restricted exhaust
Sorry didn't get to finish my post. Since I don't have a cat does that mean I have a free flow exhaust? My exhaust is somewhat loud a lot like the video.
Gene
North Carolina
North Carolina
- Nanonevol
- Patron 2018
- Posts: 828
- Joined: Thu Nov 13, 2014 9:17 am
- Your car is a: 1977 Fiat 124 Spider
- Location: Medway, Massachusetts
Re: Non-restricted exhaust
If it's loud maybe you have a leak. Otherwise, if yours is a stock '77 it has a 4 into 1 exhaust manifold and you would see improvement with a 4 into 2 manifold from an earlier or later Spider.
1977 Fiat Spider
1985 Jaguar XJ6
1967 Triumph Bonneville (hard-tail chopper)
1966 BSA Lightning
1985 Jaguar XJ6
1967 Triumph Bonneville (hard-tail chopper)
1966 BSA Lightning
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- Posts: 3996
- Joined: Sat May 23, 2009 1:23 pm
- Your car is a: 1971 124 Spider
- Location: Texas, USA
Re: Non-restricted exhaust
+1 on upgrading to the earlier moanifold and downpipe to make the system a 4-2-1.
For the rest of the system an inexpensive alternative is the Euro-1800 exhaust, which is ~2" in diamter, vs. ~1-5/8" for the US 1800. These will work for any non-catalyst 1800 (ie it will fit all 49-state models, but not California models). The center muffler slips right onto the stock downpipe.
https://autoricambi.us/collections/exha ... erformance
https://autoricambi.us/collections/exha ... erformance
For the rest of the system an inexpensive alternative is the Euro-1800 exhaust, which is ~2" in diamter, vs. ~1-5/8" for the US 1800. These will work for any non-catalyst 1800 (ie it will fit all 49-state models, but not California models). The center muffler slips right onto the stock downpipe.
https://autoricambi.us/collections/exha ... erformance
https://autoricambi.us/collections/exha ... erformance
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
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- Posts: 224
- Joined: Mon Jan 02, 2012 11:14 pm
- Your car is a: 1967 124
Re: Non-restricted exhaust
Free flow exhausts are great.
I put a 1608 in my car and was really happy. Then I went from the stock 1197cc OHV exhaust to a 2.25" with both a MagnaFlow and Borla muffler, you can see straight through both of them, I thought it was going to be really loud but its about the same volume and the power change is amazing. It used to only pull between 3-3800 RPMs now its a blast all the way up to 6K.
-G
I put a 1608 in my car and was really happy. Then I went from the stock 1197cc OHV exhaust to a 2.25" with both a MagnaFlow and Borla muffler, you can see straight through both of them, I thought it was going to be really loud but its about the same volume and the power change is amazing. It used to only pull between 3-3800 RPMs now its a blast all the way up to 6K.
-G
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- Posts: 325
- Joined: Tue Apr 26, 2016 6:51 pm
- Your car is a: 1980 Spider 2000
- Location: New Hope, PA
Re: Non-restricted exhaust
I want to play!
I have a 1980 FI spider. Stock.
1. Do I have a CAT, where is it, what's involved in removing it, what to replace it with.
2. Would I have a 4-1 exhaust or a 4-2-1 exhuast?
3. What does #2 even mean and which do I want.
4. If I'd want what I don't have, how to go about remedying that one?
I have a 1980 FI spider. Stock.
1. Do I have a CAT, where is it, what's involved in removing it, what to replace it with.
2. Would I have a 4-1 exhaust or a 4-2-1 exhuast?
3. What does #2 even mean and which do I want.
4. If I'd want what I don't have, how to go about remedying that one?
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- Posts: 3996
- Joined: Sat May 23, 2009 1:23 pm
- Your car is a: 1971 124 Spider
- Location: Texas, USA
Re: Non-restricted exhaust
If it's an FI Spider then you have a 4-2-1 system, which works well for the stock engine. To get a 2-3 HP gain you can replace the cat with a test pipe if your area allows it:
https://autoricambi.us/products/test-pipe-1980on-4-bolt
https://autoricambi.us/products/test-pipe-1980on-4-bolt
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
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- Posts: 325
- Joined: Tue Apr 26, 2016 6:51 pm
- Your car is a: 1980 Spider 2000
- Location: New Hope, PA
Re: Non-restricted exhaust
Here in PA i get to sport antique tags. Hence no emissions or inspections required . Looks like this is in my futrue, no welding required I'm down. Should I save the old cat for originality when these hit 6 figures LOL!vandor wrote:If it's an FI Spider then you have a 4-2-1 system, which works well for the stock engine. To get a 2-3 HP gain you can replace the cat with a test pipe if your area allows it:
https://autoricambi.us/products/test-pipe-1980on-4-bolt
Re: Non-restricted exhaust
you'll also need a straight-through muffler to reduce backpressure
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- Posts: 523
- Joined: Sat Dec 14, 2013 1:24 pm
- Your car is a: 1978 124 spider
- Location: Winston-Salem, NC
Re: Non-restricted exhaust
Mark, since I can't find a 4-2-1 manifold right now I have decided to change mufflers. I have a '77 carb non-cat. What you recommend?
Gene
North Carolina
North Carolina